Environmental Risk Factors for Diabetes Mellitus in Cats

A meta-analysis: dietary carbohydrates do not increase body fat or fasted insulin and glucose in cats

Commercial cat foods contain a greater carbohydrate content, such as nitrogen-free extract (NFE), compared to a typical prey species. This has led to postulations that increased carbohydrate intake is causing a rise in obesity and IR in cats. Studies investigating high-carbohydrate diets on insulin and glucose responses show inconsistent results. A meta-analysis using 16 studies was conducted to elucidate the relationship between NFE content and body fat mass (BFM, n = 9), fasted insulin (n = 12), and fasted glucose concentrations (n = 14). Dietary NFE, fat, and protein content (% metabolizable energy), as well as daily energy intake (DEI), body weight, body condition (lean, obese), and study design metrics were considered as fixed effects in univariate and multivariate models using proc mixed in SAS, treating study as a random effect. Model evaluation was conducted using corrected Akaike Information Criteria, concordance correlation coefficient, and the root mean square prediction error. The best-fitting model for BFM was the interaction between NFE content and DEI, predicting BFM to decrease when NFE content increased as a proportion of the DEI (P < 0.05). From univariate models, fasted insulin was positively associated with BFM and dietary fat content (P < 0.05), whereas an increase in NFE content was associated with a decrease in fasted insulin in a subgroup of studies (n = 6) of only lean cats (P < 0.05). No significance was observed for models predicting fasted glucose from diet or body composition variables (P > 0.05). The results of this meta-analysis indicate that dietary carbohydrates (NFE), included between 2.8% and 57% ME, are not a risk factor for greater BFM, fasted insulin, and glucose concentrations in cats, suggesting that NFE does not pose a risk for feline obesity, IR, or hyperglycemia. However, future studies should consider postprandial responses of insulin and glucose to macronutrient compositions to further investigate the role of dietary carbohydrates on IR in cats, with particular attention to the role of dietary fat, and the role of body condition.

Signalment, clinicopathological findings, management practices and comorbidities in cats with diabetes mellitus in Germany: cross-sectional study of 144 cases

OBJECTIVES

The aim of this study was to describe signalment, clinicopathological findings, management practices and the occurrence of comorbidities in feline diabetes mellitus (DM) in Germany.

METHODS

This was a cross-sectional study using questionnaires and laboratory submissions to a commercial laboratory, Antech Lab Germany, between May 2021 and July 2022. Inclusion criteria were diagnosis of DM by the attending veterinarian and submission of a completed questionnaire besides blood samples. Laboratory testing included haematology, serum biochemistry, concentration of total thyroxine (TT4), insulin-like growth factor 1 (IGF-1), cobalamin (COB), fructosamine, b-hydroxybutyrate and DGGR (1,2-O-dilauryl-rac-glycero-3-glutaric acid-[6'-methylresorufin] ester) lipase activity. Data are presented as the median (range) and analysed by non-parametric tests. P <0.05 was considered statistically significant.

RESULTS

The median (range) age of the 144 diabetic cats at diagnosis was 11 years (0.9-18.7), 66.4% were male, 84.6% were domestic shorthair, 50.4% were currently overweight and 61.5% were previously overweight (body condition score >5/9). Most cats were treated with insulin (84%), most commonly protamine zinc insulin (57.5%). Blood glucose curves or continuous glucose monitoring alone or in combination with other methods were performed to adjust insulin therapy in 70.6% of cats. Based on questionnaires, 78.6% were poorly controlled and 21.4% were well controlled. Increased TT4 occurred in 3/139 and hyperthyroidism was known in 5/139 cats (frequency of known/suspected hyperthyroidism: 5.8% [n = 8/139]); 17.5% (n = 17/97) had increased IGF-1 (IGF-1 >746 ng/ml, cut-off for hypersomatotropism with the chemiluminescence assay used in this study); 24.5% (n = 34/139) had COB <295.2 pmol/l and 54.2% (n = 78/144) had increased DGGR. Cats with IGF-1 >746 ng/ml were receiving a higher insulin dose than cats with IGF-1 ≤746 ng/ml (median 1.63 vs 0.86 U/kg/day, P = 0.018).

CONCLUSION AND RELEVANCE

Increased DGGR and increased IGF-1 indicating hypersomatotropism are common in diabetic cats and should be tested for. Almost one-quarter of diabetic cats might require COB supplementation.

