World Small Animal Veterinary Association Renal Pathology Initiative: Classification of Glomerular Diseases in Dogs.

Evaluation of canine renal biopsy tissue has generally relied on light microscopic (LM) evaluation of hematoxylin and eosin-stained sections ranging in thickness from 3 to 5 µm. Advanced modalities, such as transmission electron microscopy (TEM) and immunofluorescence (IF), have been used sporadically or retrospectively. Diagnostic algorithms of glomerular diseases have been extrapolated from the World Health Organization classification scheme for human glomerular disease. With the recent establishment of 2 veterinary nephropathology services that evaluate 3-µm sections with a panel of histochemical stains and routinely perform TEM and IF, a standardized objective species-specific approach for the diagnosis of canine glomerular disease was needed. Eight veterinary pathologists evaluated 114 parameters (lesions) in renal biopsy specimens from 89 dogs. Hierarchical cluster analysis of the data revealed 2 large categories of glomerular disease based on the presence or absence of immune complex deposition: The immune complex-mediated glomerulonephritis (ICGN) category included cases with histologic lesions of membranoproliferative or membranous patterns. The second category included control dogs and dogs with non-ICGN (glomerular amyloidosis or focal segmental glomerulosclerosis). Cluster analysis performed on only the LM parameters led to misdiagnosis of 22 of the 89 cases-that is, ICGN cases moved to the non-ICGN branch of the dendrogram or vice versa, thereby emphasizing the importance of advanced diagnostic modalities in the evaluation of canine glomerular disease. Salient LM, TEM, and IF features for each pattern of disease were identified, and a preliminary investigation of related clinicopathologic data was performed.

Light and electron microscopic analysis of consecutive renal biopsy specimens from leishmania-seropositive dogs.

Canine visceral leishmaniasis frequently causes renal damage that leads to chronic kidney disease. Fifteen dogs seropositive for Leishmania were selected and biopsied before (T0) and 60 days later after (T1) treatment with a specific anti-Leishmania pharmacological agent. Various parameters were selected for evaluating the glomerular and tubulointerstitial damage. At T0, mesangioproliferative and membranoproliferative glomerulonephritis were observed in 6 dogs, chronic glomerulosclerosis in 5, and end-stage kidney in 3; renal tissue from 1 dog was within normal histologic limits. The most frequently observed ultrastructural changes were foot-process effacement, thickening of the basement membranes, and immune deposits. One dog had mesangial immune deposits at T1 that had not been present at T0, so the diagnosis was changed to mesangioproliferative glomerulonephritis. In dogs with end-stage kidney, the number of obsolescent glomeruli and cystic atrophied glomeruli was increased at T1. However, progression of the glomerular lesions was minimal in most dogs. Worsening of tubulointerstitial scores was evident in the dogs with the most severe lesions at the first biopsy. Progression of the tubulointerstitial damage was minimal in the mildly affected dogs, and the interstitial inflammation was abated. In conclusion, renal lesions can progress over a 60-day period in canine leishmaniasis. A longer period between the renal biopsies would be necessary to demonstrate more severe changes. In addition a specific anti-Leishmania treatment could have a significant effect in the early stages of the disease.

Comparison between light and electron microscopy in canine and feline renal pathology: a preliminary study.

The aim of this study is to compare the accuracy and clinical use of light and transmission electron microscopy in detecting the early stages of renal pathologies in domestic animals. We examined 30 samples of renal tissue from cats and dogs referred to the Veterinary Hospital of the Department of Animal Pathology for different systemic diseases. The progressions of the kidney pathologies were classified using the scheme system proposed by the International Renal Interest Society. All samples were submitted for conventional histology and ultrastructural examination. Our study shows that electron microscopy is necessary to complete the histological examinations, especially to define early stages of kidney diseases (minimal changes disease, epithelial tubular pathologies, tubular basement membrane and glomerular basement membrane changes). Electron microscopy can be more accurate in defining the level of focal lesion, and permits discrimination between different clinical and pathological alterations such as fibrillary deposits. In conclusion, transmission electron microscopy associated with clinical, histological, histochemical and immunological examinations, is an essential method for diagnosis and prognosis of renal disease.

European Veterinary Renal Pathology Service: A Survey Over a 7-Year Period (2008-2015).

