Comparison of the nutrient composition of commercial dog milk replacers with that of dog milk

Nutritional cataracts in a wolf litter treated by phacoemulsification

OBJECTIVE

To describe the clinical findings in a wolf litter with nutritional cataracts and determine the treatment outcomes after phacoemulsification.

PROCEDURE

Bilateral nutritional cataracts were diagnosed in four hand-fed 10-week-old wolves (Canis lupus). The information collected included signalment, physical and ophthalmic examination findings, ocular ultrasonography and electroretinography results, and postoperative outcomes.

RESULTS

All four wolves were rejected from the dam and hand raised with a commercial artificial milk replacer from 5 days of age until weaning at 6 weeks of age. At initial presentation, bilateral cataracts were observed in all patients (8/8 eyes), with vision deficits in three of the four wolves. The main ophthalmic anomalies were mature cataracts with lens-induced uveitis (3/8 eyes, two wolves), immature cataracts (1/8 eyes, one wolf), and perinuclear and posterior cortical/subcapsular lens opacities (4/8 eyes, three wolves). Three of the four wolves (six eyes) underwent bilateral one-handed phacoemulsification with intraocular lens implantation. At the last examination 2 months following surgery, all operated eyes (6/6) were visual, Elschnig pearl proliferation was present in 2/6 eyes, and mild posterior capsular opacification was observed in 6/6 eyes. In the nonoperated wolf, the cataracts remained stable and did not affect the visual axis of either eye.

CONCLUSIONS

This is the first description of phacoemulsification surgery in wolves. Phacoemulsification is a viable treatment option for captive wolves with nutritional cataracts. Special attention should be paid to hand-raised cubs to ensure that adequate amino acid levels are present in artificial milk.

Alterations in the Intestinal Microbiome and Metabolic Profile of British Shorthair Kittens Fed with Milk Replacer

With the rising popularity of pet cats as companion animals, the survival of newborn kittens is often threatened by factors such as inadequate nursing, maternal behavior and blood incompatibility. These challenges require the use of milk replacers for nurturing. To investigate the effects that feeding kittens with an experimental milk replacer (EMR) have on growth and development, intestinal microbiota, immune response and nutrient metabolism, 12 British shorthair kittens were randomly divided into two groups after nursing for the first week of life. Kittens were fed queen's milk or EMR, whereby kittens fed queen's milk served as the control (CON) group. The findings revealed that the CON group exhibited superoxide dismutase (SOD) activity and total antioxidant capacity (T-AOC) (p < 0.01) on day 7. However, the EMR group had better growth performance during the later stage of the experiment (p < 0.05); the immunocompetence and antioxidant capacity of the EMR group were not significantly different from those of the CON group in the middle and late stages of the experiment, and the mean values of all the indexes were slightly better than those of the control group. Sequencing of the 16S rRNA gene in microbiota demonstrated that EMR increased the colonization of bacterial genera, including Lachnospiraceae, Enterococcus, Rothia and Ligilactobacillus. Compared to the CON group, acetate acid (p < 0.05), propionate acid (p < 0.01) and total SCFAs (p < 0.01) in the EMR group were significantly increased. Moreover, the intake of the EMR resulted in the production of distinct metabolites implicated in the metabolism of lipids and amino acids, among other nutrients, thus invigorating the associated metabolic pathways. These results elucidate the impact of administering a milk replacer on gastrointestinal health and nutrient assimilation in kittens. The study provides insights into the use of milk powder alternatives and sets the stage for future research on the formulation and effectiveness of kitten milk replacers.

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.

Canine Neonatal Health

This article provides a high-level overview of canine neonatal health for clinicians to use as a mental framework so that when presented with a canine neonate it is easier to construct a logical and systematic clinical approach that is less overwhelming. As early detection of the at-risk neonate results in earlier intervention, and improved health outcomes, there will be a focus on pro-active care. Where appropriate, other articles in this issue will be mentioned for a more in-depth discussion of specific areas. Key points will be highlighted throughout the text.

Nutrition and Theriogenology: A Glimpse Into Nutrition and Nutritional Supplementation During Gestation, Lactation, Weaning and Breeding Dogs and Cats

Feeding during normal reproduction is often not thought of until there is a problem with conception or gestational losses. Energy demands of lactation and early puppy/kitten are of concern, particularly in large and giant breed dogs where mineral balance is crucial to normal development. There is a paucity of information around optimizing feeding during conception and gestation with many myths around ingredients which will be explored in this article along with supplements that may be able to support spermatogenesis and conception which primarily comes from the human literature and may have validity in times of difficult conception.

