Polycystic kidney disease in a cat

Bilateral polycystic kidney disease was diagnosed in a 3-year-old female Persian cat. An elevation of blood urea nitrogen, serum creatinine levels, and serum phosphorus were the only abnormalities found with serial serum chemical and urine analyses. Intravenous urography showed radiolucent areas in both kidneys. An attempted renal biopsy produced only fluid but no kidney tissue. Necropsy and histological findings confirmed a diagnosis of polycystic kidney disease.     

CROSSED RENAL ECTOPIA WITH FUSION IN A CAT

In humans, crossed renal ectopia is a rare, usually asymptomatic, congenital malpositioning of the kidneys, involving wandering of one or both embryonic kidneys across the midline and usually fusion with its contralateral partner. This is the first report of crossed renal ectopia in the cat. A 7-year-old, neutered male cat was presented with polyuria, polydipsia, and a palpable abdominal mass. Diagnostic investigations, including clinical pathology, survey and contrast radiography, and ultrasonography, confirmed the presence of an ectopic left kidney fused with an orthotopic right kidney, with concurrent renal failure and hypertension. Many features of crossed renal ectopia in this cat are similar to those described in humans, however the vascular supply, the presence of renal failure, and the axial rotation of the fused kidney are atypical.     

Proximal ureteral ectopia causing hydronephrosis in a kitten

A 2-month-old, female cat was presented for abdomen dilation. The patient was undernourished, and severe left hydronephrosis was diagnosed after clinical, ultrasonographical and radiographical examination. Although pyelography was performed in order to visualise the ureteral course, surgery was necessary to reach a final aetiological diagnosis and treatment. At gross examination, the left ureter crossed the renal capsula at the level of the caudal renal pole, and the subcapsular ureteral segment was markedly dilated. Distal to the renal capsula, the left ureter was very thin when compared to the right. The parenchyma of the left kidney, as suggested by ultrasonographical evaluation, was extremely reduced in thickness. An ureteronephrectomy was performed. Histopathological evaluation revealed glomerular sclerosis and diffuse parenchymal fibrosis. Severe hydronephrosis derived from an altered renal pelvic anatomy and abnormal ureteral course determining functional stenosis. Diagnosis of congenital anomaly before development of complications such as hydronephrosis could have allowed a surgical renal capsulectomy and obstruction relief. To the author's knowledge, this is the first report of severe hydronephrosis associated to altered renal pelvic anatomy and proximal ureteral ectopia in cat.     

Unilateral improvement in glomerular filtration rate after permanent drainage of a perinephric pseudocyst in a cat

A 12-year-old, 6 kg, castrated male Siamese-cross cat was referred for investigation of an abdominal mass. The cat was found to have a left perinephric pseudocyst (PNP), accompanied by azotemia, with a small right kidney detected on ultrasound. Glomerular filtration rate (GFR) was determined by renal scintigraphy and was found to be low, with the left kidney contributing 64% of the total GFR. Percutaneous ultrasound-guided drainage of the PNP did not improve the GFR, and fluid reaccumulated within a short period of time. Laparoscopic fenestration of the cyst capsule was performed to allow for permanent drainage. The PNP did not recur, renal values progressively improved, and 8 months after the capsulotomy the GFR of the left kidney had increased by 50%, while renal function remained static on the right side.     

DOPPLER ULTRASONOGRAPHIC ESTIMATION OF RENAL AND OCULAR RESISTIVE AND PULSATILITY INDICES IN NORMAL DOGS AND CATS

Resistive index (RI) and pulsatility index (PI) are indirect measurements of blood flow resistance that may be used to evaluate vascular changes in renal and ophthalmologic diseases. To our knowledge, no reports are available describing values for renal and ocular PI index in the unsedated dog and ocular RI and PI indices in the unsedated cat. The purpose of this study was to measure normal values for both intrarenal and ocular RI and PI within the same subject in unsedated clinically normal dogs and cats. Twenty-seven dogs and 10 cats were considered healthy by means of physical examination, CBC, biochemical profile, urinalysis, and ultrasonography. Systolic blood pressure was measured by Doppler ultrasonography. Intrarenal and ocular arteries were scanned by pulsed Doppler ultrasonography to calculate RI and PI. No significant differences were noted between the values obtained for the right vs. the left kidney and eye. The upper values of these indices were calculated as mean+2 standard deviations resulting in 0.72 and 1.52 for dog renal RI and PI; 0.7 and 1.29 for cat renal RI and PI; 0.76 and 1.68 for dog ocular RI and PI; and 0.72 and 1.02 for cat ocular RI and PI.     

