Meningoencephalitis of unknown origin in dogs

Background: Meningoencephalitis of unknown origin (MUO) is a critical cause of neurological disorders in dogs, mainly affecting small young individuals. Its symptomatology is varied and depends on the affected neuroanatomic region. The ante mortem diagnosis of this condition is uncertain, being achieved by discarding other conditions and often occurring definitively only by performing a necropsy. Thus, this study aims to report 2 cases of meningoencephalitis, one necrotizing and the other granulomatous in dogs. Cases: Case 1. A 3-year-old, Shih Tzu bitch with a body weight of 4 kg, showing proprioceptive ataxia, behavior of walking in circles, and evolving rapidly to non-ambulatory paresis, was treated. The neurological examination showed a posture of decerebrate stiffness and absence of withdrawal reflex and proprioception, suggesting brainstem injury. Laboratory tests showed mild neutrophilia and lymphopenia, while the rapid test for distemper was non-reactive. The cerebrospinal fluid (CSF) analysis showed lymphocytic pleocytosis, and the PCR tests of the CSF, blood, and urine for the detection of infectious diseases were negative, as well as the culture. With no improvement in clinical condition and exams showing a progressive degenerative condition unresponsive to available treatments, the tutor opted for euthanasia of the patient. The subsequently requested necropsy confirmed the diagnosis of granulomatous meningoencephalitis. Case 2. This case refers to a 1-year-and-5-month-old male Maltese breed weighing 4.8 kg. This animal presented walking in circles behavior and loss of vision for a week, with signs worsening rapidly. In the neurological evaluation, the patient presented sensitivity in the middle ear, difficulty opening the mouth, hearing deficit in the right ear, blindness in the right eye, a proprioceptive deficit in the right anterior limb, and head pressing. Laboratory tests showed nonregenerative anemia and mild lymphopenia. After 1 day of hospitalization, the patient showed worsening clinical condition, with obstruction, absence of facial and auricular sensitivity, and nasal stimulus. In addition, onset of generalized seizures was observed; therefore, CSF was analyzed, which did not present significant alterations except for detecting reactive lymphocytes. The bacteriological culture of CSF resulted in no bacterial growth. In addition, the same neurological PCR panel performed for the previous patient was negative. After 5 days of intensive care, the patient presented a cardiorespiratory arrest and died. The subsequently requested necropsy confirmed the diagnosis of necrotizing meningoencephalitis. Discussion: The 2 reported cases confirm that MUO should be considered during the differential diagnoses of patients with neurological alterations. It is known that small-breed dogs are predisposed to these diseases. Laboratory tests and medical imaging are crucial for clinical guidance, helping to discard other neurological pathologies, especially those due to bacterial, fungal, and/or viral agents. However, definitive diagnosis of MUO can only be performed through necropsy and histopathological analysis. For the reported cases, CSF analysis, neurological PCR panel for detecting possible infectious agents, and bacterial culture were essential to rule out other possible causes of meningoencephalitis. Unfortunately, MUO includes progressive neurological disorders causing the patient's death.

Natural infection and molecular detection of Cytauxzoon felis in a free-ranging Puma concolor in the state of Goiás, Brazil / Infecção natural e detecção molecular de Cytauxzoon felis em Puma concolor de vida livre no estado de Goiás, Brasil

The puma (Puma concolor Linnaeus, 1771), the most widely distributed felid species in the Americas, can be found in all Brazilian biomes. Nevertheless, few studies have focused on hemoparasites in this species. Cytauxzoon felis, a hemoparasite that can infect domestic cats, has also been described in wild felids in Brazil. To the best of our knowledge, this study is the first to diagnose the natural infection and molecular detection of C. felis in a P. concolor in the state of Goiás. This animal presented non-regenerative anemia and inclusion suggestive of piroplasmids within red blood cells. The amplified 551 bp fragment of partial Piroplasmida 18S rRNA gene sequence was 100% identical to corresponding sequences of C. felis available in GenBank. No specific treatment for cytauxzoonosis was administered, and after rehabilitation, the animal was reintroduced into the wild. This finding provides some evidence that P. concolor may act as a natural host of the parasite. The epidemiology, vector and pathogenicity of this hemoparasite in wild and domestic cats in Brazil deserves further investigation.

O puma (Puma concolor Linnaeus, 1771) tem a maior distribuição entre os felídeos das Américas e é encontrado em todos os biomas do Brasil. No entanto, poucos estudos têm se concentrado nos hemoparasitos nesta espécie. Cytauxzoon felis, um hemoparasito que pode infectar gatos domésticos, também foi descrito em felídeos selvagens no Brasil. A saber, este estudo é o primeiro diagnóstico de infecção natural e detecção molecular de C. felis em um P. concolor do estado de Goiás. Este animal apresentou anemia arregenerativa e inclusão de piroplasmídeos nos glóbulos vermelhos. A amplificação do fragmento de 551 pb da sequência parcial do gene Piroplasmorida 18S rRNA foi 100% idêntica a sequências correspondentes de C. felis disponíveis no GenBank. Nenhum tratamento específico para citauxzoonose foi administrado e, após a reabilitação, o animal foi reintroduzido na natureza. Essa descoberta fornece algumas evidências de que P. concolor pode atuar como um hospedeiro natural do parasito. A epidemiologia, vetor e patogenicidade deste hemoparasito em gatos selvagens e domésticos no Brasil merecem uma investigação mais aprofundada.

Central nervous system infiltration in acute lymphoblastic leukemia in a dog

Background: Acute lymphoblastic leukemia (ALL) is a malignant neoplasia in which there is proliferation of lymphoid progenitor cells in the bone marrow, blood, and extramedullary sites. This disorder has a fast and progressive development; in dogs, cases of infiltration of ALL cells in the central nervous system (CNS) are uncommon and rare. Diagnosis can be achieved with the help of the clinical history and physical, radiographic, hematological, myelographic, and cerebrospinal fluid (CSF) tests in patients with or without neurological clinical signs. The present report aims to describe a case of ALL and the presence of lymphoblasts in the CSF of a dog with neurological clinical signs. Case: An 8-year-old Lhasa Apso dog was examined at the Veterinary Hospital of Universidade Federal do Paraná, Curitiba campus. At the physical examination, the animal exhibited apathy and paralysis of pelvic limbs, which progressed to tetraplegia. Abdominal palpation revealed presence of hepatosplenomegaly and absence of lymphadenomegaly. No alterations were observed in radiographs of the cervical, thoracic or lumbar spine. A complete blood count revealed presence of non-regenerative anemia (hematocrit = 22%), extreme lymphocytosis (185,229 cells/µL), lymphoblasts at a level of 72% (133,364 cells/µL), and thrombocytopenia (66,000 platelets/µL). The biochemical tests revealed increased alkaline phosphatase (859 IU/L). The levels of alanine aminotransferase, creatinine, urea, total protein, albumin, and globulin were normal. The diagnosis of ALL was achieved with the help of a myelogram. The myelogram findings included 39% of mature lymphocytes and 59% of lymphoblasts exhibiting large size, spherical shape, poorly delimited borders, with a high nucleus/cytoplasm ratio, marked cytoplasmic basophilia, and 2 to 3 evident nucleoli; metarubricytes (1%) and promyelocytes (0.6%) were also observed. The CSF contained an increased number of nucleated cells (27 cells/µL) comprising lymphocytes (43%), macrophages (33%), and segmented neutrophils (24%). Of the 11.6 lymphocytes per µL of CSF, 8.1 were lymphoblasts, which indicates infiltration of ALL cells in the CNS. The animal died one day after collection of bone barrow and CSF. Discussion: Relevant alterations observed in this case included the neurological signs caused by the infiltration of neoplastic cells in the CNS, severe leukocytosis and lymphocytosis, with large amounts of lymphoblasts in the blood and predominance of lymphoblasts in the bone marrow, which are alterations typically found in ALL. The animal also exhibited non-regenerative anemia and thrombocytopenia, which were secondary to infiltration of leukemic cells in the bone marrow. The CSF exhibited pleocytosis (27 cells/ µL), and 30% of the cells observed were lymphoblasts. Lymphoblast infiltration in the CNS of leukemic dogs is rare, and other studies have reported absence of neurological signs or neurological signs different from those observed in the present study. CSF analysis in indicated in cases of leukemia to assess leukemic cell infiltration in the CNS. In the case reported here, the plasma level of alkaline phosphatase was increased (859 IU/L) as a consequence of hepatomegaly and hepatic cholestasis. ALL is a very aggressive, proliferative neoplasia, and the resulting lymphoblasts infiltrated the CNS of the animal. In cases of ALL, performing complete blood count, myelogram, and CSF analysis is indicated whether the patients exhibit neurological signs or not.(AU)

