Neutering in dogs and cats: current scientific evidence and importance of adequate nutritional management

Enhancing community health: Veterinary services for underserved areas in Costa Rica with a One Health Approach

In underserved areas of Costa Rica, community veterinary services aim to provide comprehensive care for companion animals, covering preventive, therapeutic, and surgical medicine. Emphasizing a One Health approach, our model focuses on animal welfare, health, and public well-being in vulnerable regions. The project's goal is to ensure the overall well-being of animals, people, and the environment by collaboratively addressing animal health issues and recognizing their interconnected impact on optimal health. Limited resources in underprivileged areas, including restricted access to veterinary care for pets, pose challenges to overall health. Despite its global health benefits, the absence of companion animal veterinary care in these regions has been largely overlooked. Our One Health approach not only addresses animal health but also has a significant impact on human and environmental health, economies, and social factors. This innovative strategy is a pioneering effort to tackle complex health issues in Costa Rica.

Identifying the target population and preventive strategies to combat feline obesity

Feline obesity continues to be a priority health and welfare issue. Most research surrounding obesity currently focuses on obesity treatment. However, treatment for feline obesity is slow, often unsuccessful and not without consequences. Identifying high-risk populations for obesity onset is crucial for developing and implementing preventive strategies. This review identifies post-gonadectomy kittens aged 5-12 months as the primary target population for obesity prevention in domestic cats and highlights dietary and feeding management strategies to be implemented for obesity prevention.

Characteristics of Nutrition and Metabolism in Dogs and Cats

Domestic dogs and cats have evolved differentially in some aspects of nutrition, metabolism, chemical sensing, and feeding behavior. The dogs have adapted to omnivorous diets containing taurine-abundant meat and starch-rich plant ingredients. By contrast, domestic cats must consume animal-sourced foods for survival, growth, and development. Both dogs and cats synthesize vitamin C and many amino acids (AAs, such as alanine, asparagine, aspartate, glutamate, glutamine, glycine, proline, and serine), but have a limited ability to form de novo arginine and vitamin D3. Compared with dogs, cats have greater endogenous nitrogen losses and higher dietary requirements for AAs (particularly arginine, taurine, and tyrosine), B-complex vitamins (niacin, thiamin, folate, and biotin), and choline; exhibit greater rates of gluconeogenesis; are less sensitive to AA imbalances and antagonism; are more capable of concentrating urine through renal reabsorption of water; and cannot tolerate high levels of dietary starch due to limited pancreatic α-amylase activity. In addition, dogs can form sufficient taurine from cysteine (for most breeds); arachidonic acid from linoleic acid; eicosapentaenoic acid and docosahexaenoic acid from α-linolenic acid; all-trans-retinol from β-carotene; and niacin from tryptophan. These synthetic pathways, however, are either absent or limited in all cats due to (a) no or low activities of key enzymes (including pyrroline-5-carboxylate synthase, cysteine dioxygenase, ∆6-desaturase, β-carotene dioxygenase, and quinolinate phosphoribosyltransferase) and (b) diversion of intermediates to other metabolic pathways. Dogs can thrive on one large meal daily, select high-fat over low-fat diets, and consume sweet substances. By contrast, cats eat more frequently during light and dark periods, select high-protein over low-protein diets, refuse dry food, enjoy a consistent diet, and cannot taste sweetness. This knowledge guides the feeding and care of dogs and cats, as well as the manufacturing of their foods. As abundant sources of essential nutrients, animal-derived foodstuffs play important roles in optimizing the growth, development, and health of the companion animals.

Bartonella spp. in households with cats: Risk factors for infection in cats and human exposure

