Prognostic markers in feline hepatic lipidosis: a retrospective study of 71 cats

Endocrine fibroblast growth factors in domestic animals

Fibroblast growth factors (FGFs) are a group of structurally homologous yet functionally pleiotropic proteins. Canonical and intracellular FGFs have primarily autocrine or paracrine effects. However, the FGF19 subfamily, composed of FGF15/19, FGF21, and FGF23, act as endocrine hormones that regulate bile acid, metabolic, and phosphorus homeostasis, respectively. Current research in human and rodent models demonstrates the potential of these endocrine FGFs to target various diseases, including disorders of inherited hypophosphatemia, chronic liver disease, obesity, and insulin resistance. Many diseases targeted for therapeutic use in humans have pathophysiological overlaps in domestic animals. Despite the potential clinical and economic impact, little is known about endocrine FGFs and their signaling pathways in major domestic animal species compared with humans and laboratory animals. This review aims to describe the physiology of these endocrine FGFs, discuss their current therapeutic use, and summarize the contemporary literature regarding endocrine FGFs in domestic animals, focusing on potential future directions.

Dietary choline, but not L-carnitine, increases circulating lipid and lipoprotein concentrations, without affecting body composition, energy expenditure or respiratory quotient in lean and obese male cats during weight maintenance

Introduction

Due to the involvement in one-carbon metabolism and lipid mobilization, choline and L-carnitine supplementation have been recommended to minimize hepatic lipid accumulation and support fat oxidation, respectively. This study investigated the lipotropic benefits of choline or L-carnitine supplementation in lean and obese cats maintaining body weight (BW).

Methods

Lean [n = 9; body condition score (BCS): 4-5/9] and obese (n = 9; BCS: 8-9/9) adult male neutered colony cats were used in a replicated 3 x 3 complete Latin square design. Treatments included choline (378 mg/kg BW0.67), L-carnitine (200 mg/kg BW) and control (no supplement). Treatments were supplemented to the food for 6 weeks each, with a 2-week washout between treatments. Cats were fed once daily to maintenance energy requirements, and BW and BCS were assessed weekly. Fasted blood collection, indirect calorimetry, and dual-energy X-ray absorptiometry occurred at the end of each treatment period. Serum was analyzed for cholesterol (CHOL), high-density lipoprotein CHOL (HDL-C), triglycerides (TAG), non-esterified fatty acids (NEFA), glucose, creatinine (CREAT), urea, alkaline phosphatase (ALP) and alanine aminotransferase (ALT). Very low-density lipoprotein CHOL (VLDL) and low-density lipoprotein CHOL (LDL-C) were calculated. Data were analyzed using proc GLIMMIX, with group and period as random effects, and treatment, body condition, and their interaction as fixed effects, followed by a Tukey's post-hoc test when significance occurred.

Results

Cats supplemented choline had lower food intake (P = 0.025). Treatment did not change BW, BCS and body composition (P > 0.05). Obese cats had greater ALP, TAG, and VLDL, and lower HDL-C compared to lean cats (P < 0.05). Choline resulted in greater CHOL, HDL-C, LDL-C and ALT (P < 0.05). L-carnitine resulted in lower CREAT (P = 0.010). Following the post-hoc test, differences between treatment means were not present for ALP (P = 0.042). No differences were found for glucose, urea or NEFA (P > 0.05). Obese cats had a lower fed respiratory quotient (RQ), regardless of treatment (P = 0.045). Treatment did not affect fed or fasted RQ and energy expenditure (P > 0.05).

Discussion

Choline appeared to increase circulating lipid and lipoprotein concentrations regardless of body condition, likely through enhanced lipid mobilization and hepatic elimination. Neither dietary choline or L-carnitine altered body composition or energy metabolism in the lean or obese cats, as compared to control.