Atypical spleen hemophagocytic histiocytic sarcoma in a dog

Background: The histiocytic sarcoma (HS) complex is a set of malignant neoplasms originating from interstitial dendritic cells or macrophages. When it involves macrophages of the splenic red pulp and bone marrow, it is referred to as hemophagocytic histiocytic sarcoma (HHS). HHS behaves more aggressively than HS and is usually fatal. HHS can be diagnosed by cytological and histopathological examination of neoplastic tissue. HHS is confirmed by immunohistochemistry using an anti-CD11d antibody. This neoplasm is often confused with immune-mediated hemolytic anemia or Evans syndrome due to erythrophagocytosis and platelet consumption. The clinical presentation of the animals progresses with evident anemia and thrombocytopenia, leading to signs such as prostration, inappetence, and pale mucosa, making diagnosis challenging and often late. This study aimed to report the clinic-pathological aspects of a canine with atypical hemophagocytic splenic HS. Case: A 4-year-old male Shih-Tzu canine was referred to the Veterinary Hospital with a history of prostration and anorexia. Pale mucous membranes were observed on physical examination. Blood tests revealed non-regenerative anemia, leukopenia, and thrombocytopenia. Serum protein levels were below the reference values for the species in biochemical examinations. Hemoparasitosis was suspected; however, the result of the polymerase chain reaction was negative. Abdominal ultrasound revealed a splenomegaly with heterogeneous parenchyma and a slightly irregular surface, but no visible mass in the spleen. Due to the difficulty of stabilizing the patient, even after successive transfusions, the animal underwent exploratory laparotomy with medial access and posterior splenectomy. Subsequently, the spleen was surgically removed, fixed in 10% buffered formalin, and processed routinely. Macroscopically, it had an irregular reddish-brown capsular surface. Histopathological examination of the spleen revealed a densely cellular neoplasm composed of round to spindle cells (histiocytes) arranged haphazardly in variably sized sheets separating the pre-existing spleen stroma. These histopathological findings were consistent with a histiocytic malignant neoplasm. Immunohistochemical analysis was performed to better define the origin of the histiocytic neoplasm. Neoplastic cells showed positive immunostaining of more than 80% of tumor cells for the CD11d antibody and weak immunostaining for CD11c and lysozyme. The patient survived for less than 30 days after the first hospital visit. Discussion: The diagnosis of HHS was based on the histological characteristics and positive immunostaining of more than 80% of the tumor cells for the CD11d antibody. HHS is an extremely aggressive and rare tumor that affects elderly dogs of any breed. In this study, HHS had atypical histologic characteristics, in which erythrophagocytosis and hemosiderin were not observed within macrophages. HHSs arise from macrophages of the red pulp of the spleen or bone marrow and express the b2 integrin, CD11d, and have low expression of CD1 and CD11c, which are predominantly expressed by non-hemophagocytic HS. The hematological and biochemical changes observed in this case were similar to those described in other dogs with HHS. Treatment of HHS is only palliative. Erlichia ewingii, E. canis, Anaplasma phagocytophilum, A. platys, Borrelia burgdorferi, Dirofilaria immitis, Leishmania infantum and immune-mediated hemolytic anemia are the main differential diagnoses because they cause anemia and thrombocytopenia accompanied by splenomegaly.

Blood transfusion in a young Myrmecophaga tridactyla (Pilosa, Myrmecophagidae): case report / Transfusão sanguínea emMyrmecophaga tridactylafilhote (Pilosa, Myrmecophagidae): relato de caso

The present study aims to report a transfusion therapy in a juvenile Myrmecophaga tridactyla. The patient had a chronic nonregenerative anemia associated with underdevelopment. This therapy was considered after a severe worsening of the clinical condition and laboratorial tests, in which severe anemia was confirmed, with no signs of recovery. The blood used was donated by a clinically healthy adult male of the same species, raised in captivity. The procedure was performed according to medical practice for small animals, since veterinary medicine reports described for xenarthrans are scarce. The result was satisfactory, with absence of late transfusion reactions and an improvement of the patient's overall condition, which demonstrates the possibility of using blood transfusion in anteaters as a therapeutic option.

O presente trabalho tem como objetivo relatar a realização de terapia transfusional em um exemplar filhote de Myrmecophaga tridactyla. O paciente apresentava um quadro crônico de anemia arregenerativa associada a um subdesenvolvimento. A terapia foi definida após piora severa do quadro clínico e dos exames laboratoriais, nos quais observou-se anemia severa, sem sinal de regeneração. O sangue utilizado foi doado por um adulto da mesma espécie, macho, clinicamente hígido, de cativeiro. O procedimento foi realizado de acordo com o prescrito pela clínica médica de pequenos animais, visto que, os relatos descritos na medicina de xenarthras são escassos. O resultado se mostrou satisfatório, com ausência de reações transfusionais tardias e melhora do quadro geral do paciente, o que demonstra a possibilidade da utilização de transfusão sanguínea em tamanduás como opção terapêutica.

