Cognitive dysfunction is a problem of aged dogs that is distressingly similar in symptoms to human Alzheimer's disease. Older dogs may appear apathetic, irritable, anxious, disoriented, forgetful of where they are, stand as if stuck with their head in a corner, inability to sleep at night, seeming loss of housetraining, or they may pace compulsively. In dogs, we have the additional difficulty of discriminating between behavior changes from degenerative processes from those due to disease or pain. If you are a pet owner who suspects your dog is having behavior changes and haven't read Lisa Rodier's excellent article in Whole Dog Journal about cognitive dysfunction, it's worth purchasing for a thorough review of the problem.
Clinical trials have shown that antioxidants, and combinations of antioxidants with acetyl-l-carnitine, vegetable extracts and phosphatidylserine can improve daily function in these dogs. The best trials were done using Hill's B/D. In fact, the improvements noted when aged beagles were fed this food were greater than the benefits from the drug approved for the condition - selegiline. For pets who require other types of diets or owners who prefer a different food type, combinations of these nutrients can be used as nutraceutical supplements.
Your vet can offer supplements designed specifically for dogs and proven in clinical trials to be helpful. Senilife, a product by CEVA, contains ginkgo biloba, phosphatidylserine, Vitamin E and Vitamin B6. Araujo and colleagues tested the efficacy of this combination using the same test system (beagles in an experimental lab) and some of the same researchers. This trial showed that the supplement improved dogs' performances on cognitive tests significantly over placebo.
Another trial by another group tested the efficacy of SAMe (S-adenosylmethionine) on signs of cognitive dysfunction in dogs. SAMe has been used for liver disease (in animals), depression and arthritis (in people). In this trial, Novifit (made by Virbac) was administered to 36 client-owned dogs at a dose of 18.5 mg/kg for 2 months. The average improvement in the level of activity (57.1%) and awareness
(59.5%) was significant in comparison to those dogs given placebo. The results were collected from owners' evaluations of their dogs' progress.
The primary problems reported by the owners were “looks tired,” “inactive,”
“does not run anymore,” “does not climb stairs anymore,” “does not play anymore”,“sleeps too much,” “awakens at night,” “has nightmares”, and “worried,” “feels insecure,” “tries to hide,” “follows me everywhere”. I found these survey answers interesting because I have a problem calling them signs of cognitive dysfunction. And we know that antioxidants are helpful in other geriatric disorders, such as arthritis - which could cause some of these same observations to be made. These authors actually did state that locomotion scores were not improved, distinguishing an effect on arthritis from that on cognitive problems, but I don't buy it since there were no objective measurements of arthritis pain done. Antioxidants have too many multisystemic effects. Which is usually a good thing in a geriatric patient.
One other thing - old cats can develop signs that are often taken as cognitive dysfunction, and again, these are frequently due to medical disorders like hyperthyroidism or arthritis. While all of the approved and studied treatments for cognitive dysfunction are for dogs only, I think it's important to supplement geriatric cats with antioxidants in many cases, especially since we don't have great options for pain or senility, as compared with dogs.
Until very recently, we had to depend upon human supplement companies to supply us with ingredients that were proven in humans. Suddenly we have excellent probiotic products shown to work in pets, and now we have supplements proven to work for cognitive dysfunction in dogs. Ask your vet for more information if you have a family member that might benefit.
Araujo JA, Landsberg GM, Milgram NW, Miolo A. Improvement of short-term memory performance in aged beagles by a nutraceutical supplement containing phosphatidylserine, Ginkgo biloba, vitamin E, and pyridoxine. Can Vet J. 2008 Apr;49(4):379-85.
Rème CA, Dramard V, Kern L, Hofmans J, Halsberghe C, Mombiela DV. Effect of S-adenosylmethionine tablets on the reduction of age-related mental decline in dogs: a double-blinded, placebo-controlled trial. Vet Ther. 2008 Summer;9(2):69-82.