The aim of this study was to estimate the occurrence of Bartonella spp. per household in cats and the risk factors for Bartonella spp. positivity in cats and their owners from Valdivia, Chile. A total of 464 cats (distributed within 324 households) and 326 humans (control group [n = 112] and cat owner [n = 214]) distributed in 262 households were sampled. From the cat owners (n = 214), 128 humans were in households where the cat was also sampled, totaling 84 households with dual sampling. Real-time PCR (qPCR) was used for Bartonella spp. detection in blood from cats and humans, and immunofluorescent immunoassay (IFA) anti-Bartonella henselae was performed in human serum samples. Out of the total of 324 households, 20.43% presented at least one Bartonella positive cat. From the households with dual sampling, 29.7% (25/84) presented at least one qPCR-Bartonella spp. positive cat. However, Bartonella DNA was not amplified in humans, and in 7.3% (6/82) of the households was found at least one of the cat's owners exposed to B. henselae. Cats younger than one year (Odds Ratio (OR) = 5.3), non-neutered (OR 3.46), sampled at home (OR 5.82), and with improper application of tick/flea control products (OR 3.13) showed a higher risk for Bartonella spp. presence. Humans with occupational exposure involving animal contact, were more likely to exhibit B. henselae seropositivity (OR 7.5). Bartonella spp. was present in the cats a moderate number of households, but Bartonella DNA was not detected in owners' blood, inferring that there is a low risk of recent human infection in the studied population.

Changes in gut microbiota and short-chain fatty acids are involved in the process of canine obesity after neutering

Neutering is a significant risk factor for obesity in dogs. Changes in gut microbiota and its metabolites have been identified as a key player during obesity progression. However, the mechanisms that promote neuter-associated weight gain are not well understood. Therefore, in this study, sixteen clinically healthy Beagle dogs (6 male and 10 female, mean age = 8.22 ± 0.25 mo old) were neutered. Body weight (BW) and body condition score (BCS) were recorded at 1 d before neutering, 3, 6, 10, 16, and 21 mo after neutering. Dogs were grouped based on their BCS as ideal weight group (IW, n = 4, mean BW = 13.22 ± 1.30 kg, mean BCS = 5.00 ± 0.41) and obese group (OB, n = 12, mean BW = 18.57 ± 1.08 kg, mean BCS = 7.92 ± 0.82) at 21 mo after neutering. Serum lipid profile, glucose, and hormones and fecal microbiota and short-chain fatty acids (SCFAs) were measured. Our results showed that OB dogs had greater (P < 0.0001) BW (18.57 vs. 13.22 kg), BCS (7.92 vs. 5.00), and average daily gain (12.27 vs. 5.69 g/d) than IW dogs at 21 mo after neutering, and the obesity rate was up to 60%. In addition, significant increases (P < 0.05) in serum triglyceride (TG, 1.10 vs. 0.56 mmol/L) and high-density lipoprotein cholesterol (HDL-C, 6.96 vs. 5.40 mmol/L) levels and a significant decrease (P < 0.05) in serum adiponectin (APN, 54.06 vs. 58.39 μg/L) level were observed in OB dogs; serum total cholesterol (4.83 vs. 3.75 mmol/L) (P = 0.075) and leptin (LEP, 2.82 vs. 2.53 μg/L) (P = 0.065) levels tended to be greater in OB dogs; there was a trend towards a lower (P = 0.092) APN/LEP (19.32 vs. 21.81) in OB dogs. Results of fecal microbial alpha-diversity showed that Observed_species and Chao1 indices tended to be lower (P = 0.069) in OB dogs. The STAMP and LEfSe analyses revealed that OB dogs had a greater (P < 0.05 and LDA > 2) reduction in relative abundances of Bacteroides, Prevotella_9, and Megamonas than IW dogs. In addition, OB dogs also had greater (P < 0.05) reduction in fecal acetate, propionate, and butyrate concentrations than IW dogs. Moreover, clear negative correlations (|r| > 0.5 and P < 0.05) were found between SCFAs-producing bacteria and BW, TG, and HDL-C. The functional predictions of microbial communities based on PICRUSt2 analysis revealed that lipid metabolism and endocrine system were significantly disturbed in obese dogs after neutering. Thus, intervention with SCFAs-producing bacteria might represent a new target for the prevention or treatment of canine obesity after neutering. Moreover, weight control before neutering may also contribute to the prevention of canine obesity after neutering.

