Feline cholangitis/cholangiohepatitis complex - what have we learned?

Feline Cholangitis

Inflammatory biliary tract disease (cholangitis) is the commonest liver disease in cats but remains poorly understood. There are chronic lymphocytic and acute neutrophilic forms together with chronic neutrophilic cholangitis which may overlap both these categories. Acute suppurative cholangitis is often associated with bacterial infections and interruptions to bile flow. Lymphocytic forms may be immune-mediated but there is evidence of heterogenicity in histologic and clinical appearance and response to treatment which may suggest several distinct diseases. This review discusses current knowledge, presentation, and diagnosis of feline cholangitis and suggests avenues for future research.

Chemical Sensors and Biosensors for Point-of-Care Testing of Pets: Opportunities for Individualized Diagnostics of Companion Animals

Point-of-care testing (POCT) is recognized as one of the most disruptive medical technologies for rapid and decentralized diagnostics. Successful commercial examples include portable glucose meters, pregnancy tests, and COVID-19 self-tests. However, compared to advancements in human healthcare, POCT technologies for companion animals (pets) remain significantly underdeveloped. This Review explores the latest advancements in pet POCT and examines the challenges and opportunities in the field for individualized diagnostics of cats and dogs. The most frequent diseases and their respective biomarkers in blood, urine, and saliva are discussed. We examine key strategies for developing the next-generation POCT devices by harnessing the potential of selective (bio)receptors and high-performing transducers such as lateral flow tests and electrochemical (bio)sensors. We also present the most recent research initiatives and the successful commercial pet POCT technologies. We discuss future trends in the field, such the role of biomarker discovery and development of wearable, implantable, and breath sensors. We believe that advancing pet POCT technologies benefits not only animals but also humans and the environment, supporting the One Health approach.

Detection frequency, sonoanatomy and reference values of the duodenal papillae and connected anatomical structures in cats

OBJECTIVES

To describe the detection frequency, sonoanatomy and reference values of the duodenal papillae and connected anatomical structures in cats, with reference to gross anatomical and histopathological nomenclature.

MATERIALS AND METHODS

A prospective, case-controlled study of sonographic examinations of the duodenal papillae in 50 client-owned cats using an ultrasound device (Logiq E9, GE Healthcare) with a 15 MHz linear transducer.

RESULTS

The major duodenal papilla was found in 100% of cases, the minor duodenal papilla in 10%. The common bile duct and the main pancreatic duct could be traced to the duodenum in all of the cats. After an extramural part, in which the two ducts extend in a parallel fashion, they entered the duodenal wall. The subsequent intramural part was divided into three sections: the portio infundibularis, the portio submucosa and the major duodenal papilla. The 27 clinically healthy cats had a mean portio infundibularis length, width, and height in mm of 3.7, 2.5 and 2.2, respectively. These dimensions were 3.5, 2.1, 2.9 for the portio submucosa and 0.5, 2.1, 2.9 for the major duodenal papilla. Calculi in the major duodenal papilla were found in 12% of the cats. The course of the accessory pancreatic duct from the pancreas through the MIDP into the duodenum was documented.

CLINICAL SIGNIFICANCE

The ultrasonographic examination of the duodenal papillae is easy to perform and it can be considered part of the routine examination for feline patients presenting with relevant clinical signs, in some cases to help establish a diagnosis and plan treatment.

Double cholecystectomy of duplex gallbladder associated with chronic cholecystitis in a cat

A 6-year-old female neutered Persian cat presented with hyporexia and gradual weight loss over 6 months. Physical examination revealed cranial abdominal pain. Haematology and serum biochemistry were within normal limits. Abdominal ultrasonography and a computed tomography scan suggested a non-neoplastic mass compressing the gallbladder. During an exploratory laparotomy, a duplex gallbladder with two separate cystic ducts was diagnosed intraoperatively. The mass identified using the imaging techniques was an abnormal right gallbladder which was distended with immobile mucoid bile and a thickened wall. The left gallbladder and cystic duct were grossly normal. A cholecystectomy of both gallbladders was performed. Histopathology of the right gallbladder identified chronic cholecystitis. The cat made a good recovery from surgery and reported complete resolution of its hyporexia and a return to normal body weight. This is the first report of a successful cholecystectomy of a duplex gallbladder with chronic cholecystitis of a single gallbladder.

Hepadnavirus Infection in a Cat with Chronic Liver Disease: A Multi-Disciplinary Diagnostic Approach

A 3-year-old female stray, shorthair cat, with clinical signs and serum chemistry markers indicative of hepatic disease, was diagnosed with domestic cat hepadnavirus (DCH) infection. Coupling molecular and serological data, the infection was seemingly contextualized into a chronic phase, since IgM anti-core antibodies, a marker of early-stage Hepatitis B Virus (HBV) infection, were not detected. However, the cat possessed IgG anti-core, a common indicator of chronic HBV infection in human patients and did not show seroconversion to the anti-DCH surface antigen, considered protective during HBV infection and associated with long-term protective immunity. On genome sequencing, the DCH strain showed 98.3% nucleotide identity to strains previously identified in Italy.

Prevalence and clinical relevance of cholelithiasis in cats: A multicenter retrospective study of 98 cases

BACKGROUND

Cholelithiasis is an uncommon and mainly incidental finding in dogs; current literature on this topic is scarce in cats.

HYPOTHESIS

Report prevalence, clinical presentation, management, and outcome of cholelithiasis in cats.

ANIMALS

Ninety-eight cats with cholelithiasis.

