Histological and immunohistochemical features of carcinomas with pulmonary involvement in cattle.

Primary pulmonary neoplasms in cattle are rare. There are few studies on the pathological findings of these neoplasms in this species. This study aimed to describe the histological and immunohistochemical findings of primary and metastatic pulmonary carcinomas in cattle. We conducted a retrospective study of 19 cases of epithelial neoplasms with pulmonary involvement. Histologically, most of the neoplasms were classified as primary pulmonary neoplasms, including different adenocarcinoma subtypes (4/19, 21%) and adenosquamous carcinomas (3/19, 16%), followed by squamous cell carcinoma (6/19, 32%), metastatic uterine adenocarcinoma (4/19, 21%), metastatic hepatocellular carcinoma (1/19, 5%), and metastatic cholangiocarcinoma (1/19, 5%). By immunohistochemistry, all neoplasms were positive for pancytokeratin, and 4/19 (21%) were positive for vimentin. Primary pulmonary neoplasms had immunoreactivity for thyroid transcription factor-1 (6/7), while only 2 of these cases were positive for napsin A. All cases with squamous differentiation (9/9) had immunoreactivity for cytokeratin (CK) 5/6, while only 7 of these cases were positive for p40. CK20, CK7, and CK8/18 showed varied immunoreactivity in the primary and metastatic pulmonary carcinomas but were important markers to confirm the diagnosis of primary mucinous adenocarcinoma and metastatic cholangiocarcinoma. HepPar-1 was only positive in the metastatic hepatocellular carcinoma. The limited number of cases of metastatic uterine adenocarcinomas in this study precluded identification of a specific immunophenotype for this tumor. Immunohistochemistry proved to be an important tool to confirm the proper classification of these neoplasms.

Characterization of cutaneous lesions caused by natural tick infestation in cattle.

Although tick infestation is a significant health problem in livestock, there are limited studies on the dermatopathological aspects of natural tick infestation in cattle. This study aimed to describe the gross and histologic aspects of cutaneous lesions caused by tick infestation in cattle. Thirteen cases were selected based on necropsy data from a 10-year retrospective study. Predispositions were observed in beef cattle (P = .049) and the Angus breed (P = .012), and lesions occurred mainly in the fall (P = .007). Gross lesions included hypotrichosis (13/13; 100%), scales (12/13; 92%), alopecia (11/13; 85%), ulcers (7/13; 54%), crusts (7/13; 54%), and erosions (2/13; 15%). These gross lesions were mainly located in the thorax (12/13; 92%), head (11/13; 85%), abdomen (10/13; 77%), neck (9/13; 69%), limbs (9/13; 69%), and perineum (9/13; 69%). Histologically, all cases had ticks adhered to the epidermis with erosions (13/13; 100%), ulcers (11/13; 85%), orthokeratotic hyperkeratosis (13/13; 100%), irregular acanthosis (13/13; 100%), intraepidermal pustules (13/13; 100%), crusts (10/13; 77%), and ballooning degeneration (4/13; 31%). In the dermis, just below the tick insertion site, there was coagulation necrosis, fibrin deposition, and inflammatory infiltrate composed of mixed cells (neutrophils, lymphocytes, plasma cells, macrophages, and few eosinophils) (9/13; 69%), neutrophils (3/13; 23%), or eosinophils (1/13; 8%). This study reinforces the different patterns of cutaneous lesions caused by tick infestation in cattle, which should be considered as a potential cause of dermatitis in this species.

Fatal Simplexvirus humanalpha1 infection in howler-monkeys (Alouatta sp.) under human care: Clinical, molecular, and pathological findings.

