Diagnosis and treatment of a congenital portosystemic shunt in a ferret (Mustela putorius furo).

A 3-year-old female neutered ferret presented with progressive weight loss was diagnosed with portosystemic shunting based on increased fasting bile acids, rectal ammonia tolerance testing and advanced imaging. Ammonia reference values were determined in 16 healthy ferrets. A congenital extrahepatic spleno-caval shunt was visualised with ultrasonography and CT angiography of the abdomen. Complete surgical shunt closure by suture ligation was performed, without clinical improvement after surgery. Euthanasia was elected 4 months postoperatively because the clinical condition deteriorated. This is a case report of advanced diagnostics and surgical treatment of a congenital extrahepatic portosystemic shunt in a ferret, demonstrating rectal ammonia tolerance testing and imaging as feasible techniques for the diagnosis.

Secretion and uptake of copper via a small copper carrier in blood fluid.

Studies with Wilson disease model mice that accumulate excessive copper, due to a dysfunctional ATP7B "copper pump" resulting in decreased biliary excretion, showed that the compensatory increase in urinary copper loss was due to a small copper carrier (∼1 kDa) (SCC). We show here that SCC is also present in the blood plasma of normal and Wilson disease model mice and dogs, as determined by ultrafiltration and size exclusion chromatography (SEC). It is secreted by cultured hepatic and enterocytic cells, as determined by pretreatment with 67Cu nitrilotriacetate (NTA) or nonradioactive 5-10 µM Cu-NTA, and collecting and examining 3 kDa ultrafiltrates of the conditioned media, where a single major copper peak is detected by SEC. Four different cultured cell types exposed to the radiolabeled SCC all took up the 67Cu at various rates. Rates differed somewhat when uptake was from Cu-NTA. Uptake of SCC-67Cu was inhibited by excess nonradioactive Cu(I) or Ag(I) ions, suggesting competition for uptake by copper transporter 1 (CTR1). Knockout of CTR1 in fibroblasts reduced uptake rates by 60%, confirming its participation, but also involvement of other transporters. Inhibitors of endocytosis, or an excess of metal ions taken up by divalent metal transporter 1, did not decrease SCC-67Cu uptake. The results imply that SCC may play a significant role in copper transport and homeostasis, transferring copper particularly from the liver (but also intestinal cells) to other cells within the mammalian organism, as well as spilling excess into the urine in copper overload-as an alternative means of copper excretion.

Quantification of the health-status of the Dutch Labrador retriever population.

Health issues in purebred dogs are currently considered one of the biggest problems in companion animal health. The Labrador retriever (LR) is one of the most popular dog breeds. The aim of this study was to quantify LR breed health in comparison with mixed-breed dogs (MB), by using four different data sources: a veterinary practice management system (appr. 35,000 unique individuals LR + MB), data from two animal insurance companies (appr. 15,500 and 4500 individuals respectively), and a histopathological laboratory (appr. 4000 individuals). After extensive recoding of the data, health parameters utilised to quantify breed health were longevity, frequency of practice visits and insurance expense claims, and diagnostic codes. A Kaplan-Meier univariate and multivariable Cox proportional hazard model were used to evaluate longevity. A negative binomial model was used to analyse the frequency of visits, claims, and diagnostic codes in both sets of insurance data. Logistic regression was used to look into the categorical diagnostic codes in the laboratory data. The median lifespan of the LR was similar (12 years, practice data) or longer (10 versus 8 years, insurance data) than MB for individuals with a known birth and death date. When including censored individuals, survival time in the LR was comparable to MB individuals up to 10 years of age. Above 10 years of age, the LR lived a similar length as MB with a medium to large body size, but shorter than all MB. The LR visited the veterinary practice more often (risk ratio (RR) 1.2, 95% confidence interval 1.2-1.3), and also showed a higher frequency of insurance expense claims (RR 2.2 (2.1-2.3) and RR 1.2 (1.1-1.3) respectively for the two insurance data sets). The largest difference in organ systems between the LR and MB in insurance claims was related to ears (RR 5.3 (4.8-5.8) and RR 2.6 (2.3-3.1)), followed by airways (RR 2.6 (2.4-2.8)), tendons & muscles (RR 2.4 (2.2-2.6) and RR 1.4 (1.1-1.7)), and joints (RR 1.7 (1.3-2.1)), without a difference in median age at diagnosis. The data from the histopathological laboratory suggested a higher disease burden related to oncology for the LR compared to MB (OR 1.2, 95% CI 1.0-1.3). Oncological diagnoses were made at a younger age in the LR (8.8 versus 9.4 years). The disease burden was significantly higher for the LR than MB, but these results may suffer from substantial bias such as selection bias towards the database, and different behaviour of LR versus MB owners with regards to veterinary care. In the future, longer term population data can corroborate these results.