Avulsion of the left renal artery following blunt abdominal trauma in a dog

A two-year-old, male, crossbreed dog was presented three days after being involved in a motor vehicle accident. Survey radiographs showed multiple pelvic fractures and poor intraperitoneal and retroperitoneal contrast. Ultrasound indicated the left kidney to be hypoperfused, and a thrombus was visible at the origin of the left renal artery. Ultrasound-guided fine needle aspiration confirmed that free fluid visible in the retroperitoneal and peritoneal spaces was blood. No improvement was seen in the renal perfusion over a 43 hour period, and the intestinal hypomotility worsened over this time. The haemoperitoneum and the haemoretroperitoneum both resolved ultrasonographically within this 43 hour period. Surgery confirmed an avulsion of the left renal artery approximately 10 mm from its origin on the aorta and an avulsion of the left ureter at the ureteropelvic junction. An ureteronephrectomy was performed on the left kidney and the dog recovered uneventfully.     

Dilated ureters, renal dysplasia, and chronic renal failure in an African elephant (Loxodonta africana)

An ultrasonographic reproductive health examination of a 26-yr-old female African elephant (Loxodonta africana) revealed bilateral ureteral wall thickening and dilatation. On ultrasonographic examination, the bladder and both ureters were normal near the trigone; however, the cranial-most aspect of each ureter was dilated and thickened for a length of 30-50 cm. The same month, elevated blood creatinine (3.0 mg/dl), and urine protein-creatinine ratio (4.0) were observed. Chronic renal failure was diagnosed based on these abnormalities, and the persistent ureteral dilatation was seen on subsequent ultrasound examinations. Complete blood cell counts, serum chemistries, and urinalyses remained relatively unchanged until 24 mo after diagnosis, at which time azotemia, hypophosphatemia, and hypercalcemia (including elevated ionized calcium) developed. Hydronephrosis of both kidneys and prominent sacculation of the left ureter were noted on ultrasonographic examination. Lethargy, ventral edema, and oral mucosal ulceration acutely developed 30 mo after diagnosis. Although blood urea nitrogen remained elevated, creatinine, total calcium, and ionized calcium returned to within reference ranges at that time. Due to rapid clinical decline and grave prognosis, humane euthanasia was elected. Bilateral ureteral dilatation, dysplasia of the right kidney, and chronic nephritis of the left kidney were identified postmortem.     

Sarcomatoid renal cell carcinoma with scant epithelial components in an Angora cat

CASE HISTORY: A 6-year-old, neutered, female Angora cat presented with a history of lethargy and anorexia for 2 months and a clinically palpable and gradually enlarging, solid mass in the abdominal cavity extending from the last costal arch to the pelvic cavity.

CLINICAL FINDINGS: Examination of the cat revealed jaundice, dehydration and hypothermia. Haematological manifestations included lymphopenia and substantial decrease in haematocrit value. Biochemical analysis of the blood revealed hypoglycaemia, three-fold elevated blood urea nitrogen values, increased level of serum aspartate aminotransferase and increased total bilirubin while the creatinine level was normal. Ultrasonographic examination of the abdomen showed a disrupted and large hypoechoic area around the left kidney. The cat was anaesthetised and the left kidney was removed, but the cat died following surgery.

PATHOLOGICAL FINDINGS: On post-mortem examination, the left kidney was markedly enlarged and both the cortical and medullary parenchyma were replaced by confluent, multilobulated, pale tan-white, firm nodular masses protruding above the capsular surface. Metastasis was not observed. Cytological examination revealed a population of spindle-shaped cells of variable size, with abundant coarse chromatin and occasionally prominent nucleoli. Initial sections of the kidney were indicative of undifferentiated sarcoma confirmed by immunohistochemistry revealing vimentin-positive and cytokeratin-negative results in all tumour tissues. Additional sections showed very small amounts of both cytokeratin-positive and vimentin-positive areas.

