Congenital renal hypoplasia and contralateral kidney failure in a giant otter (Pteronura brasiliensis) ex situ in Southeastern Brazil

Renal hypoplasia is incomplete development of the kidneys, in which fewer than normal numbers of nephrons are present at birth. This report is the first of these conditions in mustelids. A female adult giant otter (Pteronura brasiliensis), ex situ, presented clinically an unusual behavior with prostration, anorexia, hiding in the shelter, ataxia, paraparesis, and death in a clinical course of one day. At the postmortem exam, the left kidney was markedly enlarged and pale and the right kidney was severely reduced and had mild to moderate capsular thickening. Histologically, the left kidney had mineralization, proliferation of fibrous connective tissue and a mild neutrophilic infiltrate. The right kidney presented a reduced number of glomeruli, tubular atrophy and an increase in fibrous connective tissue, which were findings compatible with congenital kidney hypoplasia. Due the clinical condition of the animal, gross and microscopic findings, the cause of death was established as kidney failure induced by renal hypoplasia.(AU)

Caroli syndrome in a dog / Síndrome de Caroli em um cão

Caroli syndrome is characterized by a combination of intrahepatic biliary ductal ectasia and congenital ductal fibrosis due to the failure of involution of ductal plates and large intrahepatic ducts. This study aims to report Caroli syndrome in a dog, with emphasis on clinical characteristics, complementary examinations, and diagnostic approach. A 1-year-old mixed-breed intact male dog was presented with a 7-day history of acute vomiting and anorexia. Clinical evaluation revealed severe jaundice, abdominal pain, dehydration, lethargy, and abdominal distension. Ultrasonography revealed hepatic cysts filled with fluid. Exploratory laparotomy was performed to clarify the imaging findings; however, the dog died shortly after surgery. Postmortem examination revealed that the liver was reduced in size and had multiple interconnected and distended saccular dilations. The bile ducts were markedly dilated and replaced a large part of the liver parenchyma. Multiple small cysts were also observed in the kidneys. Microscopically, the hepatic lesions were characterized by extensive bridging fibrosis associated with proliferating and ectatic bile ducts contiguous with the biliary tree. Marked fibrosis and small cysts were observed in the kidneys. Therefore, a final diagnosis of Caroli syndrome was made. While uncommon, this syndrome should be considered as a differential diagnosis for young dogs with biliary cysts and hepatic fibrosis.

A síndrome de Caroli é caracterizada pela combinação de ectasia biliar intra-hepática e fibrose ductal congênita, que se devem a falha na involução das placas ductais dos grandes ductos intra-hepáticos. Esse trabalho tem a intenção de reportar um caso de síndrome de Caroli em um canino, com ênfase em suas características clínicas, exames complementares, e abordagem diagnóstica. Um canídeo de um ano de idade, sem raça definida, apresentou um histórico clínico de sete dias de vômito agudo e anorexia. A avaliação clínica revelou severa icterícia, dor abdominal, desidratação, letargia e distensão abdominal. A ultrassonografia foi sugestiva de cistos hepáticos preenchidos por fluido. Uma laparotomia exploratória foi realizada para esclarecer os achados de imagem, porém, o cão morreu logo após a cirurgia. O cão foi submetido a exame de necropsia, onde se observou fígado diminuído em tamanho e com múltiplas dilatações saculares distendidas e interconectadas entre si. Os ductos biliares estavam acentuadamente dilatados e substituíam grande parte do parênquima hepático. Nos rins, múltiplos pequenos cistos eram observados. Microscopicamente as lesões hepáticas eram caracterizadas por extensa fibrose em ponte, associada a ductos biliares ectáticos e proliferados, que eram contíguos a árvore biliar. Nos rins, marcada fibrose e pequenas formações císticas foram observadas. Baseado na associação dos achados clínicos e patológicos, o diagnóstico de síndrome de Caroli foi feito. Mesmo que incomum, essa síndrome deve ser considerada como um diagnóstico diferencial para cães jovens com ductos biliares císticos e fibrose hepática.