Comparison of growth in neutered Domestic Shorthair kittens with growth in sexually-intact cats

The first aim of these studies was to compare growth patterns of healthy kittens neutered during growth with growth standards created for sexually-intact kittens. A second aim was to clarify the impact of neutering in kittens on body composition and body shape. Study 1 was a retrospective observational study comparing median growth trajectories of healthy, client-owned domestic shorthair (DSH) kittens in optimal body condition and neutered at different ages, with previously-created growth standards from a similar, sexually-intact, population. The neuter groups contained between 3.0k and 9.3k cats. For all neuter groups in both sexes, the median growth trajectory inclined upwards after the procedure, with this being more marked in female than in male kittens. This upwards inclination was less marked for kittens neutered later during growth in both sexes, with the effect being least in kittens neutered after 28-29 weeks. Study 2 was an analysis of new body composition and zoometric data from a previously-published randomised study, comparing growth-related measures between 11 pairs of sexually-intact and neutered (at 19 weeks age) female DSH cats in a research population. Before neutering, the growth pattern in neutered kittens and sexually-intact kittens was similar, but neutered kittens were heavier by 52 weeks (mean difference in fold change vs. 10 weeks 1.34, 95-CI: 1.07-1.72), had a greater fat mass (mean difference in fold change vs. 10 weeks 1.91, 95-CI 1.09-3.21) and greater lean mass (mean difference in fold change vs. 10 weeks 1.23, 95-CI: 1.03-1.48). Abdominal girth (mean difference in fold change vs. 10 weeks 1.20, 95-CI: 1.04-1.39) and rib cage length (mean difference in fold change vs. 10 weeks 1.18, 95-CI: 1.02-1.36) were also greater, but there were no differences in other zoometric measurements. Veterinarians should consider the potential impact that neutering has on gain of adipose tissue, especially early neutering in female kittens. Bodyweight should be monitored closely during growth and especially after neutering to prevent inappropriate weight gain.

Environmental risk factors in puppies and kittens for developing chronic disorders in adulthood: A call for research on developmental programming

Many dogs and cats are affected by chronic diseases that significantly impact their health and welfare and relationships with humans. Some of these diseases can be challenging to treat, and a better understanding of early-life risk factors for diseases occurring in adulthood is key to improving preventive veterinary care and husbandry practices. This article reviews early-life risk factors for obesity and chronic enteropathy, and for chronic behavioral problems, which can also be intractable with life-changing consequences. Aspects of early life in puppies and kittens that can impact the risk of adult disorders include maternal nutrition, establishment of the gut microbiome, maternal behavior, weaning, nutrition during growth, growth rate, socialization with conspecifics and humans, rehoming and neutering. Despite evidence in some species that the disorders reviewed here reflect the developmental origins of health and disease (DOHaD), developmental programming has rarely been studied in dogs and cats. Priorities and strategies to increase knowledge of early-life risk factors and DOHaD in dogs and cats are discussed. Critical windows of development are proposed: preconception, gestation, the suckling period, early growth pre-neutering or pre-puberty, and growth post-neutering or post-puberty to adult size, the durations of which depend upon species and breed. Challenges to DOHaD research in these species include a large number of breeds with wide genetic and phenotypic variability, and the existence of many mixed-breed individuals. Moreover, difficulties in conducting prospective lifelong cohort studies are exacerbated by discontinuity in pet husbandry between breeders and subsequent owners, and by the dispersed nature of pet ownership.

An overweight/obesity survey among dogs and cats attended at a veterinary teaching hospital during the second year of the COVID-19 pandemic

ABSTRACT Anecdotal reports suggest that the new coronavirus SARS-CoV-2 pandemic (COVID-19) has increased overweight and obesity prevalence in dogs and cats. The present report aimed to perform a retrospective overweight/obesity survey on 1,001 consecutive cases attended in the Veterinary Clinics Hospital from the Federal University of Rio Grande do Sul during its reopening to the public after months closed due to the pandemic. The overall overweight or obesity observed prevalence was 36.63%; being the frequency in cats slightly greater (38.37%) than compared to dogs (35.76%). No local increase in these frequencies was detected. Neutering (dogs and cats), age greater than 10 years (dogs), and male gender (cats) were factors associated with overweight/obesity. Bodyweight was not registered in about 30% of the medical records, while the body condition score was not registered in about 50% of the cases. These flaws were more often observed in feline medical records and efforts to improve these data records are warranted.

