Nutrition and Aging in Companion Animals

Summary: Dogs age and die.

Interestingness: 2

Paper by Michael G Hayek and Gary M Davenport in the Journal of Anti-Aging Medicine, Volume 1, Issue 2, Summery 1998.

(((This isn't a paper about dogs and cats as models of human aging. It is about dogs and cats aging and what we can do to slow the process down, but its mostly a descriptive article. It does often refer to studies in humans mostly for confirmation that the effect is similar in both)))

(((This paper is supposedly about companion animals but almost all the data refers to dogs)))

After the usual why-this-is-important section, there's a long list of median ages of dogs by breed from cases collected during the '80s. They range from 3.5 years for the Rottweiler to 9.3 for the miniature Poodle, with most breeds around the 6-7 year mark. There is an inverse relation between dog breed size and its life expectancy. Cats seem to have a uniform life expectancy, independent of breed.

The rest of the paper goes through some components of the dog that deteriorates/changes as it ages:

Aging dogs have lower number of white blood cells and immature neutrophils and higher counts for mature neutrophils and concentration of immunoglobulin G. They have decreased response to stimulation of T- and B-cell division.

Aging dogs and cats also have a higher percentage of body fat compared to young dogs and cats, going from 18% to 27% in dogs, 30% to 35% in cats, and a corresponding loss of muscle mass. It then says something about higher protein intake leading to higher protein turnover needed for good immune system function but I'm confused by the text. It does seem to recommend higher protein intake for the elderly (dogs and humans).

No change in nutrient absorption occurs in the aging dog. They do become worse at maintaining glucose levels and at desaturating fatty acids.

(((Conclusion: too much of a mish-mash of bits of data for me. It recommends specific dietary changes from these bits of data but I don't see much evidence in the text to quote them)))


Abstract follows:

The aging process is associated with alterations in a variety of physiological systems and metabolic processes. These alterations are not well-defined in companion animals. Understanding these age-associated changes will aid in designing nutritional interventions specific for the geriatric population of companion animals. In the dog, age-associated physiological changes include a decline in the cell-mediated parameters of the immune response and alterations in body composition (i.e., increased body fat and decreased lean body mass). Metabolic changes include decreased ability to utilize glucose and alterations in the elongation of omega-3 and omega-6 fatty acids. Nutritional interventions such as antioxidant vitamins, adequate dietary protein, and adjusted levels of long chain fatty acids have the potential to slow the aging process in these animals.