Primary Angiomatoid Melanomas in Dogs.

Melanocyte-derived tumours are common in humans and animals and their spontaneous occurrence in dogs and the clinicopathological progression in malignant presentations is comparable with humans. Melanomas are a heterogeneous group of malignant neoplasms and several subtypes have been classified, including angiomatoid melanoma, of which only five cases have been reported in humans but none in animals. We now document cases of primary angiomatoid melanoma in the skin and oral cavity of two dogs. Neoplastic cells resembling endothelial cells that lined large blood vessels in the tumours were immunonegative for CD34 but intensely positive for SOX10.

Fat, Cartilage, and Bone Metaplasia in Lungs of Cattle With Caudal Pleural Lesions and Subjacent Interstitial Fibrosis.

The changes associated with condemned lungs in cattle with chronic pleural lesions of the caudal lobes were characterized by histology and immunohistochemistry (IHC). Fibroproliferative pleural lesions were microscopically confirmed. Occasionally, the pleural lesions also included adipose, chondroid, and osseous metaplasia that were covered by mesothelial cells, mostly in the absence of inflammation. Other lungs also showed fibrosis in the subpleural interstitium and interlobular septa. In both condemned and noncondemned lungs, immunoreactivity to Wilms tumor 1 (WT1) was normally observed on surface mesothelial cells but not on the submesothelial fibroblasts and myofibroblasts. Conversely, the myofibroblasts beneath the pleura, but not the mesothelial cells, showed immunoreactivity to alpha smooth muscle actin and calponin. However, in the lungs with myofibroblastic foci in the pleura, the proliferated cells maintained WT1 immunoreactivity similar to those of some metaplastic cells. These findings may reflect the plasticity of mesothelial cells in vivo.

Immunotherapy for the treatment of canine transmissible venereal tumor based in dendritic cells pulsed with tumoral exosomes.

Context: Exosomes secreted by tumor cells are a good source of cellular components that stimulate the immune response, such as alarmins (mRNA, tetraspanins (CD9, CD63, CD81), heat-shock proteins, major histocompatibility complex class I molecules) and tumor-associated antigens. These properties permit to pulsed dendritic cells in the immunotherapy for many cancers types. The aim of this study was to demonstrate the use of exosomes derived from canine transmissible venereal tumor (CTVT) as an antigen to pulsed dendritic cells and its administration in dogs with CTVT as treatment against this disease. Material and methods: From primary culture of CTVT cells the exosomes were isolated and characterized by scanning electron microscopy assay, dot blot and protein quantification. The monocytes of each patient were differentiated to dendritic cells (DC) and pulsed with CTVT exosomes (CTVTE). Phagocytosis, tumor size, populations of lymphocytes and IFN-c levels were evaluated. Results: The CTVTE showed a size around 90 nm. CD81, CD63, CD9 and Hsp70 were expressed. Monocytes showed an expression of 85.71% for CD14+, 12.3% for CD80+, 0.1% for CD83+ and 0.8% for DLA-II. In DC 5.1% for CD14+, 86.7% for CD80+, 90.1% for CD83+ and 92.6% for DLA-II and a phagocytosis of 63% was obtained by FITC Dextran test. No side effects were observed in the experimental groups with our therapy. Tumor regression was of 100% at the seventh week, as well as an increase in the level of IFN-γ (142 pg/ml), and CD4+ (28%) and CD8+ (34%) cell percentage. Discusion and conclusion: These results have shown that DC pulsed with tumor exosomes induce regression of the TVT in dogs.