Blood transfusion in a young Myrmecophaga tridactyla (Pilosa, Myrmecophagidae): case report / Transfusão sanguínea emMyrmecophaga tridactylafilhote (Pilosa, Myrmecophagidae): relato de caso

The present study aims to report a transfusion therapy in a juvenile Myrmecophaga tridactyla. The patient had a chronic nonregenerative anemia associated with underdevelopment. This therapy was considered after a severe worsening of the clinical condition and laboratorial tests, in which severe anemia was confirmed, with no signs of recovery. The blood used was donated by a clinically healthy adult male of the same species, raised in captivity. The procedure was performed according to medical practice for small animals, since veterinary medicine reports described for xenarthrans are scarce. The result was satisfactory, with absence of late transfusion reactions and an improvement of the patient's overall condition, which demonstrates the possibility of using blood transfusion in anteaters as a therapeutic option.(AU)

O presente trabalho tem como objetivo relatar a realização de terapia transfusional em um exemplar filhote de Myrmecophaga tridactyla. O paciente apresentava um quadro crônico de anemia arregenerativa associada a um subdesenvolvimento. A terapia foi definida após piora severa do quadro clínico e dos exames laboratoriais, nos quais observou-se anemia severa, sem sinal de regeneração. O sangue utilizado foi doado por um adulto da mesma espécie, macho, clinicamente hígido, de cativeiro. O procedimento foi realizado de acordo com o prescrito pela clínica médica de pequenos animais, visto que, os relatos descritos na medicina de xenarthras são escassos. O resultado se mostrou satisfatório, com ausência de reações transfusionais tardias e melhora do quadro geral do paciente, o que demonstra a possibilidade da utilização de transfusão sanguínea em tamanduás como opção terapêutica.(AU)

Mielodisplasia na peritonite infecciosa felina: 16 casos (2000-2017) / Myelodysplasia in feline infectious peritonitis: 16 cases (2000-2017)

Apesar da prevalência da peritonite infecciosa felina (PIF) ser alta em praticamente o mundo todo, estudos anatomopatológicos recentes acerca dessa doença são escassos. Não obstante, as características microscópicas da medula óssea de gatos com PIF estão ausentes da literatura consultada. O objetivo deste artigo é descrever alterações medulares ósseas vistas em casos espontâneos de PIF. As medulas ósseas colhidas sistematicamente da região diafisária dos fêmures de 16 gatos necropsiados no Laboratório de Patologia Veterinária (LPV) da Universidade Federal de Santa Maria (UFSM), Rio Grande do Sul, entre janeiro de 2000 e junho de 2017, e que tiveram diagnóstico definitivo de PIF, foram avaliadas fenotípica (histopatologia - hematoxilina e eosina e histoquímica - reação de Perls) e imunofenotipicamente (utilizando marcadores mieloides (anti-MAC387) e de linfócitos (anti-CD79αcy e anti-CD3). Os resultados permitem afirmar que, independentemente da apresentação clinicopatológica da doença ocorrem as seguintes alterações: 1) hiperplasia mieloide; 2) hipoplasia eritroide, 3) displasia megacariocítica (dismegacariocitopoiese) e 4) plasmocitose medular. Exclusivamente nos casos de PIF seca há hemossiderose medular óssea e hepática. Essas alterações permitem estabelecer que gatos com PIF desenvolvem mielodisplasia, uma lesão mieloproliferativa muito semelhante àquela relatada em humanos infectados pelo HIV. Sugere-se que a partir dos achados aqui descritos, a mielodisplasia seja considerada a principal responsável pelas alterações hematológicas observadas na PIF, especialmente pela anemia e trombocitopenia arregenerativas frequentemente desenvolvidas pelos pacientes com essa doença.(AU)

Although the prevalence of feline infectious peritonitis (FIP) is high worldwide, recent anatomopathological studies about this disease are scarce. Information on the microscopic characteristics of the bone marrow in FIP-affected cats are absent in the available literature. Based on this, the purpose of this article is to describe bone marrow lesions seen in spontaneous cases of FIP. The bone marrow collected systematically from the femoral diaphysis of 16 cats necropsied in the Laboratory of Veterinary Pathology (LPV) of the Federal University (UFSM) of Southern Brazil, between January 2000 and June 2017, with a definitive diagnosis of FIP, were evaluated phenotypically (histopathology - hematoxylin and eosin and histochemistry - Perls stain) and immunophenotypically (immunohistochemistry using myeloid - Anti-MAC387, and lymphocytic - Anti-CD79 αcy and Anti-CD3 markers). Regardless the following was observed the clinicopathological form of the disease ("dry" - noneffusive or "wet" - effusive): 1) myeloid hyperplasia; 2) erythroid hipoplasia; 3) megakaryocytic dysplasia (dismegakaryocytopoiesis); and 4) medullary plasmacytosis. Exclusively in cases of "dry FIP" was bone marrow and hepatic hemosiderosis. These lesions allowed establishing that cats with FIP develop myelodysplasia, a myeloproliferative lesion very similar to that reported in HIV-infected humans. It is suggested that, based on the findings described here, myelodysplasia is considered to be the main cause of hematological abnormalities observed in FIP, especially for non-regenerative anemia and thrombocytopenia, frequently developed by patients.(AU)

Mielodisplasia na peritonite infecciosa felina: 16 casos (2000-2017) / Myelodysplasia in feline infectious peritonitis: 16 cases (2000-2017)

Apesar da prevalência da peritonite infecciosa felina (PIF) ser alta em praticamente o mundo todo, estudos anatomopatológicos recentes acerca dessa doença são escassos. Não obstante, as características microscópicas da medula óssea de gatos com PIF estão ausentes da literatura consultada. O objetivo deste artigo é descrever alterações medulares ósseas vistas em casos espontâneos de PIF. As medulas ósseas colhidas sistematicamente da região diafisária dos fêmures de 16 gatos necropsiados no Laboratório de Patologia Veterinária (LPV) da Universidade Federal de Santa Maria (UFSM), Rio Grande do Sul, entre janeiro de 2000 e junho de 2017, e que tiveram diagnóstico definitivo de PIF, foram avaliadas fenotípica (histopatologia - hematoxilina e eosina e histoquímica - reação de Perls) e imunofenotipicamente (utilizando marcadores mieloides (anti-MAC387) e de linfócitos (anti-CD79αcy e anti-CD3). Os resultados permitem afirmar que, independentemente da apresentação clinicopatológica da doença ocorrem as seguintes alterações: 1) hiperplasia mieloide; 2) hipoplasia eritroide, 3) displasia megacariocítica (dismegacariocitopoiese) e 4) plasmocitose medular. Exclusivamente nos casos de PIF seca há hemossiderose medular óssea e hepática. Essas alterações permitem estabelecer que gatos com PIF desenvolvem mielodisplasia, uma lesão mieloproliferativa muito semelhante àquela relatada em humanos infectados pelo HIV. Sugere-se que a partir dos achados aqui descritos, a mielodisplasia seja considerada a principal responsável pelas alterações hematológicas observadas na PIF, especialmente pela anemia e trombocitopenia arregenerativas frequentemente desenvolvidas pelos pacientes com essa doença.(AU)

Although the prevalence of feline infectious peritonitis (FIP) is high worldwide, recent anatomopathological studies about this disease are scarce. Information on the microscopic characteristics of the bone marrow in FIP-affected cats are absent in the available literature. Based on this, the purpose of this article is to describe bone marrow lesions seen in spontaneous cases of FIP. The bone marrow collected systematically from the femoral diaphysis of 16 cats necropsied in the Laboratory of Veterinary Pathology (LPV) of the Federal University (UFSM) of Southern Brazil, between January 2000 and June 2017, with a definitive diagnosis of FIP, were evaluated phenotypically (histopathology - hematoxylin and eosin and histochemistry - Perls stain) and immunophenotypically (immunohistochemistry using myeloid - Anti-MAC387, and lymphocytic - Anti-CD79 αcy and Anti-CD3 markers). Regardless the following was observed the clinicopathological form of the disease ("dry" - noneffusive or "wet" - effusive): 1) myeloid hyperplasia; 2) erythroid hipoplasia; 3) megakaryocytic dysplasia (dismegakaryocytopoiesis); and 4) medullary plasmacytosis. Exclusively in cases of "dry FIP" was bone marrow and hepatic hemosiderosis. These lesions allowed establishing that cats with FIP develop myelodysplasia, a myeloproliferative lesion very similar to that reported in HIV-infected humans. It is suggested that, based on the findings described here, myelodysplasia is considered to be the main cause of hematological abnormalities observed in FIP, especially for non-regenerative anemia and thrombocytopenia, frequently developed by patients.(AU)

