Sodium Dodecyl Sulfate Polyacrylamide Gel Electrophoresis of Canine Urinary Proteins for the Analysis and Differentiation of Tubular and Glomerular Diseases

A preliminary investigation was performed to evaluate the use of a new, noninvasive technique for the localization of canine renal lesions by electrophoresis of urinary proteins. Urine specimens from six clinically healthy, nonproteinuric dogs and 12 dogs with persistent proteinuria were examined by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS PAGE). Urine electrophoretic patterns of proteinuric dogs were classified as glomerular (n=4), tubular (n=2), or mixed (glomerular and tubular) (n=6), based on the number and molecular weight of the silver-stained protein bands. Renal tissues from biopsies or necropsies were obtained from eight of the dogs with proteinuric disease. Interpretation of seven of eight electrophoretograms agreed with the histologic interpretation of renal lesions. We concluded SDS PAGE is a potentially valuable technique for detection and localization of renal lesions in dogs with proteinuric disease.     

Progressive Juvenile Glomerulonephropathy in 16 Related French Mastiff (Bordeaux) Dogs

Background: Familial juvenile glomerulonephropathy (JGN) is reported in several breeds of dogs. The mode of inheritance and spectrum of pathological lesions vary among breeds. A progressive JGN was detected in a pedigree of French Mastiff (FM) dogs. Objectives: To describe clinical, laboratory, and histopathologic findings in related FM dogs suffering from progressive JGN and to determine the mode of inheritance of this condition. Animals: Sixteen affected and 35 healthy related FM dogs Methods: FM dogs <24 months of age and diagnosed with chronic kidney disease with evidence of proteinuria entered the study. Clinical, laboratory, histopathologic findings, and pedigree data were recorded. Results: Clinical signs were typical of progressive glomerulopathy with resultant renal failure. Increased blood urea nitrogen, creatinine and total cholesterol concentrations, and proteinuria were found in all patients. Affected dogs had abnormal kidney structure on abdominal ultrasound examination. Histopathologic examination revealed extensive cystic glomerular atrophy, glomerular hypercellularity, and capillary wall thickening without immune complex deposition when tested with immunohistochemistry or immunofluorescence. Electron microscopy did not disclose specific primary glomerular lesions. Mean age at death was 20 months and mean length of survival after diagnosis was 6 months. Both males and females from healthy parents were affected. An autosomal recessive mode of transmission is suspected, but a more complex mode of inheritance cannot be excluded. Conclusions and Clinical Importance: Progressive familial JGN occurs in FM dogs. Characterization of the pathogenesis and mode of inheritance of this disease warrants additional study.     

New form of X-linked dominant hereditary nephritis in dogs

OBJECTIVE: To determine features of a new form of hereditary nephritis (HN) in dogs. ANIMALS: Parents and 16 first-generation offspring (8 males, 8 females). PROCEDURE: Adolescent dogs that developed renal failure were euthanatized and necropsied. Unaffected dogs were monitored until they were at least 2 years old. Studies included light and electron microscopy of kidneys obtained from affected and unaffected dogs and immunolabeling for collagen-IV chains in renal and epidermal basement membranes (BM). The nucleotide sequence of a portion of exon 35 of the COL4A5 gene was determined in genomic DNA isolated from affected and unaffected males. RESULTS: 7 of 8 male and 2 of 8 female offspring had proteinuria and juvenile-onset chronic renal failure, which progressed more rapidly in the males. Labeling for alpha3-alpha6(IV) chains was completely absent in renal BM of affected males and segmentally absent in affected females. Expression of alpha1-alpha2(IV) chains in glomerular BM (GBM) of affected dogs was increased. Labeling for alpha5-alpha6(IV) chains in epidermal BM was absent in affected males and segmental in affected females. Ultrastructural changes characteristic of HN were observed in GBM of affected dogs. The sequence of exon 35 of COL4A5 was normal in affected dogs. CONCLUSIONS: This renal disease is an example of X-linked dominant HN, with typical abnormalities of GBM ultrastructure and alpha(IV) chain expression. CLINICAL RELEVANCE AND IMPLICATIONS FOR HUMAN MEDICINE: Dogs with this naturally acquired progressive renal disease can be used to investigate the pathogenesis and treatment of similar disorders in human beings and dogs.     