WT1 expression as a potential biomarker of malignancy in canine breast tumor / La expresión de WT1 como un biomarcador potencial maligno en un tumor de mama canino

SUMMARY: Veterinary oncology is very important nowadays to get a better understanding of human carcinogenesis. Estrogen receptor, progesterone receptor and Human Epidermal Growth Factor receptor 2 are frequently evaluated by immunohistochemistry (HIC) in human breast tumor. WT1 is an oncogene, its overexpression has been detected in leukemia and diverse solid tumors like breast cancer, lung cancer and mesothelioma in humans. WT1 expression was evaluated in 15 canine breast tumors (CBT) diagnosed by histopathological analysis to find its relationship with neoplasia and malignancy. IHC and RT-PCR were performed in CBT tissues. Fisher´s test was used to analyze WT1 relationship with malignancy. Of the 15 tumors, 9 (60 %) were diagnosed as benign and 6 (40 %) were malignant. With IHC, WT1 expression was positive only in biopsies diagnosed as malignant. Expression of WT1 by RT-PCR was detected in 14 of the 15 tumors (93.33 %) as well as in control healthy mammary gland. Clinical significance: This study describes for the first time a close correlation between CBT and a positive result for WT1 expression with IHC; hence, it can be used as a biomarker for this neoplasia and as an indicator of malignancy. RT-PCR analysis also showed to be good option to detect WT1 expression. These results will be useful to further investigations to elucidate WT1-related signaling pathways in CBT. Also to know molecules that regulate the translation of this protein as a marker for tumor progression.

RESUMEN: La oncología veterinaria es muy importante hoy en día para comprender mejor la carcinogénesis humana. El receptor de estrógeno, el receptor de progesterona y el receptor 2 del factor de crecimiento epidérmico humano se evalúan con frecuencia mediante inmunohistoquímica (HIC) en tumores de mama humanos. WT1 es un oncogén, su sobreexpresión se ha detectado en leucemia y en diversos tumores sólidos como el cáncer de mama, cáncer de pulmón y mesotelioma en humanos. La expresión de WT1 se evaluó en 15 tumores de mama caninos (TCC) diagnosticados mediante análisis histopatológico para encontrar su relación con la neoplasia y la malignidad. IHC y RT-PCR se realizaron en tejidos CBT. La prueba de Fisher se utilizó para analizar la relación de WT1 con la malignidad. De los 15 tumores, 9 (60 %) fueron diagnosticados como benignos y 6 (40 %) fueron malignos. Con IHC, la expresión de WT1 fue positiva solo en biopsias diagnosticadas como malignas. La expresión de WT1 por RT-PCR se detectó en 14 de los 15 tumores (93,33 %), así como en el control de la glándula mamaria sana. Importancia clínica: este estudio describe por primera vez una estrecha correlación entre la TCC y un resultado positivo para la expresión de WT1 con IHC; por lo tanto, se puede utilizar como un biomarcador para esta neoplasia y como un indicador de malignidad. El análisis por RT-PCR también demostró ser una buena opción para detectar la expresión de WT1. Estos resultados serán útiles para futuras investigaciones para dilucidar las vías de señalización relacionadas con WT1 en la TCC. También para conocer moléculas que regulan la traducción de esta proteína como marcador de progresión tumoral.

PULMONARY LESIONS CAUSED BY THE LUNGWORM (DIDELPHOSTRONGYLUS HAYESI) IN THE OPOSSUM (DIDELPHIS VIRGINIANA) IN COLIMA, MEXICO.

Didelphostrongylus hayesi is an important and prevalent pulmonary nematode in the opossum ( Didelphis virginiana ). An in-depth description of the pulmonary lesions caused by this nematode is lacking. The objective of this investigation was to make a detailed account of the gross, subgross, and microscopic changes that occur in the lungs of opossums naturally infected with D. hayesi. Forty-four opossums trapped in the state of Colima, Mexico, were euthanized by an overdose of barbiturates. Following a postmortem examination, the right lung was cut from the main bronchi and placed in a Petri dish containing a saline solution for the detection and identification of live parasites. The left lung was fixed and cut serially for subgross microscopic examination and sections of lung were cut and stained for histopathologic examination. The most remarkable gross change in parasitized lungs was a poorly collapsible pulmonary parenchyma and mild emphysema. The right lung tested positive for lungworms on gross examination in 20/44, and 11/44 (25%) of the left lungs showed tan nodules on the pleural surface. Microscopically, the bronchi of 20/44 animals harbored adult and larval stages of D. hayesi (left lung), the same 20 opossums from which nematodes were grossly evident at necropsy (right lung). Adults and larvae were present in bronchi, bronchioles, and alveoli mixed with desquamated cells and many eosinophils, and to a lesser extent neutrophils, alveolar macrophages, and giant cells. Bronchi and bronchioles exhibited goblet cell hyperplasia and metaplasia respectively, and infiltration of lymphoplasmacytic cells in the interstitium and lamina propria. The tan nodules consisted of focal alveolar endogenous lipidosis, which likely resulted from parasitic airway obstruction. The lungs of 3/20 parasitized opossums also showed alveolar bronchiolization (Lambertosis). The absence of Eucoleus aerophilus or bacterial pneumonia incriminates D. hayesi as the putative cause of pulmonary lesions in these opossums.