How did SARS-CoV-2 pandemic affect the cats' health in Hatay Province? A retrospective study

The SARS-CoV-2 pandemic affected not only the physical and emotional health of human beings but also cats. Restrictions put into effect during the pandemic resulted in changes in the daily routine of pet cats and the number of new pet owners. The current study aimed to evaluate the diseases induced by stress in cats, such as gastrointestinal, hepatobiliary, and urinary tract diseases. To this end, the study evaluated the pre-pandemic (n: 52) (March 2019-Feb 2020) and pandemic (n: 95) (March 2020-March 2021) diagnosis data of cats (n: 147) with gastrointestinal, hepatobiliary, and urinary system diseases admitted to the Internal Medicine Department of Hatay Mustafa Kemal University Veterinary Health, Practice and Research Center between March 2019 and March 2021. There was no statistically significant difference between the sexes of the cats admitted to the clinic in both periods. There was a significant change in cat breeds during the pandemic, except for the mixed-breed and Ankara breeds. The age (mean ± SEM) of the cats admitted to the clinic was 30.14 ± 4.24 months before the pandemic and 30.45 ± 3.43 during the pandemic. Distributions of gastrointestinal diseases in the pre-pandemic and pandemic periods were determined as 35.7% and 64.3%, respectively. During the pandemic, the number of gastritis cases was lower than that in the pre-pandemic period, and the number of gastroenteritis cases was higher than that in the pre-pandemic period. Except for gastrointestinal diseases (P<0.05), a statistical difference between the periods was not found. The changes, especially influencing the daily routine of cats and causing stress, seem to have had significant effects on the gastrointestinal health of domestic cats.

Serum Lipid, Amino Acid and Acylcarnitine Profiles of Obese Cats Supplemented with Dietary Choline and Fed to Maintenance Energy Requirements

Simple Summary

Research has estimated that the majority of domestic cats are overweight or obese. Current weight-loss plans tend to have disappointing outcomes and are not without risk. During periods of severe energy restriction, obesity predisposes cats to developing fatty liver. Choline has been linked to fat metabolism in other animals but has not been studied in cats. Twelve obese cats were split into two groups and were fed a control diet (n = 6; 4587 mg choline/kg dry matter) or a high choline diet (n = 6; 18,957 mg choline/kg DM) for 5 weeks. Cats were fed to maintain body weight. Choline increased serum cholesterol, triacylglycerides, lipoproteins, and plasma methionine. It also decreased serum blood urea nitrogen and alkaline phosphatase as well as the ratio of plasma acylcarnitine to free carnitine. The results suggest that choline supplementation may increase fat transport out of the liver and help maintain liver health in obese cats. Choline supplementation may prove useful for safe weight loss in obese cats by minimizing the risks of fatty liver.

Abstract

Obesity is a health concern for domestic cats. Obesity and severe energy restriction predispose cats to feline hepatic lipidosis. As choline is linked to lipid metabolism, we hypothesized that dietary choline supplementation would assist in reducing hepatic fat through increased lipoprotein transport and fatty acid oxidation. Twelve obese cats (body condition score [BCS] ≥ 8/9) were split into two groups. Cats were fed a control (n = 6; 4587 mg choline/kg dry matter [DM]) or a high choline diet (n = 6; 18,957 mg choline/kg DM) for 5 weeks, for adult maintenance. On days 0 and 35, fasted blood was collected, and the body composition was assessed. Serum lipoprotein and biochemistry profiles, plasma amino acids and plasma acylcarnitines were analyzed. The body weight, BCS and body composition were unaffected (p > 0.05). Choline increased the serum cholesterol, triacylglycerides, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, very low-density lipoprotein cholesterol and plasma methionine (p < 0.05) and decreased the serum blood urea nitrogen and alkaline phosphatase (p < 0.05). Choline also reduced the plasma acylcarnitine to free carnitine ratio (p = 0.006). Choline may assist in eliminating hepatic fat through increased fat mobilization and enhanced methionine recycling.

Safety, Tolerability, and Proof-Of-Concept Study of OKV-119, a Novel Exenatide Long-Term Drug Delivery System, in Healthy Cats

Background: Glucagon-like peptide-1 (GLP-1) is an incretin hormone that plays an important role in glucose homeostasis and food intake. In people, GLP-1 receptor agonists (GLP-1RAs) are commonly used for the treatment of type 2 diabetes mellitus (DM) and obesity; however, non-adherence to injectable medications is common. OKV-119 is an investigational drug delivery system intended for subdermal implantation and delivery of the GLP-1RA exenatide for up to 6 months.