BACKGROUND: The European Veterinary Renal Pathology Service (EVRPS) is the first Web-based registry for canine renal biopsy specimens in Europe. HYPOTHESIS/OBJECTIVES: The aim was to verify whether differences exist between the clinical and laboratory presentation of dogs with nephropathy according to renal pathological findings, as defined by light and electron microscopy of renal biopsy specimens submitted to EVRPS. ANIMALS: Renal biopsy specimens of dogs were collected from the archive of the service (n = 254). Cases were included if both light and electron microscopy were available (n = 162). METHODS: Renal biopsy specimens were classified based on the morphological diagnoses. Thereafter, they were grouped into 3 disease categories, including immune-complex-mediated glomerulonephritis (ICGN), non-immune-complex-mediated GN (non-ICGN), and renal lesions not otherwise specified (RL-NOS). Differences among morphological diagnoses and among disease categories were investigated for clinical and laboratory variables. RESULTS: Serum albumin concentration was lower in dogs with ICGN than in those with non-ICGN (P = 0.006) or RL-NOS (P = 0.000), and the urine protein-to-creatinine ratio (UPC) was significantly higher in ICGN than in the other 2 disease categories. Regarding morphological diagnoses, albumin was significantly lower in amyloidosis (AMY) and membranous (MGN), membranoproliferative (MPGN) or mixed glomerulonephritis (MixGN) than in minimal change disease, primary (FSGS I) or secondary (FSGS II) focal and segmental glomerulosclerosis and juvenile nephropathies (JN). The UPC was higher in MPGN than in FSGS I and FSGS II. CONCLUSIONS AND CLINICAL IMPORTANCE: Dogs with ICGN, in particular MPGN, had higher protein loss than those with non-ICGN or RL-NOS, leading to more severe hypoalbuminemia. Clinical and laboratory differentiation among dogs with the different morphological diagnoses and among dogs with different disease categories was difficult due to overlapping results.

Effects of Benazepril on Survival of Dogs with Chronic Kidney Disease: A Multicenter, Randomized, Blinded, Placebo-Controlled Clinical Trial.

BACKGROUND: Chronic kidney disease (CKD) is an important cause of morbidity and mortality in dogs. OBJECTIVE: To evaluate the efficacy in prolonging survival and safety of benazepril administration to dogs with CKD. ANIMALS: Forty-nine client-owned dogs with CKD. METHODS: Dogs were randomized to benazepril (0.25 to <0.5 mg/kg) or placebo once daily for up to 2 years in a prospective, multicenter, blinded clinical trial. The primary endpoint variable was the renal survival time, defined as the time from inclusion in the study to the treatment failure endpoint of death or euthanasia or need for administration of parenteral fluids related to renal failure. RESULTS: No benefit of benazepril versus placebo was detected for renal survival time in all dogs; median (95% confidence interval (CI)) survival times were 305 (53-575) days in the benazepril group and 287 (152-not available) in the placebo group (P = .53). Renal survival times were not significantly longer with benazepril compared to placebo for subgroups: hazard ratios (95% CI) were 0.50 (0.21-1.22) with P = .12 for initial urine protein-to-creatinine ratio (UPC) >0.5, and 0.38 (0.12-1.19) with P = .080 for initial UPC >0.5 plus plasma creatinine ≤440 µmol/L. Proteinuria, assessed from the UPC, was significantly (P = .0032) lower after treatment with benazepril compared to placebo. There were no significant differences between groups for clinical signs or frequencies of adverse events. CONCLUSIONS AND CLINICAL RELEVANCE: Benazepril significantly reduced proteinuria in dogs with CKD. Insufficient numbers of dogs were recruited to allow conclusions on survival time.

Factors associated with upper respiratory tract disease caused by feline herpesvirus, feline calicivirus, Chlamydophila felis and Bordetella bronchiseptica in cats: experience from 218 European catteries.

A full history of the management practices and the prevalence of upper respiratory tract disease (URTD) at 218 rescue shelters, breeding establishments and private households with five or more cats was recorded. Oropharyngeal and conjunctival swabs and blood samples were taken from 1748 cats. The prevalences of feline herpesvirus (FHV), feline calicivirus (FCV), Chlamydophila felis and Bordetella bronchiseptica were determined by PCR on swab samples. An ELISA was applied to determine the prevalence of antibodies to B. bronchiseptica. The rates of detection by PCR of each pathogen in the cats in catteries with and without ongoing URTD were, respectively, FHV 16 per cent and 8 per cent; FCV 47 per cent and 29 per cent; C. felis 10 per cent and 3 per cent; and B. bronchiseptica 5 per cent and 1.3 per cent; the seroprevalences of B. bronchiseptica were 61 per cent and 41 per cent, respectively. There was evidence that FHV, FCV and B. bronchiseptica played a role in URTD. The risk factors associated with the disease were less than excellent hygiene, contact with dogs with URTD, and larger numbers of cats in the cattery or household.