Coccidioidomycosis in Biopsies with Presumptive Diagnosis of Malignancy in Dogs: Report of Three Cases and Comparative Discussion of Published Reports.

Coccidioidomycosis is a respiratory fungal infection with occasional systemic dissemination. The disseminated coccidioidomycosis is considered a multifaceted disease. In medicine, disseminated coccidioidomycosis is included within a group of infectious diseases that have been referred as the great imitators. In many cases, malignancies are included in the presumptive diagnosis. In veterinary medicine, disseminated coccidioidomycosis is common in dogs. Nonetheless, despite of being a diagnostic dilemma, disseminated coccidioidomycosis is underestimated and frequently not included into differentials, even in endemic zones. Herein, we describe three cases of granulomatous inflammation caused by Coccidioides spp. which were masquerading malignancies in dogs (0.39 %). The presumptive diagnoses in these cases were osteosarcoma, lymphoma and neurofibroma, respectively. A PCR assay employing tissues in paraffin blocks resulted positive for C. posadasii in one of these cases. A comparative discussion on the ambiguous clinic-pathological presentation of disseminated coccidioidomycosis in dogs and humans is included.

Bovine diseases causing neurological signs and death in Mexican feedlots.

The number of large feedlot operations, similar to that of USA and Canada, has notably increased in Mexico in the last three decades. Clinical and laboratory diagnoses of neurological diseases in feedlot cattle are crucial in Mexico and Central America because of the high incidence of bovine paralytic rabies (BPR). Because of its zoonotic potential, BPR must be promptly diagnosed and differentiated from other bovine neurological diseases such as thrombotic meningoencephalitis (TME), polioencephalomalacia (PEM) and botulism. More recently, BPR and botulism have been diagnosed with increasing frequency in Mexican feedlots. Neither BPR nor botulism has relevant gross lesions, thus post-mortem diagnosis without laboratory support is impossible. Herein, we describe five outbreaks of neurological diseases in Mexican feedlots in which BPR, botulism and PEM were diagnosed either independently or in combination. A diagram illustrating the most conspicuous pathologic findings and ancillary laboratory test required to confirm the diagnoses of these neurological diseases in feedlot cattle is proposed.

Presencia del virus de la diarrea viral bovina y su asociación con otros cuadros patológicos en ganado en corral de engorda / Presence of bovine virus diarrhea in association with other pathologies in feedlot cattle

Bovine feedlots are intensive production systems of significant importance in Mexico. The present study describes the presence of bovine virus diarrhea (BVD) causing subacute to chronic lesions in feedlot cattle, associated with other pathologies. Animals included in this study were discarded after they received therapy several times due to chronic pneumonia, or anaplamosis. Bovine virus diarrhea antigen was identified by immunohistochemistry in small intestine and myocardium in six cases of chronic suppurative bronchopneumonia with extensive areas of casseous necrotic bronchiectasis, previously diagnosed as Mycoplasma bovis pneumonias (retrospective group, n = 6). Furthermore, based on characteristic histopathologic lesions other nine cases were included (prospective group, n = 9). Bovine virus diarrhea antigen was recognized in two animals with pneumonic lesions, including a case with fibrinous bronchopneumonia as well as suggestive lesions of infectious bovine rinotracheitis (1/9), and another one with suppurative bronchopneumonia and myocarditis suggestive of Histophilus somni (1/9). In addition, one positive case was associated to anaplasmosis (1/9). Other two positive cases showed a conspicuous fibrinous peritonitis (2/9). The rest of the animals in this group resulted negative (4/9). Histopathological characteristics of the lesions and their association with the antigen in situ confirm the presence of BVD. This presentation is compatible with the acute infection syndrome. This is the first report of BVD infection and concomitant pathologies in feedlot cattle in Mexico.

