Immunohistochemistry has been used extensively to evaluate protein expression in clinical and research settings. However, immunohistochemistry is not always successful in veterinary medicine due to the lack of reliable antibody options, poor tissue preservation, labor-intensive staining, and antigen-retrieval optimization processes. RNAscope in-situ hybridization (ISH) is a powerful technology that uses a specific sequence probe to identify targeted mRNA. In this study, we demonstrate RNAscope ISH in 4 common canine malignancies, which are traditionally diagnosed by histopathology and immunohistochemistry. Probes were designed for commonly targeted mRNA markers of neoplastic tumors; these included c-kit in mast cell tumor, microphthalmia-associated transcription factor in malignant melanoma, ionized calcium-binding adapter molecule(-1) in histiocytic sarcoma, and alkaline phosphatase in osteosarcoma. A strong staining signal was obtained by these 4 targets in each canine malignancy. These results support the use of RNAscope ISH for definitive diagnosis in canine malignancies.

OBJECTIVE To characterize the biochemical, functional, and histopathologic changes associated with lomustine-induced liver injury in dogs. ANIMALS I0 healthy purpose-bred sexually intact female hounds. PROCEDURES Dogs were randomly assigned to receive lomustine (approx 75 mg/m2, PO, q 21 d for 5 doses) alone (n = 5) or with prednisone (approx 1.5 mg/kg, PO, q 24 h for 12 weeks; 5). For each dog, a CBC, serum biochemical analysis, liver function testing, urinalysis, and ultrasonographic examination of the liver with acquisition of liver biopsy specimens were performed before and at predetermined times during and after lomustine administration. Results were compared between dogs that did and did not receive prednisone. RESULTS 7 of the I0 dogs developed clinical signs of liver failure. For all dogs, serum alanine aminotransferase (ALT) and alkaline phosphatase (ALP) activities, bile acid concentrations, and liver histologic score increased and hepatic reduced glutathione content decreased over time. Peak serum ALT (r = 0.79) and ALP (r = 0.90) activities and bile acid concentration (r = 0.68) were positively correlated with the final histologic score. Prednisone did not appear to have a protective effect on histologic score. CONCLUSIONS AND CLINICAL RELEVANCE In dogs, liver enzyme activities, particularly ALT and ALP activities, should be closely monitored during lomustine treatment and acute increases in those activities may warrant discontinuation of lomustine to mitigate liver injury. Nonspecific ultrasonographic findings and abnormal increases in liver function tests were not detected until the onset of clinical liver failure. Glutathione depletion may have a role in lomustine-induced hepatopathy and warrants further investigation.

OBJECTIVE To evaluate the usefulness of intestinal biomarkers in determining the presence of intestinal epithelial damage in neonatal calves with diarrhea caused by 4 etiologic agents. ANIMALS 40 neonatal calves that were healthy (n = 10) or had diarrhea (30). PROCEDURES The study was a cross-sectional study. Results of hematologic analyses and serum concentrations of intestinal fatty acid–binding protein (I-FABP), liver fatty acid–binding protein (L-FABP), trefoil factor 3 (TFF-3), Claudin-3 (CLDN-3), γ-enteric smooth muscle actin (ACTG2), intestinal alkaline phosphatase (IAP), interleukin-8 (IL-8), platelet-activating factor (PAF), and leptin (LP) were compared among calves grouped according to whether they were healthy (control group; G-1) or had diarrhea caused by K99 Escherichia coli (G-2; n = 10), bovine rota- or coronavirus (G-3; 5 each), or Cryptosporidium spp (G-4; 10). RESULTS Across the 3 time points at which blood samples were obtained and evaluated, the groups of calves with diarrhea generally had markedly higher mean serum concentrations of L-FABP, TFF-3, IAP, IL-8, and LP, compared with the control group. In addition, G-2 also consistently had markedly higher mean serum concentrations of I-FAB and ACTG2 and lower mean serum concentrations of CLDN-3, compared with the control group. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that degree of intestinal epithelial damage differed among calves grouped by the etiologic agent of diarrhea and that such damage might have been more severe in calves with diarrhea caused by K99 E coli. Additionally, our results indicated that serum concentrations of I-FABP, L-FABP, TFF-3, IAP, IL-8, ACTG2, LP, and CLDN-3 were useful biomarkers of intestinal epithelial damage in calves of the present study.

The present study describes the serum biochemical alterations and histopathological abnormalities in the liver tissue of dogs with liver disease. A survey of hepatic lesions was conducted using ultrasound-guided percutaneous needle biopsies. The hematologic and biochemical changes in dogs with liver lesions were recorded. Chronic hepatitis was the most common liver histopathologic finding (37.9%). Other common findings included liver fibrosis (19.5%), vacuolar hepatopathy (10.3%), cholangiohepatitis (9.2%), hepatocellular carcinoma (4.6%), cholangitis (3.4%), cholangiocarcinoma (2.3%), and congestive hepatopathy (2.3%). Greater than 2-fold elevation of serum alanine aminotransferase (ALT) was a useful indicator, with a sensitivity of 40% to 65% for diagnosing all liver pathologies. Greater than 2-fold elevation of serum alkaline phosphatase (ALP) without significant elevation of ALT was useful for diagnosing liver diseases affected by inflammatory or regressive changes (sensitivity of 40% to 50%). Elevation of ALT, ALP, or a combination of ALT and ALP had a high sensitivity of up to 90% for identifying dogs with liver pathology. Hepatic injury and cholestasis enzymes should be interpreted together with patient history, clinical signs, and liver ultrasonographic appearance before performing a liver biopsy.