Evaluation of laboratory findings indicating pancreatitis in healthy lean, obese, and diabetic cats

BACKGROUND

Obesity is a risk factor for diabetes mellitus, which commonly coexists with pancreatitis in cats. However, obesity has not previously been associated with pancreatitis in cats.

OBJECTIVES

To evaluate factors affecting serum concentrations of pancreatic lipase immunoreactivity (fPLI), trypsin-like immunoreactivity (fTLI), cobalamin and folate in clinically healthy lean, overweight and obese, or diabetic cats.

ANIMALS

Seventy-nine client-owned cats (27 healthy lean [LN, BCS 4-5/9], 30 healthy overweight and obese [OW, BCS 7-9/9], and 22 diabetic [DM]) were included.

METHODS

Cross-sectional study. The cats underwent physical examination, and blood tests. Linear regression models compared differences in fPLI, fTLI, cobalamin, and folate concentrations. Fisher's exact test assessed the proportions of cats with fPLI and fTLI indicative of pancreatitis, and hypocobalaminemia. A random forest algorithm identified explanatory variables for cats having fPLI levels indicative of pancreatitis.

RESULTS

No LN cats, while 6/30 (20%) of OW and 10/22 (45%) of DM cats had fPLI concentrations indicative of pancreatitis. Body condition score (P = .02) and body weight (P = .002) were positively associated with fPLI levels in LN and OW cats. Higher fPLI, and lower cobalamin concentrations were associated with higher age across groups.

CONCLUSIONS AND CLINICAL IMPORTANCE

Body condition score and body weight were associated with higher fPLI levels in nondiabetic cats. A larger proportion of OW and DM cats had fPLI concentrations indicative of pancreatitis compared to LN cats. Whether this indicates subclinical pancreatitis remains to be determined. Hypocobalaminemia was less frequent in OW compared to DM cats.

Exocrine pancreatic inflammation in canine diabetes mellitus - An active offender?

The purpose of this review is to examine the current scientific literature regarding the interplay between the exocrine and endocrine pancreas, specifically the role of the exocrine pancreas in the pathogenesis of canine diabetes mellitus. β-cell death caused by exocrine pancreatic inflammation is thought to be an under-recognised contributor to diabetes mellitus in dogs, with up to 30 % of canine diabetic patients with concurrent evidence of pancreatitis at post-mortem examination. Current diagnostics for pancreatitis are imprecise, and treatments for both diseases individually have their own limitations: diabetes through daily insulin injections, which has both welfare and financial implications for the stakeholders, and pancreatitis through treatment of clinical signs, such as analgesia and anti-emetics, rather than targeted treatment of the underlying cause. This review will consider the evidence for exocrine pancreatic inflammation making an active contribution to pancreatic β-cell loss and insulin-deficiency diabetes in the dog and explore current and potential future diagnostic and treatment avenues to improve outcomes for these patients.

Overweight and obesity in domestic cats: epidemiological risk factors and associated pathologies

The domestic cat has evolved in various aspects in its journey from original domestication to the present day. Many domestic cats today lead a sedentary indoor lifestyle with low environmental stimulation. In addition, cats have changed their eating habits, transitioning from being carnivorous hunters to animals that eat commercial processed foods. Eating patterns have also changed since cats no longer need to hunt for food but instead have access to several portions throughout the day. All these variables, known as extrinsic epidemiological factors, added to animal-specific or intrinsic epidemiological factors (genetics, sex and breed, among others), predispose cats to the development of overweight and obesity (O&O). The prevalence of O&O has significantly increased in the global cat population, making them a growing clinical concern for companion animals. In turn, O&O contribute to the onset of other pathologies by either increasing susceptibility or creating conditions that allow existing or incipient pathologies to manifest or worsen. Some of these diseases correspond to changes in the musculoskeletal tissue, insulin resistance, type 2 diabetes, skin disorders, and kidney and urinary tract diseases, among others. Therefore, the aim of this review was to analyze the epidemiological variables and diseases associated with O&O in the domestic cat.