El ganado en corral de engorda es un sistema de producción intensivo de gran importancia en México. En este trabajo se describe la infección por diarrea viral bovina (DVB), ocasionado por lesiones subagudas y crónicas en bovinos en corral de engorda, y su asociación con otras patologías. Los animales de este estudio fueron considerados de rechazo después de ser tratados en diferentes ocasiones por enfermedad respiratoria, o bien anaplasmosis. El antígeno de DVB fue identificado por inmunohistoquímica (IHQ) en intestino delgado y miocardio en seis casos de bronconeumonía supurativa crónica con extensas áreas de bronquiectasia con necrosis caseosa, los cuales habían sido previamente diagnosticados como neumonías por Mycoplasma bovis (grupo retrospectivo, n = 6). Además, se incluyeron otros nueve casos con base en las características histopatológicas de las lesiones (grupo prospectivo, n = 9). El antígeno de DVB se reconoció en dos animales con lesiones neumónicas, uno de ellos con bronconeumonía fibrinosa, incluyendo además lesiones probables de rinotraqueítis infecciosa bovina (1/9), y el otro con bronconeumonía supurativa y también miocarditis probable por Histophilus somni (1/9). Adicionalmente, un caso positivo estuvo asociado a anaplasmosis (1/9). Otros dos casos positivos presentaron una distintiva peritonitis fibrinosa (2/9). El resto de los animales de este grupo resultaron negativos a DVB (4/9). Las características histopatológicas de las lesiones y su asociación con el antígeno in situ, confirman la presencia de DVB. Esta presentación es compatible con el síndrome denominado infección aguda. Este es el primer informe de infección por DVB y otras patologías concomitantes en ganado de engorda en México.

Histopathological analogies in chronic pulmonary lesions between cattle and humans: basis for an alternative animal model.

Most of the natural cases of pneumonia in feedlot cattle are characterized by a longer clinical course due to chronic lung lesions. Microscopically, these lesions include interstitial fibroplasia, bronchitis, bronchiectasis, bronchiolitis obliterans, and epithelial metaplasia of the airways. Herein, the aim was to review, under a medical perspective, the pathologic mechanisms operating in these chronic pneumonic lesions in calves. Based on the similarities of these changes to those reported in bronchiolitis obliterans/organising pneumonia (BO/OP) and chronic obstructive pulmonary disease (COPD) in human beings, calves are proposed as an alternative animal model.

Etiología, patogénesis, diagnóstico y tratamiento de osteocondrosis (OC) / Etiology, pathogenesis, diagnosis and treatment of osteochondrosis (OC)

Osteochondrosis (OC) is a term used to describe a wide range of different skeletal lesions between different species. Osteochondrosis is a problem that affects fast growing animals and it has been defined as a failure in the endochondral ossification of the articular-epiphyseal cartilage. This failure leads to cartilage thickening and retention, basal necrosis, subchondral bone damage and loose bone fragments in the articular joint. Osteochondrosis is a multifactorial disease in which nutritional, hereditary, endocrine factors, biomechanical influences, and failures of blood supply to growth cartilage play an important role. The aim of this review is to offer an updated approach to the knowledge of the mechanisms that intervene in the pathogenesis of osteochondrosis, as well as alternatives to its diagnosis and treatment.

