Amebiasis in a Backyard Red-Foot Tortoise (Chelonoidis carbonaria)

Background: Amebiasis is a parasitic infection caused by obligate or facultative amoeboid protozoans, as well as free-living forms. The genus Entamoeba includes both pathogenic and commensal species that can affect humans and animals. Entamoeba histolytica is the most important species associated with intestinal and extraintestinal infections in humans, while Entamoeba invadens is considered the most common and serious pathogen to many reptile species, including lizards, snakes and crocodilians. The aim of this manuscript is to report a case of amebiasis in a backyard red-foot tortoise in northeastern Brazil.Case: A 10-month-old male red-foot tortoise (Chelonoidis carbonaria) was presented at the Animal Pathology Laboratory of the Veterinary Hospital of Federal University of Campina Grande for necropsy with a 1-week history of anorexia, apathy, and reluctance to move. According to the owner, the animal suffered from heat stress in the backyard, where it was housed with another male red-foot tortoise. At post-mortem examination, there were approximately 1 mL of yellowish viscous transudate in the coelomic cavity. The liver was large, with rounded edges and multifocal to coalescing yellowish areas in the subcapsular surface. When cut, the parenchyma was more friable and yellowish. At the opening of the small intestine, the mucosa was thickened, reddened, and contained many variably sized, dark red ulcers with depressed and hemorrhagic centers. Histopathology of the liver reveals diffuse macro and microvacuolar degeneration of the hepatocyte cytoplasm, often displacing the nucleus peripherally (fatty degeneration). There were extensive and multifocal areas of necrosis characterized by shrunken, hypereosinophilic and pyknotic hepatocytes. Amebic trophozoites were seen through the areas of necrosis and degeneration and the morphological features were suggestive of the genus Entamoeba. In the portal triads and slightly extending to the sinusoidal spaces, there is a moderate inflammatory infiltrate of macrophages, lymphocytes, plasma cells and rare heterophils. There were amebic trophozoites and thrombi in hepatic vessels, and mild intracanalicular cholestasis. The small intestine contained areas of transmural necrosis and ulceration associated with inflammatory infiltrate of macrophages, lymphocytes and plasma cells. The ulcers were covered by a thick fibrinonecrotic exudate mixed with a varying number of heterophils and macrophages. The submucosa contained hemorrhage and edema. Similar amebic trophozoites were found within the mucosa and submucosa, and also detected in the lumens of blood vessels at the submucosa. The amebic trophozoites, seen in the liver and intestine, were intensely Periodic acid–Schiff positive.Discussion: The diagnosis of amebiasis was based on the epidemiological, clinical and anatomopathological findings. Amebiasis is a well-recognized disease that usually is diagnosed post-mortem in numerous species of reptiles. Unfortunately, there are no scientific articles describing these cases in Brazil. In reptiles, the major pathogenic specie is Entamoeba invadens, while several other species are considered non-pathogenic, such as E. barreti, E. insolita, E. terrapinae, E. ctenosaurae, and E. knowlesi, among others. Although cultivation of E. invadens was not undertaken, the anatomopathological findings and the morphological appearance of the agent is highly suggestive of infection with this organism. In conclusion, amebiasis is a severe infectious disease that can affect young red-footed tortoises under adverse environmental conditions. Clinical signs are nonspecific and may be difficult to identify. The diagnosis is usually made post-mortem by anatomopathological findings and the morphological appearance of the agent

South American Rattlesnake (Crotalus durissus spp.) Envenomation in Dogs in the Semiarid Region of Brazil