Hipoplasia renal bilateral em felino / Bilateral renal hypoplasia in feline

A hipoplasia renal ocorre quando há o desenvolvimento incompleto do rim, resultando em um menor número de néfrons, lóbulos e cálices ao nascimento do animal. A gravidade dessa anomalia depende do nível de acometimento. Quando unilateral, ocorre a hipertrofia compensatória do rim saudável e, em casos bilaterais, é frequente a ocorrência de insuficiência renal e infecções. Foi retratada como uma afecção hereditária em algumas raças puras ou mestiças de suínos, potros, caprinos, bovinos e cães, contudo, é incomum em felinos. O presente trabalho tem como objetivo relatar o caso de uma felina, sem raça definida, de dois meses de idade, com queixa de apatia, anorexia e êmes por três dias. No exame físico, foi observada desidratação estimada em 10%, tempo de preenchimento capilar de três segundos, hipotermia, hipoglicemia e letargia. Frente a essas alterações, foram solicitados exames complementares para melhor elucidação do quadro. Os exames bioquímicos revelaram azotemia e hiperfosfatemia grave, bem como hipercalcemia e hipercalemia leve. Já a urinálise, indicou redução da densidade urinária associada à presença de cilindros hialinos e céreos. A ultrassonografia abdominal evidenciou perda de diferenciação córtico-medular e diminuição de ambos os rins, alterações essas compatíveis com nefropatia. Instituiu-se tratamento paliativo visando minimizar complicações secundárias da injúria renal aguda, contudo, a paciente veio a óbito. Na necropsia, os rins apresentavam tamanho reduzido bilateralmente e o exame histopatológico revelou a presença de moderados glomérulos primitivos multifocais associados à distensão do espaço glomerular. A avaliação clínica e as lesões histopatológicas foram consistentes com o diagnóstico de hipoplasia renal congênita.

Renal hypoplasia occurs when there is incomplete development of the kidney, resulting in fewer nephrons, lobes and calyces at birth. The severity of this anomaly depends on the level of involvement. When unilateral, compensatory hypertrophy of the healthy kidney occurs and, in bilateral cases, renal failure and infections are frequent. It has been portrayed as an inherited condition in some pure or mixed breeds of pigs, foals, goats, cattle and dogs, however, it is uncommon in felines. This paper aims to report the case of a feline, mixed breed, two months old, with complaints of apathy, anorexia and emesis for three days. Physical examination showed an estimated dehydration of 10%, capillary refilling time of three seconds, hypothermia, hypoglycemia and lethargy. In view of these changes, complementary exams were requested to better clarify the condition. Biochemical examinations revealed severe azotemia and hyperphosphatemia, as well as hypercalcemia and mild hyperkalemia. Urinalysis, on the other hand, indicated a reduction in urinary density associated with the presence of hyaline and brain cylinders. Abdominal ultrasound showed a loss of corticomedullary differentiation and a decrease in both kidneys, changes compatible with nephropathy. Palliative treatment was instituted in order to minimize secondary complications of acute kidney injury, however, the patient died. At necropsy, the kidneys were bilaterally reduced in size and histopathological examination revealed the presence of moderate multifocal primitive glomeruli associated with distention of the glomerular space. Clinical evaluation and histopathological lesions were consistent with the diagnosis of congenital renal hypoplasia.

Ultrasonographic detection of interstitial nephritis in a canine fetus

Background: A detailed ultrasound examination of the fetal urinary tract as part of prenatal care is important to detect possibleabnormalities. Early diagnosis can prevent more serious damage such as loss of kidney function. Interstitial nephritis cancompromise renal functionality. Also, acute interstitial nephritis is a frequent cause of acute kidney injury and can becomechronic if not treated. Besides, a renal biopsy can help in the diagnosis and at the staging of the disease. Therefore, thisreport aims to describe the ultrasonographic findings of the renal tissues in a canine fetus affected by interstitial nephritis.Case: Gestational ultrasound evaluations were performed in a female Pug, at the 25th, 45th, and 58th gestational days.Ultrasound examination was performed with a 9.0 MHz linear transducer and a high-resolution digital transducer with afrequency standardized at 17.0 MHz. During the first evaluation, embryonic vesicles were detected and were compatible withthe gestational period. At 45 days of gestation, some abnormalities were observed in the kidneys of one of the fetuses, suchas increased cortical echogenicity, cortical thickening, loss of corticomedullary ratio (1:1), renal pelvis and ureter dilatationby echogenic content. Biparietal and abdominal diameters were also lower than that from the other fetuses, which did notshow abnormalities, being compatible with the estimated gestational age. However, the heart rate was similar among allfetuses. On the 58th day, we observed in the underdeveloped fetus that both kidneys still presented the abnormalities seenpreviously, in addition to the presence of a cystic structure in the right kidney, in the cranial...