El término osteocondrosis (OC) se refiere a una gran variedad de lesiones esqueléticas en diferentes especies. La osteocondrosis es un problema que afecta a los animales de rápido crecimiento y se ha definido como una falla en la osificación endocondral del cartílago articular epifiseal. Dicha falla provoca un engrosamiento y retención del cartílago, necrosis basal, daño al hueso subcondral y desprendimiento de fragmentos óseos en la cavidad articular. La osteocondrosis es una enfermedad de etiología multifactorial donde factores nutricionales, hereditarios, biomecánicos, endocrinos, así como la falla en el aporte sanguíneo del cartílago en crecimiento juegan un papel importante. La finalidad de esta revisión es ofrecer un acercamiento al conocimiento de los mecanismos que intervienen en la patogénesis de la osteocondrosis, así como a las alternativas para su diagnóstico y tratamiento.

Informe de tres casos de rabia paralítica y babesiosis bovina en el municipio de Aldama, Tamaulipas / Report of three cases of bovine paralytic rabies and babesiosis in Aldama, Tamaulipas

History of diseases, clinical manifestations, pathologic and histopathological findings, as well as the results of complementary studies of three animals considered representatives of an outbreak of mortality in beef cattle in a ranch located in Aldama, Tamaulipas, during the first trimester of the 2008 are presented. Babesiosis and paralytic rabies were the presumptive diagnosis in two cases. Both diseases are considered enzootic in this area. Laboratory studies demonstrated that rabies was the main problem (3/3); however, in two of them (2/3) also Babesia bovis was recognized. In enzootic areas, the presence of both diseases, bovine paralytic rabies and babesiosis, occurs simultaneously making diagnosis difficult.

Se presentan los antecedentes, las manifestaciones clínicas, los hallazgos patológicos e histopatológicos, así como los resultados de los estudios complementarios de tres animales representativos de un problema de mortalidad en ganado de carne en un rancho localizado en el municipio de Aldama, Tamaulipas, durante el primer trimestre de 2008. El diagnóstico presuntivo en dos casos fue babesiosis y en el otro fue rabia. La zona es considerada endémica para ambas enfermedades. Los resultados demostraron que el problema primordial fue rabia (3/3); sin embargo, en dos de ellos (2/3) también se registró la presencia de Babesia bovis. En zonas endémicas, la presencia de ambas enfermedades, rabia paralítica bovina y babesiosis ocurre simultáneamente haciendo difícil el diagnóstico.

Localización de Serratia marcescens en perfil bacteriológico y fúngico de la conjuntiva de caballos clínicamente sanos en Monterrey, Nuevo León, México / Localization of Serratia marcescens in bacterial and fungal profile of conjunctiva of clinically healthy horses from Monterrey, Nuevo Leon, Mexico

The conjunctival normal microflora, formed by fungi, yeast and bacteria, of 50 clinically healthy horses from Monterrey, Nuevo Leon, was identified using three to 12 year-old horses of different breeds and gender. Samples were taken from the conjunctival sac of both eyes (n =100 eyes) using a cotton swab under sterile conditions. No eye was negative to the presence of the microorganism. There were differences in colony types in each eye of the same animal. One hundred percent were positive to fungal and bacteria colonies in both eyes, while 60% were positive to yeast. In the present study Serratia marcescens, a pathogenic, opportunist and multidrug-resistant organism, is reported for the first time in the conjunctival sac in horses. Serratia marcescens was isolated from 21 clinically healthy horses (42%) with a number of colony forming units (cfu) that ranged from 9 to 42.

Se identificó la microflora normal, formada por hongos, levaduras y bacterias, de la conjuntiva en 50 caballos clínicamente sanos, de diferente raza y sexo, de tres a 12 años de edad, del área metropolitana de Monterrey, Nuevo León. Las muestras se tomaron del saco conjuntival de ambos ojos (n = 100 ojos) con un hisopo bajo condiciones estériles. Ningún ojo fue negativo a la presencia de microorganismos. Hubo a menudo diferencias en los tipos de colonias entre los ojos del mismo animal, 100% fueron positivos a la presencia de hongos y bacterias en ambos ojos, y 60% positivos a la presencia de levaduras. Este estudio presenta, por vez primera en conjuntiva de caballos, la presencia de Serratia marcescens, considerada microorganismo patógeno oportunista con multirresistencia a fármacos. En esta investigación, Serratia marcescens se logró aislar de 21 caballos clínicamente sanos (42%) con rango de nueve a 42 unidades formadoras de colonias (ufc).