Background:  South American rattlesnake (Crotalus durissus spp.) envenomation is rarely reported in small animals and livestock in Brazil. Minor swelling at the snakebite site, skeletal muscle, and renal damage, and severe neurological signs characterize the crotalic envenomation. This case report aims to present epidemiological, clinical, and pathological data of two cases of Crotalus durissus spp envenomation in dogs in the Northeast of Brazil.Cases: Envenomation by Crotalus durissus spp. was recorded in two dogs in Patos, State of Paraíba, Brazil. In Case 1, the dog presented flaccid paralysis, hyporeflexia, a deficit of cranial nerves, epistaxis, and gingival hemorrhages. Laboratory assay showed proteinuria, myoglobinuria, regenerative thrombocytopenia, and increased serum activities of creatine kinase (CK), aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP). The dog was medicated with crotalic antivenom and wholly recovered from local and systemic clinical signs. In Case 2, the dog died and was detected fang marks at the ventral region of the left mandible (two small parallel perforations spaced 2.0 cm apart) at the snakebite site. Cyanosis of the oral cavity, congestion, and hemorrhages in several organs were observed at necropsy. Tubular nephrosis, muscular necrosis, hepatocytes swelling were observed. The owners witnessed snakebites, and the rattlesnakes (Crotalus durissus spp.) identified by the rattle at the end portion of the tail in both cases. Discussion: Natural South American rattlesnake envenomation presents complex clinical signs that makes diagnosis a challenge for veterinary practitioners. The criteria for the correct diagnosis and observed in the two dogs include witness of the snakebite, identification of the snake, detection of fang marks, clinical-pathological findings, and therapeutic response to treatment with specific anti-venom. The dog’s owners did not identify the subspecies of rattlesnakes; however, Crotalus durissus cascavella and Crotalus durissus collilineatus are the only species found in the Northeast region of Brazil. Crotoxin is the primary toxic component of South American rattlesnake, which induces neuromuscular blockage, and neurological signs (skeletal muscle flaccid paralysis, apathy, hyporeflexia, cranial nerve deficits). These clinical signs are similar to those observed in the two dogs. Respiratory distress, cyanosis, pulmonary edema, and hemorrhage are secondary to respiratory muscle paralysis and also detected in a dog (Case 2) with crotalic envenomation. Minor local swelling at the snakebite site,  myotoxicity observed in both dogs (high serum activities of CK and AST - Case 1), degeneration and necrosis of muscle fibers - Case 2), and fang marks observed in Case 2, strengthen the diagnosis of Crotalus durissus envenomation. Nephrotoxicity was also detected in both dogs (increased specific gravity of urine - Case 1 and myoglobin deposition and degeneration of renal epithelial tubular cells - Case 2). Coagulative disorders and hepatotoxicity are infrequently in domestic animals and humans with crotalic envenomation. High serum activities of ALP and ALT in Case 1, and swelling of hepatocytes in Case 2, suggest liver damage associated with the crotalic envenomation. The differential diagnosis of South American rattlesnake envenomation should be included in dogs with acute neuromuscular flaccid paralysis, associated or not with bleeding disorders, myoglobinuria, and acute kidney injury

Primary Kidney Lymphoma in a Dog

Background: Lymphoma is a malignant lymphoid tumor originating in the lymph nodes or other solid organs and comprises 90% of all hematopoietic tumors in dogs. However, primary renal lymphoma is rare and is associated with nonspecific clinical signs. Tumor invasion in both kidneys can cause severe clinical signs due to renal failure, complicating the patient's treatment and prognosis. The aim of this case was to report the case of a dog affected by bilateral primary renal lymphoma. In addition, to characterize the clinical and histopathological presentation due to the intense morphological changes. Case:  A 5-year-old male Poodle canine was admitted showing apathy and emesis for 5 days. On physical examination, the dog showed 10% of dehydration, reddish oral mucous membranes, poor body condition (score 1/5), uremic breath, and pain in the kidney area. Complementary tests revealed severe low white blood cells count, high BUN levels, high levels of potassium, calcium, and phosphorus (serum biochemistry). Abdominal ultrasound showed bilateral kidney enlargement. Fine needle aspiration of the mass (guided by ultrasound) revealed round cell tumor. Radiographs showed no alterations. The dog died due to his poor condition and necropsy was performed. On post-mortem examination, the kidneys were both enlarged, pale, and with an irregular subcapsular surface. The histopathological diagnostic was primary renal lymphoma. Immunohistochemical staining revealed that neoplastic cells were strongly positive for anti CD20 and PAX5, while negative for CD3, supporting the diagnosis of B-cell lymphoma. Discussion: The diagnosis was based on clinical, complementary tests, fine needle aspiration, histopathological and immunohistochemical findings. In dogs, primary kidney tumors are uncommon and usually malignant. The presence of vomiting, uremic breath, dehydration, weight loss, and erosive and ulcerative lesions on the tongue (uremic glossitis) are clinical signs of chronic renal failure, and this condition was later confirmed by laboratory tests and histopathological findings. Dogs diagnosed with extra-nodal renal lymphoma, present clinical signs such as polydipsia, polyuria, vomiting, and uremic breath in some cases. These changes are compatible with changes observed in cases of renal failure. In this case, the severe azotemia, hyperphosphatemia, hypocalcemia, and hyperkalemia were due to the neoplastic infiltration in both kidneys. Additionally, the abdominal ultrasound revealed the tumor in both kidneys. Almost 38% of dogs with renal lymphoma presented in urine evaluation normal urine density and a large amount of protein in the urine, similar to those observed in this dog. When the lesions are on both kidneys, kidney failure develops and uremic extra-renal lesions appear, as observed in this case. The prevalence of primary kidney tumors in domestic animals corresponds to less than 1% of the total of the tumors reported, and they are usually in one kidney. In dogs, almost 60 - 70% of lymphomas are B cells, 30 - 40% are T cells, and less than 1% are null cells. B-cell lymphomas usually show less aggressive behavior when compared to T-cell lymphomas. Kidney lymphoma can be included as an important cause of kidney failure, and has slow and progressive development, making early diagnosis and treatment difficult. Keywords: dog disease, lymphoproliferative disorder, renal neoplasm, uremia. Título: Linfoma renal primário em cãoDescritores: doença de cão, distúrbio linfoproliferativo, neoplasma renal, uremia.