Ultrasonographic detection of interstitial nephritis in a canine fetus

Background: A detailed ultrasound examination of the fetal urinary tract as part of prenatal care is important to detect possibleabnormalities. Early diagnosis can prevent more serious damage such as loss of kidney function. Interstitial nephritis cancompromise renal functionality. Also, acute interstitial nephritis is a frequent cause of acute kidney injury and can becomechronic if not treated. Besides, a renal biopsy can help in the diagnosis and at the staging of the disease. Therefore, thisreport aims to describe the ultrasonographic findings of the renal tissues in a canine fetus affected by interstitial nephritis.Case: Gestational ultrasound evaluations were performed in a female Pug, at the 25th, 45th, and 58th gestational days.Ultrasound examination was performed with a 9.0 MHz linear transducer and a high-resolution digital transducer with afrequency standardized at 17.0 MHz. During the first evaluation, embryonic vesicles were detected and were compatible withthe gestational period. At 45 days of gestation, some abnormalities were observed in the kidneys of one of the fetuses, suchas increased cortical echogenicity, cortical thickening, loss of corticomedullary ratio (1:1), renal pelvis and ureter dilatationby echogenic content. Biparietal and abdominal diameters were also lower than that from the other fetuses, which did notshow abnormalities, being compatible with the estimated gestational age. However, the heart rate was similar among allfetuses. On the 58th day, we observed in the underdeveloped fetus that both kidneys still presented the abnormalities seenpreviously, in addition to the presence of a cystic structure in the right kidney, in the cranial...(AU)

Crossed renal ectopia with fusion in a female feline: case report / Ectopia renal cruzada com fusão em uma gata: relato de caso

A 3 year old female feline of mixed breed was sent to the diagnostic imaging sector under suspicion of bleeding due to ovariohysterectomy. An abdominal ultrasonography was performed to confirm the initial suspicion. However, no signs of bleeding were found, instead it was observed that the left renal silhouette had two pelvises and was elongated and larger than normal. The right kidney was not found. Excretory urography was requested to evaluate the condition of the ureters. The final diagnosis was crossed renal ectopia with fusion in an asymptomatic cat with no changes in renal function.(AU)

Uma gata, sem raça definida, com três anos de idade, foi encaminhada para o setor de diagnóstico por imagem sob suspeita de hemorragia devido à ovário-histerectomia. Foi realizada ultrasonografia abdominal para confirmar a suspeita inicial, mas nenhum sinal de hemorragia foi encontrado; visibilizou-se, entretanto, a silhueta renal esquerda alongada, com presença de duas pelves. O rim direito não foi encontrado. Solicitou-se exame de urografia excretora para avaliação de ureteres. O diagnóstico foi de ectopia renal cruzada com fusão em um felino assintomático e sem alterações na função renal.(AU)

Crossed renal ectopia with fusion in a female feline: case report / Ectopia renal cruzada com fusão em uma gata: relato de caso

A 3 year old female feline of mixed breed was sent to the diagnostic imaging sector under suspicion of bleeding due to ovariohysterectomy. An abdominal ultrasonography was performed to confirm the initial suspicion. However, no signs of bleeding were found, instead it was observed that the left renal silhouette had two pelvises and was elongated and larger than normal. The right kidney was not found. Excretory urography was requested to evaluate the condition of the ureters. The final diagnosis was crossed renal ectopia with fusion in an asymptomatic cat with no changes in renal function.(AU)

Uma gata, sem raça definida, com três anos de idade, foi encaminhada para o setor de diagnóstico por imagem sob suspeita de hemorragia devido à ovário-histerectomia. Foi realizada ultrasonografia abdominal para confirmar a suspeita inicial, mas nenhum sinal de hemorragia foi encontrado; visibilizou-se, entretanto, a silhueta renal esquerda alongada, com presença de duas pelves. O rim direito não foi encontrado. Solicitou-se exame de urografia excretora para avaliação de ureteres. O diagnóstico foi de ectopia renal cruzada com fusão em um felino assintomático e sem alterações na função renal.(AU)

Renal dysplasia in dogs: retrospective study (2008-2013) / Displasia renal em cães: estudo retrospectivo (2008-2013)