Demostración inmunohistoquímica de Mycoplasma bovis en lesiones neumónicas crónicas en ganado en corral de engorda / Immunohistochemical demonstration of Mycoplasma bovis in chronic lung lesions in feedlot cattle

Bovine feedlots are intensive production systems of significant importance in México, United States of America and Canadá. Respiratory diseases are the single most important cause of morbidity and mortality in feedlot cattle. Herein, the gross and microscopic findings in the lungs of cattle with unusually persistent pneumonia unresponsive to aggressive antibiotic treatment in feedlots localized in General Escobedo, Nuevo Leon; Morelia, Michoacan; Mexicali, Baja California, and Culiacan, Sinaloa, Mexico are described. Eight chronic suppurative bronchopneumonia cases with multifocal areas of casseous necrosis were selected. Microscopically, these lesions were bronchocentric and characterized by foci of necrosis surrounded by a pyogranulomatous reaction. Immunohistochemical studies revealed positive reaction to Mycoplasma bovis in all cases. Gross and microscopic lesions associated with M. bovis pneumonia have a conspicuous pattern. This is the first report of M. bovis causing pneumonia in feedlot cattle in Mexico.

El corral de engorda es un sistema de producción intensivo de gran importancia en la ganadería de carne en México, Canadá y Estados Unidos de América. Estudios epidemiológicos indican que las enfermedades respiratorias de los bovinos son el principal problema en corrales de engorda. En este trabajo se describen las lesiones macroscópicas y microscópicas en pulmones de ganado de carne con severa neumonía crónica, a pesar de haber recibido tratamiento con antibióticos en más de tres ocasiones. Se realizaron estudios post mortem de ganado en corrales de engorda localizados en General Escobedo, Nuevo León; Morelia, Michoacán; Mexicali, Baja California y Culiacán, Sinaloa, todos en México. Se seleccionaron ocho casos crónicos de bronconeumonía supurativa con múltiples focos nodulares de exudado necrótico-caseoso. Estos focos necróticos estaban microscópicamente centrados en bronquios y bronquiolos y sus bordes estaban claramente limitados por una reacción piogranulomatosa. Los estudios de inmunohistoquímica demostraron positividad a Mycoplasma bovis en todos los casos. Las lesiones neumónicas macro y microscópicas asociadas con M. bovis tienen un patrón conspicuo. Este es el primer informe de M. bovis en neumonías en ganado de corral de engorda en México.

Tumor venéreo transmisible con metástasis a un hemangioma esplénico en una perra / Transmissible venereal tumor with metastasis to a spleen hemangioma in a bitch

This report describes a case of transmissible venereal tumor (TVT) with metástasis to spleen in areas previously affected with a hemangioma in an adult mongrel stray bitch. In addition, the animal had seborrheic dermatitis associated with demodicosis, suggesting a deficient immune response. In Mexico, TVT is a common entity; however, metastases to internal organs are extremely rare. This is the first report of metastasis of TVT to an internal organ with a previous established tumour.

Este informe describe un caso del tumor venéreo transmisible (TVT) con metástasis en bazo y en áreas previamente afectadas con hemangioma en una perra adulta mestiza. Además, el animal tenía dermatitis seborreica asociada con dermodicosis, la cual sugería una respuesta inmune deficiente. En México, el TVT canino es una entidad común; sin embargo, las metástasis a los órganos internos son extremadamente raras. Este es el primer informe de metástasis de TVT a un órgano interno con un tumor previamente establecido.