Cerebral Candida albicans Infection in Two dogs

Background: Candida spp. are pleomorphic fungi that are commensal inhabitants of the oral, gastrointestinal, upper respiratory and urogenital mucosa of mammals. Candida albicans is described as the most important species. This opportunistic pathogen may produce local or systemic infections in dogs. Local infections have been reported in several tissues and systemic infection is rare in dogs with few reports in the literature describing this presentation. The aim of the present study was to report two cases of cerebral Candida albicans infection in dogs in Brazil.Case: Two cases of cerebral Candida albicans infection in dogs that showed nervous signs are described. In both cases, the brain showed marked asymmetry of the telencephalic hemispheres with multifocal to coalescing yellowish or reddish areas and a partial loss of distinction between gray and white matter. In Case 1, the mediastinal, tracheobronchial and mesenteric lymph nodes, as well as the right kidney and adrenal gland, showed altered architecture due to numerous whitish gray nodules. Histological lesions were characterized by granulomatous (case 1) or pyogranulomatous (case 2) necrotizing meningoencephalitis with intralesional fungal organisms. In case 1, similar granulomatous infiltrate with intralesional fungal organisms was also seen in the lymph nodes, kidney and adrenal gland. In case 2, there was evidence consistent with an underlying infection of canine distemper virus. Were observed lymphoplasmocytic interstitial pneumonia, lymphoid rarefaction in lymph nodes, and viral intracytoplasmic inclusion bodies in the epithelial cells of the stomach and vesical urothelium. In these two cases, the fungal organisms displayed three different morphological patterns. The first pattern was characterized by delicate tubular structures with thin parallel walls that were rarely septate and tended to undulate slightly, and measured approximately 4-20 µm (true hyphae). The second pattern was characterized by chains of elongated yeast, separated by constrictions at septal sites, and measured approximately 4-10 µm (pseudohyphae). The other morphological pattern, which was rarely observed, was characterized by round budding yeast cells that measured 3-4 µm in diameter and were often elongated by the germ tube. Sections were also stained using immunohistochemical antibodies against Candida albicans. The fungi revealed strong immunolabelling of the cytoplasm and wall for Candida albicans.Discussion: The diagnosis was based on the histomorphological and immunohistochemical characteristics of the agent, which were consistent with Candida albicans. In these two cases, immunocompromise appeared to have been an important factor in the progression of the infection. In case 1, the dog was senile and treated with corticosteroids, conditions that could effectively limit innate, humoral and cell-mediated immune response to infection. In case 2, the dog displayed cachexia and was infected by canine distemper virus, evidenced by the presence of viral inclusion bodies. The inflammatory reactions in both cases were characteristic of fungal infections, but were distinct due to differences in the infectious process. In case 1, there was a subacute to chronic progression; while in case 2 neutrophilic infiltrate predominated, suggesting an acute progression. The different morphological patterns of the fungi suggested a pleomorphic fungi and the immunohistochemistry allowed us to identify the infectious agent. In conclusion, opportunistic infections caused by Candida albicans should be considered when diagnosing diseases that affect the central nervous system of dogs, particularly in immunosuppressed animals