Remission of diabetes mellitus induced by prednisolone in combination with cyclosporine toxicity in a cat

A 6-year-old spayed female domestic short-hair cat was presented for primary complaints of anorexia and lethargy. The cat was being treated with cyclosporine (25 mg/cat, PO q24h) and prednisolone (1 mg/kg, PO q12h) for feline hypersensitivity dermatitis and inflammatory bowel disease for 1 year, wherein prednisolone was withdrawn 2 weeks prior to presentation. At presentation, dehydration, hyperglycaemia, ketonaemia, increased fructosamine, glucosuria, ketonuria and metabolic acidosis were observed. The cat was diagnosed with diabetic ketoacidosis (DKA). Immediate treatments with insulin continuous-rate infusion and intravenous fluid therapy were initiated. A serum cyclosporine concentration was >2100 ng/mL, indicating cyclosporine toxicity. Cyclosporine was discontinued immediately. The cat's acidosis and ketonaemia were resolved within a week, allowing a switch from insulin continuous-rate infusion to subcutaneous glargine (1 IU/cat), which was eventually discontinued due to persistent normoglycaemia 12 days after initial presentation. Hyperglycaemia was not observed for 28 days thereafter without insulin, indicating remission of diabetes mellitus. This report suggests that using prednisolone, particularly immune suppressive doses, could be problematic in cats receiving long-term cyclosporine therapy. Additionally, diabetic cats receiving immune-suppressive agents can possibly achieve diabetic remission after surviving DKA through regular monitoring of blood glucose concentration, elimination of prednisolone and intensive blood glucose management.

Signalment and laboratory findings in cats with diabetes mellitus in Germany: a retrospective review of laboratory submissions of 129,505 cats

OBJECTIVES

The aims of this study were to compare signalment and laboratory parameters between diabetic (D) and non-diabetic (ND) cats and poorly-controlled diabetic (PD) and well-controlled diabetic (WD) cats in Germany.

METHODS

Laboratory data from Antech Lab Germany between 2015 and 2018 were retrospectively analysed. Age, sex, red blood cell count (RBC), creatinine (CREA), alkaline phosphatase (AP), alanine aminotransferase (ALT), bilirubin (BILI), cholesterol (CHOL), triglycerides (TRI), glucose (GLU) and total thyroxine (TT4) were compared between D (fructosamine ⩾340 µmol/l) and ND cats, and PD (fructosamine >500 µmol/l) and WD (fructosamine 340-500 µmol/l) cats. The proportion of cats with anaemia (RBC ⩽4.21 ×1012/l), CREA >250 µmol/l, ALT >455 U/l, AP >315 U/l, BILI ⩾35 µmol/l and TT4 > reference interval (RI) was compared between PD and WD cats. Data are presented as median and interquartile range (IQR) and analysed using non-parametric tests. Significance was P<0.05, and effect size was assessed by Cramér V or r.

RESULTS

In total, 129,505 cats were included (D: n = 9334 [prevalence 7.2%], WD: n = 5670/9334 [60.7%]). The median age of D and ND cats was 12 years (IQR D 9-14; ND 9-15); there was no difference in sex. A significant difference was found between groups (D vs ND; PD vs WD) for all parameters studied. Considering the effect sizes and medians outside the RI, the only relevant difference was higher CHOL, TRI, AP and GLU in PD compared with WD (CHOL: PD 7.46 [5.85-9.32] vs WD 5.44 [4.32-6.97] mmol/l, P<0.001, r = 0.39; TRI: PD 1.44 [0.84-3.66] vs WD 0.78 [0.5-1.35] mmol/l, P <0.001, r = 0.35; AP: PD 66 [47-92] vs WD 35 [23-59] U/l, P <0.001, r = 0.39; GLU: PD 23.7 [20.15-27.3] vs WD 6.89 [5-11.31] mmol/l, P <0.001, r = 0.69).

CONCLUSIONS AND RELEVANCE

Laboratory changes in diabetic cats were mild and mainly associated with lipid derangements.

Uncommon dermatologic manifestation (paronychia) in a cat with diabetes mellitus

A 3.5-year-old male intact domestic short hair cat presented for a chronic wound and crusts over the claw and claw folds over several months. The cat was diagnosed with diabetes mellitus based on the presence of persistent hyperglycemia, glucosuria, and compatible clinical signs which consist of polyuria, polydipsia, polyphagia, and weight loss. Glipizide (Glucotrol XL, Pfizer, Indonesia) 2.5 mg orally twice daily was prescribed. By the seventeenth day, the patient's claws and skin around the paw had normalized and the abnormal claw sloughed off, revealing a normal claw underneath. Blood glucose, urinalysis and serum fructosamine were also normalized by the thirtieth day. The patient underwent diabetic remission, and the skin and claw lesions have remained in remission and not recurred since the treatment of the diabetes mellitus. This is the first report of a diabetic cat with dermatologic changes to the skin and claw regions. As the diabetes mellitus went into clinical remission, so too did the dermatologic manifestations, even without any specific dermatologic treatment.