Potential role of serum inhibitors of erythropoiesis in the anemia associated with infection, renal disease and malignancy in the dog

Serum from dogs with anemia secondary to infection, malignancy and chronic renal disease was tested for the capacity to inhibit in vitro erythropoiesis. Serum inhibition was found in seven of 10 dogs with infectious diseases, four of 10 dogs with malignant diseases, and two of 10 dogs with chronic renal failure. The results were reproducible with at least three different marrow donor dogs. Serum inhibition did not correlate with decreased packed cell volumes. However, serum inhibition occurred in the two dogs with greatest azotemia suggesting that inhibitors of erythropoiesis are present only in advanced stages of renal failure.     

Serum Lipoprotein Changes in Dogs with Renal Disease

Background

People with renal disease develop a dyslipidemia that contributes to progression of renal injury and development of cardiovascular disease. Lipoproteins in dogs with renal disease have not been investigated.

Hypothesis

Dogs with chronic kidney disease (CKD) have dyslipidemia characterized by increased lower density lipoproteins and decreased high‐density lipoproteins (HDLs). The degree of dyslipidemia is positively correlated with severity of disease, as reflected by serum creatinine concentration.

Animals

Prospective study of client‐owned dogs presented to the Cornell University Hospital for Animals: 29 dogs with confirmed CKD, 5 dogs with nephrotic syndrome (NS), and 12 healthy control dogs presented for routine vaccinations, dental cleaning, or owned by students.

Methods

Lipoprotein electrophoresis was used to quantify relative proportions of the 3 main classes of lipoproteins in canine serum: low‐density lipoproteins (LDL), very low‐density lipoproteins (VLDL), and HDL. Serum cholesterol and creatinine concentrations; urinalysis and urine protein‐to‐creatinine ratio were measured by standard methods.

Results

Dyslipidemia was consistently found in dogs with CKD and NS and was characterized by a decrease in HDL and variable increases in LDL and VLDL. Dogs with NS had a proportionately greater increase in the VLDL fraction, as compared with dogs with CKD.

Conclusion and Clinical Importance

Dyslipidemia similar to that documented in people with renal disease occurs in dogs with CKD, despite serum cholesterol concentrations often being within the reference interval. The contribution of altered lipoproteins to the pathogenesis of renal disease in dogs warrants additional study.     

Primary renal neoplasia of dogs

BACKGROUND: Primary renal tumors are diagnosed uncommonly in dogs. HYPOTHESIS: Signs and survival will differ among different categories of primary renal tumors. ANIMALS: Data were collected from the medical records of 82 dogs with primary renal tumors diagnosed by examination of tissue obtained by ultrasound-guided biopsy, needle aspiration, surgery, or at postmortem examination. METHODS: This was a multi-institutional, retrospective study. RESULTS: Forty-nine dogs had carcinomas, 28 had sarcomas, and 5 had nephroblastomas. The dogs were geriatric (mean 8.1 years; range: 1-17) with a weight of 24.9 kg (range: 4.5-80). Tumors occurred with equal frequency in each kidney with 4% occurring bilaterally. Initial signs included one or more of hematuria, inappetance, lethargy. weight loss, or a palpable abdominal mass. Pain was reported more frequently in dogs with sarcomas (5/28). The most common hematologic abnormalities were neutrophilia (22/63), anemia (21/64), and thrombocytopenia (6/68). Polycythemia was present in 3 dogs and resolved with treatment. Hematuria (28/49), pyuria (26/49), proteinuria (24/50), and isosthenuria (20/56) were the most frequently observed abnormalities on urinalysis. Pulmonary metastases were noted on thoracic radiographs in 16% of dogs at diagnosis. Seventy-seven percent of dogs had metastatic disease at the time of death. Median survival for dogs with carcinomas was 16 months (range 0-59 months), for dogs with sarcomas 9 months (range 0-70 months), and for dogs with nephroblastomas 6 months (range 0-6 months). CONCLUSIONS AND CLINICAL IMPORTANCE: Primary renal tumors in dogs are generally highly malignant with surgery being the only treatment that improves survival.     