Hypothesis/Objectives: Develop protocols for the subcutaneous (SC) insertion and removal of OKV-119 and to evaluate its tolerability, in vivo drug-releasing characteristics, and weight-loss effects in cats.

Animals: Two cadaveric and 19 purpose-bred cats.

Methods: In cadavers, OKV-119 insertion protocol and imaging were performed at three SC locations. The safety and tolerability of OKV-119 implants were assessed in a small (n = 4 cats) 62-day study. Weekly plasma exenatide concentrations and body weight were measured in a 42-day proof-of-concept study designed to evaluate OKV-119 prototypes implanted in cats (n = 15).

Results: In anesthetized cats, the duration of insertion and removal procedures was 1–2 min. OKV-119 was easily identified on radiographs, and well-tolerated without any apparent implant site reactions. Following implantation, exanatide plasma concentrations were observed for up to 35 days. Plasma exenatide concentrations were correlated to weight loss.

Conclusion and clinical importance: Our findings suggest that OKV-119 could be easily inserted and removed during a routine clinic visit and can be used to safely and effectively deliver exenatide. Future studies of OKV-119, configured to release exenatide for a longer extended months-long duration, are warranted to determine whether the combination of metabolic improvements and beneficial weight-loss, coupled with minimal impact on pet-owner's lifestyle, lead to improved outcomes for obese cats and feline DM patients.

Feline chronic enteropathy

Feline chronic enteropathy is a common disorder, especially in the senior cat population, with rising incidence over the past decade. Feline chronic enteropathy is considered an umbrella term comprising different diseases including food-responsive enteropathy, idiopathic inflammatory bowel disease and alimentary small cell lymphoma. However, differentiation between those diseases is often difficult in practice. This review will discuss the clinical approach to cats with chronic enteropathy, state-of-the-art diagnostic tests and pitfalls thereof as well as current therapeutic approaches. Although, much of the etiopathogenesis is still unknown, increased research efforts in this field have brought new insights into diagnostic and therapeutic options for these cats.

Hypocholesterolemia in cats: a multicenter retrospective study of 106 cats

OBJECTIVES

The aim of this study was to describe the clinicopathologic findings and associated diseases found in a population of hypocholesterolemic cats referred to two tertiary care facilities.

METHODS

An electronic medical record search was performed at two veterinary university referral centers to identify cats with serum cholesterol values below the reference interval between January 2004 and 2016. Clinicopathologic data were reviewed for each case and cats were classified into specific disease categories based on clinical diagnosis. Median cholesterol values were compared between disease categories, as well as between survivors and non-survivors.

RESULTS

In total, 106 hypocholesterolemic cats were included. The median age of the cats was 6 years (range 0.24-18 years). The most common disease categories were gastrointestinal (25.9%), hepatobiliary (19.8%), hematologic (14.8%) and urogenital (14.8%). Though median serum cholesterol values did not differ significantly between survivors and non-survivors, cats with concurrent hypoalbuminemia were at higher risk (odds ratio 15.6, 95% confidence interval 5.2-46.6; P <0.0001) of not surviving to discharge than cats with normal serum albumin concentrations.

CONCLUSIONS AND RELEVANCE

Taken together, our data suggest that while the degree of hypocholesterolemia did not appear to influence survival rates, the concurrent presence of hypocholesterolemia and hypoalbuminemia was associated with a worse prognosis.

Is It Being Overdiagnosed? Feline Pancreatitis

In recent years, increased awareness of feline pancreatitis by the veterinary profession and improved diagnostic modalities have led to an increased frequency of diagnosis of pancreatitis in this species. Consequently, pancreatic diseases, especially chronic pancreatitis, are considered highly prevalent, even in populations of apparently healthy individuals. This prevalence has led to the suspicion that the condition may be overdiagnosed. This article summarizes the difficulties of diagnosis of acute and chronic pancreatitis, assesses the reasons why this is a challenging disease to recognize, and considers whether these difficulties could result in either overdiagnosis or underdiagnosis.