Assessment of glucocorticoid and antibiotic exposure as risk factors for diabetes mellitus in selected dog breeds attending UK primary-care clinics

BACKGROUND

Diabetes mellitus (DM) is an important endocrine disorder in dogs. This study explored prior exposure to glucocorticoids or antibiotic treatment as risk factors for developing DM in dogs attending primary-care VetCompass clinics in the UK.

METHODS

A breed frequency matched case-control study nested in a cohort of dogs (n = 480,469) aged 3 years or over was used to explore associations between glucocorticoid and antibiotic exposure and the odds of developing DM.

RESULTS

A total of 565 cases and 2179 controls were included. Dogs with DM had over four times the odds of exposure to glucocorticoids within 6 weeks prior to diagnosis (odds ratio [OR] 4.07, 95% confidence interval [CI] 2.41-6.89, p < 0.001) compared to controls within 6 weeks prior to a randomly selected quasi-date of diagnosis. Dogs that had only one unique documented antibiotic course had a decreased odds of developing DM (OR 0.65, 95% CI 0.46-0.91, p = 0.012) compared to dogs that had no documented courses of antibiotics.

LIMITATIONS

This study only included selected breeds, so the results may not be generalisable to all dog breeds.

CONCLUSIONS

Exposure to glucocorticoids is associated with a substantial increase in the risk of developing DM for the dog breeds included in this analysis.

Pathophysiology of Prediabetes, Diabetes, and Diabetic Remission in Cats

Diabetes mellitus (DM) has a heterogenous cause, and the exact pathogenesis differs between patients. Most diabetic cats have a cause similar to human type 2 DM but, in some, DM is associated with underlying conditions, such as hypersomatotropism, hyperadrenocorticism, or administration of diabetogenic drugs. Predisposing factors for feline DM include obesity, reduced physical activity, male sex, and increasing age. Gluco(lipo)toxicity and genetic predisposition also likely play roles in pathogenesis. Prediabetes cannot be accurately diagnosed in cats at the current time. Diabetic cats can enter remission, but relapses are common, as these cats might have ongoing, abnormal glucose homeostasis.

Survival, remission, and quality of life in diabetic cats

BACKGROUND

Remission is documented in a substantial proportion of cats with diabetes. The effects of diabetes mellitus (DM) on the lives of cats and their owners should be considered when evaluating treatment success.

OBJECTIVES

To study outcome in cats with DM and the impact DM has on the life situation of cat and owner.

ANIMALS

Domestic and pedigree cats with a diagnosis of DM (n = 477) insured by a Swedish insurance company during 2009 to 2013.

METHODS

Retrospective cross-sectional study. A questionnaire was sent to 1369 owners of cats diagnosed with DM. The questions concerned the cat, treatment, owner perceptions of the disease and treatment and disease outcome. Data were analyzed using multiple linear and logistic regression, with outcomes set as survival for more than 4 weeks after diagnosis, survival time, achieving remission, remission without relapse and quality of life (QoL) for the cat.

RESULTS

The response rate was 35%, leaving 477 questionnaires for analysis. The remission rate among treated cats was 29% (118/405). Feeding a commercially available wet diet was associated with both remission (OR 3.16, 95% confidence interval 1.27-8.12) and remission without relapse (OR 14.8, 95% confidence interval 2.25-153.8). Remission was associated with a better QoL for the cat.

CONCLUSIONS AND CLINICAL IMPORTANCE

The association between feeding a commercially available wet diet and remission is important and strengthens the role of diet in treatment of DM in cats. Linking remission and a better QoL for the cat emphasizes remission as a goal in disease management.

Commercial vs Homemade Cat Diets: What you need to know

PRACTICAL RELEVANCE

A feeding plan recommendation for cats, both healthy and with disease, should include diet choice, amounts to feed and the feeding method. Diet choice can be complex owing to the abundance of products, sometimes with conflicting marketing messages, and the prevalence of information with no scientific basis. It is important to be aware of the specific challenges of both commercial and homemade diets. Moreover, a nutritional assessment is a prerequisite when recommending a diet to ensure that it is safe, appropriate for the cat's life stage and nutritious for long-term feeding.