Familial protein-losing enteropathy and protein-losing nephropathy in Soft Coated Wheaten Terriers: 222 cases (1983-1997)

Records and pedigrees of Soft Coated Wheaten Terriers (SCWT) with protein-losing enteropathy (PLE) or protein-losing nephropathy (PLN) were studied retrospectively. Criteria for inclusion were defined based on analysis of blood (panhypoproteinemia for PLE, hypoalbuminemia for PLN) and urine (proteinuria for PLN) and histopathologic examination of tissue. Two hundred twenty-two affected dogs (female:male ratio = 1.6, P < .001) were clinically identified. Dogs were diagnosed with PLE earlier (P < .005; mean +/- SD age: 4.7+/-2.6 years, n = 76) than with PLN (6.3+/-2.0 years, n = 84) or with both diseases (5.9+/-2.2 years, n = 62). Clinical signs included vomiting, diarrhea, weight loss, pleural and peritoneal effusions, and less commonly thromboembolic disease. Dogs with PLE generally had panhypoproteinemia and hypocholesterolemia; intestinal lesions included inflammatory bowel disease, dilated lymphatics, and lipogranulomatous lymphangitis. Dogs with PLN generally had hypoalbuminemia, proteinuria, hypercholesterolemia, and azotemia; renal lesions typically showed chronic glomerulonephritis/glomerulosclerosis, and less commonly endstage renal disease. Dogs with combined PLE/PLN had intermediate mean values (P < .001) for serum total protein, albumin, globulin, and cholesterol but had a higher mean urine protein:creatinine ratio than did PLN dogs (P < .05); intestinal and renal lesions in these dogs were similar to those in the other groups. Two dogs had incidental mild renal dysplasia. Pedigree analysis from 188 dogs demonstrated a common male ancestor, although the mode of inheritance is unknown. Both PLE and PLN are common diseases in this small breed population. The prognosis is poor. Compared with previously reported intestinal and renal diseases in dogs, a new, distinctive familial predisposition for both PLE and PLN has been recognized in the SCWT breed.     

Renal amyloidosis in related English foxhounds

Renal amyloidosis was diagnosed in six related English foxhounds from two separate hunting kennels. There was no apparent age or sex predilection. All the dogs had clinical and laboratory findings compatible with renal disease. The onset of clinical signs was acute in all cases with death or euthanasia in five of the six affected dogs occurring within one week of presentation. The remaining dog was treated with diuresis which produced a temporary improvement. Histological examination of renal tissue from affected dogs identified the presence of both glomerular and interstitial amyloid, which was confirmed by immunohistochemical staining to be of the reactive type (amyloid A). There were occasional sclerosed glomeruli or glomeruli with thickened Bowman's capsules, in addition to interstitial and periglomerular infiltration with a predominance of plasma cells and lymphocytes and secondary changes including tubular eosinophilic casts. Renal papillary necrosis was identified in three dogs. One hound had concurrent multicentric lymphoma. Pedigree analysis of the affected dogs revealed that four individuals shared a common great grandsire and that the same dog was the grand-sire of a further case. Pedigree analysis of five additional dogs from one of the kennels, all of which had clinical signs of acute renal failure but from which renal tissue was not available, revealed a close relationship to those foxhounds with confirmed renal amyloidosis.     

MOST DOGS WITH MEDULLARY RIM SIGN ON ULTRASONOGRAPHY HAVE NO DEMONSTRABLE RENAL DYSFUNCTION

The medullary rim sign is a distinct hyperechoic line in the renal medulla parallel to the corticomedullary junction that has been reported in dogs with a variety of renal diseases. To examine the association between medullary rim sign and renal disease, the medical records of thirty-two dogs that had medullary rim sign were reviewed retrospectively. Eighteen dogs (56%) had no evidence of renal dysfunction; 14 (44%) had clinicopathological evidence of renal disease, including 6 (19%) that had hypercalcemic nephropathy. Most dogs (72%) in which medullary rim sign was the only ultrasonographic finding affecting the kidneys had no evidence of renal dysfunction. In contrast, 78% dogs that had medullary rim sign and other renal signs (reduced size, increased medullary echogenicity, and pyelectasia) had renal disease. On the basis of this study, the medullary rim sign appears to be a non-specific ultrasonographic sign; however, the possibility cannot be excluded that is a sentinel sign of subclinical renal disease.     