Identification of potential drugs for treatment of hepatic lipidosis in cats using an in vitro feline liver organoid system

Background

Hepatic lipidosis is increasing in incidence in the Western world, with cats being particularly sensitive. When cats stop eating and start utilizing their fat reserves, free fatty acids (FFAs) increase in blood, causing an accumulation of triacylglycerol (TAG) in the liver.

Objective

Identifying potential new drugs that can be used to treat hepatic lipidosis in cats using a feline hepatic organoid system.

Animals

Liver organoids obtained from 6 cats.

Methods

Eight different drugs were tested, and the 2 most promising were further studied using a quantitative TAG assay, lipid droplet staining, and qPCR.

Results

Both T863 (a diacylglycerol O‐acyltransferase 1 [DGAT1] inhibitor) and 5‐aminoimidazole‐4‐carboxamide 1‐β‐D‐ribofuranoside (AICAR; an adenosine monophosphate kinase activator) decreased TAG accumulation by 55% (P < .0001) and 46% (P = .0003), respectively. Gene expression of perilipin 2 (PLIN2) increased upon the addition of FFAs to the medium and decreased upon treatment with AICAR but not significantly after treatment with T863.

Conclusions and Clinical Importance

Two potential drugs useful in the treatment of hepatic lipidosis in cats were identified. The drug T863 inhibits DGAT1, indicating that DGAT1 is the primary enzyme responsible for TAG synthesis from external fatty acids in cat organoids. The drug AICAR may act as a lipid‐lowering compound via decreasing PLIN2 mRNA. Liver organoids can be used as an in vitro tool for drug testing in a species‐specific system and provide the basis for further clinical testing of drugs to treat steatosis.

Altered lipoprotein profiles in cats with hepatic lipidosis

OBJECTIVES

The aim of this study was to assess serum lipoprotein profiles using rapid single-spin continuous lipoprotein density profiling (CLPDP) in healthy control cats and cats with hepatic lipidosis (HL).

METHODS

Analysis of serum lipoprotein profiles using the CLPDP was performed in 23 cats with HL and 20 healthy control cats. The area under the curve for each lipoprotein fraction, triglyceride (TG)-rich lipoproteins (TRLs), low-density lipoproteins (LDLs) and high-density lipoproteins (HDLs), was calculated. Serum cholesterol and TG concentrations were measured using a clinical chemistry analyzer.

RESULTS

Serum cholesterol and TG concentrations were not significantly different between healthy control cats and cats with HL ( P = 0.5075 and P = 0.2541, respectively). LDL content was significantly higher in cats with HL than in healthy control cats ( P = 0.0001), while HDL content was significantly lower in cats with HL than in healthy control cats ( P = 0.0032). TRL content was not significantly different between the two groups ( P = 0.0699). The specific fraction (1.037-1.043 g/ml) within nominal LDL in serum distinguished healthy control cats from cats with HL with a sensitivity of 87% and a specificity of 90%.

CONCLUSIONS AND RELEVANCE

Serum lipoprotein profiles were altered in cats with HL, even though serum cholesterol and TG concentrations were not significantly different compared with healthy control cats. The CLPDP might be a useful tool for assessing lipid metabolism in cats with HL.

A retrospective study of 157 hospitalized cats with pancreatitis in a tertiary care center: Clinical, imaging and laboratory findings, potential prognostic markers and outcome

BACKGROUND

Pancreatitis in cats (FP) has been increasingly diagnosed in recent years, but clinical studies of large numbers of affected cats are scarce.

OBJECTIVES

To describe a large cohort of cats with FP requiring hospitalization.

ANIMALS

One hundred and fifty-seven client-owned cats.

METHODS

Retrospective study, including cats diagnosed with pancreatitis based on sonographic evidence, positive SNAP feline pancreatic lipase immunoreactivity test results, increased 1,2-o-dilauryl-rac-glycerol-glutaric Acid-(6'-methylresorufin ester)-lipase activity, histopathology, or some combination of these.