METÁSTASE ÓSSEA E PULMONAR DE ADENOCARCINOMA ESCAMOSO MAMÁRIO EM CADELA

Mammary tumors are the most common in bitches, and bone and pulmonary metastases are not well described. Adenosquamous mammary carcinoma is a rare tumor that can be classified as a type of metaplastic tumor.  This report describes the clinical and histopathological findings of this atypical presentation of mammary carcinoma in an 11-year-old, spayed, Poodle. Surgery was performed to remove malignant mammary nodules with a provisional diagnosis of carcinoma on cytologic examination. Thirteen months later, the dog returned showing left pelvic limb lameness that had persisted for 6 months prior to the consultation. The patient showed right pelvic limb lameness and a mass in the same limb. Radiographs of the affected limb revealed a pathological fracture in the femoral diaphysis and proliferation of the periosteum. After clinical staging, a left pelvic limb amputation was performed. A diagnosis of grade II adenosquamous mammary carcinoma was made through histopathology and immunohistochemistry. Although uncommon, bone and pulmonary metastases from mammary tumors, such as adenosquamous carcinoma, can be considered differential diagnoses for bony tumors. This report highlights the aggressive nature and significant metastatic potential of the adenosquamous carcinoma.Os tumores mamários são os mais comuns em cadelas e as metástases ósseas e pulmonares não são bem descritas. O carcinoma mamário adenoescamoso é um tumor raro que pode ser classificado como um tipo de tumor metaplásico. Este relato descreve os achados clínicos e histopatológicos dessa apresentação atípica de carcinoma mamário em um Poodle de 11 anos de idade, castrado. A cirurgia foi realizada para remover nódulos mamários malignos com diagnóstico provisório de carcinoma no exame citológico. Treze meses depois, a cadela retornou apresentando claudicação do membro pélvico esquerdo que persistia por seis meses antes da consulta. O paciente apresentava claudicação do membro pélvico direito e uma massa no mesmo membro. A radiografia do membro afetado revelou fratura patológica na diáfise femoral, proliferação do periósteo e áreas de osteopenia. Após estadiamento clínico, foi realizada amputação do membro pélvico esquerdo. O diagnóstico de carcinoma adenoescamoso mamário grau II foi feito através da histopatologia e imunohistoquímica. Embora incomuns, as metástases ósseas e pulmonares de tumores mamários, como o carcinoma adenoescamoso, podem ser consideradas diagnósticos diferenciais para tumores ósseos. Este relatório destaca a natureza agressiva e significativo potencial metastático do carcinoma adenoescamoso

Nocardiosis in Cats - Clinical, Anatomopathological and Morphotintorial Characteristics

Background: Nocardiosis is an infectious bacterial disease that can cause cutaneous/ subcutaneous, pulmonary and systemic lesions in different species of domestic animals. The type of transmission occurs through mechanical lesions on the skin or contamination of wounds, in cases of skin involvement, inhalation of aerosols and ingestion of contaminated materials are involved in the pathogenesis of the respiratory and digestive form of the disease. This paper described 4 cases of nocardiosis in cats, addressing the clinical, anatomopathological and morphotintorial characteristics of Nocardia sp.Cases: Four cases of nocardiosis in cats were reviewed, in which data related to breed, sex, age, origin, clinical signs, macroscopic and histological lesions described in necropsy protocols were evaluated. The histological tissue sections stained with Hematoxylin and Eosin (HE) were evaluated in order to characterize the inflammatory response in each case. In addition, paraffin blocks of fragments from affected organ were selected to perform special histochemical staining techniques of Grocott Methenamine Silver (GMS), modified Ziehl-Neelsen, Gram Brown-Brenn and Giemsa stain which are the most characterized techniques used for histopathological diagnoses and it was also used an immunohistochemical test with polyclonal antibody anti-Nocardia sp. (non-commercial). The animals were adults of both sexes, mixed breed, not castrated and semi-domesticated. Neither immunosuppressive factors nor concomitant diseases were identified in the cases studied. The main clinical signs were apathy, anorexia, dehydration, phlegmon and draining tracts. Macroscopically, skin / subcutaneous tissue (3/4), skeletal muscle (2/4), lymph nodes (2/4), liver (2/4), omentum (1/4), spleen (1/4) were affected. In addition, it could be noted that mandibular bone (1/4), pleural tissue (1/4), left testicle (1/4) and Central Nervous System (CNS) (1/4) were also affected by this disease. Microscopically, regarding all cases, there was a pyogranulomatous inflammation in the affected organs. With respect to cases 1, 3 and 4, filamentous, branched, slightly basophilic structures in loose or individual aggregates in the interior of the pseudo-rosettes and in the necrotic areas were observed in the HE-stained tissue sections. In all cases submitted to special histochemical techniques, filamentous, branched, individual or loose aggregate structures were observed, the samples were impregnated with silver, and bacteria appear as blue using the Brown-Brenn Gram technique, and stained red in the modified Ziehl-Neelsen, and stained faintly pink in Giemsa stain. The bacteria were observed mainly in the border of the pyogranulomas, in the center of the pseudo-rosettes and in the necrotic areas, being compatible with the infection by Nocardia sp. All cases were positive for immunohistochemistry (IHC).Discussion: Nocardiosis was diagnosed in all cats in this study based on the anatomopathological findings associated with the visualization of the agent and its morphotintorial characteristics by using special histochemical stains and being confirmed by IHC. It occurs mainly in the cutaneous and/or subcutaneous tissues, with systemic involvement and death of the affected animals, in addition to affecting bone tissue considered an uncommon site for the disease. The diagnosis can be established based on the anatomopathological findings associated with the morphotintorial characteristics by using special histochemical stains, which are important for evidencing and morphologically characterizing the agent, as well as being confirmed by IHC.Keywords: disease in cat, pyogranulomatous inflammation, Nocardia sp.Título: Nocardiose em gatos - achados clínicos, anatomopatológicos e morfotintoriais Descritores: doença de gato, inflamação piogranulomatosa, Nocardia sp. 