COMMERCIAL VS HOMEMADE DIETS

There are a variety of commercial diets available, allowing considerable customisation. These products are regulated and can be tested to determine nutritional adequacy and safety, although as the industry is partly self-regulated, choice of manufacturer is important. Properly formulated homemade diets can be customised to the patient and are a good option when no commercial product that meets the patient's needs exists. Homemade diets can be an owner preference. A serious limitation is the lack of testing, potentially affecting safety and also resulting in a reliance on database information to determine nutritional adequacy. Generic homemade diet recipes (eg, sourced from the internet) have additional risks of deficiencies and imbalances, and are not recommended. Homemade diets should be devised by a veterinary nutrition specialist with consideration of both patient and owner factors.

CLINICAL CHALLENGES

Dietary misinformation, which is all too readily available on the internet, may result in owners making questionable feeding choices for their pets. A homemade diet may be requested by owners based on the perception that there are poor ingredients in commercial foods. The veterinary healthcare team needs to have good evidence-based information to present to owners about diet choice.

EVIDENCE BASE

Several decades of research on feline nutrition forms the basis for nutritional requirements and dietary recommendations. There are varying degrees of evidence regarding requirements for each nutrient, and a lack of data on the effects of different types of processing on nutrient needs.

Is methylprednisolone acetate-related insulin resistance preventable in cats?

Methylprednisolone acetate (MPA) is often prescribed to cats despite being recognized eventually as diabetogenic. To assess MPA-related insulin resistance and evaluate the efficacy of metformin or an obesity and diabetes mellitus (O&D) adjuvant diet as protective factors, a randomized clinical trial was conducted with 28 owned cats undergoing glucocorticoid therapy. A single MPA dose of 20 mg intramuscularly was administered to each cat. Controls (n=10) received only MPA. In the diet group (n=9), replacement of their habitual diet by ad-libitum feeding of a feline commercial O&D diet (Equilíbrio O&D, Total Alimentos ADM) was made. In the metformin group (n=9), metformin chlorhydrate 25mg/cat PO/q24h was administered for 30 days. All patients were clinically evaluated at baseline (T0), day 15 (T15), and day 30 (T30) and blood draw for complete blood count, serum biochemistry, and determination of insulin concentrations. Fasting Insulin Sensitivity Index (SI), Amended Insulin to Glucose Ratio (AIGR), Homeostatic Model Assessment of Insulin Resistance (HOMA-IR), and Homeostatic Model Assessment of beta-cell function (HOMA-B) were calculated based on fasting glycemia and insulinemia. All groups showed significantly higher levels (p < 0.05) of neutrophils, albumin, glucose, cholesterol, triglycerides, and serum insulin at T15. Patients in the metformin group showed also higher SI, AIGR, and HOMA-IR results at T15. Also, at T15, reduced levels (p < 0.05) of eosinophils, lymphocytes, and creatinine were documented in all groups. An MPA single dose induced changes in insulin sensitivity in cats; however, neither metformin nor O&D feeding used in this study was effective as protective factors against MPA-related insulin resistance.

Falciform fat:femur length ratio provides a novel method for objective postmortem estimation of total body fat in overweight and obese cats

Determination of the nutritional condition, including estimation of amounts of total body fat (tBF), at routine postmortem examination of cats is typically based on subjective visual assessment. Subjective assessment may result in uncertainties regarding degree of overweight, and objective methods that provide a numerical value reflecting the tBF could be valuable to accurately judge excess body fat. We investigated if the falciform fat pad weight (FFPW) was correlated to tBF and could be used to detect overweight and obesity in cats. The FFPW and the femur length (FL) were recorded at postmortem examination in 54 cats and the FFPW:FL ratio (FFR) calculated. Each cat was additionally assigned to a fat category (FC) according to subjective assessment. Computed tomography was used to determine tBF as the body fat percentage (%BF), the body fat volume (BFV), and BFV normalized to animal size (nBFV) in 39 cats. There was strong correlation between the FFPW and the BFV (r = 0.888) and between the FFR and the nBFV (r = 0.897). The correlation between the nBFV and %BF was very strong (r = 0.974). Using a lower FFR cutoff value of 3.5 for obesity and 1.6 for overweight, there was a discrepancy in FC between using the FFR and subjective assessment in 6 of 54 cats (11%). We conclude that the FFPW increases proportionally with tBF and that the FFR provides a method for objective tBF estimation. We suggest introducing the FFR to feline postmortem examination protocols as an objective estimate of tBF.