Population dynamics of inherited copper toxicosis in Dutch Bedlington terriers (1977-1997)

Inherited copper toxicosis in Bedlington terriers was 1st reported in 1975 and the entire Dutch population was examined from 1976 until the present for presence of the disease. To examine the effect on the prevalence of the disease of excluding affected dogs from breeding we have compared 2 time cohorts, the 1st consisting of dogs born from January 1, 1976, to January 1, 1986 (n = 155), and the 2nd of dogs born from January 1, 1990, to January 1, 1997 (n = 195). The diagnosis was made in the 1st cohort by evaluating liver biopsies, and in the 2nd cohort with a DNA marker. The population was also resolved into clusters of related dogs to analyze the familial distribution of the disease in the population and to search for ancient founders of the disease among the ancestors of sick dogs. Forty-six percent of dogs examined between 1976 and 1986 had copper toxicosis. Eleven percent of dogs examined in the 2nd cohort had evidence of disease. This reduction was achieved while maintaining the already limited genetic heterogeneity of the population: the number of clusters and the mean relatedness between the clusters were similar in both time cohorts. The disease was evenly distributed over the clusters of related dogs in both cohorts. All ancestors had contributed to the distribution of copper toxicosis and no specific founders could be identified. This indicates that when the breed was established in The Netherlands, the disease was already highly prevalent in the founding dogs.     

Familial po1ycystic kidnev disease in bull terriers

Polycystic kidney disease was observed in eight related bull terriers. Two dogs died suddenly, two were presented for haematuria, while the remainder were outwardly normal but detected during ultrasonographic screening programmes. A definitive diagnosis was made at either necropsy or using renal ultrasonography, although affected dogs also had abnormal urinalyses with haematuria, proteinuria, cast formation and sometimes bacterial infection. Valvular heart disease was detected clinically or at necropsy in all the affected dogs. The presence of polycystic kidney disease in several related dogs suggests that this condition is familial. The disease has clinical and pathological similarities with autosomal dominant polycystic kidney disease of humans.     

A multicentric retrospective study of serum/plasma urea and creatinine concentrations in dogs using univariate and multivariate decision rules to evaluate diagnostic efficiency

BACKGROUND: Urea and creatinine are the most frequently used indirect markers in plasma and serum of glomerular filtration rate in dogs. Both have been shown to lack sensitivity but their diagnostic efficiency for the diagnosis of kidney disease has been minimally investigated. OBJECTIVE: The purpose of this retrospective study was to investigate the influence of possible factors of variation on both analytes and to determine whether specific decision rules should be drawn up for subpopulations of dogs. METHODS: The results of urea and creatinine measurements, breed, sex, age, and health status (healthy, renal disease, or nonrenal disease) of 3822 dogs were collected from the archives of 5 veterinary clinics. Data were analyzed with univariate and multivariate decision rules with and without adjustment. RESULTS: There were significant effects and interactions of almost all of the sources of variation. Slight improvements in diagnostic efficiency were obtained by adjusting the decision rules to these sources of variations. Univariate decision rules gave approximately the same diagnostic efficiency for urea and creatinine concentrations, with sensitivity and specificity in the range of 70% and 90%, respectively, using the upper limit of the reference interval as the threshold value. Multivariate decision rules provided only minor improvements in diagnostic efficiency. CONCLUSION: Simultaneous measurement of both urea and creatinine is of limited diagnostic value over the analysis of a single variable. Creatinine is the preferred analyte as it is affected by fewer extrarenal factors of variation.     

A retrospective study of clinical signs and epidemiology of chronic valve disease in a group of 207 Dachshunds in Poland

Background

Chronic mitral valve disease is frequently seen in the Dachshund. Dachshunds (n=207) made up 11.73% of the dogs admitted to the Cardiology Service at the Small Animal Clinic, Warsaw University of Life Sciences, Poland (first visits only).