BACKGROUND: Simplexvirus humanalpha1 (HuAHV-1) are common anthropozoonosis reported in marmosets but rare in howler monkeys (Alouatta sp.). METHODS: Necropsy of two brown-howler monkeys (A. caraya) and one red-howler monkey (A. guariba clamitans) from different zoo collections were performed. Fragments of all organs were examined through microscopy. Samples were submitted to IHC for Simplexvirus humanalpha 2 (HuAHV-2) [sin. Herpesvirus simplex type 2] and PCR. RESULTS: Grossly, only the A. guariba showed liver lesions characterized by multifocal, pinpoint white areas corresponding microscopically as random necrotizing herpetic hepatitis and ulcerative glossitis. Both A. caraya showed necrotizing meningoencephalitis with Cowdry A-type body inclusions within neurons and astrocytes. Immunolabeling for HuAHV-1/2 was observed in the tongue, liver, and brain. HuAHV-1 was confirmed in all samples by PCR, Sanger sequencing, and phylogenetic analyses. CONCLUSION: Necrotizing meningoencephalitis was appreciated in 2/3 of animals, and it is associated with neurologic signs. Along with ulcerative glossitis, a hallmark lesion in marmosets, it was present in one animal. Regarding herpetic hepatitis, it is not frequent in monkeys and occurs mainly in immunocompromised animals. HuAHV-1 infection was confirmed corroborating with a human source. This is the second report on captive black-howler monkeys and the first gross, histologic, immunohistochemical, and molecular description of herpetic hepatitis and ulcerative glossitis in red-howler monkeys (A. guariba).

Motor and somatosensory degenerative myelopathy responsive to pantothenic acid in piglets.

This report describes 2 events of degenerative myelopathy in 4- to 27-day-old piglets, with mortality rates reaching 40%. Sows were fed rations containing low levels of pantothenic acid. Piglets presented with severe depression, weakness, ataxia, and paresis, which were more pronounced in the pelvic limbs. No significant gross lesions were observed. Histologically, there were degeneration and necrosis of neurons in the spinal cord, primarily in the thoracic nucleus in the thoracic and lumbar segments, and motor neurons in nucleus IX of the ventral horn in the cervical and lumbar intumescence. Minimal-to-moderate axonal and myelin degeneration was observed in the dorsal funiculus of the spinal cord and in the dorsal and ventral nerve roots. Immunohistochemistry demonstrated depletion of acetylcholine neurotransmitters in motor neurons and accumulation of neurofilaments in the perikaryon of neurons in the thoracic nucleus and motor neurons. Ultrastructurally, the thoracic nucleus neurons and motor neurons showed dissolution of Nissl granulation. The topographical distribution of the lesions indicates damage to the second-order neurons of the spinocerebellar tract, first-order axon cuneocerebellar tract, and dorsal column-medial lemniscus pathway as the cause of the conscious and unconscious proprioceptive deficit, and damage to the alpha motor neuron as the cause of the motor deficit. Clinical signs reversed and no new cases occurred after pantothenic acid levels were corrected in the ration, and piglets received parenteral administration of pantothenic acid. This study highlights the important and practical use of detailed neuropathological analysis to refine differential diagnosis.

Pathological findings associated with Dipetalonema spp. (Spirurida, Onchocercidae) infection in two species of Neotropical monkeys from Brazil.

Among vector-borne helminths, filarioids of the genus Dipetalonema (Spirurida: Onchocercidae) localize in several tissues and body cavities of several animal species, causing mild to moderate lesions. The pathological findings associated with Dipetalonema spp. infection in Neotropical monkeys from southern Brazil are herein described, along with a fatal case due to filarial polyserositis and entrapment of an intestinal segment. At necropsy, nematodes were observed in abdominal and thoracic cavities, or in the pericardium of 37 (31.3%) out of the 118 individuals examined (i.e., 35 Alouatta guariba clamitans and two Sapajus nigritus). In addition, at histology, 27.0% of positive animals presented microfilarie (inside blood vessels of lung, spleen, liver, and brain) and 8.1% presented adult nematodes in the heart, lung, and liver. In two cases, cross-sections of filarioids were associated with areas of epicardial thickening with intense fibrosis and pyogranulomatous inflammation in the brain, heart, liver, lungs, or spleen. The DNA fragment was amplify using the cox1 gene, sequenced and analyzed to identify the nematode species collected; presence of Wolbachia was assessed in the filarioids using the 16S rRNA gene. At BLAST analysis of the cox1 gene, 10 sequences showed 91.7% nucleotide identity with Dipetalonema gracile, and two with D. gracile (98.5%) and Dipetalonema graciliformis (98.3%). Phylogenetic analyses clustered sequences of the cox1 obtained in this study in two clades corresponding with the host species. Wolbachia sp. endosymbiont was detected in four samples. Data herein reported provide a description of pathological lesions associated with the infection by Dipetalonema spp., suggesting that they may cause disease in Neotropical monkeys. In addition, a better understanding of diversity and biology of Dipetalonema spp. in South America is needed to assess the impact they may cause in native non-human primates from Brazil.