METHODS

Retrospective multicenter case series. Electronic databases from 3 hospitals were searched for cats diagnosed with cholelithiasis by ultrasonography (US). Cholelithiasis was classified as incidental (IC) or symptomatic (SC) depending on clinicopathological signs, biliary tract US appearance, and presence of another disease potentially explaining the clinical presentation. Multivariate analysis was used to investigate factors associated with clinical expression of cholelithiasis and, within the SC group, survival.

RESULTS

The observed prevalence of cholelithiasis was 0.99% (95% confidence interval [CI], 0.79%-1.19%) among cats that underwent abdominal US. Cholelithiasis was classified as IC in 41% and SC in 59%. Choleliths found in multiple locations within the biliary tract (odds ratio [OR], 8.11; 95% CI, 2.32-34.15; P = .001) or associated with US signs of obstruction (OR, 18.47; 95% CI, 2.13-2413.34; P = .004) were significantly associated with SC. Concurrent hepatobiliary diseases were suspected or confirmed in 83% of cases with SC. Forty-three cats (74%) with SC survived to discharge. Biliary tract obstruction (BTO) was negatively associated with survival (OR, 13.87; 95% CI, 1.54-124.76; P = .001). None of the cats with IC that had available follow-up (47%) developed clinicopathological signs related to cholelithiasis.

CONCLUSIONS AND CLINICAL IMPORTANCE

Cholelithiasis is uncommon and can be asymptomatic in cats. Symptomatic cholelithiasis frequently is associated with another hepatobiliary disease or BTO or both. Biliary tract obstruction is associated with poorer outcome.

Surgical Management Of Feline Biliary Tract Disease: Decision-making and techniques

PRACTICAL RELEVANCE

Diseases of the hepatobiliary system are not uncommon in first-opinion practice. The anatomy of the feline hepatobiliary tract differs from that of dogs and may predispose cats to inflammatory hepatobiliary disease. Case management can be challenging, and the prognosis is variable and dependent on the underlying disease process.

CLINICAL CHALLENGES

Biliary tract disease in the cat has non-specific clinical signs that overlap with those of diseases of other body systems. Diagnostic tests of the hepatobiliary system are widely available, but interpretation of results can be challenging. Deciding on medical or surgical management can also be challenging; for example, various degrees of cholestasis may be seen with different diseases and disease severities, and will influence the decision to manage the patient medically or surgically. Surgery is indicated in cases of bile peritonitis, severe cholestasis, focal neoplasia or disease that is refractory to medical management. Intensive perioperative and postoperative management, with 24 h hospitalisation facilities, is essential.

AUDIENCE

This review article is written for the small animal general/primary care practitioner, with an emphasis on decision-making in the surgical management of feline hepatobiliary disease.

EVIDENCE BASE

Evidence available in the published literature is reviewed and presented, and the inherent limitations are discussed.

Feline Morbillivirus: Clinical Relevance of a Widespread Endemic Viral Infection of Cats

Feline morbillivirus (FeMV) was first isolated in 2012 from stray cats in Hong Kong. It has been found in association with tubulointerstitial nephritis (TIN), the most common cause of feline chronic kidney disease (CKD). However, viral host spectrum and virus tropism go beyond the domestic cat and kidney tissues. The viral genetic diversity of FeMV is extensive, but it is not known if this is clinically relevant. Urine and kidney tissues have been widely tested in attempts to confirm associations between FeMV infection and renal disease, but samples from both healthy and sick cats can test positive and some cross-sectional studies have not found associations between FeMV infection and CKD. There is also evidence for acute kidney injury following infection with FeMV. The results of prevalence studies differ greatly depending on the population tested and methodologies used for detection, but worldwide distribution of FeMV has been shown. Experimental studies have confirmed previous field observations that higher viral loads are present in the urine compared to other tissues, and renal TIN lesions associated with FeMV antigen have been demonstrated, alongside virus lymphotropism and viraemia-associated lymphopenia. Longitudinal field studies have revealed persistent viral shedding in urine, although infection can be cleared spontaneously.

Shear wave velocity values measured by 2D-shear wave elastography are not different between awake and anesthetized cats without clinically significant hepatic fibrosis

Two-dimensional shear wave elastography (2D-SWE) is widely used as a noninvasive method to quantify liver stiffness. In humans, liver stiffness approximates histologic hepatic fibrosis. While histology is the gold standard for diagnosing liver disease, 2D-SWE may be a minimally invasive alternative to biopsy in feline patients. The objectives of this prospective, observational, crossover study were trifold: (1) to assess the feasibility of performing 2D-SWE in awake cats, (2) to determine whether anesthesia altered shear wave velocity (SWV) measurements, and (3) to correlate hepatic stiffness with histologically quantified hepatic fibrosis. Eleven healthy, purpose-bred cats underwent 2D-SWE in awake and anesthetized states. SWV measurements were compared with histologic fibrosis measurements obtained from liver biopsies during the anesthetic period. The mean velocities were not significantly different between awake (1.47 ± 0.18 m/s) and anesthetized (1.47 ± 0.24 m/s) cats. Premedication and anesthetic drugs did not impact mean SWV. There was a higher variability in the SWV values in the awake group. The data points were reliably replicated, with an interquartile range of 0.24 and 0.32 in anesthetized and awake groups, respectively. There was moderate agreement between observers (intraclass correlation coefficient = 0.66). All cats had clinically insignificant fibrosis. There was no correlation between the SWV measurements and the histological fibrosis values. This study demonstrates that 2D-SWE is feasible in awake cats and that the anesthetic protocol employed did not significantly alter mean SWV. This work is the first to histologically validate normal SWV values in cats and show that 2D-SWE cannot differentiate minimal differences in feline hepatic fibrosis.