Piotórax crônico em cão por vagem de Acácia Imperial (Cassia fistula) / Chronic Pyothorax in a dog due pod of acacia imperial (Cassia fistula)

Background: Pyothorax is characterized by the accumulation of septic purulent fluid within the pleural space. Most of the times, it is the true identified infection way in only 2 to 22% of dog cases. Reports show that the most common cause is the migration of grass edges and plant materials, mainly in regions of California, USA. The current study reports an unusual case of a Cassia fistula pod (Brazilian Acácia Imperial), of around 10x3 cm long, causing chronic Pyothorax in a Border Collie female dog. Case: It was admitted in a Teaching Veterinary Hospital a 2-year-old female Border Collie, weighing 16.5 kg. The complaint was producing of severe cough, dyspnoea, hyporexia and loss of weight in the past three months. The animal could have been horse-kicked, as it is used to herding. In the physical examination, it was detected bilateral thick lung crepitations, more evident in the ventral skull area, dyspnoea, tachypnea, fever, splenomegaly and low body condition score (3/9). The laboratory tests revealed nonregenerative anemia and leukemoid reaction. The chest x-ray showed intense pulmonary opacification and free fluids in the pleural space along with a heterogenic cylindrical image of the mixed radiopacity. This image was then confirmed as the intrathoracic foreing body by the use of a computerized tomography. In this exam it was also possible to observe the damage of part of the middle and inferior right lung lobe. The cytology of the pleural effusion found mixed inflammation and coccoid bacteria, and the microbiological culture Streptococcus sp., and Escherichia coli. The dog underwent thoracotomy in order to remove the foreign body, which was later identified as being a Cassia fistula pod (Brazilian Acácia Imperial), of around 10x3 cm long. Due to the intense lung damage, a right pneumonectomy was required. After 30 days the animal was fully recovered.[...]

Piotórax crônico em cão por vagem de Acácia Imperial (Cassia fistula) / Chronic Pyothorax in a dog due pod of acacia imperial (Cassia fistula)

Background: Pyothorax is characterized by the accumulation of septic purulent fluid within the pleural space. Most of the times, it is the true identified infection way in only 2 to 22% of dog cases. Reports show that the most common cause is the migration of grass edges and plant materials, mainly in regions of California, USA. The current study reports an unusual case of a Cassia fistula pod (Brazilian Acácia Imperial), of around 10x3 cm long, causing chronic Pyothorax in a Border Collie female dog. Case: It was admitted in a Teaching Veterinary Hospital a 2-year-old female Border Collie, weighing 16.5 kg. The complaint was producing of severe cough, dyspnoea, hyporexia and loss of weight in the past three months. The animal could have been horse-kicked, as it is used to herding. In the physical examination, it was detected bilateral thick lung crepitations, more evident in the ventral skull area, dyspnoea, tachypnea, fever, splenomegaly and low body condition score (3/9). The laboratory tests revealed nonregenerative anemia and leukemoid reaction. The chest x-ray showed intense pulmonary opacification and free fluids in the pleural space along with a heterogenic cylindrical image of the mixed radiopacity. This image was then confirmed as the intrathoracic foreing body by the use of a computerized tomography. In this exam it was also possible to observe the damage of part of the middle and inferior right lung lobe. The cytology of the pleural effusion found mixed inflammation and coccoid bacteria, and the microbiological culture Streptococcus sp., and Escherichia coli. The dog underwent thoracotomy in order to remove the foreign body, which was later identified as being a Cassia fistula pod (Brazilian Acácia Imperial), of around 10x3 cm long. Due to the intense lung damage, a right pneumonectomy was required. After 30 days the animal was fully recovered.[...](AU)

Bone marrow bi-hypoplasia in a dog with a sertoli cell tumor / Hipoplasia dupla de medula óssea em um cão com tumor de células de sertoli

A 20-year-old unneutered male poodle presented prostration, apathy, staggering gait, lack of appetite and tick infestation. The dog was diagnosed with a Sertoli cell tumor in an undescended testicle by cytological, histopathological and immunohistochemical tests. Pancytopenia with moderate nonregenerative anemia, leukopenia and severe thrombocytopenia were detected in the complete blood count. Cytological and histopathological evaluation of the bone marrow revealed a cellularity of 30%, with erythroid (59%), lymphoid (40%) and mast cells (1%), and an absence of granulocytic, monocytic and megakaryocytic lineage cells. In post-mortem examinations, changes related to hemostatic disorders were found. The absence of microorganisms in molecular tests and an estrogen serum concentration over reference values confirmed hyperestrogenism as a possible cause of pancytopenia. The literature describes a Sertoli cell tumor hyperestrogenism that induced pancytopenia, along with bone marrow hypoplasia of all hematopoietic lineages. In contrast, in the present case, the erythroid precursor cells were preserved in the bone marrow, although there were no reticulocytes circulating in the blood. This case, therefore, should be considered in future investigations of pancytopenia induced by Sertoli cell tumor hyperestrogenism.(AU)

Um cão Poodle, macho, de 20 anos, não castrado, apresentou prostração, apatia, andar cambaleante, falta de apetite e infestação por carrapatos. Nesse animal, foi diagnosticado tumor de células de Sertoli em um testículo não descendente, utilizando-se citologia, histopatologia e imuno-histoquímica. Pancitopenia com anemia moderada não regenerativa, leucopenia e trombocitopenia intensas foram detectadas no hemograma. Na avaliação citológica e histopatológica da medula óssea, havia celularidade de 30%, constituída pelas linhagens eritroide (59%) e linfoide (40%) e por mastócitos (1%), com ausência de células das linhagens granulocítica, monocítica e megacariocítica. Em exames post mortem, mudanças relacionadas à hemostasia foram encontradas. A ausência de micro-organismos nos testes moleculares e a concentração sérica de estrogênio acima dos valores de referência confirmaram hiperestrogenismo como a possível causa da pancitopenia. A literatura descreve hiperestrogenismo em tumores de células de Sertoli induzindo pancitopenia associada com hipoplasia da medula óssea de todas as linhagens hematopoiéticas. Em contraste, no presente caso, as células precursoras eritróides estavam preservadas na medula óssea, embora não houvesse reticulócitos no sangue. Assim, o relato apresentado deve ser considerado em futuras investigações de pancitopenia induzida por hiperestrogenismo em tumor de células de Sertoli.(AU)

Bone marrow bi-hypoplasia in a dog with a sertoli cell tumor / Hipoplasia dupla de medula óssea em um cão com tumor de células de sertoli

