The Role of Vitamin D in Small Animal Bone Metabolism

A Case Series of Four Dogs Presenting with Neurological Deficits Due to Suspected Nutritional Secondary Hyperparathyroidism after Being Fed an Exclusive Diet of Raw Meat

Nutritional secondary hyperparathyroidism (NSH) in dogs is a condition that develops in response to a vitamin D deficiency or an imbalanced calcium-to-phosphorus ratio in dog food. Puppies of large-breed dogs exclusively fed a non-supplemented, boneless raw meat diet are especially susceptible to developing NSH due to their elevated calcium requirement. Reports on NSH in companion animals have been sparse in the last decades due to dog owners having easy access to commercially balanced dog foods. However, with the rising popularity of meat-based raw feeding, this condition has re-emerged. In this case series, four large-breed puppies fed exclusively non-supplemented, boneless raw meat diets presented with complaints of acute onset of pain and paresis. Radiographs and/or computed tomography (CT) scans showed reduced radio density of the skeleton in all four puppies. Two of the dogs had pathological fractures, and these two puppies were euthanized. One was subjected to a post mortem examination, which revealed cortical bone resorption and hypertrophy of the parathyroid glands. The remaining two puppies rapidly improved after receiving pain medication and a commercial, balanced diet. This case series demonstrates a risk of young dogs developing severe neurological deficits when fed a non-supplemented, boneless raw meat diet.

Pet Wellness and Vitamin A: A Narrative Overview

The health of companion animals, particularly dogs and cats, is significantly influenced by nutrition, with vitamins playing a crucial role. Vitamin A, in particular, is indispensable, with diverse roles ranging from vision to immune modulation and reproduction. Despite its importance, the metabolism and dietary requirements of vitamin A in companion animals remain complex and not fully understood. This review provides a comprehensive overview of the historical perspective, the digestion, the metabolism, the physiological roles, the deficiency, the excess, and the interactions with other micronutrients of vitamin A in companion animals. Additionally, it highlights future research directions and gaps in our understanding. Insights into the metabolism of vitamin A in companion animals, personalized nutrition strategies based on genetic variability, longitudinal studies tracking the status of vitamin A, and investigations into its immunomodulatory effects are crucial for optimizing pet health and wellness. Furthermore, understanding the stability and bioavailability of vitamin A in pet food formulations is essential for ensuring the provision of adequate micronutrients. Overall, this review underscores the importance of vitamin A in companion animal nutrition and the need for further research to enhance our understanding and to optimize dietary recommendations for pet health and well-being.

A Novel UHPLC-MS/MS Method for the Measurement of 25-Hydroxyvitamin D3 in Canine Serum and Its Application to Healthy Dogs

Several studies have shown the importance of vitamin D3 supplementation in small animals. In dogs, a low vitamin D3 status is associated not only with bone metabolism but also with different kinds of disorders, such as congestive heart failure, gastrointestinal diseases, chronic kidney diseases, and some types of cancer. However, it is crucial to maintain balance and monitor the introduction of this essential nutrient through the diet because over-supplementation can result in toxicity. Due to the clinical importance of assessing the vitamin D3 status in small animal patients, a quick, simple, and highly performing analytical method for its measurement is needed. In this study, we describe the development of a novel liquid chromatography-tandem mass spectrometry method for 25-hydroxyvitamin D3 quantification in canine serum. The approach was successfully validated following current European guidelines, proving excellent linearity (R2 always ≥0.996), accuracy (always within ±13%) and precision (always <10%). The application of the validated approach to samples collected from 40 healthy dogs made possible the definition of a reliable reference interval for 25-hydroxyvitamin D3, the main biomarker of vitamin D3. In addition, variations below 5% in the results obtained quantifying the same samples using a water-based calibration curve demonstrated that a surrogate matrix may be used without affecting data accuracy. Thanks to its simplicity, the proposed technique represents a useful tool for supporting clinical routine and investigating correlations between serum concentrations of this metabolite and multiple diseases. Additionally, it could enable the monitoring of supplementation in small animal patients in veterinary clinical practice.

Effect of UV-B irradiated vitamin D enriched yeast supplementation on milk performance and blood chemical profiles in dairy cows

OBJECTIVE

The objective was to evaluate the effects of UV-B irradiated vitamin D-enriched yeast supplementation on milk yield, milk composition, vitamin D in milk, milk fatty acids, blood chemistry, and 25(OH)D status in dairy cows.