A genome-wide association study identifies novel candidate genes for susceptibility to diabetes mellitus in non-obese cats

Diabetes mellitus (DM) is a common feline endocrinopathy, which is similar to human type 2 diabetes (T2DM) in terms of its pathophysiology. T2DM occurs due to peripheral insulin resistance and/or β-cell dysfunction. Several studies have identified genetic and environmental factors that contribute to susceptibility to human T2DM. In cats, environmental factors such as obesity and physical inactivity have been linked with DM, although to date, the only genetic association that has been demonstrated is with a polymorphism in the feline MC4R gene. The aim of this study was to perform a genome-wide association study (GWAS) to identify polymorphisms associated with feline DM. Illumina Infinium 63k iSelect DNA arrays were used to analyse genomic DNA samples from 200 diabetic domestic shorthair cats and 399 non-diabetic control cats. Data was analysed using PLINK whole genome data analysis toolset. A linear model analysis, EMMAX, was done to test for population structure and HAPLOVIEW was used to identify haplotype blocks surrounding the significant SNPs to assist with candidate gene nomination. A total of 47,497 SNPs were available for analysis. Four SNPs were identified with genome-wide significance: chrA2.4150731 (praw = 9.94 x10-8); chrUn17.115508 (praw = 6.51 x10-8); chrUn17.394136 (praw = 2.53 x10-8); chrUn17.314128 (praw = 2.53 x10-8) as being associated with DM. The first SNP is located within chromosome A2, less than 4kb upstream of the dipeptidyl-peptidase-9 (DPP9) gene, a peptidase involved in incretin inactivation. The remaining three SNPs are located within a haplotype block towards the end of chromosome A3; within this region, genes of interest include TMEM18 and ACP1, both previously associated with T2DM. This study indicates a polygenic component to susceptibility to DM in cats and has highlighted several loci and candidate genes worthy of further investigation.

Validation of a flash glucose monitoring system in outpatient diabetic cats

BACKGROUND

Interstitial glucose (IG) concentration measurement using a flash glucose monitoring system (FGMS) is a noninvasive, affordable, and informative method to regulate patients with diabetes mellitus (DM) but has not been fully validated in outpatient cats with DM.

OBJECTIVES

To further validate the FreeStyle Libre FGMS in outpatient diabetic cats.

ANIMALS

Eight client-owned cats with DM.

METHODS

Prospective observational validation study. Tissue glue was used to attach the sensor to the cat. Lin's concordance correlation coefficient (ρc ) was used to compare IG concentrations measured by the FGMS to blood glucose concentrations measured using an automated biochemistry analyzer (ABA) and point-of-care glucometer (POCG).

RESULTS

Data from 15 sensor placements in 8 cats were analyzed. Paired IG and ABA glucose concentrations (139 samples) had excellent correlation (ρc  = 0.96) as did IG and POCG glucose concentrations (142 samples, ρc  = 0.92). Sensor failure or displacement were recorded for 12/15 (80%) sensor placements. Median time of sensor activity was 7 days (range, 2-13 days).

CONCLUSIONS AND CLINICAL IMPORTANCE

In outpatient cats with DM, the FGMS-measured IG concentration correlated well with ABA-measured blood glucose concentration, but a high rate of sensor failures was observed.

Prednisolone-induced diabetes mellitus in the cat: a historical cohort

OBJECTIVES

Prednisolone is a commonly used drug in cats and potential adverse effects include hyperglycaemia and diabetes mellitus. The aims of this study were to evaluate the frequency and investigate potential predisposing risk factors for the development of prednisolone-induced diabetes mellitus (PIDM) in cats.

METHODS

The electronic records of a tertiary referral centre were searched for cats receiving prednisolone at a starting dose of ⩾1.9 mg/kg/day, for >3 weeks and with follow-up data available for >3 months between January 2007 and July 2019. One hundred and forty-three cats were included in the study.

RESULTS

Of the 143 cats, 14 cats (9.7%) were diagnosed with PIDM. Twelve out of 14 cats (85.7%) developed diabetes within 3 months of the initiation of therapy.

CONCLUSIONS AND RELEVANCE

Cats requiring high-dose prednisolone therapy should be closely monitored over the first 3 months of therapy for the development of PIDM.

The shared risk of diabetes between dog and cat owners and their pets: register based cohort study

OBJECTIVE

To investigate whether dog and cat owners and their pets share a risk of developing diabetes.

DESIGN

Cohort study.

SETTING

Register based longitudinal study, Sweden.

PARTICIPANTS

208 980 owner-dog pairs and 123 566 owner-cat pairs identified during a baseline assessment period (1 January 2004 to 31 December 2006).

