As we are making advancements in medicine and nutrition, we are seeing our pets live longer, and with aging come age-related diseases. An ailment that often goes under-diagnosed, as it is often difficult to realize, is cognitive dysfunction. It turns out that some of the quirks our pets develop as they age may be related to a neurological degenerative disorder – very similar to Alzheimer’s in humans.
This disease is relatively common in dogs with prevalence upwards of 35%. It causes amyloid plaque accumulation, brain atrophy, and neurotransmitter imbalances. It can also cause microhemorrahges in the brain, which can sometimes be picked up on MRIs. These changes in the brain can cause disorientation (wandering, staring into space), memory loss (forgetting familiar faces, regression in housebreaking), altered sleep-wake cycle (up at night, often restless) and increased anxiety. It can sometimes be difficult to differentiate cognitive dysfunction from concurrent age-related issues. For example, a dog may have trouble with stairs, and it could be that they either are painful, have trouble seeing, or have forgotten how to use the stairs. Diagnosis is based on clinical signs, ruling out other medical causes, and a positive response to therapy.
As with other age-related illnesses, this is not curable, but early diagnosis and intervention can slow progression. It is important to know that dogs as young as 6 years can begin to show changes in their brain associated with cognitive dysfunction. Diagnosis starts with a thorough history and physical evaluation with your veterinarian. They can discuss additional tests with you to rule out other diseases and recommend treatment options that are best for you and your pet. They may also suggest you try a Cognitive Dysfunction Syndrome Evaluation Tool known as DISHAA from the Purina Institute. This is a helpful tool that will objectively determine if your pet is at risk for this disease and track response to treatment.
Treatment is aimed at environmental enrichment, diet, and supplements. Regular exercise, especially during the daylight hours is important, as is engaging in play, offering new toys, puzzles, and teaching new tricks. Learning new things can replace damaged parts of the brain. The most helpful diet is one high in antioxidants, essential fatty acids, and medium chain triglycerides. There are several prescription diets available, and diets with whitefish, sweet potatoes, green leafy vegetables, and whole grains are often used. Supplements including S-adenosylmethionine (SAMe), melatonin, dog-appeasing pheromone (DAP) – or Feliway in cats – and Chinese supplements are useful in supporting brain health. Acupuncture has been considered, and there are experimental models, but no concrete recommendations at this time. There is an association between cognitive dysfunction and periodontal disease in dogs and treating the disease (with dental cleaning and antibiotics) often helps improve cognitive function. Likewise, there appears to be a connection between the gastrointestinal system – breakdown in the intestinal barrier can allow microbes and toxins to cross the blood brain barrier leading to the amyloid plaque production as discussed above.
Unfortunately, there is not much data on cats and cognitive dysfunction. Most of the above information is from canine studies and is used to extrapolate information and treatment options in our feline friends. It’s common for older cats to be more vocal at night, suggesting they also exhibit similar signs and disease pathology.
As our pets age, their mobility and their minds become affected, and it is important to recognize the signs so that we can help to keep them as happy and comfortable for as long as they are with us.