Outbreak of toxoplasmosis in a flock of domestic chickens (Gallus gallus domesticus) and guinea fowl (Numida meleagris).

Toxoplasmosis is a disease with a worldwide distribution that affects a wide variety of animal species, though with rare descriptions in chickens. We describe the clinical, epidemiological, pathological, and molecular aspects of a toxoplasmosis outbreak in domestic chickens and guinea fowl in southern Brazil. The flock was composed of 47 domestic chickens and 29 guinea fowl. Of these, 22 birds showed clinical signs of lethargy, anorexia, and neurological signs over a clinical course of 24-72 h, and 15 died. Epidemiological data were obtained through fieldwork performed at the chicken farm and necropsies of six birds. Gross lesions were absent at necropsy, and histopathological findings included inflammatory infiltrate of macrophages, lymphocytes, and plasma cells and necrosis in several tissues associated with intralesional Toxoplasma gondii. Immunohistochemistry for T. gondii was positive. Additionally, restriction fragment length polymorphism (RFLP) analysis with 11 markers (SAG1, SAG2 (5'3'SAG2 and alt. SAG2), SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, Apico, and CS3) and microsatellite (MS) analysis with 15 markers (TUB2, W35, TgMA, B18, B17, M33, IV.1, XI.1, N60, N82, AA, N61, N83, M48, and M102) were performed. PCR-RFLP revealed T. gondii genotype ToxoDB-PCR-RFLP #280, and MS analysis also showed a unique genotype. This is the first description of this genotype in chickens and adds to the evidence suggesting considerable genotypic diversity of T. gondii in Brazil.

Pathological and microbiological characterization of mastitis in dairy cows.

Mastitis may be caused by a wide range of microorganisms able to induce distinct lesions in mammary tissues. This study aims to characterize the gross and microscopic features of mastitis in dairy cows and to correlate them with the pathogens involved. The udders of slaughtered dairy cows were inspected and milk samples from each mammary quarter or fragments of the parenchyma were sent for microbiological analysis, and tissue collected for histopathological evaluation. A total of 148 cows and 592 mammary quarters were collected. From these, 432 quarters (73%) had mastitis and in 160 (27%), no changes were observed. Mastitis was classified into seven patterns based on the histopathological findings, of which mixed, lymphoplasmacytic, and suppurative mastitides were the most prevalent with 35.9% (155/432), 27.1% (117/432), and 14.3% (62/432) of the cases, respectively. These patterns were associated with the same set of pathogens: Streptococcus spp., coagulase-negative Staphylococcus (CNS), Staphylococcus aureus, Streptococcus agalactiae, Streptococcus uberis, and Corynebacterium bovis. The pyogranulomatous pattern represented 7.2% (31/432) of the cases with distinct distribution based on the agent involved, mostly S. aureus and Nocardia sp. Abscedative mastitis accounted for 6.0% (26/432) of the cases; it was characterized by multiple abscesses in the parenchyma and was mainly caused by Trueperella pyogenes. Necrosuppurative mastitis represented 5.8% (25/432) of the cases which were characterized by severe parenchyma necrosis and were caused by bacteria such as CNS and Escherichia coli. The granulomatous pattern represented 3.7% (16/432) of the cases and was occasionally associated with Mycobacterium sp.

Monensin poisoning outbreak in free-ranging and captive birds.

