BackgroundCholangitis in dogs appears to be more common than previously thought, but understanding of the disease remains incomplete.ObjectiveTo describe a population of dogs with cholangitis or cholangiohepatitis.AnimalsFifty‐four client‐owned dogs with cholangitis or cholangiohepatitis.MethodsMedical records of dogs with cholangitis or cholangiohepatitis confirmed by histopathology between January 2004 and December 2014 were identified using a computer‐based search and retrospectively reviewed.ResultsClinical signs included vomiting (72.2%), lethargy (70.4%), and inappetence (64.8%). Most dogs (49/50) had increased liver enzyme activities, hyperbilirubinemia (32/50), and hypercholesterolemia (24/43). Ultrasonographic abnormalities of the hepatobiliary system were seen in 84% of cases. On histopathology, 53 of 54 affected dogs had neutrophilic cholangitis (NC) or cholangiohepatitis, whereas 1 dog had lymphocytic cholangitis. Most cases (42/54) were chronic. Evidence of concurrent biliary disease (46.2%) and biliary tract obstruction (42.6%) was common. Seventeen of 36 biliary and 11 of 25 liver cultures were positive for bacterial growth; Escherichia coli and Enterococcus spp. were most common. Median patient survival was 671 days (95% confidence interval [CI]: 114–1,426). On Cox regression, dogs that did not have a cholecystectomy performed had a 2.1 greater hazard for death (P = 0.037; 95% CI: 1.0–4.3) compared to cholecystectomized dogs. Dogs >13 years old had a 5.0 greater hazard for death (P = 0.001; 95% CI: 1.9–13.2) compared to younger dogs.Conclusions and Clinical SignificanceChronic NC or cholangiohepatitis was most common. Cholecystitis and biliary tract obstruction often occurred in conjunction with cholangitis. Cholecystectomized dogs had decreased risk of death; thus, cholecystectomy may improve patient outcome.

The local production of gamma interferon (IFN-γ) is important to control Toxoplasma gondii in the brain, but the basis for these protective effects is not fully understood. The studies presented here reveal that the ability of IFN-γ to inhibit parasite replication in astrocytes in vitro is dependent on signal transducer and activator of transcription 1 (STAT1) and that mice that specifically lack STAT1 in astrocytes are unable to limit parasite replication in the central nervous system (CNS). This susceptibility is associated with a loss of antimicrobial pathways and increased cyst formation in astrocytes. These results identify a critical role for astrocytes in limiting the replication of an important opportunistic pathogen.

Pathologic features of 12 cats with naturally acquired systemic hypertension and concomitant hypertensive encephalopathy were analyzed. All cats demonstrated acute onset of signs localized to the forebrain and/or brainstem, including stupor, coma, and seizures. All cats had systemic hypertension, ranging from 160 to 300 mm Hg. Gross lesions were identified in 4 of 12 cases, including caudal herniation of the cerebrum and cerebellum, sometimes with compression of the rostral colliculus and medulla. Histologically, all cases featured bilaterally symmetrical edema of the cerebral white matter. Associated vascular lesions, especially arteriolar hyalinosis, were also observed. Concurrent lesions were chronic tubulointerstitial nephritis (11/12 cases), adenomatous hyperplasia of the thyroid gland (4 cases), hypertensive choroidal arteriopathy (6 cases), and left ventricular hypertrophy (5 cases). This study demonstrates that the typical histologic manifestation of spontaneous hypertensive encephalopathy in cats is bilaterally symmetrical edema of the subcortical cerebral white matter.

Objectives The objective was to evaluate the safety and diagnostic utility of percutaneous ultrasound-guided cholecystocentesis (PUC) in cats with suspected hepatobiliary disease. Methods Medical records of 83 cats with suspected hepatobiliary disease that underwent PUC were retrospectively reviewed. Results At the time of PUC, at least one additional procedure was performed in 79/83 cats, including hepatic aspiration and/or biopsy (n = 75) and splenic aspiration (n = 18). Complications were noted in 14/83 cases, including increased abdominal fluid (n = 11), needle-tip occlusion (n = 1), failed first attempt to penetrate the gall bladder wall (n = 1) and pneumoperitoneum (n = 1). There were no reports of gall bladder rupture, bile peritonitis or hypotension necessitating treatment with vasopressor medication. Blood products were administered to 7/83 (8%) cats. Seventy-two cats (87%) survived to discharge. Of the cats that were euthanized (9/83) or died (2/83), none were reported as a definitive consequence of PUC. Bacteria were identified cytologically in 10/71 samples (14%); all 10 had a positive aerobic bacterial culture. Bile culture was positive in 11/80 samples (14%). Of the cases with a positive bile culture, cytological description of bacteria corresponded to the organism cultured in fewer than 50% of cases. The most common cytologic diagnosis was hepatic lipidosis (49/66). The most common histopathologic diagnosis was cholangitis (10/21). Conclusions and relevance PUC was safe in this group of cats with suspected hepatobiliary disease. Complications were likely associated with ancillary procedures performed at the time of PUC. Bile analysis yielded an abnormal result in nearly one-third of cats with suspected hepatobiliary disease. Complete agreement between bile cytology and culture was lacking. Further evaluation of the correlation between bile cytology and bile culture is warranted.

A domestic shorthair kitten was presented for evaluation and further treatment of seizures. Magnetic resonance imaging of the brain revealed a large multilobulated mass in the third ventricle extending into the right lateral ventricle with secondary obstructive hydrocephalus. The mass was homogeneously isointense to gray matter on T2W, T2-FLAIR, T2 W, T1W, and ADC images, and hyperintense on DW-EPI. There was no appreciable contrast enhancement. Seizures were managed medically and with subsequent ventriculoperitoneal shunt placement. Clinical status later deteriorated and the cat was euthanized. Histopathology confirmed that the mass was the result of neuronal heterotopia. To the authors' knowledge this is the first report of neuronal heterotopia in a cat.