METHODS

Six Thai Friesian cows (milk production, 11.2±2.0 kg/d; body weight, 415.0±20.0 kg; and days in milk, 90.0±6.0) were allocated to each treatment in a 3×3 Latin square design, with three treatments and three periods. Each period of the Latin square lasted 49 days consisting of 14 days for diet adaptation and 35 days for sample collection. Dairy cows were randomly assigned to one of three treatments: i) feeding a basal diet without yeast (CON); ii) basal diet + 5 g of live yeast (75 IU/head/d of vitamin D2; LY); and iii) basal diet + 5 g of UV-B irradiated vitamin D enriched yeast (150,000 IU/head/d of vitamin D2; VDY). Feed intake and milk production were recorded daily, milk sample collection occurred on days 14 and 35 of each collection period, and blood plasma was collected on days 0, 7, 14, 21, 28, and 35 of each collection period.

RESULTS

The results show that after a trial period of 14 and 35 days, the VDY group had significantly higher vitamin D content in milk than the LY and CON groups (376.41 vs 305.15, 302.14 ng/L and 413.46 vs 306.76, 301.12 ng/L, respectively). At days 7, 14, 21, 28, and 35 of the experiment, cows fed the VDY group had significantly higher 25(OH)D2 status in blood than the CON and LY groups (51.07 vs 47.16, 48.05 ng/mL; 54.96 vs 45.43, 46.91 ng/mL; 56.16 vs 46.87, 47.16 ng/mL; 60.67 vs 44.39, 46.17 ng/mL and 63.91 vs 45.88, 46.88 ng/mL), respectively.

CONCLUSION

In conclusion, UV-B irradiated vitamin D-enriched yeast supplementation could improve vitamin D content in the milk and 25(OH)D status in dairy cows during the lactation period.

The influence of sex and age on bone turnover markers in the adult to geriatric Kangal shepherd dogs

OBJECTIVES

The objective of this research was to learn more about bone metabolism in intact female and male Kangal shepherd dogs during the aging process following skeletal maturity. It also evaluated the potential application of biochemical bone indicators in veterinary clinical practice.

METHODS

Bone markers were determined as bone alkaline phosphatase (BALP), osteocalcin (OC), C-terminal telopeptide of type I collagen (CTX), and cross-linked C-telopeptide of type I collagen (ICTP) in this study. Kangal shepherd dogs of different age (adult, senior, and geriatric) and sex (male and female) groups were split into six groups of equal numbers (n = 8/group).

RESULTS

In this study, the effect of age was observed on serum BALP, OC, CTX, and ICTP concentrations. Specifically, BALP was highest in geriatric female Kangal shepherd dogs, while serum OC, CTX, and ICTP concentrations were highest in geriatric male Kangal shepherd dogs. However, no effects of sex and age-sex interactions were identified. Moreover, the effects of age, sex, and age-sex interactions had no significant effect on serum creatinine, CK, LDH, Mg, and P concentrations or ALT activities. However, only sex was found to affect serum AST activities and gradually decreased with age in females. The effect of age and age-sex interactions on serum Ca concentrations was significant (the lowest serum Ca concentrations were in geriatric females), but the effect of sex was not.

CONCLUSIONS

These results show the effect of age and sex on bone turnover in Kangal shepherd dogs and provide information about bone biomarkers.

Vitamin D in dairy cows: metabolism, status and functions in the immune system

The function of vitamin D in calcium homoeostasis in dairy cows, such as in other vertebrates, is known for many years. In recent years, new and interesting, non-classical functions of vitamin D have been elucidated, including effects on the immune system. The major aim of this review is to provide an overview of effects of vitamin D or its metabolites on the immune system in dairy cows. The first part of the review provides an overview of vitamin D metabolism, with particular reference to the role of various proteins (25- and 1-hydroxylases, vitamin D binding protein, vitamin D receptor) in vitamin D signalling. The second part deals with the role of the concentration of 25-hydroxyvitamin D [25(OH)D] in plasma as an indicator of the vitamin D status in dairy cows, and its dependence on sunlight exposure and dietary vitamin D supplementation. In this part also the "free hormone hypothesis" is discussed, indicating that the concentration of free 25(OH)D might be a more valid indicator of the vitamin D status than the concentration of total 25(OH)D. The third part deals with classical and the non-classical functions of vitamin D. Among the non-classical functions which are based on an autocrine vitamin D signalling, particular reference is given to the effects of vitamin D and vitamin D metabolites on the immune system in bovine immune cells and in dairy cows. Recent findings provide some indication that vitamin D or its metabolite 25(OH)D could enhance the immune function in dairy cows and be useful for the prevention and therapy of mastitis. However, the number of studies reported so far in this respect is very limited. Thus, much more research is required to yield clear concepts for an optimised usage of vitamin D to improve the immune system and prevent infectious diseases in dairy cows.