Background: Renal dysplasia, which has been reported in some dogs and human patients, refers to a developmental disorder of renal parenchyma due to imperfect inductive interaction between the mesonephric duct and the metanephric blastemal. In dogs, the characteristic histological findings on which diagnosis is based include (1) persistent metanephric ducts surrounded by primitive mesenchyme, (2) fetal or immature glomeruli, (3) fetal or immature tubules, and (4) anomalous presence of interstitial fibrous tissue. The aim of this study was to report the major pathological and immunohistochemical features of nine young dogs necropsied with renal dysplasia.Cases: The necropsy files from the Laboratório de Patologia Veterinária (LPV) of the Universidade Federal do Mato Grosso (UFMT) were reviewed between the years 2008 and 2013. Dogs diagnosed with chronic kidney failure and macroscopic and histopathological renal lesions consistent with renal dysplasia were selected. Kidney fragments in paraffin blocks were cut and stained with hematoxylin and eosin and by immunohistochemistry (IHC) using anti-vimentin and anti-cytokeratin monoclonal antibodies. The staining was considered positive for the presence of at least one renal cell marked with brown cytoplasmic staining clear and unambiguous. A total of 787 necropsies of dogs were performed. Of these, 64 had a clinical diagnosis of [...]

Renal dysplasia in dogs: retrospective study (2008-2013) / Displasia renal em cães: estudo retrospectivo (2008-2013)

Background: Renal dysplasia, which has been reported in some dogs and human patients, refers to a developmental disorder of renal parenchyma due to imperfect inductive interaction between the mesonephric duct and the metanephric blastemal. In dogs, the characteristic histological findings on which diagnosis is based include (1) persistent metanephric ducts surrounded by primitive mesenchyme, (2) fetal or immature glomeruli, (3) fetal or immature tubules, and (4) anomalous presence of interstitial fibrous tissue. The aim of this study was to report the major pathological and immunohistochemical features of nine young dogs necropsied with renal dysplasia.Cases: The necropsy files from the Laboratório de Patologia Veterinária (LPV) of the Universidade Federal do Mato Grosso (UFMT) were reviewed between the years 2008 and 2013. Dogs diagnosed with chronic kidney failure and macroscopic and histopathological renal lesions consistent with renal dysplasia were selected. Kidney fragments in paraffin blocks were cut and stained with hematoxylin and eosin and by immunohistochemistry (IHC) using anti-vimentin and anti-cytokeratin monoclonal antibodies. The staining was considered positive for the presence of at least one renal cell marked with brown cytoplasmic staining clear and unambiguous. A total of 787 necropsies of dogs were performed. Of these, 64 had a clinical diagnosis of [...](AU)

Hipoplasia renal em caprino relato de caso / Renal hypoplasia in goat case report

Os rins são órgãos filtradores do conteúdo sanguíneo, em caprinos possuem a forma de feijão e são importantes contribuintes para a manutenção da homeostasia. São órgãos retroperitoniais, então estão localizados fora da cavidade peritoneal, entretanto mais firmemente presos à parede abdominal pela fáscia, vasos e ao peritônio do que os outros órgãos. A hipoplasia é, na maioria dos casos, proveniente de algum fator congênito e caracteriza-se pelo desenvolvimento reduzido ou ausente de um ou ambos os rins, com redução de suas funções. (AU)

The kidneys are filtrating blood content organs that in goats have the form of beans and are important contributors to the maintenance of homeostasis. As retroperitoneal organs, are located outside the peritoneal cavity, though more firmly attached to the abdominal wall by fascia, vessels and peritoneum that other organs. Hypoplasiais, generally, from a congenital factor and is characterized by lower or absent development of one or both kidneys, reducing its functions. (AU)

Hipoplasia renal em caprino – relato de caso / Renal hypoplasia in goat – case report

Os rins são órgãos filtradores do conteúdo sanguíneo, em caprinos possuem a forma de feijão e são importantes contribuintes para a manutenção da homeostasia. São órgãos retroperitoniais, então estão localizados fora da cavidade peritoneal, entretanto mais firmemente presos à parede abdominal pela fáscia, vasos e ao peritônio do que os outros órgãos. A hipoplasia é, na maioria dos casos, proveniente de algum fator congênito e caracteriza-se pelo desenvolvimento reduzido ou ausente de um ou ambos os rins, com redução de suas funções.