T-cell Lymphoma in the Nasal Cavity in Goat

Background: Lymphomas are considered uncommon in goats, being the multicentric form with the highest number of cases for the species. Primary intranasal lymphomas are often diagnosed in dogs, cats, and humans. In the literature, there is only a description of a multicentric case involving the frontal sinuses and mucosa of the nasal cavity in a goat; therefore, it is important to describe unusual cases of this disease for the inclusion of new clinical and pathological characteristics in the ruminant clinic medicine. The objective of this work is to describe a case of T-cell lymphoma in the nasal cavity of a young goat.Case: The animal had dyspnea and respiratory noise for 15 days. Clinical examination showed nodulation in the right nasal cavity associated with serosanguinous secretion. Tracheostomy was performed; however, after 30 days the animal was euthanized. A sagittal plane of the head showed a pinkish-gray mass in the right and left nasal cavity, with a smooth, multilobulated surface, smooth adhering to the rostral portion of the dorsal concha and occluding the dorsal nasal meatus. Submandibular lymph nodes were slightly enlarged. Histopathological examination of the nasal cavity revealed a non-encapsulated, poorly delimited and ulcerated tumor composed of round cells arranged in a mantle supported by a discrete fibrovascular stroma extending the mucosa and lamina propria. Cells were round with sparse, eosinophilic and poorly delimited cytoplasm. Nuclei varied from round to elongated with condensed chromatin and evident nucleoli. Occasionally, aberrant nuclei, reniform shape and multinucleated cells were seen. Pleomorphism was moderate characterized by anisocytosis and anisocariosis. Typical and atypical mitosis were frequent (0-4 per field of highest magnification [400x]). Amidst the neoplasm, there were multifocal areas of necrosis and hemorrhage associated with a mild lymphocytic inflammatory infiltrate. Immunohistochemistry showed positive immunostaining for Vimentin antibodies and CD3, and negative for pan CK and CD20.Discussion: The lymphomas immunophenotyping is little used when it comes to farm animals, and there are few studies that use this technique for the definitive diagnosis of these neoplasms for small ruminants. The use of this technique must be considered in each case, in order to determine the pathogenesis, the accurate diagnosis and the origin of the neoplastic lymphocytes. In goats, T-cell lymphomas are the most diagnosed, although cases of multicentric B-cell lymphomas with ocular involvement have been diagnosed. In view of the clinical picture of the case described, infectious rhinitis already described in goats, such as aspergillosis and protothecosis, should be included as differential diagnoses. However, the anatomopathological findings facilitate the direction of the diagnosis, since infectious rhinitis presents as nodules / ulcerated masses or focal areas of necrosis associated with purulent secretion and in the histopathological examination it is possible to observe the intralesional etiological agents. In addition, the enzootic ethmoidal tumor must be included, as it has similar clinical signs and affects young animals, but they are adenomas/adenocarcinomas that affect the ethmoidal nasal shells induced by a retrovirus. Lymphomas in the caprine species are rare in the Northeastern semi-arid, but that in the present diagnostic routine occasionally occurs, being important the first description of its nasal shape for its inclusion in the differential diagnoses of diseases that present with clinical obstruction and dyspnea for the species. Keywords: hematopoietic neoplasia, immunophenotyping, lymphocytes, dyspnea.Descritores: neoplasia hematopoietica, imunofenotipagem, linfócitos, dispneia.Título: Linfoma de células T na cavidade nasal de caprino.