Descripción de un caso similar a miositis osificante localizada en un perro / A case of myositis ossificans circumscripta-like condition in a dog

A case of myositis ossificans circumscripta in an eight-year-old, male, Weimaraner dog, is described. The animal was originally submitted with presumptive diagnosis of hernia. The lesion was a firm, subcutaneous nodule, 5 cm long by 3 cm width, localized in the right perineum muscles. After the radiologic study the lesion was interpreted as a neoplasm from coccygeal vertebrae. The surgical procedure to eliminate the neoplastic tissue confirmed its hardness. Excision was not complete and the sample was submitted to pathology. The mass was hard, well circumscribed, vascularized and surrounded by muscle tissue. The histopathological study revealed a heterotopic ossification with zones of atrophy, degeneration and muscle necrosis, alternating with zones of trabecular ossification toward the periphery, limited by abundant fibrous connective tissue. These findings are characteristic of myositis ossificans circumscripta. This case represents the first report in a dog in Mexico, of a condition resembling the myositis ossificans circumscripta in humans.

Se describe un caso de miositis osificante localizada en un perro de raza Weimaraner, macho, de ocho años de edad. El animal fue originalmente remitido con diagnóstico presuntivo de hernia. La lesión era un nódulo subcutáneo firme con 5 cm de largo por 3 cm de ancho, localizada en los músculos del perineo derecho. Después del estudio radiológico la lesión fue interpretada como una neoplasia originada de vértebras coccígeas. Su dureza se constató durante el procedimiento quirúrgico para eliminar la neoformación. La lesión se extirpó parcialmente y la muestra se remitió a patología. La masa era dura, bien delimitada, vascularizada y con tejido muscular a su alrededor. El estudio histopatológico reveló osificación heterotópica con zonas de atrofia, degeneración y necrosis muscular, alternando con zonas de osificación trabecular en la periferia, limitadas por abundante tejido conectivo fibroso. Estos hallazgos son característicos de la miositis osificante localizada. Este caso constituye el primer informe de esta condición patológica en un perro en México, similar a la miositis osificante localizada en humanos.

Tumor multilobular óseo: Presentación de dos casos en perros / Multilobular tumor of bone: Report of two cases in dogs

The multilobular tumor of bone (MTB) is considered as a slow-growth malignant tumor, which generally occurs on the cranium and facial bones of dogs, although it has been reported in other domestic animals. This study presents two cases of MTB in dogs. The first case was manifested in an 8-year-old male Bull Terrier, while the second one affected a 5.5-year-old female German Shepherd. Both animals were submitted for post-mortem examination. MTB diagnosis was confirmed by histopathological examination. The aim of this report was to describe the main clinical-pathologic features of MTB, such as its slow, diffuse and deforming growth pattern, as well as the histomorphological image peculiarities that are unmistakable from other tumors such as chondrosarcoma and osteosarcoma, that should be considered as differential diagnoses. Up to date, this is the first report of canine MTB in Mexico.

El tumor multilobular óseo (TMO) es considerado como tumor maligno de crecimiento lento, que ocurre generalmente en el cráneo y en los huesos faciales del perro, aunque también se ha registrado en otras especies animales. Aquí se presentan dos casos de TMO en perros. El primero ocurrió en un Bull Terrier, macho, de ocho años de edad, el segundo en Pastor Alemán, hembra, de 5.5 años. Ambos animales fueron remitidos para su examen post-mortem. El tumor multilobular óseo fue confirmado por histopatología. El objetivo de este trabajo fue describir las principales características clínico-patológicas del TMO en perros, como su crecimiento lento, difuso y deformante, al igual que las peculiaridades histomorfológicas de la imagen, que son inconfundibles con otros tumores; por ejemplo, condrosarcoma y osteosarcoma, que deben considerarse dentro de los diagnósticos diferenciales. Éste es el primer informe de TMO canino en México.

Combined distemper-adenoviral pneumonia in a dog.

A 3 1/2-month-old pug with oculonasal discharge and seizures was submitted for postmortem examination. Grossly, the lungs had cranioventral consolidation, and microscopically, 2 distinct types of inclusion bodies compatible with Canine distemper virus and Canine adenovirus type 2. Presence of both viruses was confirmed via immunohistochemical staining.

Surfactant protein D expression in normal and pneumonic ovine lung.