The kidneys are filtrating blood content organs that in goats have the form of beans and are important contributors to the maintenance of homeostasis. As retroperitoneal organs, are located outside the peritoneal cavity, though more firmly attached to the abdominal wall by fascia, vessels and peritoneum that other organs. Hypoplasiais, generally, from a congenital factor and is characterized by lower or absent development of one or both kidneys, reducing its functions.

Dioctophyme renale Goeze, 1782 in a cat with a supernumerary kidney / Dioctophyme renale Goeze, 1782 em gata com rim supranumerário

This study reports a case of parasitism by Dioctophyme renale in a supernumerary kidney and abdominal cavity of a female cat in Brazil. The three-year-old cat of indeterminate breed presented abdominal distension and was taken to the University of Contestado Veterinary Hospital in Canoinhas, state of Santa Catarina, since the owner suspected pregnancy. An ultrasound scan did not confirm pregnancy but revealed parasitism in the kidney. This case is worth reporting because domestic cats are rarely hosts of this nematode species.

Relata-se um caso de parasitismo por Dioctophyme renale em rim supranumerário e em cavidade abdominal de um gato do Brasil. Uma fêmea adulta, não castrada, sem raça definida e com aproximadamente três anos de idade, foi encaminhada ao Hospital Veterinário da Universidade do Contestado, em Canoinhas-SC, com aumento de volume abdominal e o proprietário suspeitava de gestação. Após ultrassonografia foi descartada a gestação e foi detectado parasitismo em rim. Como gatos domésticos são considerados hospedeiros incomuns desse parasita, relata-se o presente caso.

Achados patológicos em caninos com displasia renal no Sul do Brasil / Pathological findings in dogs with renal dysplasia in Southern Brazil

Renal dysplasia results from a disturbance which occurs during nephrogenesis. The disease may be unilateral or bilateral, and leads to abnormal kidney differentiation leading to renal failure in young dogs. Several agents, including viruses, can cause the dysplasia till three months after birth, when the early nephron formation of the developing kidney is completed. Eleven renal dysplasia cases were diagnosed in 186 dogs with renal failure of 5,846 dogs necropsied in the Veterinary Pathology Sector, Federal University of Rio Grande do Sul, in the period 2002-2013. Tissue samples collected during necropsy were fixed in 10% formaldehyde and stained with hematoxylin-eosin (HE) and Masson’s trichrome protocol. Upon necropsy, kidneys were pale, smaller than normal, irregular and firm, and presented lower cortex diameter. Some exhibited cysts and whitish, parallel radially arranged striae in the medulla. Primary and secondary renal lesions were observed during histological examination. Primary lesions included fetal glomeruli and tubules, quantitative reduction in glomeruli, adenomatous tubules, and persistence of metanephric ducts. As for secondary lesions, Masson trichrome staining revealed intense interstitial fibrosis in all cases; furthermore, dilation of tubules and of Bowman’s capsules, glomerular atrophy, and glomerulosclerosis were observed. Even though most cases were associated with breed, the results obtained indicate high prevalence of renal dysplasia in mixed-breed dogs, possibly because they were the majority of animals referred for necropsy. Although primary lesions were easily identified using HE, Masson’s trichrome protocol is useful to characterize the extent of fibrosis.

A displasia renal resulta de um distúrbio na nefrogênese, com diferenciação anormal dos rins, podendo ser unilateral ou bilateral, e causa insuficiência renal em cães jovens. Qualquer agente agressor, incluindo vírus, pode causar a lesão até três meses após o nascimento, quando encerra o desenvolvimento embrionário do néfron. Foram diagnosticados 11 casos de displasia renal dentre 186 casos de cães com insuficiência renal de um total de 5.846 cães submetidos à necropsia no Setor de Patologia Veterinária da Universidade Federal do Rio Grande do Sul no período 2002-2013. Amostras teciduais coletadas na necropsia foram fixadas em 10% de formol e coradas com hematoxilina e eosina (HE) e tricrômico de Masson. Na necropsia, os rins estavam pálidos, diminuídos de tamanho, irregulares e firmes, com diâmetro da cortical diminuído. Alguns ainda eram císticos e apresentavam estriações brancacentas paralelas dispostas radialmente na medular. Ao exame histológico os rins exibiam lesões primárias e secundárias. As lesões primárias identificadas foram glomérulos e túbulos fetais, diminuição quantitativa de glomérulos, túbulos adenomatosos e persistência de ductos metanéfricos. Dentre as lesões secundárias, a coloração de tricrômico de Masson evidenciou intensa fibrose intersticial em todos os casos. Além disso, foram observadas dilatação de túbulos e da cápsula de Bowman, atrofia glomerular e glomeruloesclerose. Ainda que a maioria dos casos tenha sido relacionada com linhagens raciais, esse trabalho demonstra uma alta frequência de diagnóstico de displasia renal em cães sem raça definida, possivelmente devido ao fato de que estes representam a maioria dos cães encaminhados ao laboratório. Apesar das lesões primárias serem facilmente identificadas pela coloração de hematoxilina eosina, a coloração de tricrômico de Masson auxilia na identificação da extensão da fibrose.