Amino acid nutrition and metabolism in domestic cats and dogs

Domestic cats and dogs are carnivores that have evolved differentially in the nutrition and metabolism of amino acids. This article highlights both proteinogenic and nonproteinogenic amino acids. Dogs inadequately synthesize citrulline (the precursor of arginine) from glutamine, glutamate, and proline in the small intestine. Although most breeds of dogs have potential for adequately converting cysteine into taurine in the liver, a small proportion (1.3%-2.5%) of the Newfoundland dogs fed commercially available balanced diets exhibit a deficiency of taurine possibly due to gene mutations. Certain breeds of dogs (e.g., golden retrievers) are more prone to taurine deficiency possibly due to lower hepatic activities of cysteine dioxygenase and cysteine sulfinate decarboxylase. De novo synthesis of arginine and taurine is very limited in cats. Thus, concentrations of both taurine and arginine in feline milk are the greatest among domestic mammals. Compared with dogs, cats have greater endogenous nitrogen losses and higher dietary requirements for many amino acids (e.g., arginine, taurine, cysteine, and tyrosine), and are less sensitive to amino acid imbalances and antagonisms. Throughout adulthood, cats and dogs may lose 34% and 21% of their lean body mass, respectively. Adequate intakes of high-quality protein (i.e., 32% and 40% animal protein in diets of aging dogs and cats, respectively; dry matter basis) are recommended to alleviate aging-associated reductions in the mass and function of skeletal muscles and bones. Pet-food grade animal-sourced foodstuffs are excellent sources of both proteinogenic amino acids and taurine for cats and dogs, and can help to optimize their growth, development, and health.

The metabolic differences of anestrus, heat, pregnancy, pseudopregnancy, and lactation in 800 female dogs

Introduction

Reproduction causes major hormonal and physiological changes to the female body. However, the metabolic changes occurring during canine reproduction are scarcely studied.

Methods

In this cross-sectional study, we assessed the metabolic effects of canine reproductive status using a ¹H NMR metabolomics platform optimized and validated for canine use. The study population consisted of a total of 837 healthy, intact female dogs in breeding age, of which 663 dogs were in anestrus, 78 in heat, 43 were pseudopregnant, 15 were pregnant, and 38 were lactating. The differences in metabolite profiles between these states were studied by the Kruskal-Wallis test with post-hoc tests performed using the Dunn's test, and visualized by box plots and a heatmap. The ability of the metabolite profile to differentiate pregnant dogs from non-pregnant ones was assessed by creating a multivariate Firth logistic regression model using forward stepwise selection.

Results

Lactation, pregnancy and heat all were associated with distinct metabolic changes; pregnancy caused major changes in the concentrations of glycoprotein acetyls, albumin and creatinine, and smaller changes in several lipids, citrate, glutamine, and alanine. Pseudopregnancy, on the other hand, metabolically largely resembled anestrus. Lactation caused major changes in amino acid concentrations and smaller changes in several lipids, albumin, citrate, creatinine, and glycoprotein acetyls. Heat, referring to proestrus and estrus, affected cholesterol and LDL metabolism, and increased HDL particle size. Albumin and glycoprotein acetyls were the metabolites included in the final multivariate model for pregnancy detection, and could differentiate pregnant dogs from non-pregnant ones with excellent sensitivity and specificity.

Discussion

These results increase our understanding of the metabolic consequences of canine reproduction, with the possibility of improving maternal health and ensuring reproductive success. The identified metabolites could be used for confirming canine pregnancy.

A model of puppy growth during the first three weeks

Neonatal mortality in puppies is highly variable, with large scale surveys still reporting average values around 10% –15%. Weight measurement is the simplest way to monitor the development of the puppies, and a weight loss during the first 48 hr has been recognized as one of the factors that puts puppies at a higher risk of neonatal mortality. However, little is known about what constitutes optimum growth up to 3 weeks. In this study, a mathematical formula with the form P = P₀ exp (0.13084 x ‐ 0.001616 x²), where P is weight on Day x and P₀ is weight on Day 0, obtained by multiple linear regression, is presented and validated with data from 345 puppies belonging to 60 litters of 19 different breeds, from toy to giant size, showing that it appropriately describes maximum puppy growth rate during the neonatal period for all breeds. This formula is in agreement with previous studies and generic recommendations that can be found in the literature on puppy growth from birth to 21 days regarding relative daily weight gain. It can be easily introduced in a spreadsheet or used to build growth charts that can help the breeder or the veterinarian in monitoring and evaluating puppy growth during the neonatal period. Although deviations from the maximum growth rate can now be quantified, there is still a need to determine the limits beyond which supplementary feeding is advised/required.