Monensin poisoning is uncommon and has been rarely reported in birds. This work aimed to described clinical-pathological aspects of an outbreak of monensin poisoning in captive and free-ranging birds. Thirty-seven of 600 captive birds fed a diet containing 893.19 mg/kg of monensin died within 10 days (mortality 6.17%). There was no ionophore antibiotics on the feed label supplied to captive birds, which established an error in feed production. Necropsies were performed on twelve animals: Muscovy duck (Cairina moschata) (2/12), greater rhea (Rhea americana) (2/12), black-necked swan (Cygnus melancoryphus) (2/12), garganey (Anas querquedula) (1/12), ostrich (Struthio camelus) (1/12), and common pigeon (Columbus livia) (4/12). These four common pigeons were free-ranging birds and died after eating the same contaminated feed. Birds were mainly found dead, however in animals which clinical signs were observed (Columba livia, Rhea americana, Cairina moschata, Anas querquedula, and Struthio camelus), they included incoordination, inability to stand, and intense prostration, that ranged from 24 to 72 h until death. Grossly, five birds had focally extensive pale firm areas in the myocardium and two had in the skeletal muscles, one being concomitant lesions. Histologically, muscle necrosis and degeneration were observed in striated musculature (skeletal and/or heart) in all birds analyzed. Monensin poisoning outbreaks can affect free-ranging birds that are fed on external feeders, as well as captive birds, due to an error in the feed formulation.

Primary third eyelid lymphoma with aggressive local behavior in a dog.

Lymphoma is the most common hematopoietic neoplasm in dogs. However, cases primarily involving the third eyelid are rarely reported in the species. The subtype most frequently described in this location is marginal zone lymphoma of the mucosa-associated lymphoid tissue, which has an indolent behavior. A 10-year-old intact female Poodle was presented with a 2-month history of a nodule in the left third eyelid for evaluation. This nodule was surgically excised; however, local recurrence was detected nineteen days postoperatively, with the formation of a mass that expanded and replaced the extraocular orbital tissues and infiltrated the eye. Euthanasia was elected due to the deteriorating clinical condition, and a necropsy was performed. Macroscopically, the mass infiltrated and expanded the eyelids with narrowing of the palpebral fissure, expanded into the orbital space, and infiltrated the cornea and bulbar conjunctiva. Histologically, the mass was composed of sheets of intermediate to large neoplastic lymphocytes, with frequent epitheliotropism and tingible bodies. Neoplastic lymphocytes were immunoreactive for PAX5, CD20, and CD79a and were not immunoreactive for CD3. The neoplasm was restricted to the left eyelid and orbit. A diagnosis of primary third eyelid lymphoma (extranodal) with immunophenotype B and locally aggressive behavior was made based on the macroscopic, histological, and immunohistochemical findings.

Pulmonary acinar adenocarcinoma in a captive lioness (Panthera leo).

Neoplasms in wild felids are more frequently observed in captive animals, of which clinicopathological features of pulmonary tumors are not commonly described. This study aimed to describe the clinical and pathological aspects of a case of diffuse pulmonary acinar adenocarcinoma in a 23-year-old, captive lioness with clinical history of dyspnea, progressive weight loss and inappetence. At necropsy, the lungs were mildly pale, moderately firm, and the pleural surface was diffusely irregular with multifocal to coalescent, grey to white areas. No masses or superficial nodules were detected, but, on the cut surface, there were numerous, spherical, firm, white to yellow areas up to 0.5 cm in diameter affecting all pulmonary lobes. Histologically, in the lungs, there were extensive, non-delineated areas of neoplastic proliferation of columnar, ciliated epithelial cells arranged in irregular tubuloacinar structures. Immunohistochemical analysis revealed immunolabeling of neoplastic cells for pan-cytokeratin and thyroid transcription factor-1. Napsin-A exhibited only scarce and scattered immunolabeling in the neoplastic cells. The gross, histologic and immunohistochemical findings confirmed the final diagnosis of primary diffuse pulmonary adenocarcinoma.

Anatomopathological characterization of branchial cysts in slaughtered pigs.

Branchial cysts are a congenital anomaly in humans and other animal species. In this study, twenty commercially bred slaughtered pigs ranging from 120 to 150 days of age, sourced from different farms and lots, were found to have cysts in the oropharyngeal region at meat inspection despite the absence of clinical signs. Two cysts were selected for histopathological examination. The first cyst was surrounded by fibrous connective tissue and lined by a simple single cell layer of epithelium. The second cyst comprised a squamous pseudostratified to simple stratified epithelium, accompanied by a mild inflammatory infiltrate. This cyst was also surrounded by fibrous connective tissue and glands. The pathological diagnosis of branchial cysts in slaughtered pigs was established on the basis of their anatomical location and gross and microscopic findings.