Achados patológicos em caninos com displasia renal no Sul do Brasil / Pathological findings in dogs with renal dysplasia in Southern Brazil

Renal dysplasia results from a disturbance which occurs during nephrogenesis. The disease may be unilateral or bilateral, and leads to abnormal kidney differentiation leading to renal failure in young dogs. Several agents, including viruses, can cause the dysplasia till three months after birth, when the early nephron formation of the developing kidney is completed. Eleven renal dysplasia cases were diagnosed in 186 dogs with renal failure of 5,846 dogs necropsied in the Veterinary Pathology Sector, Federal University of Rio Grande do Sul, in the period 2002-2013. Tissue samples collected during necropsy were fixed in 10% formaldehyde and stained with hematoxylin-eosin (HE) and Massons trichrome protocol. Upon necropsy, kidneys were pale, smaller than normal, irregular and firm, and presented lower cortex diameter. Some exhibited cysts and whitish, parallel radially arranged striae in the medulla. Primary and secondary renal lesions were observed during histological examination. Primary lesions included fetal glomeruli and tubules, quantitative reduction in glomeruli, adenomatous tubules, and persistence of metanephric ducts. As for secondary lesions, Masson trichrome staining revealed intense interstitial fibrosis in all cases; furthermore, dilation of tubules and of Bowmans capsules, glomerular atrophy, and glomerulosclerosis were observed. Even though most cases were associated with breed, the results obtained indicate high prevalence of renal dysplasia in mixed-breed dogs, possibly because they were the majority of animals referred for necropsy. Although primary lesions were easily identified using HE, Massons trichrome protocol is useful to characterize the extent of fibrosis.(AU)

A displasia renal resulta de um distúrbio na nefrogênese, com diferenciação anormal dos rins, podendo ser unilateral ou bilateral, e causa insuficiência renal em cães jovens. Qualquer agente agressor, incluindo vírus, pode causar a lesão até três meses após o nascimento, quando encerra o desenvolvimento embrionário do néfron. Foram diagnosticados 11 casos de displasia renal dentre 186 casos de cães com insuficiência renal de um total de 5.846 cães submetidos à necropsia no Setor de Patologia Veterinária da Universidade Federal do Rio Grande do Sul no período 2002-2013. Amostras teciduais coletadas na necropsia foram fixadas em 10% de formol e coradas com hematoxilina e eosina (HE) e tricrômico de Masson. Na necropsia, os rins estavam pálidos, diminuídos de tamanho, irregulares e firmes, com diâmetro da cortical diminuído. Alguns ainda eram císticos e apresentavam estriações brancacentas paralelas dispostas radialmente na medular. Ao exame histológico os rins exibiam lesões primárias e secundárias. As lesões primárias identificadas foram glomérulos e túbulos fetais, diminuição quantitativa de glomérulos, túbulos adenomatosos e persistência de ductos metanéfricos. Dentre as lesões secundárias, a coloração de tricrômico de Masson evidenciou intensa fibrose intersticial em todos os casos. Além disso, foram observadas dilatação de túbulos e da cápsula de Bowman, atrofia glomerular e glomeruloesclerose. Ainda que a maioria dos casos tenha sido relacionada com linhagens raciais, esse trabalho demonstra uma alta frequência de diagnóstico de displasia renal em cães sem raça definida, possivelmente devido ao fato de que estes representam a maioria dos cães encaminhados ao laboratório. Apesar das lesões primárias serem facilmente identificadas pela coloração de hematoxilina eosina, a coloração de tricrômico de Masson auxilia na identificação da extensão da fibrose.(AU)