The Demographics of Canine Hip Dysplasia in the United States and Canada

Canine hip dysplasia (CHD) is a common problem in veterinary medicine. We report the demographics of CHD using the entire hip dysplasia registry from the Orthopedic Foundation for Animals, analyzing differences by breed, sex, laterality, seasonal variation in birth, and latitude. There were 921,046 unique records. Each dog was classified using the American Kennel Club (AKC) and Fédération Cynologique Internationale (FCI) systems. Statistical analysis was performed with bivariate and logistic regression procedures. The overall CHD prevalence was 15.56%. The OR for CHD was higher in females (1.05), those born in spring (1.14) and winter (1.13), and those in more southern latitudes (OR 2.12). Within AKC groups, working dogs had the highest risk of CHD (OR 1.882) with hounds being the reference group. Within FCI groups, the pinscher/molossoid group had the highest risk of CHD (OR 4.168) with sighthounds being the reference group. The similarities between CHD and DDH are striking. Within DDH there are two different types, the typical infantile DDH and the late onset adolescent/adult acetabular dysplasia, with different demographics; the demographics of CHD are more similar to the later onset DDH group. Comparative studies of both disorders should lead to a better understanding of both CHD and DDH.

Canine and feline colostrum

Puppy and kitten survival over the first weeks is particularly dependent on colostrum, a specific secretion of the mammary gland produced during the first 2 days post-partum. Colostrum is a source of nutrients and immunoglobulins. It also contributes to the digestive tract maturation. Colostrum differentiates from milk mainly based on its concentration in immunoglobulins G: 20-30 g/L in dog colostrum, 40-50 g/L in cats' vs <1 g/L in milk. IgG concentration rapidly drops after parturition (-50% in 24 hr). Immune quality of colostrum is highly variable between bitches, with no relationship with maternal blood IgG level, dam's age, breed size or litter size. In addition to systemic immune protection, colostrum also plays a major role for local digestive protection, due to IgA, lysozyme, lactoferrin, white blood cells and various cytokines. Energetic concentration of canine and feline colostrum is not superior to that of mature milk. It depends on colostrum fat concentration and is affected by breed size (higher in breeds <10 kg adult body weight). As puppies and kittens are almost agammaglobulinemic at birth, transfer of IgG from their digestive tract into their bloodstream is crucial for their survival, IgG absorption ending at 12-16 hr after birth. Energetic supply over the two first days of life, as evidenced by growth rate over the two first days of life, also affects risk of neonatal mortality. Early and sufficient suckling of colostrum is thus the very first care to be provided to newborns for their later health and survival.

Nutritional analysis and microbiological evaluation of commercially available enteral diets for cats

OBJECTIVE

To determine the prevalence of nutrients less than or greater than accepted standards in commercially available enteral diets for cats, and to identify contamination incidence in enteral diets for cats.

DESIGN

Prospective cross-sectional study.

SETTING

University teaching hospital.

SAMPLES

Seven commercial enteral diets for cats.

INTERVENTIONS

Labels were evaluated to determine if diets were intended to be nutritionally complete and balanced. One diet under storage techniques partially representative of clinical conditions was sampled on days 0, 1, 3, 5, and 7 of storage for aerobic bacterial culture.

MEASUREMENTS AND MAIN RESULTS

All 7 diets were analyzed for key nutrients and results were compared to Association of American Feed Control Officials (AAFCO) Nutrient Profiles for Adult Cats for maintenance and National Research Council recommended allowance (NRC-RA). From label information, 4 diets were classified as complete and balanced and 3 diets were classified as not complete and balanced. All 7 diets had at least 1 nutrient less than the AAFCO minimums and the NRC-RA. The total number of nutrients less than AAFCO minimums ranged from 3 to 9 (median = 4), with iron, potassium, and manganese being the most common. Concentrations of some nutrients were undetectable. None of the samples tested had a positive aerobic culture at baseline (day 0) or on subsequent samples from days 1, 3, 5, and 7 under any storage condition.

CONCLUSIONS

None of the diets analyzed met all of the minimum nutrient concentrations. While short-term feeding may not be of concern for an individual patient, clinicians should be aware of potential nutritional limitations when feeding enteral diets to ill or injured cats.