Pathological and immunohistochemical characterization of pancreatic carcinoma in cats.

The aim of this study was to characterize the pathological and immunohistochemical aspects of pancreatic carcinoma in cats, through a retrospective study. From January 2010 to December 2021, 1,908 cat necropsies were performed, in which 20 cases of exocrine pancreatic neoplasia were diagnosed (1.04%). Affected cats were mature adults and seniors, except for one 1-year-old cat. In 11 cases the neoplasm was a soft, focal nodule on the left (8/11) or right (3/11) lobe. In nine cases there were multifocal nodules throughout the pancreatic parenchyma. The size of the single masses ranged from 2 to 12 cm, and the multifocal masses from 0.5 to 2 cm. The most frequent tumour type was acinar carcinoma (11/20), followed by ductal carcinoma (8/20), undifferentiated carcinoma (1/20) and carcinosarcoma (1/20). On immunohistochemical evaluation, all the neoplasms were remarkably reactive to pancytokeratin antibody. The ductal carcinomas were strongly reactive for cytokeratins 7 and 20, which proved to be a good marker for pancreatic ductal carcinoma in cats. The main form of metastasis was abdominal carcinomatosis, with a marked invasion of blood and lymphatic vessels by neoplastic cells. Our findings reinforce the fact that pancreatic carcinoma should be rated highly in the differential diagnosis in mature adult and senior cats with abdominal masses, ascites and/or jaundice.

Acute necrotic hepatotoxicity caused by Melanthera latifolia (Asteraceae) in cattle.

This study aims to report a spontaneous and experimental intoxication in cattle by Melanthera latifolia (Asteraceae) for the first time, and to describe its epidemiological, clinical, and pathological findings. An outbreak of acute toxic hepatopathy in cattle occurred from December of 2021 to January of 2022 in a beef cattle farm from Rio Grande do Sul state, Southern Brazil, and resulted in 94 deaths from a herd of 430 animals. At necropsy, lesions consisted of enhanced lobular pattern of the liver, transmural gallbladder edema, and hemorrhages on the surface of multiple organs. The main microscopic lesion was marked hepatocellular necrosis in the centrilobular region associated with hemorrhage and infiltration of neutrophils. During the outbreak, multiple specimens of M. latifolia were noted in the paddocks where affected cattle were grazing and many showed signs of consumption. No other known acute hepatotoxic plants were found. Two 12-month-old steers were experimentally intoxicated with a single oral dose of the fresh plant (flowers, leaves, and less fibrous stalks). One bovine ingested a dose of 10 g/kg and was euthanized after 48 h, and the other ingested 15 g/kg and was euthanized 17 h later. Clinical signs, macroscopic, and microscopic lesions in both animals were similar to those observed in the spontaneous cases. Thus, this study demonstrates that M. latifolia was the cause of the outbreak of acute toxic hepatopathy with significant mortality in cattle. M. latifolia nor any plant of the genus Melantherahad ever been reported as toxic.

Encephalic meningioangiomatosis in a dog with high-grade undefined glioma.

Meningioangiomatosis (MA) is a rare proliferative meningovascular disorder that affects mainly the cerebral cortex, brainstem and spinal cord of humans and animals and can coexist with other proliferative disorders. A 7.5-year-old male Brazilian Campeiro Bulldog died after a convulsive crisis and cardiorespiratory arrest. At necropsy, a firm, white mass involving the piriform and right occipital lobes was seen. Histologically, the mass consisted of two morphologically distinct entities that collided: a congenital malformation characterized by a proliferation of meningothelial cells around blood vessels, within the perivascular spaces; and a neoplasm composed of two cell populations with astrocytic and oligodendrocytic differentiation. Meningothelial cells and neoplastic glial cells immunolabelled for vimentin. This first reported case of encephalic MA with a high-grade undefined glioma in a dog was confirmed through clinical signs, pathological and immunohistochemical findings.