Results

Of these, 35 dogs had no clinically detectable heart disease while 172 had chronic valve disease with the mitral valve affected most often (130 dogs), both mitral and tricuspid valves infrequently (39 dogs) and rarely the tricuspid valve (3 dogs). Males were affected more frequently than females and the average age of dogs with chronic valve disease was 11.9 years for females and 11.3 years for males. A majority of the diseased Dachshunds were classified as ISACHC 2 (79), followed by ISACHC 1 (60). Most frequent clinical signs noted by owners included coughing, exercise intolerance, dyspnea and tachypnea. Heart murmurs were generally louder with increased disease severity; however there were 20 dogs in the ISACHC 1 group with no audible heart murmurs. The most frequent electrocardiographic abnormalities included an increased P wave and QRS complex duration, increased R wave amplitude and tachycardia. With increased disease severity, echocardiography revealed an increase in heart size. A higher ISACHC class was related to increased heart size (based on echocardiography) and increased percentage of patients exhibiting enlargement of both left atrium and left ventricle (based on radiography).

Conclusions

The Dachshund is often affected by chronic mitral valvular disease with a late onset of associated clinical signs and few cardiac complications.     

A variant form of neuronal ceroid lipofuscinosis in American bulldogs

Neuronal ceroid lipofuscinoses (NCLs) are inherited neurodegenerative diseases characterized by accumulations of autofluorescent lipopigments within cells of the nervous system. Nine related American Bulldogs demonstrated dysmetria in all limbs and paraparesis. Nonambulatory tetraparesis was observed only in the later stages of the disease. The clinical signs developed between 1 and 3 years of age and were slowly progressive over several years, which is inconsistent with most reports in other breeds. Results from blood tests for 8 different lysosomal storage diseases on 4 affected and 6 related but unaffected dogs were negative. Four affected dogs were euthanized and histopathologic examinations showed diffuse accumulations of periodic acid-Schiff-positive inclusions in neurons and axonal spheroids along the entire neuraxis and retinae. The most severe lesions were in the brainstem proprioceptive nuclei and spinal cord, consistent with clinical signs. The storage material was autofluorescent and immunohistochemically positive for products of lipid peroxidation. Ultrastructural analysis was consistent with NCL. Pedigree analysis supports an autosomal-recessive mode of inheritance. NCL has not been previously reported in the American Bulldog and these findings suggest a variant form of the canine disease.     

Proteinuria as an indicator of early renal disease in bull terriers with hereditary nephritis

A group of non-azotaemic bull terriers from families with hereditary nephritis had significant subclinical renal disease. Of the renal function tests carried out, proteinuria, almost exclusively albumin, was a reliable and early indicator of glomerular abnormality. While 24-hour urinary protein excretion (24 UPE) in the bull terriers was significantly higher than in a group of normal dogs of other breeds, urinary protein excretion (UPE) was also significantly higher when measured by simple single sample tests such as the urinary protein to urinary creatinine ratio (UP/C). UPE in bull terriers was correlated with increasing age, in contrast to lack of correlation in the normal dogs. The degree of proteinuria in affected bull terriers from which renal biopsies were taken correlated with the severity of histopathological changes which mainly affected glomeruli. Light microscopic examination revealed segmentally thickened glomerular and tubular basement membranes, thickened Bowman's capsules and adhesions between glomerular capillaries and Bowman's capsules. Other renal function tests were performed but failed to detect subclinical disease. It is suggested that hereditary nephritis (HN) in bull terriers is similar to that seen in samoyeds, dober-mann pinschers and humans.     

Ultrasound-guided percutaneous drainage for treatment of pyonephrosis in two dogs

Pyonephrosis refers to suppurative destruction of the parenchyma of the kidney with complete or nearly complete loss of renal function. In dogs, nephrectomy is still the most common treatment for pyonephrosis; however, in the present report, a method for percutaneous ultrasound-guided drainage of the renal pelvis in dogs with pyonephrosis that does not require local or general anesthesia was described, and results of the procedure in 2 dogs were reported. Briefly, dogs were positioned in lateral recumbency with the affected side up, and skin overlying the affected kidney was aseptically prepared. The dilated renal pelvis was punctured percutaneously, under ultrasound guidance, with a 22-gauge needle, and a sample of material was obtained for analysis. The needle was then replaced with an IV catheter, and as much pus as possible was removed from the renal collecting system. A povidone iodine solution was then used to lavage the renal pelvis. Ultrasound-guided drainage and lavage of the renal pelvis was repeated daily until the renal pelvis was so small that it could no longer be punctured. Both dogs recovered and were reported by the owners to be healthy after the procedure.     