A 20-year-old unneutered male poodle presented prostration, apathy, staggering gait, lack of appetite and tick infestation. The dog was diagnosed with a Sertoli cell tumor in an undescended testicle by cytological, histopathological and immunohistochemical tests. Pancytopenia with moderate nonregenerative anemia, leukopenia and severe thrombocytopenia were detected in the complete blood count. Cytological and histopathological evaluation of the bone marrow revealed a cellularity of 30%, with erythroid (59%), lymphoid (40%) and mast cells (1%), and an absence of granulocytic, monocytic and megakaryocytic lineage cells. In post-mortem examinations, changes related to hemostatic disorders were found. The absence of microorganisms in molecular tests and an estrogen serum concentration over reference values confirmed hyperestrogenism as a possible cause of pancytopenia. The literature describes a Sertoli cell tumor hyperestrogenism that induced pancytopenia, along with bone marrow hypoplasia of all hematopoietic lineages. In contrast, in the present case, the erythroid precursor cells were preserved in the bone marrow, although there were no reticulocytes circulating in the blood. This case, therefore, should be considered in future investigations of pancytopenia induced by Sertoli cell tumor hyperestrogenism.(AU)

Um cão Poodle, macho, de 20 anos, não castrado, apresentou prostração, apatia, andar cambaleante, falta de apetite e infestação por carrapatos. Nesse animal, foi diagnosticado tumor de células de Sertoli em um testículo não descendente, utilizando-se citologia, histopatologia e imuno-histoquímica. Pancitopenia com anemia moderada não regenerativa, leucopenia e trombocitopenia intensas foram detectadas no hemograma. Na avaliação citológica e histopatológica da medula óssea, havia celularidade de 30%, constituída pelas linhagens eritroide (59%) e linfoide (40%) e por mastócitos (1%), com ausência de células das linhagens granulocítica, monocítica e megacariocítica. Em exames post mortem, mudanças relacionadas à hemostasia foram encontradas. A ausência de micro-organismos nos testes moleculares e a concentração sérica de estrogênio acima dos valores de referência confirmaram hiperestrogenismo como a possível causa da pancitopenia. A literatura descreve hiperestrogenismo em tumores de células de Sertoli induzindo pancitopenia associada com hipoplasia da medula óssea de todas as linhagens hematopoiéticas. Em contraste, no presente caso, as células precursoras eritróides estavam preservadas na medula óssea, embora não houvesse reticulócitos no sangue. Assim, o relato apresentado deve ser considerado em futuras investigações de pancitopenia induzida por hiperestrogenismo em tumor de células de Sertoli.(AU)

Clinical and hematological evaluation of Rangelia vitalii-naturally infected dogs in southeastern Brazil

Rangelia vitalii, a tick-borne piroplasm that infects dogs, has been recently molecularly characterized in Brazil, Uruguay and Argentina. Studies on molecular characterization of these piroplasms in different Brazilian regions are scarce. The aim of this study was to evaluate clinical and hematological changes in dogs caused by R. vitalii in the mountainous region of the state of Rio de Janeiro. Blood samples from 36 dogs were evaluated for piroplasms and hematological disorders using light microscopy and molecular analysis. Blood samples from all the animals included in this study were confirmed to be positive for R. vitalii through genetic sequencing. Clinical signspresented by 24 of the 36 dogs of the study were evaluated during appointments or hospitalization within private practice. The most frequent clinical disorders in these dogs that were naturally infected with R. vitalii were fever, spontaneous cutaneous bleeding and diarrhea. Normochromic non-regenerative anemia and thrombocytopenia were the most common hematological disorders in these R. vitalii-positive dogs and therefore should be considered in hematological evaluations on suspected cases.(AU)

Rangelia vitalii, um piroplasma transmitido por carrapatos que infecta cães, foi sendo recentemente caracterizado molecularmente no Brasil, Uruguai e Argentina. Nas diferentes regiões brasileiras são escassos os estudos acerca da caracterização molecular destes piroplasmídeos. O objetivo deste estudo foi avaliar as alterações clínicas e hematológicas em cães causadas por R. vitalii na região serrana do Rio de Janeiro. Amostras de sangue total de 36 cães foram examinadas quanto à presença de piroplasmas pela microscopia de luz, alterações hematológicas e análise molecular. Todos os cães do presente estudo foram positivos para R. vitalii através do sequenciamento genético. Dos 36 animais positivos para R. vitalii, 24 foram avaliados clinicamente. As alterações mais frequentemente observadas foram febre, sangramento cutâneo espontâneo e diarréia. Anemia normocítica normocrômica arregenerativa e trombocitopenia foram as alterações hematológicas mais observadas em cães positivos para R. vitalii, devendo ser consideradas na avaliação hematológica de cães suspeitos.(AU)

Increased serum alkaline phosphatase in a FeLV-positive cat

Background: Feline Leukemia Virus (FeLV) is an oncogenic virus that usually invades bone marrow causing non-regenerative anemia and thrombocytopenia. In FeLV positive cats, the myeloid leukemia is characterized by intense proliferation of blast cells in a bone marrow with myeloid precursor predominance and several malignancies degree. The leukocyte alkaline phosphatase is found secondary granules of mature neutrophils of humans, horses and cows but not in dogs and cats, which demonstrate the enzyme activity in myeloblast and promyeloblasts cells. In this case is describing a FeLV-positive case with leukemic disorder accompanied by extremely high levels of serum alkaline phosphatase. Case: A 8-year-old castrated male Domestic Short Hair cat with a 3-month history of convulsions, pica, vomits, lethargy, hypodipsia and anorexia was examined and showed mild dehydration, severe jaundice and hyperpnoea. Laboratory results evidenced severe normocytic hypochromic non-regenerative anemia, moderated leukocytosis with severe degenerative neutrophil left shift, moderated lymphocytosis and severe thrombocytopenia. Serum biochemical profile showed mild hyperalbuminemia, moderated increment in alanine transaminase and severe increment in alkaline phosphatese. The cat was positive for ELISA point of care FeLV antigen and negative for FIV antibodies. Urinalysis revealed moderated bilirubinuria [...]

Increased serum alkaline phosphatase in a FeLV-positive cat

Background: Feline Leukemia Virus (FeLV) is an oncogenic virus that usually invades bone marrow causing non-regenerative anemia and thrombocytopenia. In FeLV positive cats, the myeloid leukemia is characterized by intense proliferation of blast cells in a bone marrow with myeloid precursor predominance and several malignancies degree. The leukocyte alkaline phosphatase is found secondary granules of mature neutrophils of humans, horses and cows but not in dogs and cats, which demonstrate the enzyme activity in myeloblast and promyeloblasts cells. In this case is describing a FeLV-positive case with leukemic disorder accompanied by extremely high levels of serum alkaline phosphatase. Case: A 8-year-old castrated male Domestic Short Hair cat with a 3-month history of convulsions, pica, vomits, lethargy, hypodipsia and anorexia was examined and showed mild dehydration, severe jaundice and hyperpnoea. Laboratory results evidenced severe normocytic hypochromic non-regenerative anemia, moderated leukocytosis with severe degenerative neutrophil left shift, moderated lymphocytosis and severe thrombocytopenia. Serum biochemical profile showed mild hyperalbuminemia, moderated increment in alanine transaminase and severe increment in alkaline phosphatese. The cat was positive for ELISA point of care FeLV antigen and negative for FIV antibodies. Urinalysis revealed moderated bilirubinuria [...](AU)