MAIN OUTCOME MEASURES

Type 2 diabetes events in dog and cat owners and diabetes events in their pets, including date of diagnosis during the follow-up period (1 January 2007 to 31 December 2012). Owners with type 2 diabetes were identified by combining information from the National Patient Register, the Cause of Death Register, and the Swedish Prescribed Drug Register. Information on diabetes in the pets was extracted from veterinary care insurance data. Multi-state models were used to assess the hazard ratios with 95% confidence intervals and to adjust for possible shared risk factors, including personal and socioeconomic circumstances.

RESULTS

The incidence of type 2 diabetes during follow-up was 7.7 cases per 1000 person years at risk in dog owners and 7.9 cases per 1000 person years at risk in cat owners. The incidence of diabetes in the pets was 1.3 cases per 1000 dog years at risk and 2.2 cases per 1000 cat years at risk. The crude hazard ratio for type 2 diabetes in owners of a dog with diabetes compared with owners of a dog without diabetes was 1.38 (95% confidence interval 1.10 to 1.74), with a multivariable adjusted hazard ratio of 1.32 (1.04 to 1.68). Having an owner with type 2 diabetes was associated with an increased hazard of diabetes in the dog (crude hazard ratio 1.28, 1.01 to 1.63), which was attenuated after adjusting for owner's age, with the confidence interval crossing the null (1.11, 0.87 to 1.42). No association was found between type 2 diabetes in cat owners and diabetes in their cats (crude hazard ratio 0.99, 0.74 to 1.34, and 1.00, 0.78 to 1.28, respectively).

CONCLUSIONS

Data indicated that owners of a dog with diabetes were more likely to develop type 2 diabetes during follow-up than owners of a dog without diabetes. It is possible that dogs with diabetes could serve as a sentinel for shared diabetogenic health behaviours and environmental exposures.

Mapping the genetic basis of diabetes mellitus in the Australian Burmese cat (Felis catus)

Diabetes mellitus, a common endocrinopathy affecting domestic cats, shares many clinical and pathologic features with type 2 diabetes in humans. In Australia and Europe, diabetes mellitus is almost four times more common among Burmese cats than in other breeds. As a genetically isolated population, the diabetic Australian Burmese cat provides a spontaneous genetic model for studying diabetes mellitus in humans. Studying complex diseases in pedigreed breeds facilitates tighter control of confounding factors including population stratification, allelic frequencies and environmental heterogeneity. We used the feline SNV array and whole genome sequence data to undertake a genome wide-association study and runs of homozygosity analysis, of a case–control cohort of Australian and European Burmese cats. Our results identified diabetes-associated haplotypes across chromosomes A3, B1 and E1 and selective sweeps across the Burmese breed on chromosomes B1, B3, D1 and D4. The locus on chromosome B1, common to both analyses, revealed coding and splice region variants in candidate genes, ANK1, EPHX2 and LOX2, implicated in diabetes mellitus and lipid dysregulation. Mapping this condition in Burmese cats has revealed a polygenic spectrum, implicating loci linked to pancreatic beta cell dysfunction, lipid dysregulation and insulin resistance in the pathogenesis of diabetes mellitus in the Burmese cat.

The Burmese cat as a genetic model of type 2 diabetes in humans

The recent extension of genetic tools to the domestic cat, together with the serendipitous consequences of selective breeding, have been essential to the study of the genetic diseases that affect them. Cats are increasingly presented for veterinary surveillance and share many of human's heritable diseases, allowing them to serve as natural models of these conditions. Feline diabetes mellitus is a common condition in domestic cats that bears close pathological and clinical resemblance to type 2 diabetes in humans, including pancreatic β-cell dysfunction and peripheral insulin resistance. In Australia, New Zealand and Europe, diabetes mellitus is almost four times more common in cats of the Burmese breed than in other breeds. This geographically based breed predisposition parallels familial and population clustering of type 2 diabetes in humans. As a genetically isolated population, the Australian Burmese breed provides a spontaneous, naturally occurring genetic model of type 2 diabetes. Genetically isolated populations typically exhibit extended linkage disequilibrium and increased opportunity for deleterious variants to reach high frequencies over many generations due to genetic drift. Studying complex diseases in such populations allows for tighter control of confounding factors including environmental heterogeneity, allelic frequencies and population stratification. The homogeneous genetic background of Australian Burmese cats may provide a unique opportunity to either refine genetic signals previously associated with type 2 diabetes or identify new risk factors for this disease.