Effect of clinical signs, endocrinopathies, timing of surgery, hyperlipidemia, and hyperbilirubinemia on outcome in dogs with gallbladder mucocele.

Gallbladder mucocele (GBM) is a common extra-hepatic biliary syndrome in dogs with death rates ranging from 7 to 45%. Therefore, the aim of this study was to identify the association of survival with variables that could be utilized to improve clinical decisions. A total of 1194 dogs with a gross and histopathological diagnosis of GBM were included from 41 veterinary referral hospitals in this retrospective study. Dogs with GBM that demonstrated abnormal clinical signs had significantly greater odds of death than subclinical dogs in a univariable analysis (OR, 4.2; 95% CI, 2.14-8.23; P<0.001). The multivariable model indicated that categorical variables including owner recognition of jaundice (OR, 2.12; 95% CI, 1.19-3.77; P=0.011), concurrent hyperadrenocorticism (OR 1.94; 95% CI, 1.08-3.47; P=0.026), and Pomeranian breed (OR, 2.46; 95% CI 1.10-5.50; P=0.029) were associated with increased odds of death, and vomiting was associated with decreased odds of death (OR, 0.48; 95% CI, 0.30-0.72; P=0.001). Continuous variables in the multivariable model, total serum/plasma bilirubin concentration (OR, 1.03; 95% CI, 1.01-1.04; P<0.001) and age (OR, 1.17; 95% CI, 1.08-1.26; P<0.001), were associated with increased odds of death. The clinical utility of total serum/plasma bilirubin concentration as a biomarker to predict death was poor with a sensitivity of 0.61 (95% CI, 0.54-0.69) and a specificity of 0.63 (95% CI, 0.59-0.66). This study identified several prognostic variables in dogs with GBM including total serum/plasma bilirubin concentration, age, clinical signs, concurrent hyperadrenocorticism, and the Pomeranian breed. The presence of hypothyroidism or diabetes mellitus did not impact outcome in this study.

Use of Serum MicroRNAs as Biomarker for Hepatobiliary Diseases in Dogs.

BACKGROUND: Current biochemical indicators cannot discriminate between parenchymal, biliary, vascular, and neoplastic hepatobiliary diseases. MicroRNAs are promising new biomarkers for hepatobiliary disease in humans and dogs. OBJECTIVE: To measure serum concentrations of an established group of microRNAs in dogs and to investigate their concentrations in various types of hepatobiliary diseases. ANIMALS: Forty-six client-owned dogs with an established diagnosis of hepatobiliary disease and stored serum samples and eleven client-owned healthy control Labrador Retrievers. METHODS: Retrospective study. Medical records of dogs with parenchymal, biliary, vascular, or neoplastic hepatobiliary diseases and control dogs were reviewed. Concentrations of miR-21, miR-122, miR-126, miR-148a, miR-200c, and miR-222 were quantified in serum by real-time polymerase chain reaction. RESULTS: No different microRNA concentrations were found in the adenoma and congenital portosystemic shunt groups. In all other diseases, miR-122 concentrations were elevated with the highest concentration in the mucocele group (267-fold, CI: 40-1,768, P < .001). In dogs with biliary diseases, miR-21 and miR-222 were only increased in dogs with mucoceles (26-fold, CI: 5-141, P = .005 and 13-fold, CI: 2-70, P = .025, respectively). Uniquely increased microRNAs were found in the hepatocellular carcinoma group (miR-200c, 35-fold increase, CI: 3-382, P = .035) and the chronic hepatitis group (miR-126, 22-fold increase, CI: 5-91, P = .002). CONCLUSIONS AND CLINICAL IMPORTANCE: A microRNA panel consisting of miR-21, miR-122, miR-126, miR-200c, and miR-222 can distinguish between parenchymal, biliary, and neoplastic hepatobiliary diseases. Serum microRNA profiling is a promising new tool that might be a valuable addition to conventional diagnostics to help diagnose various hepatobiliary diseases in dogs.