Acute Oral Chromium Exposure Resulting in Ulcerative Gastritis and Perforated Ulcers in Swine.

Heavy metal poisoning poses a challenge in diagnostic practices and environmental safety. This study describes the epidemiological, clinical, and pathological aspects of a chromium (Cr) poisoning outbreak in growing/finishing pigs housed in pens with bedding of pine wood shavings containing Cr. A visit to the affected farm was conducted. Epidemiological data were collected, and necropsy and histopathological examinations and heavy metal quantifications were performed. Up to 30% of the animals from the affected pens displayed clinical signs 48 h after housing, characterized by apathy, rigid gait, distended abdomen, pain to abdominal palpation, fever, vomiting, and skin cyanosis. The lethality rate reached 76.6%. Main postmortem findings consisted of ulcerative gastritis with perforation of the glandular stomach in all necropsied swine. Heavy metal analysis revealed a higher concentration of Cr in the bedding of the affected pens, along with elevated levels of Cr in the livers of the affected swine. Given that Cr is a known cause of poisoning in humans (with acute oral exposure resulting in corrosive lesions in the gastrointestinal tract), this study marks the first diagnosis of acute oral natural Cr poisoning in animals. This diagnosis was established through the association of epidemiological, pathological, and heavy metal quantification data.

Rehabilitation and release of confiscated songbirds into the wild: A pilot study.

Songbirds are currently the most prevalent animals in illegal trafficking in Brazil and other countries, so they are often confiscated, and this poses legal, ethical, and conservation challenges. Returning them to nature requires complex and expensive management, a topic that is sparingly addressed in the literature. Here, we described the processes and costs associated with an attempt to rehabilitate and release confiscated songbirds into the wild. A total of 1,721 songbirds of several species were quarantined, rehabilitated, and released, primarily on two farms located within their typical geographical distribution. Health assessments were performed on samples from 370 birds. Serology revealed no antibodies against Newcastle disease, and Salmonella spp. cultures were negative. Real-time polymerase chain reactions detected M. gallisepticum in samples from seven birds. Atoxoplasma spp. and Acuaria spp. infections, sepsis, and trauma were the top causes of bird death. About 6% of the released birds were recaptured, within an average period of 249 days after release, and at a mean distance of 2,397 meters from the release sites. The majority of these birds were found with free-living mates within or close to fragments of transitional ecoregions with native or cultivated grasslands, and native groves/forests, and shrublands. However, eucalyptus plantations with rich understory regeneration provided a suitable environment for the released forest species to settle, since they were recaptured during the defense of these sites. Over half of the recaptured birds presented behavioral profiles with both dominant and tame traits. Birds with dominant traits are more likely to settle in habitats and face the live decoys during fieldwork, whereas birds with tame characteristics tend to accept close contact with humans. Ultramarine grosbeak (Cyanoloxia brissonii), the least common species among those released, at the release sites showed an almost 2-fold recapture rate in the shortest mean distances from the release sites. This suggests less territory competition, perhaps a major factor of bird re-establishment here. The total per-bird cost was USD 57. Our findings suggested suitable survival and re-establishment of confiscated songbirds in the wild, when managed as we describe.

Pathology of Salmonella enterica Subspecies enterica Serotype Typhimurium Infection in Chinchillas (Chinchilla lanigera).

Septicaemia is the main pathological manifestation of Salmonella infection in chinchillas (Chinchilla lanigera), although information on its pathology is limited. We now describe the gross, histological and immunohistochemical features of Salmonella enterica subspecies enterica serotype Typhimurium (S. Typhimurium) infection in ranched chinchillas. Eighty-five adult pregnant chinchillas had anorexia, prostration, weight loss, hyperthermia and abortion. Necropsy of 13 animals revealed splenomegaly, hepatomegaly, mesenteric lymphadenomegaly, prominent Peyer's patches, pulmonary oedema, white pinpoint lesions in multiple organs and petechiae in the urinary bladder. In all cases, histological lesions were consistent with septicaemia, characterized by acute necrotizing hepatitis, splenitis, lymphadenitis, cystitis, pneumonia, enterocolitis, gastritis and/or nephritis. Immunohistochemistry for Salmonella spp on seven cases revealed intralesional immunolabelling in all affected organs. Salmonella sp was isolated from liver, spleen, intestinal contents and blood of 10 chinchillas. Isolates of four animals were identified as S. Typhimurium.