Determining the protocol requirements of in-home dog food digestibility testing

In-home pet food testing has the benefit of yielding data which is directly applicable to the pet population. Validated and standardised in-home test protocols need to be available, and here we investigated key protocol requirements for an in-home canine food digestibility protocol. Participants were recruited via an online survey. After meeting specific inclusion criteria, sixty dogs of various breeds and ages received, during 14 consecutive days, a relatively low and high digestible complete dry extruded food containing titanium (Ti) dioxide. Both foods were given for 7 d in a cross-over design. Owners collected faeces daily allowing daily faecal Ti concentrations and digestibility of nitrogen (N), dry matter (DM), crude ash, organic matter (OM), crude fat (Cfat), starch and gross energy (GE) to be determined. Faecal Ti and digestibility values for all nutrients were not different (P > 0·05) from the second day onwards after first consumption for both foods. One day of faecal collection yielded reliable digestibility values with additional collection days not reducing the confidence interval around the mean. Depending on the accepted margin of error, the food and the nutrient of interest, the minimal required sample size was between 9 and 43 dogs. Variation in digestibility values could in part be explained by a dog's neuter status (N, crude ash) and age (crude ash, Cfat) but not sex and body size. Future studies should focus on further identifying and controlling sources of variation to improve the in-home digestibility protocol and reduce the number of dogs required.

Profile qualitative variables on the dynamics of weight loss programs in dogs

Obesity is the most common nutritional disorder in dogs and it is associated with many comorbidities. Some obesity risk factors have already been established, however, the evaluation of the effect of different individual variables on weight loss induced by calorie restriction, although very important, is still poorly explored. The weight loss protocol can be updated and improved by more precise and adjusted equations throughout the weight loss program in the clinical routine practice. Therefore, the objective of this study was to analyze weight loss program dynamics in groups according to reproductive status, age, body size, and breed, as well as to define more accurately the amount of calories per target metabolic weight throughout the program. Data of 1,053 cases, presented between 2012 and 2019 at the Veterinary Hospital of the School of Veterinary Medicine and Animal Science of the University of São Paulo (FMVZ-USP) were retrospectively analyzed. A total of 77 obese dogs (body condition scores 8/9 or 9/9) of different ages, breeds, sizes, and reproductive status were selected. These dogs did not have any concomitant illnesses and successfully completed the weight loss program. Statistical analysis was performed and values of p≤0.05 were considered significant. The proposed weight loss program was based on an energy restriction protocol where daily energy intake (in kcal) was estimated as 70 kcal × target weight0.75. The target weight (TW) was defined as 80% of the animal's current weight. The average calorie intake for weight loss (calories x target weight0.75) was lower for spayed females (62.36), differing from intact males (66.14) and neutered males (65.41), while intact females (63.66) showed intermediate values without differing between groups (p = 0.015). There were no differences between weight loss calories according to age (p = 0.473) or body size (p = 0.084), allowing the use of the same mathematical equation for intact and neutered dogs; for dogs older than 1 year and of different body sizes. Regarding the breed, the average calorie intake was lower (p = 0.002) in mixed breed dogs (61.54xTW0.75) when compared to obesity-prone purebred dogs (64.17xTW0.75) and other purebreds (65.27xTW0.75). It was concluded that spayed females and mixed breed dogs have greater difficulty in losing weight, that is, they need fewer calories per metabolic body weight for the weight loss program to succeed. A more accurate equation for energy requirement for weight loss can improve chances of success, therefore improving compliance and helping clinical management of obesity in dogs.

Supplementation of omega-3 and dietary factors can influence the cholesterolemia and triglyceridemia in hyperlipidemic Schnauzer dogs: A preliminary report