DIAGNOSIS: Sarcomatoid renal cell carcinoma (SRCC) with scant epithelial components originating from left kidney.

CLINICAL RELEVANCE: Clinical and pathological features were similar to those of human SRCC, even though there was no evidence of metastases. Immunohistochemistry for vimentin and cytokeratin may be useful for definitive diagnosis of renal cell carcinoma with sarcomatoid differentiation, although staining of sections from several different parts of the tumour may be necessary. When a primary renal tumour is presented, SRCC should be considered as this diagnosis may influence treatment protocols and the clinical outcome.     

Scintigraphic, sonographic, and histologic evaluation of renal autotransplantation in cats.

OBJECTIVE: To determine scintigraphic, sonographic, and histologic changes associated with renal autotransplantation in cats. ANIMALS: 7 adult specific-pathogen-free cats: 5 males, 2 females, 1 to 9 years old. PROCEDURE: Renal autotransplantation was performed by moving a kidney (5 left, 2 right) to the left iliac fossa. Before and at multiple times after surgery, for a total of 28 days, cats were evaluated by B-mode and Doppler ultrasonography, scintigraphy, and renal biopsy. RESULTS: By 24 hours after surgery, a significant decrease (42%) in mean glomerular filtration rate (GFR) and an increase in mean renal size (81% increase in cross-sectional area) were evident in the transplanted kidney, compared with preoperative values. By postsurgery day 28, reduction in GFR was 23%. Significant changes in renal blood flow velocity were identified in both kidneys. Consistent changes in resistive index or pulsatility index for either kidney could not be identified. When all postoperative histologic data were combined, the histologic score, indicating degree and numbers of abnormalities detected, for the transplanted kidney was significantly higher than that for the control kidney. CONCLUSIONS: Significant changes in renal function, size, and histologic abnormalities develop secondary to acute tubular necrosis in cats after uncomplicated renal autotransplantation. CLINICAL RELEVANCE: Evaluation of renal size and function may be of benefit for clinical evaluation of feline renal transplant patients, whereas measurement of the resistive index may be of little clinical value.     

Oral masses in two cats

Incisional biopsies from the oral cavity of 2 adult cats were submitted for histological investigation. Cat No. 1 showed a solitary well-circumscribed neoplasm in the left mandible. Cat No. 2 demonstrated a diffusely infiltrating neoplasm in the left maxilla. Both tumors consisted of medium-size epithelial cells embedded in a fibrovascular stroma. The mitotic index was 0 to 1 mitosis per high-power field. The epithelial cells showed an irregular arrangement forming nests or streams in cat No. 1, whereas a palisading growth was noted in cat No. 2. Both tumors, especially that of cat No. 1, showed multifocal accumulations of amyloid as confirmed by Congo red staining and a distinct green birefringence under polarized light, which lacked cytokeratin immunoreactivity as well as and AL and AA amyloid immunoreactivity. In addition, the amyloid in cat No. 2 was positive for the odontogenic ameloblast-associated protein, formerly termed APin. In sum, both cats suffered from an amyloid-producing odontogenic tumor, but their tumors varied with respect to morphology and type of amyloid produced.     

Generalized nodular dermatofibrosis in the absence of renal neoplasia in an Australian Cattle Dog

A 13-year-old, spayed, female Australian Cattle Dog had at least a 10-year history of numerous subcutaneous nodules for which fine-needle aspiration and cytologic evaluation were nondiagnostic. Abdominal ultrasound 3.5 months before necropsy detected a small left kidney but no cysts or neoplasms. At gross necropsy, innumerable, firm, round to oval, white, 0.25 to 2 cm masses were detected throughout the subcutaneous tissues of the axial and appendicular skeleton, epimysium of numerous muscles, and parietal peritoneum of the lateral abdominal body wall. The left kidney was approximately half the size of the right, and there was severe bilateral renal medullary (papillary) necrosis. Histologically, the subcutaneous nodules were well-demarcated masses of mature, hypocellular collagen that were consistent with previous reports of nodular dermatofibrosis and renal cystadenomas or cystadenocarcinomas. In addition to diffuse acute medullary necrosis, both kidneys were affected by severe chronic lymphoplasmacytic interstitial nephritis. This is the first known report of nodular dermatofibrosis in a dog without renal cysts, cystadenoma, or cystadenocarcinoma.     