ALTERAÇÕES LABORATORIAIS EM CÃES COM ANEMIA HEMOLÍTICA IMUNOMEDIADA SECUNDÁRIA (AHIM) RESPONSIVA E NÃO RESPONSIVA

A anemia hemolítica imunomediada (AHIM) é um dos tipos de anemia mais comumente diagnosticada em pequenos animais. A de origem secundária é mais prevalente em cães, a qual pode ser desencadeada por processos que culminam em resposta imunológica contra antígenos nãopróprios opsonisados à membrana eritrocitária. Logo, a destruição dessas células ocorre devido uma reação de hipersensibilidade do tipo II, em que os anticorpos antieritrocitários atuam contra hemácias que possuem antígenos ligados à sua superfície. Algumas raças possuem predisposição para este tipo de anemia, além de estudos terem demonstrado predileção para sexo e idade. Para diagnóstico laboratorial, são levados em consideração a presença de esferócitos e autoaglutinação em solução salina, juntamente com o histórico clínico do animal, embora a negatividade desses testes não exclua a origem hemolítica da anemia. Uma das características deste tipo de anemia é a regeneração medular, marcada por presença de reticulócitos circulantes, apesar de uma grande parcela não apresentar regeneração no momento do diagnóstico. Sendo assim, o objetivo deste trabalho foi avaliar o comportamento hematológico de cães com AHIM secundária classificados como responsivos e não responsivos à anemia por meio da citometria de fluxo. Foi observado que 53,3% dos animais eram machos, enquanto 46,6% eram fêmeas, com a porcentagem de 6,25% e 21,4% abaixo de um ano de idade, respectivamente. A maior porcentagem (66,6%) dos cães foi de animais com idade igual ou maior a oito anos de idade. Quanto a responsividade medular, 73,3% dos animais tiveram anemia não regenerativa no momento do diagnóstico, sendo apenas 26,6% responsivos, os quais apresentaram menores resultados quanto aos valores de neutrófilos segmentados, bastonetes, eritroblastos e bilirrubina total, assim como menores índices de VCM e HCM, obtendo resultados superiores apenas nos valores de eritrócitos. Conclui-se que há possibilidade de diagnóstico deste tipo de anemia com testes laboratoriais aplicáveis na rotina e de baixo custo e que há diferença na avaliação laboratorial de animais com AHIM secundária responsiva e não responsiva, fazendo com que a investigação e determinação da não responsividade da anemia seja de extrema importância para melhor diagnóstico e tratamento do paciente.

Immune-mediated hemolytic anemia (IMHA) is one of the most commonly diagnosed types of anemia in small animals. A of secondary origin is more prevalent in dogs, which can be triggered by processes that culminate in immune response against opsonized antigens to the erythrocyte membrane. Therefore, the destruction of these cells occurs due to a type II hypersensitivity reaction, in which anti-erythrocyte antibodies act against erythrocytes that have antigens attached to their surface. Some breeds are predisposed to this type of anemia, in addition to studies showing a predilection for sex and age. For laboratory diagnosis, the presence of spherocytes and autoagglutination in saline together with the animal's clinical history are considered, although the negativity of these tests does not exclude the hemolytic origin of the anemia. One of the characteristics of this type of anemia is the medullary regeneration, marked by the presence of circulating reticulocytes, although a large portion does not present regeneration at the time of diagnosis. Thus, the objective of this study was to evaluate the hematological behavior of dogs with secondary AHIM classified as responsive and not responsive to anemia by means of flow cytometry. It was observed that 53.3% of the animals were male, while 46.6% were females, with a percentage of 6.25% and 21.4% under one year of age, respectively. The highest percentage (66.6%) of the dogs was from animals aged 8 years or more. As for spinal cord responsiveness, 73.3% of the animals had non-regenerative anemia at the time of diagnosis, and only 26.6% were responsive, which presented lower results regarding the values of segmented neutrophils, rods, erythroblasts and total bilirubin, as well as lower VCM and HCM indexes, obtaining superior results only in erythrocyte values. It is concluded that it is possible to diagnose this type of anemia with routine and low-cost laboratory tests and that there is a difference in the laboratory evaluation of animals with secondary non-responsive AHIM, causing the investigation and determination of non-responsiveness anemia is of utmost importance for better diagnosis and treatment of the patient.

FRAGILIDADE OSMÓTICA ERITROCITÁRIA E RETICULOCITOMETRIA EM CÃES ACOMETIDOS POR DOENÇA RENAL CRÔNICA

A anemia é considerada um dos fatores para avaliar progressão da doença renal e diminuição da qualidade de vida do paciente. Conforme a doença renal progride, ocorre aumento gradativo na produção de toxinas urêmicas que reduz a meia vida dos eritrócitos circulantes por interferir na estabilidade da membrana eritrocitária. Para tanto, utiliza-se a contagem de reticulócitos para classificar a anemia como regenerativa ou não regenerativa. Objetivou-se neste estudo avaliar a resistência da membrana das hemácias, utilizando-se do teste de Fragilidade Osmótica Eritrocitária (FOE) em cães com doença renal crônica (DRC) e avaliação de reticulócitos. Foram avaliados 43 cães provenientes da rotina do Serviço de Nefrologia e Urologia do Hospital Veterinário Governador Laudo Natel da Faculdade de Ciências Agrárias e Veterinárias - UNESP - campus Jaboticabal. As referidas unidades experimentais foram distribuídas em três grupos, quais sejam, G0 (n=13), composto por cães hígidos e G1, DRC estádios 1 e 2 (n=14) e G2, DRC estádios 3 e 4 (n=16), classificados de acordo com o recomendado pela International Renal Interest Society. A fim de definir os critérios de inclusão dos cães foram feitos, além do exame físico, a avaliação de pressão arterial, hemograma, contagem de reticulócitos, exames bioquímicos, urinálise e relação proteína/creatinina urinária (UP/C). Para execução do teste de FOE as hemácias foram diluídas em concentrações decrescentes de cloreto de sódio e analisadas por citometria de fluxo. As concentrações de creatinina sérica (sCr), ureia sérica (sUreia), fosfato sérico (sP) e UP/C foram superiores no grupo G2 quando comparado ao G0 (p<0,05). Com relação às variáveis hematológicas, foram observadas diferença estatística entre o número de hemácias (p<0,009), hematócrito (p<007) e hemoglobina (p<0,007), que decresceu conforme a doença renal avançava. A FOE e os reticulócitos apesar de terem variado individualmente, dependendo do estádio da DRC de cada paciente, não apresentaram diferença estatística quando comparado aos animais controle e doentes, e tampouco quando foram confrontados os diferentes estádios de cães com DRC (p>0,05).Os resultados obtidos neste estudo demonstram, portanto que, embora a reticulocitometria seja fiadora da contagem de reticulócitos, a contabilização manual de reticulócitos ainda é uma opção segura e somente com a FOE não é possível predizer alterações na membrana do eritrócito em cães com DRC.