Primary hyperlipidaemia in Schnauzer is characterized by increased plasma triglycerides (TG) and/or total cholesterol (TC) concentration and is associated with an increased risk of developing pancreatitis, insulin resistance and seizures. In humans, omega-3 fatty acids in addition to a low-fat diet can be used to reduce TG and TC. This study evaluated the therapeutic efficacy of omega-3 fatty acids associated to a diet management with two different fat content in Schnauzer with primary hyperlipidaemia. Eighteen dogs with primary hyperlipidaemia were divided into two groups: group 1, n = 10, 8 females, 2 males, age (mean ± standard deviation) of 7.13 ± 2.70 years and body weight (BW) (mean ± standard deviation) of 7.25 ± 1.22 kg were treated with fish oil (approximately 730 mg/day of omega-3) associated with a low-fat and low-calorie diet (approximately 24g of fat/1000 kcal) for 90 days (T90); and group 2, n = 8 dogs, 6 females, 2 males, with 7.0 ± 1.77 years old and average BW of 8.36 ± 1.51 kg, treated with fish oil (approximately 730 mg/day of omega-3) and maintenance diet with moderate amount of fat (approximately 33g of fat/1000 kcal) for 90 days. Plasma TG and TC concentrations and lipoprotein (LP) profile (VLDL, LDL, HDL) were evaluated before and after treatment. TG and TC serum concentrations, expressed in mg/dL (mean ± standard deviation), before and after treatment in group 1 were: TG = 391.30 ± 487.86 (T0) and 118.7 ± 135.21 (T90); TC = 308.2 ± 63.06 (T0) and 139 ± 36.91 (T90). As for group 2, TG = 391.63 ± 336.89 (T0) and 250.75 ± 211.56 (T90); TC = 257.25 ± 92.88 (T0) and 207.25 ± 63.79 (T90). A reduction (p<0.05) of TG and TC was observed in both groups. The distribution of TG and TC among LP was not different between the pre (T0) and post treatment (T90) periods. After 90 days of treatment, the administration of omega-3 fatty acids, associated with a low-fat or maintenance diet reduced triglyceridemia and cholesterolemia without altering LP profile. The current investigation shows that both therapies were effective in reducing plasma TC and TG concentrations without altering LP profile.

Pyometra-associated insulin resistance assessment by insulin binding assay and tyrosine kinase activity evaluation in canine muscle tissue

Diestrus is associated with insulin resistance in bitches and pyometra can further impair insulin sensitivity. This study aimed to compare insulin sensitivity, insulin binding, and tyrosine kinase activity in bitches in anestrus, diestrus, or with pyometra. Patients submitted to elective ovariohysterectomy were divided into anestrus (n = 11) or diestrus (n = 13) according to reproductive history, vaginal cytology, and uterine histology. The group pyometra (n = 8) included bitches diagnosed with the disease based on clinical presentation and abdominal ultrasound findings and further confirmed by uterine histopathology. All patients were submitted to an intravenous glucose tolerance test (IVGTT) before ovariohysterectomy, and rectus abdominis muscle samples were collected during surgery for plasmatic membrane suspension preparation. Muscle-membranes were submitted to cold saturation insulin binding assay for dissociation constant (Kd) and maximum binding capacity (Bmax) determination, as well as exogenous substrate Poly (Glu: Tyr 4:1) phosphorylation assay for basal tyrosine kinase evaluation. Bitches with pyometra showed higher basal insulin (P < 0.001) and higher area under the curve (AUC) for insulin (P = 0.01) and glucose (P < 0.001) response during the IVGTT in comparison with bitches in anestrus or diestrus. Diestrus (P < 0.0001) and pyometra (P = 0.001) were associated with reduced tyrosine kinase activity in comparison with anestrus. No differences were documented in Kd and Bmax results for the low-affinity/high-capacity insulin receptors; however, high-affinity/low-capacity insulin receptors showed higher Kd and Bmax results in bitches in diestrus or with pyometra (P < 0.05) in comparison with anestrus. Despite the pyometra group showed the highest Kd values (P < 0.01), its Bmax results did not differ from the diestrus group (P > 0.05). Diestrus' higher Kd values and reduced tyrosine kinase activity in muscle tissue were compensated by increased total insulin binding capacity. Absent differences in IVGTT results between diestrus and anestrus bitches corroborate this finding. However, in bitches with pyometra, the highest Kd values were not compensated by increased total insulin binding capacity. This finding was associated with insulin resistance and glucose intolerance in IVGTT results. Moreover, pyometra resolution restored insulin sensitivity and glucose tolerance. These features can play a key role in pyometra-associated CDM, as well as in diabetic remission after pyometra resolution.