NUTRITIONAL

Seniors are Special II

There are a number of nutritional supplement ingredients that will address brain function, eye health and digestion in aging dogs and cats.

By L Phillips Brown, DVM

There are a variety of products and services that can help promote vitality and longevity in aging pets.  Supplements can complement pet food to improve quality of life.

Promoting Thinking & Memory

Although pet owners accept that older dogs experience a certain degree of physical limitations, they often don’t realize that the aging process also affects brain function.  Like humans, dogs and cats lose sharpness of the higher-level functions of memory and cognition as they grow old. Brain neurotransmitters become less effective as they naturally accumulate deposits of betaamyloid and slowly become overwhelmed with increased oxidative damage that can lead to canine Cognitive Dysfunction Syndrome (CDS), a memory-related disorder similar to Alzheimer’s disease. A dog with CDS may become forgetful, disorientated, no longer recognize family members and have more “accidents” in the house. It is estimated that canine and feline cognitive disorders affect 10 to 15 million cats and dogs in the U.S.

There are a variety of pet supplements specifically formulated to improve cognitive function and learning in older animals by helping boost neurotransmitter function while simultaneously promoting circulation and reducing the negative effects of external stressors.

The key brain health ingredients are:

• Phosphatidyserine (PS) is the major acidic phospholipid in the brain that helps enhance cellular metabolism and communication, protect nerve cells from free-radical damage and increase nutrition to the brain. PS has been shown in animal studies to be an effective and safe supplement for enhancing and restoring cognition and memory.

• Phosphatidylcholine is a major part of the membrane surrounding cells, and it is used to make acetylcholine, a chemical essential for proper brain function. It also helps improve memory recall.

• Inositol is an amino acid that contributes to the function of nerves and has a calming effect.

• The omega-3 fatty acids from fish oil–particularly eicosapentanoic (EPA) and docosahexaenoic acid (DHA)–may play an important role in mood and cognitive health.

• Antioxidants like vitamins A, C and E, copper, zinc and selenium have been shown effective in improving cognitive function and complex learning in older dogs.

In addition to using natural supplements, pet owners should engage their pets in activities that encourage mental stimulation and require the use of all of their senses. Training exercises performed as a younger dog or cat, as well as learning new tricks, stimulate brain function and may slow memory loss.

Maintaining Eye Health

Older animals are more at risk of developing senile cataracts, glaucoma and dry eye. Cataracts, the opacity of the lens that causes light to scatter, remain the leading cause of low vision among older dogs and, very rarely, cats.  Glaucoma, an elevation of intraocular pressure, is also a frequent cause of irreversible blindness in dogs and cats. Dry eye is a condition in which there is insufficient tear production.  While only a veterinary ophthalmic exam that includes measurement of the pressure in the eye will identify the specific problem to prevent permanent damage to the eye, natural supplements can help maintain ocular function and decrease the risk of vision loss.

Long-term supplementation with antioxidants can protect the lens and support eye health:

• The carotenoids lutein and zeaxanthin occur naturally in the retina and absorb the blue light that enters the eye that can lead to light-associated damage to the lens and retina. Studies in humans have shown that supplementation with lutein and vitamin E improved visual acuity and reduced glare sensitivity in patients with age-related cataracts. Although these supplements will most likely not reverse vision loss from cataracts, they may stabilize the condition.

• Lycopene, the ingredient responsible for the bright colors of many fruits and vegetables, may protect against cataract development.

• Antioxidants, such as vitamins C and E and zinc, have been shown to have value in preventing age-related cataract development in people, especially if begun early.

• Flavinoids, such as bilberry (related to the blueberry), black current, green tea and French Maritime pine bark extract, have been tried in pets with cataracts, but results were variable.

• The omega-3 fatty acids DHA and EPA have been shown to play a role in various processes in human eye tissues, but in-depth investigations in dogs and cats have not yet been done.

Digestive Health

Keeping an elderly pet’s intestinal tract functioning properly is vital for maintaining a healthy immune system and coping with the stresses of age. Fortunately, most pets don’t routinely challenge their digestive apparatus with fried foods, pizza, burgers or carbonated and alcoholic drinks, and most likely eat healthier than their owners. One of the top ten key trends in human supplements, according to U.K.-based New Nutrition Business, is digestive health.  Supplemental digestive enzymes and direct-fed microbials can help maintain proper nutrient assimilation and keep bowels well stocked with normal intestinal flora.

The feeding of prebiotics, probiotics, digestive enzymes and high-fiber diets has become the norm for many pet owners. There are several types of supplements that offer digestive health benefits to the elderly (and young) animal:

• Probiotic bacteria, also known as “friendly” bacteria, are described as “live microorganisms that are involved in the healthy development of the immune system, prevention of infection from pathogenic or opportunistic microbes and maintenance of intestinal barrier function.” There is growing evidence in humans suggesting that probiotics can be effective in preventing recurrent urinary tract infection. The most common probiotics are Lactobacillus and Bifidobacterium, as well as the heat- and oxygen-tolerant strains Pediococcus and Saccharomyces.

• Prebiotic soluble fibers like inulin, beet pulp or soy hulls support the health of the lower intestinal tract.

• Digestive enzymes help complete the breakdown and absorption of nutrients as food passes through the stomach, small intestine and large intestine. Plant-based enzymes (amylase, lactase and cellulase) work in the widest range of pH and temperature and are better for the majority of seniors than animal-based pancreatic enzymes like amylase, lipase, protease, trypsin and chymotrypsin.

• Brewer’s yeast contains enzymes, B-complex vitamins and other nutrients that support intestinal health. 

The effects of probiotics are dependent on their viability. It is difficult to keep digestive enzymes intact and probiotics alive and viable in pet foods because often they cannot survive the extremes of pressure and temperature during the cooking of canned foods or the baking or extrusion of dry kibble. Some pet food manufacturers blend digestive enzymes with the raw ingredients prior to cooking or add probiotics after the cooking process is complete.  It is difficult to maintain the viability of Lactobacillus and Bifidobacterium at room temperature under constant opening and closure of the container. Natural supplements provide an easy and effective way to add these important dietary components on a daily basis. The label claim should not indicate the number of bacteria at the time of manufacture, but rather the number available at the time of consumption.

Supporting Liver Function

The liver is the largest solid organ in the body and it is essential for removing or neutralizing toxins from the blood, manufacturing immune agents that control infection and assisting in the removal of bacteria from the body. It also plays a key role in the metabolism of fats, proteins and carbohydrates, as well as in the absorption of fat-soluble vitamins A, D, E and K. In addition, the liver synthesizes factors important in blood clotting and removes worn-out red blood cells.

It is essential that optimum liver function is maintained as animals age.  The ultimate goal is to provide the needed nutrition while decreasing the workload of the liver. A key ingredient in liver support supplements is Silymarin (an extract of milk thistle) and is used to promote general health and efficient detoxification by stimulating the production of the body’s own primary antioxidant, glutathione.  It is a far more potent and aggressive antioxidant than vitamin C or vitamin E.

This is part two of a three-part series on supplementing senior pet health. In next month’s issue, part three will deal with some of the newest concepts in nutrition of the older animals, current vaccination recommendations from the American Veterinary Medical Association and the American Animal Hospital Association and how to understand changes in behavior of senior pets.

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

Helpful links:

Essential Digestive Kit for Dogs

Essential Digestive Kit for Cats

Essential Liver Support Kit for Dogs

Essential Liver Support Kit for Cats