| Senile Cats and Cognitive Dysfunction Syndrome (CDS) |
| By Dr. Betty Chow, Victoria Veterinary Clinics |
|
Advancement in veterinary medicine and nutrition as led to longer life expectancies in our animal population, and there are more senior / geriatric cats than before. With that comes more potential health problems, and increasing number of cats show signs of altered behaviour and “senility”. These may result from many different disorders, many of which are common in geriatric cats:
Recent studies indicate 28% of cats aged 11–14 years and over 50% for cats of 15 years of age or older develop at least one geriatric-onset behavioural problem. Cognitive Dysfunction Syndrome (CDS) is a term that refers to age-related deterioration of cognitive abilities, characterised by behavioural changes (listed below), where no medical cause can be found. Pathogenesis: The cause of CDS is unknown. Suggested causes include:
Clinical Signs:
Diagnosis: CDS is a diagnosis by exclusion. As clinical signs are often vague and non-specific, vets are encouraged to spend more time in history-taking and to ask more searching questions. A questionnaire regarding the cat’s behaviour and motility is often useful while the owner is in the waiting room. Investigations must be carried out to rule out other common diseases such as kidney disease, liver disease, gastrointestinal disease, diabetes, hypertension (high blood pressure) and hyperthyroidism. A thorough physical exam (including eyes) and blood pressure measurement, should be performed, as well as an in-practice mobility assessment if possible. Blood work including FeLV/FIV test if appropriate. Urine analysis, and where necessary, Diagnostic Imaging (x-rays / ultrasound) are also recommended. Management: While there are no published studies relating to the treatment of cats with CDS it is possible to consider potential treatment options by extrapolation from studies of humans with Alzheimer’s Disease and dogs with CDS. Potential interventions therefore include dietary modification, environmental management, and drug therapies. Environmental enrichment: This includes toys, company, interaction, and food hunting games. Unfortunately, instigating environmental change can have a negative effect once cats develop severe CDS as these cats often become very stressed and cope poorly with change, and their response to stress is to show more obvious signs of CDS. For these cats, change should be kept to a minimum or made gradually with assurance if it cannot be avoided. Cat severely affected by CDS may benefit from having a reduced area of access (ie. to a single room containing everything they need) - this core territory should be kept safe and constant. Environmental application of synthetic feline pheromone (Feliway® - Ceva) can also help to reduce feline anxiety Dietary Modification: Diets enriched with antioxidants and other supportive compounds (ie. vitamin E and essential fatty acids) are believed to reduce oxidative damage and improve cognitive function. A five year study feeding healthy old cats a diet (Nestlé Purina Pro Plan Age 7+®) supplemented with antioxidants and essential fatty acids resulted in the supplemented cats living significantly longer and more healthily than the un-supplemented ones. Other supplemented diets include Hill’s Feline j/d?, designed for cats with arthritis, which is supplemented with antioxidants, essential fatty acids, and ingredients which also aids in protecting joints and obesity management, and has been shown in a small study to improve cognitive function and mobility in >70% and >50% cats respectively. The combination of environmental stimulation and a diet enriched with antioxidants is believed to have a synergistic action in improving cognitive function. Potential Drug Therapies: There are no drugs licensed for the treatment of CDS in cats, and no particular drug(s) has been proven to work in treating feline CDS. Different drugs have been used in this species with various success. These include:
Other drugs that have been used to treat CDS in cats anecdotally include
A small open trial using selegiline showed a positive effect, and the American Association of Feline Practitioners supports the use of this drug for the treatment of CDS. Summary: Behavioural changes is old cats are often attributed by owners and vets to “normal senile changes” and are often neglected. It is important to recognize and manage CDS in cats as it can significantly improve the welfare and quality of life of our feline patients. Thorough investigation should be carried out and treatment should be individualised for each patient. Main source of references from Prof. Danielle Gunn-Moore, Professor of Feline Medicine in The University of Edinburgh |