Dietary management of labrador retrievers with subclinical hepatic copper accumulation.

BACKGROUND: Genetic and environmental factors, including dietary copper intake, contribute to the pathogenesis of copper-associated hepatitis in Labrador retrievers. Clinical disease is preceded by a subclinical phase in which copper accumulates in the liver. OBJECTIVE: To investigate the effect of a low-copper, high-zinc diet on hepatic copper concentration in Labrador retrievers with increased hepatic copper concentrations. ANIMALS: Twenty-eight clinically healthy, client-owned Labrador retrievers with a mean hepatic copper concentration of 919 ± 477 mg/kg dry weight liver (dwl) that were related to dogs previously diagnosed with clinical copper-associated hepatitis. METHODS: Clinical trial in which dogs were fed a diet containing 1.3 ± 0.3 mg copper/Mcal and 64.3 ± 5.9 mg zinc/Mcal. Hepatic copper concentrations were determined in liver biopsy samples approximately every 6 months. Logistic regression was performed to investigate effects of sex, age, initial hepatic copper concentration and pedigree on the ability to normalize hepatic copper concentrations. RESULTS: In responders (15/28 dogs), hepatic copper concentrations decreased from a mean of 710 ± 216 mg/kg dwl copper to 343 ± 70 mg/kg dwl hepatic copper after a median of 7.1 months (range, 5.5-21.4 months). Dogs from a severely affected pedigree were at increased risk for inability to have their hepatic copper concentrations normalized with dietary treatment. CONCLUSIONS AND CLINICAL IMPORTANCE: Feeding a low-copper, high-zinc diet resulted in a decrease in hepatic copper concentrations in a subset of clinically normal Labrador retrievers with previous hepatic copper accumulation. A positive response to diet may be influenced by genetic background. Determination of clinical benefit requires further study.

Canine hepacivirus and idiopathic hepatitis in dogs from a Dutch cohort.

Liver diseases are highly prevalent in the general dog population, though the etiology is often unknown. Recently a homolog of human hepatitis C virus was discovered in dogs with respiratory infections. Although this canine hepacivirus (CHV) was detectable in some liver samples, a clear link with liver disease has not been established. A recent study by Bexfield et al. showed that in a large cohort of dogs from the UK with idiopathic hepatitis, no evidence can be found for exposure to, or carrier state of CHV both in liver and in serum. The authors however state that 'the absence of CHV infection on dogs from the UK might not represent the global ecology of the virus'. We investigated CHV-infection in 267 liver biopsies from 120 dogs idiopathic hepatitis and 135 control animals, in a population from the Netherlands. Using a highly sensitive PCR assay for CHV-NS3, no CHV was detected in all 267 liver samples. Our data show that the lack of association between canine hepacivirus and chronic liver disease in dogs is not limited to the UK, but is also found in an independent cohort from the European continent.

Urinary excretion of copper, zinc and iron with and without D-penicillamine administration in relation to hepatic copper concentration in dogs.