Anemia is considered one of the factors to assess the kidney disease progress and the decrease in patient's quality of life. As kidney disease progresses, there is a gradual increase in urinary toxin production that shortens the circulating erythrocyte half-life by interfering with erythrocyte membrane stability. To do this, use a reticulocyte count to classify anemia as regenerative or non-regenerative. The objectives of this study were to evaluate the resistance of the red blood cells, using the Erythrocyte Osmotic Fragility test in dogs with chronic kidney disease (CKD) and to evaluate reticulocytes. Forty-three dogs were charged, followed by the routine of the Nephrology and Urology Service of the Governor Laudo Natel Veterinary Hospital of the Faculty of Agricultural and Veterinary Sciences - UNESP - Campus Jaboticabal. The experimental units were divided into three groups, namely, G0 (n = 13), consisting of healthy dogs and G1, CKD stages 1 and 2 (n = 14) and G2, CKD stages 3 and 4 (n = 16), classification proposed by the International Renal Interest Society. In order to define the inclusion criteria of dogs made, in addition to physical examination, an assessment of blood pressure, blood count, reticulocyte count, biochemical tests, urinalysis, and urinary protein/creatinine ratio. To perform the erythrocyte osmotic fragility test, red blood cells were diluted in decreasing sodium chloride filters (0.9 to 0.0%) and analyzed by flow cytometry. As creatinine serum concentration (sCr), serum urea (sUL), serum phosphorus (sP) and urinary protein/creatinine ratio. were higher in group G2 when compared to G0 (p <0.05). Regarding hematological variables, statistical differences were observed between the number of red blood cells (p <0.009), hematocrit (p <007) and hemoglobin (p <0.007), which decreased according to the advanced kidney disease. A cross-referenced FOE despite varying the number of participants, depending on each patient's CKD stage, shows no statistical difference when it shows control animals and damage, and shows when it is confronted with different cases of dogs with CKD (p> 0, 05) The results obtained in this study demonstrate, therefore, that although reticulocytometry is a guarantor of reticulocyte counting, manual reticulocyte counting is still a safe option and only with FOE it is not possible to predict changes in the erythrocyte membrane in dogs with CKD.

Número de policromatófilos na diferenciação das anemias não regenerativas de regenerativas em cães / Polycromatophilic cell count in differentiation of non regenerative anemia from regenerative anemia in dogs

O método de quantificação de eritrócitos policromatófilos é utilizado na rotina dos laboratórios clínicos veterinários para identificar a resposta da medula óssea. Entretanto, não há padronização desse método em relação ao número absoluto de reticulócitos. No presente estudo foram avaliadas amostras sanguíneas de 135 cães anêmicos e de 21 cães saudáveis de um total de 1875 cães atendidos no Hospital Veterinário da Universidade Federal do Paraná, entre o período de 01 de julho de 2011 a 18 de outubro de 2012. Foram realizados hemogramas e quantificações de eritrócitos policromatófilos e reticulócitos. Os valores de policromatófilos por campo e a contagem absoluta de reticulócitos foram comparados por análises estatísticas para determinar se há correlação entre os dois métodos. Os valores da sensibilidade, especificidade, acurácia e teste Kappa do número de policromatófilos foram, respectivamente, de 86,11%, 87,5%, 87,12% e 71%. O coeficiente de correlação de Pearson (r) foi de 0,8125 e o coeficiente de determinação da equação (R2) foi de 0,6603, entre o número de policromatófilos e de reticulócitos. A presença de dois policromatófilos por campo diferenciou a anemia não regenerativa da regenerativa, mas não foi possível associar o número de reticulócitos ao número de policromatófilos e nem classificar a anemia quanto à intensidade de regeneração.(AU)

The method of quantitation of polychromatophilic cell is routinely used in veterinary clinical laboratories to identify the bone marrow response. However, there is no standardization of this approach over the absolute reticulocyte count. The present study evaluated blood samples from 135 anemic dogs and 21 healthy dogs. CBC and quantification of reticulocytes and polychromatophilic cell were performed. The sensitivity, specificity, accuracy and Kappa of the polychromatophilic cell count were, respectively, 86.11%, 87.5%, 87.12% and 71%. The Pearson correlation coefficient (r) was 0.8125 and the coefficient of determination equation (R2) was 0.6603, between the number of polychromatophilic cell and reticulocytes. The identification of two polychromatophilic cells per field could allow a differentiation between regenerative and nonregenerative anemia, but it was not possible to associate it to the absolute reticulocyte count and classify the intensity of regeneration of anemia.(AU)

Anemia mielotísica por osteopetrose em um cão: relato de caso / Mielotisic anemia caused by osteopetrosis in a dog: case report

A osteopetrose é uma doença rara, caracterizada pelo aumento generalizado da densidade óssea. Tem como característica principal, a reabsorção osteoclástica defeituosa, resultando no acúmulo de massa óssea. Além disso, pode ocorrer retardo do crescimento, desnutrição progressiva, anemia e caquexia. O presente relato descreve o caso de uma cadela, com aproximadamente nove meses de idade, sem raça definida, com histórico de apatia e disorexia. Hemogramas seriados demonstraram pancitopenia persistente. Vários exames laboratoriais foram realizados para excluir doenças como erliquiose, leishmaniose e cinomose, porém todos foram negativos. O mielograma constatou hipocelularidade relativa por provável aplasia/hipoplasia medular. Exames radiográficos evidenciaram o aumento da radiopacidade óssea e hipertrofia da região cortical, e a necropsia confirmou a redução do canal medular. O exame histopatológico confirmou a osteopetrose. Conclui-se que a osteopetrose pode causar comprometimento na produção de células sanguíneas, sendo uma causa rara de anemia mielotísica, além de alterações neurológicas secundárias à má-formação dos ossos do crânio.(AU)

Osteopetrosis is a rare disease characterized by generalized increase in bone density. The defective osteoclastic resorption results in the accumulation of bone mass. Furthermore, there may be growth delay, progressive malnutrition, anemia and cachexy. This report describes the case of a nine month old, mixed breed, female dog presented with apathy and disorexia. Laboratory tests were performed to rule out Ehrlichiosis, Leishmaniasis, and Canine distemper, but all were negative. Hemogram showed persistent pancytopenia and myelogram showed relative hypocellularity, probably due to spinal cord aplasia/hypoplasia. Radiographs showed increased bone opacity and hypertrophy of the cortical region, and the necropsy confirmed the reduction of the medullary canal. Histopathological examination confirmed osteopetrosis. In conclusion, osteopetrosis can compromise blood cell production, and is a rare cause of mielotisic anemia. It can also cause neurological deficits due to cranium bone deformation.(AU)

Phenotipic, cytological and functional characterization of bone marrow cells in FELV-negative and FELV- positive cats.

