A review of phosphorus homeostasis and the impact of different types and amounts of dietary phosphate on metabolism and renal health in cats.

Elevated concentrations of serum phosphate are linked with progression and increased case fatality rate in animals and humans with chronic kidney disease. Elevated concentrations of serum phosphate can be a risk factor for development of renal and cardiovascular diseases or osteoporosis in previously healthy people. In rodents, an excess intake of dietary phosphorus combined with an inverse dietary calcium : phosphorus ratio (<1 : 1) contributes to renal calcification. Renal injury also has occured in cats fed experimental diets supplemented with highly soluble phosphate salts, especially in diets with inverse calcium : phosphorus ratios. However, not all phosphorus sources contribute similarly to this effect. This review, which focuses on cats, summarizes the published evidence regarding phosphorus metabolism and homeostasis, including the relative impact of different dietary phosphorus sources, and their impact on the kidneys. No data currently shows that commercial cat foods induce renal injury. However, some diets contain high amounts of phosphorus relative to recommendations and some have inverse Ca : P ratios and so could increase the risk for development of kidney disease. While limiting the use of highly soluble phosphates appears to be important, there are insufficient data to support a specific upper limit for phosphate intake. This review also proposes areas where additional research is needed in order to strengthen conclusions and recommendations regarding dietary phosphorus for cats.

Understanding the Nutritional Needs of Healthy Cats and Those with Diet-Sensitive Conditions.

Diets for cats must provide complete nutrition and meet the needs of the individual patient. There is no single diet that is perfect for all cats, and veterinarians must consider the needs of the cat as well as the preferences of the owners when making dietary recommendations. This article focuses on the interface between animal factors and nutritional needs in cats and is divided into 3 sections. Section 1 addresses the dietary needs of healthy cats, including differences among life stages. Section 2 addresses common myths regarding feline nutrition. Section 3 addresses common nutrient-sensitive conditions in cats, including sarcopenia of aging.

Controversies in Veterinary Nephrology: Renal Diets Are Indicated for Cats with International Renal Interest Society Chronic Kidney Disease Stages 2 to 4: The Con View.

Renal diets typically incorporate protein and phosphorus restriction, supplement with potassium and Omega-3 fatty acids, and address metabolic acidosis. Compared to "maintenance" diets, these modifications appear to benefit cats with chronic kidney disease (CKD). However, there is limited data in cats justifying the specific amounts of the nutrients used in these diets, and there is little evidence supporting protein restriction in cats with CKD. Energy intake, maintenance of body weight, and muscle and body condition need to be addressed, and may take precedence over special diets. Further research is needed to better define optimum diets for cats with CKD.

Myths and misperceptions about ingredients used in commercial pet foods.

Information and misinformation about pet nutrition and pet foods, including ingredients used in pet foods, is widely available through various sources. Often, this "information" raises questions or concerns among pet owners. Many pet owners will turn to their veterinarian for answers to these questions. One of the challenges that veterinarians have is keeping up with the volume of misinformation about pet foods and sorting out fact from fiction. The goal of this article is to provide facts regarding some common myths about ingredients used in commercial pet foods so as to better prepare veterinarians to address their client's questions.

Nutrition of aging cats.

At least one-third of cats seen by veterinarians are mature, defined as 7 years of age or older, and approximately 13% of cats are geriatric, defined as 12 years of age or older. The article reviews physiologic differences between these life stages and relates the changes to nutritional needs. Geriatric cats have increased requirements for dietary energy and protein. Feeding management addresses what, when, how, and where food is provided. This article provides an update on diet-sensitive conditions, including cognitive dysfunction, diabetes mellitus, chronic kidney disease, osteoarthritis, and hyperthyroidism. Although guidelines are provided, patients must be evaluated and fed according to their individual needs.

Understanding and managing obesity in dogs and cats.

Treatment of diabetes mellitus (DM) is a common disease, and nutrition has become an integral part of management. This article focuses on the role of nutrition and dietary ingredients in OA, evaluating current evidence for obesity management, omega-3 fatty acids, and chondromodulating agents. Additionally, Keeping an animal in optimal to slightly lean body condition has been shown to decrease the risk of development of OA and to aid in management of dogs with OA.

Dietary trial using a commercial hypoallergenic diet containing hydrolyzed protein for dogs with inflammatory bowel disease.

Six dogs with inflammatory bowel disease (IBD) received a commercially available hypoallergenic diet containing an enzymatically hydrolyzed defatted soy globulin as the only protein source. Five of the six dogs had been refractory to a variety of controlled diets, and four dogs had failed to respond to previous medical therapy. All dogs were fed the test diet twice daily for 10 weeks. Dogs not showing adequate improvement in clinical signs after 2 to 4 weeks on diet alone had appropriate medical therapy added to the dietary regimen. Gastroduodenoscopy and biopsy were performed on Day 0 and repeated at the conclusion of the study. Intestinal biopsies were evaluated by a pathologist using a numeric grading scheme to describe histologic alterations and mucosal architecture. Dietary therapy alone provided adequate clinical improvement in four dogs, and concurrent medical therapy was required in two dogs, one of which had exocrine pancreatic insufficiency. Mean fecal scores improved after therapy. Five dogs showed mild to moderate histologic improvement in duodenal biopsies after therapy. The clinical improvement observed cannot be solely attributed to the hydrolyzed nature of the protein source because the diet tested was highly digestible, contained cornstarch (rather than intact grains) and a source of medium-chain triglycerides (23% of fat), and had an altered ratio of omega-6 to omega-3 polyunsaturated fatty acids. Nevertheless, the resolution of clinical signs and improved biopsy scores demonstrate the importance of conducting further studies to critically assess the role of diets containing a hydrolyzed protein source for the management of dogs with previously refractory IBD.