Initial evaluation of canine urinary cystatin C as a marker of renal tubular function

Objectives : To evaluate the performance of a particle‐enhanced turbidimetric assay for measuring canine urinary cystatin C and to investigate if the urinary cystatin C to creatinine ratio is higher in dogs with renal disease than in non‐renal disease dogs. Methods : Urinary cystatin C was measured by particle‐enhanced turbidimetric assay using an avian antihuman cystatin C antibody and the performance of this assay was evaluated. Clinical relevance was tested in 46 dogs that were divided into three groups: healthy dogs (n=14), non‐renal disease dogs (n=17) and dogs with renal disease (n=15). Results : The assay was linear (R2=0·99) and precise (mean intra‐ and inter‐assay coefficients of variation were 2·3 and 2·9%, respectively). The recovery was 111·5% and the limit of blank was 0·02 mg/L. Urinary cystatin C and urinary cystatin C to creatinine ratio differed significantly (P<0·001) between the three cohorts of dogs. Clinical Significance : Measurement of cystatin C by particle‐enhanced turbidimetric assay performed with high precision and linearity. This assay can be processed on automated clinical chemistry analysers making it widely available to commercial laboratories. Urinary cystatin C to creatinine ratio can differentiate dogs with renal disease from dogs without renal disease. These preliminary results suggest that urinary cystatin C to creatinine ratio is a promising marker for evaluating renal tubular function.     

Clinicopathologic findings and outcome in dogs with infective endocarditis: 71 cases (1992-2005)

OBJECTIVES: To evaluate clinical, laboratory, and necropsy findings in dogs with infective endocarditis (IE). DESIGN: Retrospective case series. ANIMALS: 71 dogs with possible or definite IE. PROCEDURES: Medical records were reviewed for signalment, clinical features, and results of clinicopathologic testing and diagnostic imaging. Yearly incidence and the effect of variables on survival were determined by use of survival curve analysis. RESULTS: The overall incidence of IE was 0.05%. Most affected dogs were of large breeds, and > 75% were older than 5 years. The aortic valve was affected in 36 of the 71 (51%) dogs, and the mitral valve was affected in 59%. Lameness caused by immune-mediated polyarthritis, septic arthritis, or peripheral arterial thromboembolism was observed in 53% of the dogs. Neurologic complications were diagnosed in 17 of 71 (24%) dogs. Thromboembolic disease was suspected in 31 of 71 (44%) of dogs. The mortality rate associated with IE was 56%, and median survival time was 54 days. Factors negatively associated with survival included thrombocytopenia, high serum creatinine concentration, renal complications, and thromboembolic complications. CONCLUSIONS AND CLINICAL RELEVANCE: A diagnosis of IE should be suspected in dogs with fever, systolic or diastolic murmur, and locomotor problems. Dogs with thrombocytopenia, high serum creatinine concentration, thromboembolism, or renal complications may have a shorter survival time.     

A MACROSCOPIC AND RADIOLOGIC INVESTIGATION OF DENTAL DISEASES OF THE DOG

The type and frequency of dental diseases and disorders were determined in 162 randomly selected dogs available for necropsy. There were 82 males and 80 females ranging in age from seven months to 14 years. There were 150 purebred dogs (50 different breeds) and 12 mongrels. Only four breeds were represented by ten individuals or more: Poodles (Miniature and Toy), German Shepherds, Dachshunds, and Boxers. The oral cavity was examined macroscopically, and missing teeth, dental caries, dental calculus (tartar), and gingival epulides were recorded as to frequency and distribution. After macroscopic examination of the oral cavity, the head of each dog was sawed at the midline, fixed in formalin, and radiographed. The frequency, severity, and distribution of marginal periodontitis, periapical destruction, and root resorption were recorded. The most frequently noted disease was periodontitis, which increased in frequency and severity with increasing age of the dogs. The disease varied markedly among and within different breeds. Small dogs were more often affected with periodontitis than large dogs. Periapical destruction was a common finding. Caries and root resorption were less common. Missing teeth was a frequent disorder regardless of age. Most of the dogs had dental calculus.