O vírus da leucemia viral felina (FeLV) tem distribuição mundial e pode causar diferentes tipos de alterações no organismo, sejam elas neoplásicas (linfoma, fibrossarcoma e doenças mieloproliferativas) ou não neoplásicas como anemia regenerativa ou arregenerativa. Além disso, podem causar imunossupressão e tornar os gatos mais susceptíveis às infecções oportunistas, como coinfecções com protozoários. A transmissão da FeLV ocorre principalmente pela saliva contaminada. Os objetivos do presente estudo foram avaliar as alterações hematológicas relacionadas ao vírus da FeLV, descrever as características funcionais, citológicas e imunofenotípicas das células hematopoéticas da medula óssea em gatos negativos e positivos para FeLV, assim como determinar a ocorrência dos retrovírus FIV (vírus da imunodeficiência felina) e FeLV e a coinfecção pelos protozoários Toxoplasma gondii, Neospora caninum e Sarcocystis neurona em gatos no sul do Brasil. Para isso, o presente trabalho foi divido em três capítulos. No primeiro capítulo, um total de 142 gatos domésticos foram testados por PCR em tempo real (qPCR) para detectar a infecção pelo vírus da FeLV e pelo vírus da imunodeficiência felina (FIV). No segundo capítulo, foram coletadas amostras de medula óssea de 19 gatos, sendo 12 negativos e sete positivos para FeLV, considerando resultados por imunoabsorção enzimática (ELISA) e qPCR, e realizado mielograma, ensaio clonogênico, imunofenotipagem por citometria de fluxo e análise de carga viral, sendo esta última avaliada no sangue também. No terceiro capítulo, em 167 gatos domésticos foi realizado teste sorógico por ELISA para detecção de FIV e FeLV, e realizadas sorologia por reação de imunofluorescência indireta (RIFI) para detecção de T. gondii, N. caninum e S. neurona. Dos 142 gatos do primeiro capítulo, o vírus da FeLV foi encontrado em 41 (28,8%) animais. Entre os animais positivos, 27 (19%), 55,5% tinham anemia. As alterações mais prevalentes nestes 41 gatos positivos para FeLV foram anemia, anisocitose, neutrofilia e linfopenia. Nas amostras de medula óssea do segundo capítulo não houve diferença com relação ao crescimento de unidades formadoras de colônias em gatos portadores ou não do vírus. Das sete amostras de medula óssea dos gatos FeLV positivos, em duas verificou-se hipoplasia granulocítica e hiperplasia eritróide. No gato com hiperplasia eritróide foi encontrada a maior carga viral/mL no sangue (2.352.025.174,98) e na medula óssea (1.640.070.897,77). Na caracterização imunofenotípica os marcadores que apresentaram diferença foram o CD8, CD19 e o CD45 que foram mais expressivos em gatos infectados pelo vírus da FeLV. Verificou-se que em gatos infectados pelo vírus da leucemia felina na medula óssea, não houve interferência no desenvolvimento de células precursoras. A maior carga viral foi observada na medula óssea de um gato com hiperplasia eritróide e anemia não regenerativa, demonstrando que apesar da alta produção de células eritróides na medula óssea, o vírus em alta quantidade não permite a maturação das células no sangue periférico. Dos 167 gatos do terceiro capítulo, 27% (45/167) foram soropositivos para T.gondii; 29,3% (49/167) para N. caninum e 3,6% (6/167) para S.neurona. O vírus da FeLV foi detectado em 24,6% e da FIV em 1,7% destes gatos. Os gatos do sul do Brasil foram expostos aos protozoários T. gondii, N. caninum e S. neurona. Observou-se maior ocorrência de anticorpos para T. gondii do que em estudos anteriores realizados na mesma região. O presente estudo demonstrou a maior ocorrência de anticorpos anti N.caninum em gatos do Brasil. A soropositividade para S. neurona é o primeiro relato em gatos no sul do Brasil. Verificou-se coinfecção por mais de um protozoário. Foi observada soropositividade com diferença estatística (p<0,05) entre o protozoário N. caninum e o retrovírus FeLV. Foi notável a maior ocorrência (p=0,1) da FeLV em gatos semidomiciliados, condizente com o estudos que observaram o acesso a rua como fator de risco para este vírus. Entre os machos e fêmeas, não foi observada maior positividade para os agentes, exceto para S. neurona que foi observada maior prevalência para fêmeas. A análise da carga viral da medula óssea, das alterações hematológicas, e das coinfecções relacionadas ao vírus da FeLV devem ser realizadas com mais frequência em estudos científicos e na rotina clínica. Estes dados são de extrema importância para entendermos o modo de ação do vírus e, conseqüentemente, obter prognósticos mais precisos e, futuramente, tratamento.

Feline viral leukemia virus (FeLV) has a worldwide distribution and can cause different types of abnormalities in the body, whether they are neoplastic (lymphoma, fibrosarcoma and myeloproliferative diseases) or non-neoplastic, such as regenerative or arregenerative anemia. In addition, they can cause immunosuppression and make cats more susceptible to opportunistic infections, such as coinfections with protozoa. The transmission of FeLV occurs mainly by contaminated saliva. The objectives of the present study were to evaluate the hematological changes related to the FeLV virus, to describe the functional, cytological and immunophenotypic characteristics of hematopoietic cells of the bone marrow in FeLV positive and negative cats, as to determine the occurrence of the retrovirus FIV (feline immunodeficincy virus) and FeLV and coinfection by the protozoa Toxoplasma gondii, Neospora caninum and Sarcocystis neurona in cats in southern Brazil. For this, the present work was divided in three chapters. In the first chapter, a total of 142 domestic cats were tested by real-time PCR (qPCR) to detect infection by FeLV virus and feline immunodeficiency virus (FIV). In the second chapter, bone marrow samples were collected from 19 cats, 12 negative and 7 positive for FeLV, considering results by enzyme-linked immunosorbent assay (ELISA) and qPCR, and myelogram, clonogenic assay, flow cytometric immunophenotyping and load analysis viral activity, the latter being evaluated in the blood as well. In the third chapter, 167 domestic cats were tested by ELISA for FIV and FeLV, and indirect immunofluorescence (IFR) serology was performed for the detection of T. gondii, N. caninum and S. neurona. Of the 142 cats in the first chapter, FeLV virus was found in 41 (28.8%) animals. Among the positive animals, 27 (19%),55.5% had anemia. The most prevalent changes in these 41 FeLV positive cats were anemia, anisocytosis, neutrophilia and lymphopenia. In the samples of bone marrow of the second chapter there was no difference with respect to the growth of colony forming units in cats with or without virus. Of the seven bone marrow samples from FeLV-positive cats, two showed granulocytic hypoplasia and erythroid hyperplasia. In the cat with erythroid hyperplasia, the highest viral load / mL was found in the blood (2.352.025.174.98) and in the bone marrow (1.640.070.897.77). In the immunophenotypic characterization the markers that showed difference were the CD8, CD19 and CD45 that were more expressive in cats infected with FeLV virus. It was found that in cats infected with the feline leukemia virus in the bone marrow, there was no interference in the development of precursor cells. The highest viral load was observed in the bone marrow of a cat with erythroid hyperplasia and non-regenerative anemia, demonstrating that despite the high production of erythroid cells in the bone marrow, the virus in high quantity does not allow the maturation of the cells in the peripheral blood. Of the 167 cats in the third chapter, 27% (45/167) were seropositive for T.gondii, 29.3% (49/167) for N. caninum and 3.6% (6/167) for S. neurona. FeLV virus was detected in 24.6% and FIV in 1.7% of these cats. Cats from southern Brazil were exposed to protozoa T. gondii, N. caninum and S.neurona. There was a higher occurrence of antibodies to T. gondii than in previous studies conducted in the same region. The present study demonstrated the highest occurrence of N. caninum antibodies in Brazilian cats. Seropositivity for S. neurona is the first report in cats in southern Brazil. Coinfection was observed by more than one protozoan. Seropositivity was observed with statistical difference (p<0.05) between the protozoan N. caninum and the retrovirus FeLV. A highest occurrence (p=0.1) of FeLV in semi-domiciled cats was notable, consistent with studies that observed access to the street as a risk factor for this virus. Among males and females, no higher positivity was observed for the agents, except for S. neurona that a higher prevalence was observed for females. Analysis of bone marrow viral load, haematological abnormalities, and coinfections related to FeLV virus should be performed more frequently in scientific studies and clinical routine. These data are extremely important to understand the mode of action of the virus and, consequently, to obtain more accurate prognoses and, in the future, treatment.