RESULTS

One-hundred and twenty-two cats (77.7%) survived to discharge. Median time from onset of clinical signs to presentation was longer (P = .003) in nonsurvivors. Causes of FP included recent general anesthesia, trauma, hemodynamic compromise, and organophosphate intoxication, but most cases (86.6%) were idiopathic. Ultrasonographic findings consistent with pancreatitis were documented in 134 cats, including pancreatomegaly (81.3%), decreased (31.3%), or increased (14.9%) pancreatic echogenicity, extra-hepatic biliary tract dilatation (24%), and increased peri-pancreatic echogenicity (13%). Lethargy (P = .003), pleural effusion (P = .003), hypoglycemia (P = .007), ionized hypocalcemia (P = .016), azotemia (P = .014), parenteral nutrition administration (P = .013), and persistent anorexia during hospitalization (P = .001) were more frequent in nonsurvivors, whereas antibiotics were more frequently administered to survivors (P = .023). Nevertheless, when Bonferroni's correction for multiple comparisons was applied, none of the variables was statistically significant.

CONCLUSIONS AND CLINICAL IMPORTANCE

Previously unreported, clinically relevant, potential prognostic factors, including hypoglycemia, azotemia, parenteral nutrition, and withholding antibacterial treatment were identified in this exploratory study. These preliminary results should be examined further in confirmatory studies.

Interventional Potential of Recombinant Feline Hepatocyte Growth Factor in a Mouse Model of Non-alcoholic Steatohepatitis

Background and Aims: Hepatocyte growth factor (HGF) is a multifunctional pleiotropic protein involved in tissue regeneration, protection, angiogenesis, anti-inflammatory and anti-fibrotic responses, and tumorigenesis, through binding to its receptor MET. Recombinant HGF protein has been shown to mitigate various liver disease models, such as alcohol-induced liver injury, hepatic ischemia-reperfusion injury, and fibrosis. This study aimed to investigate the anti-inflammatory, anti-fibrotic, and anti-lipogenic effects of exogenous administration of feline HGF on a non-alcoholic steatohepatitis (NASH) mouse model. Methods: Wild-type C57BL/6 mice were fed a choline-deficient amino acid defined (CDAA) diet for 3 weeks to create the mouse model of NASH, which displays hepatic steatosis, inflammation, injury, and very mild fibrosis. One mg/kg of recombinant feline HGF was administered intravenously daily in the last 7 days of the total 3 weeks of CDAA diet feeding. Then, hepatic steatosis, inflammation, injury, and fibrogenic gene expression was examined. Results: After 3 weeks of a CDAA diet-feeding, the vehicle-treated mice exhibited evident deposition of lipid droplets in hepatocytes, inflammatory cell infiltration, and hepatocyte ballooning along with increased serum ALT levels whereas recombinant HGF-treated mice showed reduced hepatic steatosis, inflammation, and ballooned hepatocytes with a reduction of serum ALT levels. Recombinant HGF administration promoted hepatocyte proliferation. Increased hepatic lipid accumulation was accompanied by elevated expression of lipogenesis genes Fasn and Dgat1 in vehicle-treated mice. In HGF-treated mice, these genes were reduced with a decrease of lipid accumulation in the liver. Consistent with the anti-inflammatory property of HGF, augmented macrophage infiltration and upregulation of chemokines, Cxcl1, Ccl2, and Ccl5 in the CDAA diet fed mice, were suppressed by the addition of the HGF treatment. Finally, we examined the fibrotic response. The vehicle-treated mice had mild fibrosis with upregulation of Col1a1, Acta2, Timp1, Tgfb1, and Serpine1 expression. Recombinant HGF treatment significantly suppressed fibrogenic gene expression and collagen deposition in the liver. Conclusion: Recombinant feline HGF treatment suppressed the progression of NASH in a CDAA diet feeding mouse model.This suggests that recombinant HGF protein has therapeutic potential for NASH.