Generalized and fatal felid alphaherpesvirus-1 natural infection with liver involvement in a feline leukaemia virus-positive adult cat: a case report.

Generalized and fatal felid alphaherpesvirus-1 (FeHV-1) natural infection with liver involvement is rarely reported in cats, and the occurrence of herpesvirus viraemia with internal organ histologic lesions in adult cats is unknown. A 1.5-year-old cat, female, mixed breed, positive for feline leukaemia virus (FeLV) presented in a veterinary teaching hospital with sneezing, nasal discharge, anorexia, and diarrhoea after two weeks, evolving to inspiratory dyspnoea. Complete blood count and serum biochemistry analysis showed marked leukopenia and thrombocytopenia. After clinical worsening and lack of treatment response, the cat was euthanized. Pathological findings included hepatic necrosis, fibrinonecrotic tracheitis, and bronchointerstitial pneumonia. Marked amounts of coccobacillary bacteria were observed covering the necrotic tracheal and bronchial mucosa, at the cytoplasm of alveolar macrophages, and free in alveoli lumen, mimicking a primary bacterial tracheitis and pneumonia. Both lung and tracheal bacteria exhibited marked immunolabeling in anti-Escherichia coli immunohistochemistry. In addition, rare epithelial cells of bronchi contained round, eosinophilic, intranuclear viral inclusion bodies (4-7 µm) that marginate the chromatin, characteristic of FeHV-1 infection. Strong multifocal anti-FeHV-1 immunolabeling was observed in necrotic epithelial cells of the liver, trachea, and lungs. Generalized herpesvirus infection with the occurrence of acute hepatic necrosis and severe respiratory illness is a potential differential diagnosis in FeLV-positive cats with respiratory signs. The immunodepression in these cats probably favours a FeHV-1 viraemia in addition to the development of opportunistic bacterial infections, such as Escherichia coli, and it is associated with a poor outcome.

Pet Pyometra: Correlating Bacteria Pathogenicity to Endometrial Histological Changes.

Pyometra is a life-threatening infectious disease that frequently affects bitches and queens. Although histopathological patterns of pyometra have been extensively explored, the microbiological aspects, such as bacteria pathogenicity, have not been correlated to microscopy endometrial lesions so far. In this study, these two pathological aspects of pyometra were analysed and correlated. Uterus fragments and intrauterine content samples were collected from pets diagnosed with pyometra (30) and submitted to histopathology analysis and bacterial culture, respectively. The degree of endometrial histopathological lesions in pyometra cases were classified as mild, moderate and severe. Thirty different bacteria isolates were identified from intrauterine content culture. Escherichia coli (E. coli) was pure isolated in 57.7% and highly related to severe endometrial lesions. Immunohistochemistry assay revealed the adhesion and invasion of this bacteria agent to the injured endometrium. Virulence aspects of these E. coli strains were explored, demonstrating biofilm formation ability and a set of virulence genes in most isolates. These results support the adaptive genetic and phenotypic advantages of E. coli for uterus infection, and justify the high frequency of this agent involved in pyometra cases.

Wischnewski Spots and Black Oesophagus in Suspected Fatal Hypothermia in a Brown Howler Monkey (Alouatta guariba clamitans) and a Rabbit (Oryctolagus cuniculus).

Fatal hypothermia represents a diagnostic challenge in veterinary pathology. Wischnewski spots (WS) and black oesophagus (BO) have been described in human cases of fatal hypothermia but rarely in animals. We now describe WS and BO in suspected fatal hypothermia in a free-ranging brown howler monkey (Alouatta guariba clamitans) and a pet rabbit (Oryctolagus cuniculus). Both animals had dark spots resembling WS on the gastric mucosa and the monkey also had BO with haematin deposition. In both cases, stress factors and relatively cold environmental conditions were present prior to death.