Hereditary copper-associated hepatitis in dogs resembles Wilson's disease, a copper storage disease in humans. Values for urinary copper excretion are well established in the diagnostic protocol of Wilson's disease, whereas in dogs these have not been evaluated. The objectives of this study were to characterize both basal and D-penicillamine induced urinary copper, zinc and iron excretion in dogs in relation to hepatic copper concentration. Beagles, Beagle-Bedlington terrier cross-breeds homozygous for the COMMD1 gene mutation that causes copper toxicosis, and Labrador retrievers with normal or increased hepatic copper concentrations were investigated. The hepatic copper phenotype was determined by histological evaluation of liver biopsies and measurement of the hepatic copper concentration by instrumental neutron activation analysis. Urinary excretion of copper, iron and zinc was measured via inductively coupled plasma optical emission spectrometry under basal conditions and after oral administration of a single dose (20mg/kg bodyweight) of the chelator D-penicillamine. There was a rapid increase in urinary excretion of copper and zinc, but not iron after D-penicillamine administration. This increase was not different between dogs with high or normal hepatic copper concentrations. D-penicillamine-induced urinary copper excretion and the copper/creatinine ratio did not correlate with hepatic copper concentrations in the dogs studied, although basal urinary copper/zinc ratios did correlate with hepatic copper concentrations in Labrador retrievers. The latter parameter may be useful in diagnostic and follow-up protocols for copper-associated hepatitis in Labrador retrievers.

Association of dietary copper and zinc levels with hepatic copper and zinc concentration in Labrador Retrievers.

BACKGROUND: Copper-associated hepatitis is an inherited disease in the Labrador Retriever. Apart from genetic factors, dietary intake of copper and zinc are suspected to play a role in the pathogenesis. OBJECTIVES: To investigate whether dietary copper and zinc levels of commercially available dry diets are associated with hepatic copper and zinc concentrations in Labrador Retrievers. ANIMALS: Fifty-five Labrador Retrievers that were fed a single brand and type of commercial dry food for at least 1 year. Of these, 44 dogs were family members of Labrador Retrievers with copper-associated hepatitis. METHODS: Liver biopsies, blood samples, and diet samples were obtained. Liver specimens were scored histologically and copper and zinc concentrations were quantified. Dietary concentrations of copper and zinc were measured. The association between dietary intake of copper and zinc and hepatic copper and zinc concentrations was investigated by linear regression analysis. RESULTS: High dietary copper and low dietary zinc levels were significantly associated with high hepatic copper levels. No association between dietary intake and hepatic zinc was present. CONCLUSIONS AND CLINICAL RELEVANCE: Dietary copper and zinc at current levels in commercially available dry dog food can influence hepatic copper and can be a risk factor for the development of copper-associated hepatitis in Labrador Retrievers with a genetic susceptibility to copper.

Expression of hepatocyte growth factor and the proto-oncogenic receptor c-Met in canine osteosarcoma.

Hepatocyte growth factor (HGF) and the proto-oncogenic receptor c-Met are implicated in growth, invasion, and metastasis in human cancer. Little information is available on the expression and role of both gene products in canine osteosarcoma. We hypothesized that the expression of c-Met is associated with malignant histologic characteristics, a short survival time, and a reduced disease-free interval in canine osteosarcoma. Quantitative real-time polymerase chain reaction was used to analyze the messenger RNA (mRNA) expression of both HGF and c-Met in 59 canine osteosarcoma samples. The relationship between HGF and c-Met expression, patient outcome, and histologic characteristics of the tumor were studied. Western blot analysis was performed to investigate the presence of active HGF protein. The expression pattern of c-Met in 16 slides of canine osteosarcoma was identified by immunohistochemistry. Coexpression of HGF and c-Met mRNA in all canine osteosarcoma samples suggested autocrine or paracrine receptor activation. A significant, moderately positive correlation was found between c-Met and HGF mRNA expression. c-Met mRNA expression was not associated with survival time or disease-free interval. Expression of c-Met was significantly associated with metastasis via the lymphogenic route. Immunolabeling with c-Met revealed a cytoplasmic staining pattern in all osteosarcoma cell types. In this study, c-Met mRNA expression in canine osteosarcoma was found to be of no influence on survival time and disease-free interval. Further studies are necessary to confirm the involvement of the c-Met pathway in the lymphogenic route of metastasis.