NUTRITIONAL

SUPPLEMENTS

Seniors Are Special III

New research is providing valuable insight into how pet foods and vaccinations are affecting the overall health of older companion animals.

By L Phillips Brown, DVM

The first two parts of this series discussed the role of natural supplements in supporting the special needs of aging pets. This third section provides feeding information based on some of the newer concepts of nutrition for dogs and cats over seven years of age, as well as insights into their immunization needs. Of course, no discussion would be complete without a brief insight into the idiosyncratic behavior of older pets.

Senior Pet Foods

There is no one best food for every older animal, because a senior dog of one breed is different from a senior dog of another breed, and even dogs of the same breed vary in their genetic makeup, lifestyle, history and environment.  The most important thing is that foods consist of high-quality protein from poultry, beef, lamb or fish (but no byproducts or textured vegetable protein), reasonable fat and fiber levels, and balanced amounts of bio-available vitamins and chelated minerals.

While many “senior foods” are fortified with glucosamine and chondroitin, the levels do not appear efficacious in light of current veterinary research. Incorporating digestive enzymes and probiotics into foods after cooking is helpful, but adding them prior to cooking provides more marketing than nutritional benefits. Smaller-sized kibble promotes enhanced digestibility and nutrient assimilation, even for giant breeds.  Supplemental fiber, such as wheat bran, helps prevent constipation and promote lower-bowel health.

Although pet food manufacturers advertise special “light” diets or protein-reduced foods for older dogs, there is actually no proven benefit from these special diets, and, in some cases, there may be some harm. Exercise and food intake management (and no table food, treats or excessive amounts of carbohydrates) are still the best ways to prevent excessive weight gain in older pets.

Data over the past decade has refuted earlier research that suggested high-protein diets were causative factors for kidney disease.  Increased protein in a dog’s diet does not put more stress on this vital organ. In perhaps the most noted clinical trial examining effects of a high-protein diet on the progression of canine renal disease (CRD), groups of dogs diagnosed with CRD were fed either high-protein diets or low protein diets. No significant difference was observed in the rate of progression of CRD in the high-protein group, compared to the low-protein group. Therefore, excess protein in the diet did not appear to compromise renal function, even in the presence of high endogenous levels of protein associated with disease.  In fact, on an individual basis, some of the CRD dogs in the high-protein diet group faired better.

Vaccinating Senior Pets

In 2002, the American Veterinary Association (AVMA) urged veterinarians to customize their vaccination protocols for individual patients, since there is “inadequate data to determine a single best protocol.” In 2006, The American Animal Hospital Association (AAHA) provided guidelines that separated canine vaccines into different categories–core, optional and not recommended at all:

Dogs–While the “core” vaccinations for canine hepatitis (adenovirus-2), distemper, parvovirus and rabies must be given as a three-part series for all puppies, many veterinarians no longer “boost” these vaccinations in elderly pets. Studies have shown that dogs properly immunized as puppies maintain a lifetime of immunity. The administration of a rabies vaccination is established by state laws, which, in most cases, is required every three years.

The “optional” vaccinations against leptospirosis, Lyme disease, Bordetella and parainfluenza should be given only if an animal is at risk to contact the disease, and in most cases, these vaccines need not be given to elderly animals. In fact, dogs that are walked regularly or frequent dog parks often develop a natural immunity to airborne pathogens, such as canine parainfluenza virus and Bordetella, the causative agents of kennel cough.

Vaccinations against Adenovirus-1, coronavirus, giardia, rattlesnake venom and periodontal disease caused by Porphyromonas sp. are not recommended

for older dogs (or dogs of any age, for that matter).

Cats–The American Association of Feline Practitioners (AAFP) provided vaccination guidelines in 2007. Core vaccines against highly contagious agents that cause Feline parvovirus (panleukopenia), Feline herpesvirus-1, Feline calicivirus and rabies are recommended for all kittens and cats.

For kittens and cats in shelters and catteries, AAFP recommends vaccinations

to prevent feline leukemia, feline immunodeficiency virus (FIV), Chlamydophilia felis and Bordetella bronchiseptica.

Behavior of the Older Animal

There are many behavioral changes associated with older animals, most of which result from diminished organ function associated with the natural aging process. As the senses of sight, touch and hearing become dulled; many older animals become a little “cranky” or just want to be left alone. Aging animals can become disorientated as memory and thought processing decline. Some become less responsive to commands, even to the point of biting, rather than retreating.

Mobility discomfort affects a pet’s ability to get around and may even reduce the desire or ability to use the normal elimination area. Sleep patterns often become irregular to the point where both cats and dogs have been known to pace about the house most of the night or wander off to a place they normally never go. Older animals seem to be less able to tolerate the extremes of cold and hot temperatures because of the slowdown of the body’s natural thermoregulatory mechanisms.

Disease or organ dysfunction is certainly more common in the aging animal and can have profound effects on behavior. For example, disease of the kidneys or bladder can result in increased volume or frequency of urination, discomfort during urination or loss of control. Similarly, increased volume, frequency or inappropriate defecation can result from altered intestinal tone, discomfort during elimination, or decreased control associated with a tumors. The overproduction or reduction of hormones can cause a variety of behavioral changes, including lethargy, depression, irritability or aggression.

Any disease process that directly affects the central nervous system can cause behavioral changes. Only a thorough physical examination by a veterinarian can rule an underlying disease based cause.

Catering to Aging Pets

Senior pets’ nutritional needs are indeed different from those of younger animals because their bodies are changing with age and lifestyle.  The numbers of dogs over seven years of age and cats over ten years is increasing.  It’s easy for owners to ignore the old dog or aging cat, thinking, “Oh, he’s just old,” or, “She wants to be left alone,” but this is not always the best way to go. By choosing foods and services that keep these older pets active, they can remain vital members of the family for many years.

L Phillips Brown, DVM, is the senior vice president of research and development for Nutri-Vet Animal Health Care Products.