Mitotane (o, p'-DDD) treatment in a cat with hyperadrenocorticism

An 11-year-old male castrated Persian cat with spontaneous hyperadrenocorticism was presented. Both adrenals were grossly enlarged and calcified. A diagnosis of pituitary-dependent hyperadrenocorticism was made. Signs of hyperadrenocorticism resolved with long-term mitotane treatment. Concurrent diabetes mellitus resolved after 220 days of therapy. No severe adverse drug reactions were noted.     

Progesterone secreting adrenal mass in a cat with clinical signs of hyperadrenocorticism

A 7-year-old 7-kg (16-lb) neutered male Himalayan cat had nonpruritic progressive alopecia of 9 months' duration. The cat had hyperglycemia and glucosuria. Physical examination revealed complete alopecia along the abdomen, inguinal area, medial and caudal areas of the thighs, ventral area of the thorax, and axilla. Clinical signs were consistent with endocrine-induced alopecia and hyperadrenocorticism, however, results of diagnostic tests (ACTH stimulation and low-dose dexamethasone suppression) were not supportive of hyperadrenocorticism. Abdominal ultrasonography revealed a mass cranial to the left kidney. Blood samples were obtained before and after ACTH stimulation to measure sex hormone concentrations. Analysis revealed markedly high blood progesterone concentrations before and after ACTH stimulation. An adrenalectomy was performed and histologic examination of the mass revealed a well-differentiated adrenocortical carcinoma. The right adrenal gland could not be viewed during surgery and was assumed to be atrophic. Following surgery, the hyperglycemia and glucosuria resolved. Within 4 months of surgery, the hyperprogesteronemia had resolved, and at 12 months the cat's coat quality appeared normal. Findings suggest that cats with signs of hyperadrenocorticism should be evaluated not only for abnormal cortisol concentrations, but also for sex hormone abnormalities.     

Idiopathic renal haematuria in an Egyptian Arabian stallion

A 17-year-old Egyptian Arabian stallion was presented for haematuria and blood clots in the urine of 4 days’ duration. During micturition, haematuria was noted mid-stream with passage of blood clots occurring at the end of urination. Physical examination findings were unremarkable aside from pale mucous membranes. Cystoscopic examination revealed intermittent passage of frank blood (with clots) from the left ureteral orifice compared to grossly normal-appearing urine issuing from the right ureteral orifice. Transcutaneous ultrasonographic evaluation of the right kidney yielded normal findings while the left kidney exhibited pyelectasia, a decreased cortico-medullary ratio, and markedly increased echogenicity of the renal pelvis. Diagnosis of idiopathic renal haematuria was confirmed at necropsy.     

Neosporosis in cats

Six cats (Nos. 1-6) were inoculated intramuscularly with (1 x 10(6)) and orally (5 x 10(5)) tachyzoites of Neospora caninum. Three (Nos. 1-3) of the six cats were given 40 mg/kg methylprednisolone acetate 7 days before and on the day of inoculation with N. caninum tachyzoites, and three cats (Nos. 4-6) were not given methylprednisolone acetate. Two of the cats (cat Nos. 1 and 2) given methylprednisolone acetate died suddenly. Cat No. 1 died 8 days post-inoculation, and cat No. 2 died 16 days post-inoculation. Cat No. 3 was euthanatized 21 days post-inoculation. Cat No. 1 had lesions of gram-positive bacterial septicemia. Necrotizing encephalitis, myelitis, disseminated skeletal muscle necrosis, hepatic necrosis, interstitial pneumonia, and renal tubular necrosis were the main lesions in cat Nos. 2 and 3. The cats that were not given methylprednisolone acetate remained clinically normal except for slight weight loss in cat No. 6. All three of these cats were euthanatized 55 days post-inoculation. Mild myositis and encephalitis were noted on microscopic examination of tissues from these three cats. Neuromuscular lesions were not seen in six control cats (Nos. 7-12) not inoculated with N. caninum and euthanatized 21 or 22 days after administration of the first two doses of methylprednisolone acetate (40 mg/kg), given at a weekly interval.     

