Pathogenetic factors in tooth loss in young cats on a high daily oral intake of vitamin A

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.

Hypervitaminosis A in the cat: a case report and review of the literature

A case of hypervitaminosis A with secondary entrapment and compression of the left brachial plexus nerve roots is described. A 9-year-old male castrated domestic shorthair, fed a home-made diet based on raw pork liver, was submitted for examination for a left forelimb lameness that evolved to paralysis over a 2-month period. Clinical examination revealed a flaccid paralysis and atrophy of all left forelimb muscles. An ipsilateral Horner's syndrome was also noted. Radiological examination of the cervical and thoracic spine showed massive new bone formation at the ventral aspect of the second cervical to sixth thoracic vertebra. The diagnosis of hypervitaminosis A was made, based on the clinical and radiographic findings, as well as the determination of serum vitamin A concentration, which was 630 microg/dl, three times above the upper normal limit for this species. Despite the unfavourable initial prognosis, the cat progressively regained function of the affected limb approximately 6 months after the diet was changed to a commercial canned food.

Feline odontoclastic resorptive lesions an unsolved enigma in veterinary dentistry

This article presents a comprehensive review of the literature on feline odontoclastic resorptive lesions (FORLs), including etiopathogenesis, prevalence and predisposition, classification, histopathologic appearance, diagnosis, and treatment. Approximately one-third of all domestic cats may develop FORLs during their life span, and the risk of developing FORLs increases with age. Sophisticated dental treatments promise neither cure nor permanent improvement of affected teeth. Extraction is the current treatment of choice. Research on the etiology of FORLs has not been rewarding in recent years, and the causative factors contributing to the development of FORLs are still unknown.

Feline gingivitis-stomatitis-pharyngitis

Inflammatory conditions of the feline mouth are commonly encountered in small animal practice. Although the majority can be attributed to dental disease and a small percentage are due to autoimmune diseases, the eosinophilic granuloma complex, neoplasia, and other miscellaneous syndromes, many cases appear to be due to a gingivitis-stomatitis-pharyngitis complex, which is likely multifactorial in origin. Viruses, bacterial infection, diet, dental disease, oral conformation, genetic predisposition, hypersensitivities, immunoinsufficiencies, and other defects in oral defense mechanisms may all be contributory. The complexities of this syndrome have made it one of the most challenging diagnostic and therapeutic problems in feline medicine.

Etiopathogenesis of feline dental resorptive lesions

There are several factors in the etiopathology of feline resorptive lesions. They may be considered as local immune-response mediating cell and humoral factors; release of biochemical components in dental and paradental tissues to attract odontoclasts; mechanical stress, including occlusal mechanism; and local and systemic calcium regulation, including remodeling of mineralized tissue and dietary intake of calcium.

Vitamin A concentrations in commercial foods for dogs and cats

The vitamin A concentration was determined in 89 Australian brands of commercial foods for dogs and cats. It was found that 8% of the dog foods and 14% of the cat foods had concentrations of vitamin A below the minimum recommended 1.1 mg/kg dry matter (dm) for dogs and 1.8 mg/kg dm for pregnant or lactating cats. Canned and fish-labelled cat foods were the only varieties with less than the minimum recommended concentration of Vitamin A, of which 71% were the same brand. The minimum recommended concentration of vitamin A was exceeded in all canned dog food tested. Concentrations of vitamin A in dry (ca. 6% moisture) dog and cat foods and semi-moist dog foods (ca. 23% moisture) never exceeded 10 mg vitamin A/kg dm. In contrast, canned pet foods stated to contain liver or kidney showed vitamin A concentrations from 13 to 284 mg/kg dm.

Retinol, supplemental vitamin A and bone status

Studies of hypervitaminosis A in animals and anecdotal reports of accidental vitamin A poisoning in humans suggest impairment of bone remodeling and increased numbers of fractures. Because of the widespread use of high-dose vitamin A supplements which may produce subclinical hypervitaminosis associated with decreased bone mass and increased risk of fracture, we studied the relationship between current vitamin A supplement use, serum retinol levels, radial bone mass and fracture history in a geographically-defined population of 246 postmenopausal women, 55-80 years of age. More than 36% of this population used a vitamin A supplement with 8% of these consuming an amount in excess of 2000 retinol equivalents (RE)/day. Serum retinol was measured using high-pressure liquid chromatography and radial bone mass was measured using single photon absorptiometry. After controlling for age, current estrogen replacement, and current thiazide antihypertensive use, we observed no statistically significant relationship between vitamin A supplement use or serum retinol with radial bone mass or fractures.