Case Report: Human Recombinant Growth Hormone Therapy in a DSH Cat Presented With Dwarfism

A 6-month-old kitten, male, domestic shorthair cat was presented with dwarfism, ocular and nasal discharge, and Ascaris infestation. Congenital hyposomatotropism was diagnosed on the basis of serum level of insulin-like growth factor-1 (IGF-I). The cat was treated with human recombinant growth hormone for 9 weeks. After that, his liver enzymes became elevated, and the therapy was discontinued. His IGF-I levels were normal at the end of the therapy. Normal IGF-I was present 3 months after discontinuation of therapy with human recombinant growth hormone and even half a year after the discontinuation. All other comorbidities were addressed with the therapy. The cat is now the size of normal cats, living with the first author.

Nutritional and Functional Properties of Colostrum in Puppies and Kittens

Simple Summary

The post-natal period is a crucial time for all animal species. During the course of their first two weeks of life, puppies and kittens face several risks to their health due to their scarce energy storage and weak immune system. Colostrum is the first production of the mammary glands that plays a pivotal role for puppies and kittens. Colostrum is an important source of immunoglobulins and key nutrients such as lipids and carbohydrates, which are fundamental for the health of newborns. Puppies and kittens must ingest a sufficient amount of colostrum within a few hours of birth to ensure their survival. On the other hand, there are some particular compounds that are not strictly essential, but their presence may play an important role in nutrition and health. As there are no recent studies on companion animals, we have reported published articles describing animal studies in different species to review the nutrition of newborn mammals, with particular emphasis on companion animals.

Abstract

The present review aims toward a better understanding of the nutrition of newborn puppies and kittens. The post-natal period is very sensitive in dogs and cats, as in other animal species. During the first two weeks of life, puppies and kittens are at high risk of dehydration, hypothermia, and hypoglycemia, as well as infectious diseases as they start to acquire the physiological functions of the adult. Neonatal hepatic glycogen storage is low, and newborns depend on colostrum intake to survive. Colostrum provides immunoglobulins and other important substances such as lipids and carbohydrates. Immunoglobulins are central to the immunological link that occurs when the mother transfers passive immunity. The mechanism of transfer varies among mammalian species, but in this review, we focused our attention on dogs and cats. Furthermore, there are components of colostrum which, although their presence is not absolutely necessary, play an important role in nutrition. These components have received considerable interest because of their presumed safety and potential nutritional and therapeutic effects both in humans and animals; however, unfortunately, there are few recent studies in companion animals. Here, we have gathered the published articles that describe studies involving different species of animals, emphasizing companion animals. In particular, the purpose of this narrative of the nutritional and functional proprieties of queens’ and bitches’ colostrum.

Metabolomics in Bone Research

Identifying the changes in endogenous metabolites in response to intrinsic and extrinsic factors has excellent potential to obtain an understanding of cells, biofluids, tissues, or organisms' functions and interactions with the environment. The advantages provided by the metabolomics strategy have promoted studies in bone research fields, including an understanding of bone cell behaviors, diagnosis and prognosis of diseases, and the development of treatment methods such as implanted biomaterials. This review article summarizes the metabolism changes during osteogenesis, osteoclastogenesis, and immunoregulation in hard tissue. The second section of this review is dedicated to describing and discussing metabolite changes in the most relevant bone diseases: osteoporosis, bone injuries, rheumatoid arthritis, and osteosarcoma. We consolidated the most recent finding of the metabolites and metabolite pathways affected by various bone disorders. This collection can serve as a basis for future metabolomics-driven bone research studies to select the most relevant metabolites and metabolic pathways. Additionally, we summarize recent metabolic studies on metabolomics for the development of bone disease treatment including biomaterials for bone engineering. With this article, we aim to provide a comprehensive summary of metabolomics in bone research, which can be helpful for interdisciplinary researchers, including material engineers, biologists, and clinicians.