Bilateral renal ischemia as a model of acute kidney injury in cats

The objective of this study was to evaluate the effect of 1h, bilateral, warm ischemia-reperfusion kidney injury as a model of acute kidney injury in the cat. Four adult healthy cats underwent 60 min of bilateral, in vivo renal warm ischemia; three cats were sham operated controls. Kidney function was evaluated with creatinine and BUN concentration, urine protein: creatinine, and glomerular filtration rate. Post-reperfusion endothelin and renin was measured by ELISA and RT-qPCR. Blood pressure (BP), platelet count, and platelet aggregation were monitored. Renal biopsy specimens were evaluated histopathologically. There was significant reduction in renal function characterized by severe azotemia and proximal tubular brush border loss. Changes in renin or endothelin gene expression or serum concentration were not detected. No changes were detected in BP. Platelet count and hematocrit decreased markedly after ischemia and reperfusion. Sixty minutes bilateral renal ischemia is an effective model for acute renal injury.     

ULTRASONOGRAPHIC EVALUATION OF RENAL AUTOGRAFTS IN NORMAL CATS

The purpose of this study was to determine changes in resistive index (RI) and renal size that occur in normal feline kidney autografts in the immediate post-transplant period. Qualitative changes in renal parenchymal echogenicity and pelvic dilation were also noted, although this was not a major focus of the study. Fourteen domestic short-haired cats underwent bilateral nephrectomies followed by an autograft of the right kidney to either the aorta or external iliac artery. Due to post-operative complications, only nine of these cats completed the study. Ultrasonographic determination of the RI and renal size was made before transplantation and on days 1, 4, 7, 10, and 13 following transplantation. No significant changes in renal RI were identified during the study. Renal size increased significantly, peaking at 63% above baseline on day 7, and stayed elevated at 50% above baseline on day 13. There was no evidence of rejection or other abnormalities found on histologic evaluation of the transplanted kidneys. It was concluded that the RI of normal feline renal autografts does not significantly change in the immediate post-operative period. However, significant renal enlargement, likely due to a combination of post-operative edema and hypertrophy, does occur. This study provides baseline information for comparison with feline allografts in the immediate post-transplant period.     

Chronic renal failure in an English bull terrier with polycystic kidney disease

An entire female English bull terrier, aged five years and one month, was diagnosed with polycystic kidney disease by renal ultrasonography. It had thickening and abnormal motion of the mitral valve on 2D and M mode echocardiography, and left ventricular outflow tract obstruction, characterised by turbulence in the left ventricular outflow tract and elevated aortic blood flow velocity, detected by colour flow and spectral Doppler echocardiography, respectively. Two years later, haematology, serum biochemistry and urinalysis data suggested the presence of compensated renal failure. The dog was euthanased at 10 years and eight months of age, with haematology, serum biochemistry and urinalysis data Indicating decompensated chronic renal failure. Postmortem examination confirmed polycystic kidney disease, chronic renal disease, mitral and aortic valvular myxomatous degeneration, and mixed mammary neoplasia. This case demonstrates that bull terriers with polycystic kidney disease may develop associated chronic renal failure.     

Segmental aplasia of the uterine horn with ipsilateral renal agenesis in a cat

A nine-month-old domestic short haired cat was admitted with the history of acute vomiting, depression and shivering. Abdominal ultrasonography revealed minimum enlargement of the right uterine horn filled with anechoic fluid. On excretory urography, functionally and anatomically normal, enlarged left kidney was found, but right kidney was absent. It was preliminary diagnosed as hydrometra with right renal agenesis. Aiming at the correction of hydrometra, we performed ovariohysterectomy. During spaying, we found a missing segment of distal part of the right uterine horn and absence of ipsilateral kidney and ureter. Compressed uterine structure and segmental aplasia of right uterine horn were found in histopathological investigation. Taken together, it was diagnosed as a segmental aplasia of uterine horn with ipsilateral renal agenesis.