Surfactant protein D (SP-D) is a collagenous calcium-dependent lectin constitutively expressed by alveolar type II pneumocytes and non-ciliated bronchiolar epithelial (Clara) cells. It binds to surface glycoconjugates expressed by a wide variety of microorganisms such as Gram-negative bacteria, influenza A virus, and various fungi, leading to pathogen inactivation or enhanced neutrophil and macrophage activity. Since a hallmark of bronchopneumonia is the initiation of inflammation in the bronchi and bronchoalveolar junction, we chose a classic ruminant model of bronchopneumonia caused by Mannheimia haemolytica to study the expression of SP-D within the bronchioles of infected lambs. Healthy weaned lambs were inoculated with either pyrogen-free saline (controls) or M. haemolytica intrabronchially using a fiber-optic bronchoscope. SP-D protein and mRNA expression in lung was detected by immunohistochemistry (IHC) and fluorogenic real-time relative quantitative reverse transcriptase polymerase chain reaction (real-time RT-PCR), respectively, during acute (1 day), subacute (15 days), and chronic (45 days) bronchopneumonia. At 15 and 45 days post-inoculation, areas of lung had peribronchiolar inflammatory cell infiltrate, epithelial cell hyperplasia, tortuosity of the airway lumens, and decreased intensity of SP-D protein staining and number of positive cells. The levels of SP-D mRNA were not increased or significantly altered by M. haemolytica infection when compared to control animals. In conclusion, cell-associated SP-D protein expression significantly decreases within hyperplastic epithelium of lungs from infected animals during chronic bronchopneumonia. Exhaustion of SP-D protein reserves and absence of SP-D gene upregulation during the progression of bacterial pneumonia into chronicity may result in failure to clear the pathogen from the lung and/or cause animals to be more susceptible to re-infection.

Clinical efficacy of meloxicam (Metacam) and flunixin (Finadyne) as adjuncts to antibacterial treatment of respiratory disease in fattening cattle.

The clinical efficacy of two non-steroidal anti-inflammatory drugs (NSAIDs), meloxicam (Metacam 20 mg/ml) and flunixin meglumine (Finadyne), as adjuncts to antibacterial therapy in the treatment of acute febrile respiratory disease in cattle was compared. The randomised blind, positive controlled study was conducted under feedlot conditions in Mexico. Overall, 201 female cattle (weighing 220-250 kg) diagnosed with bronchopneumonia at the feedlot were recruited into the study. On Day 0 all animals were treated with 20 mg oxytetracycline/kg body-weight (Bivatop 200) by subcutaneous injection, in conjunction with either meloxicam (0.5 mg/kg subcutaneously, Metacam 20 mg/ml, n = 100), or flunixin meglumine (2.2 mg/kg intravenously, Finadyne, n = 101). According to label instructions, meloxicam was administered as a single dose, whereas flunixin meglumine could be administered daily for up to 3 consecutive days depending on the rectal temperature (with re-administration, if rectal temperature > or = 40.0 degrees C). Rectal temperature, respiratory rate, appetite, dyspnoea, coughing, nasal discharge and general condition were recorded on Days 0 (prior to treatment), 1, 2, 3 and 7 using a weighted numerical score. Scores were summed to generate a 'Clinical Sum Score' (CSS, range 7 to 24 points). Individual animal body weights were measured on Days 0 and 7. Nasal swabs were collected from 10 animals per treatment group on Day 0 for microbiological culture. Clinical parameters and the mean CSS showed no significant differences between treatment groups with mean CSS on Days 0 and 7 of 16.18 and 10.55 in the meloxicam group and 16.41 and 10.88 in the flunixin meglumine group. However, a significantly lower mean rectal temperature was measured in the meloxicam group on Day 2 (p < or = 0.01). No significant differences in mean body weights were found between groups. Repeated administration of flunixin meglumine was performed in 45% of the animals. No suspected adverse drug events related to treatments were reported. It is concluded that a single subcutaneous dose of meloxicam was as clinically effective as up to 3 consecutive daily intravenous doses of flunixin meglumine when used as an adjunctive therapy to antibacterial therapy in the treatment of acute febrile respiratory disease in feedlot cattle.