The Fecal Microbiota in the Domestic Cat (Felis catus) Is Influenced by Interactions Between Age and Diet; A Five Year Longitudinal Study

In humans, aging is associated with changes in the gastrointestinal microbiota; these changes may contribute to the age-related increase in incidence of many chronic diseases, including Type 2 diabetes. The life expectancies of cats are increasing, and they are also exhibiting the same types of diseases. While there are some studies investigating the impacts of diets on gastrointestinal microbiota in young cats, the impacts of aging in older cats has not been explored. We followed a cohort of related kittens, maintained on two commercial diets (kibbled and canned) from weaning (8 weeks) to 5 years of age (260 weeks). We hypothesized that the long-term feeding of specific diet formats would (a) lead to microbial composition changes due to aging, (b) impact body composition, and (c) affect insulin sensitivity in the aging cat. We observed that both diet and age affected fecal microbial composition, and while age correlated with changes in body composition, diet had no effect on body composition. Similarly insulin sensitivity was not affected by age nor diet. 16S rRNA sequencing found unclassified Peptostreptococcaceae were prominent across all ages averaging 21.3% of gene sequence reads and were higher in cats fed canned diets (average of 25.7% of gene sequence reads, vs. 17.0% for kibble-fed cats). Age-related effects on body composition and insulin sensitivity may become apparent as the cats grow older; this study will continue to assess these parameters.

Overweight in adult cats: a cross-sectional study

Background

Overweight in cats is a major risk factor for diabetes mellitus and has also been associated with other disorders. Overweight and obesity are believed to be increasing problems in cats, as is currently seen in people, with important health consequences. The objectives of the present study were to determine the prevalence of overweight in cats from two different cohorts in a cross-sectional study design and to assess associations between overweight and diagnoses, and between overweight and demographic and environmental factors. Data were obtained from medical records for cats (n = 1072) visiting an academic medical center during 2013–2015, and from a questionnaire on insured cats (n = 1665). From the medical records, information on body condition score, breed, age, sex, neutering status, and diagnosis was obtained. The questionnaire included questions relating to the cat’s body condition, breed, age, sex, neutering status, outdoor access, activity level, and diet. Data were analyzed by multivariable logistic regression.

Results

The prevalence of overweight was 45% in the medical records cohort and 22% in the questionnaire cohort, where owners judged their pet’s body condition. Overweight cats in the medical records cohort were more likely to be diagnosed with lower urinary tract disease, diabetes mellitus, respiratory disease, skin disorders, locomotor disease, and trauma. Eating predominantly dry food, being a greedy eater, and inactivity were factors associated with an increased risk of overweight in the final model in the questionnaire cohort. In both cohorts, the Birman and Persian breeds, and geriatric cats, were less likely to be overweight, and male cats were more likely to be overweight.

Conclusions

The prevalence of overweight cats (45%) as assessed by trained personnel was high and in the same range as previously reported. Birman and Persian cats had a lower risk of overweight. The association with dry food found in adult, neutered cats is potentially important because this type of food is commonly fed to cats worldwide, and warrants further attention. Drawbacks related to the study design need to be acknowledged when interpreting the results, such as a potential for selection bias for cats visiting an animal hospital, and an information bias for questionnaire data. The high occurrence of overweight in cats needs to be addressed because it negatively affects their health.

Electronic supplementary material

The online version of this article (10.1186/s13028-018-0359-7) contains supplementary material, which is available to authorized users.

Cats and Carbohydrates: The Carnivore Fantasy?

The domestic cat’s wild ancestors are obligate carnivores that consume prey containing only minimal amounts of carbohydrates. Evolutionary events adapted the cat’s metabolism and physiology to this diet strictly composed of animal tissues and led to unique digestive and metabolic peculiarities of carbohydrate metabolism. The domestic cat still closely resembles its wild ancestor. Although the carnivore connection of domestic cats is well recognised, little is known about the precise nutrient profile to which the digestive physiology and metabolism of the cat have adapted throughout evolution. Moreover, studies show that domestic cats balance macronutrient intake by selecting low-carbohydrate foods. The fact that cats evolved consuming low-carbohydrate prey has led to speculations that high-carbohydrate diets could be detrimental for a cat’s health. More specifically, it has been suggested that excess carbohydrates could lead to feline obesity and diabetes mellitus. Additionally, the chances for remission of diabetes mellitus are higher in cats that consume a low-carbohydrate diet. This literature review will summarise current carbohydrate knowledge pertaining to digestion, absorption and metabolism of carbohydrates, food selection and macronutrient balancing in healthy, obese and diabetic cats, as well as the role of carbohydrates in prevention and treatment of obesity and diabetes mellitus.