Preventing and treating cognitive dysfunction in senior pets (Proceedings)
Behavior problems in senior pets
Even if a medical problem is diagnosed it can be a challenge to determine whether the problem is causing or contributing to the signs in which case a therapeutic trial might prove useful. In addition, an extensive history is required to determine if there are environmental factors (e.g. schedule changes, new member of the household, new pet, moving), relationship issues and owner responses (consequences) that might play a role in the cause or progression of the problem. This is of particular concern in the older pet which may be more sensitive and less adaptable to change.
Behavioral signs such as changes in activity levels, altered responses to stimuli, altered social interactions, anxiety, altered sleep-wake cycles, housesoiling, confusion or memory deficits may arise as a result of brain aging (e.g. cognitive dysfunction syndrome or CDS). In some cases, behavioral signs may precede other clinical signs, and may be the first or only indication of pain or illness. Therefore, monitoring for behavior changes in senior pets is essential for the early detection of disease, sensory decline and cognitive dysfunction, but is also an important welfare concern for the prompt recognition and treatment of discomfort and pain.The case distribution of veterinary behaviorists provides some insight into the more serious behavior problems in senior pets. In one study of 62 dogs aged 9 years or older, separation anxiety was seen in 29% of cases followed by aggression towards people (27%); housesoiling (23%); excessive vocalization (21%); phobias (19%); waking at night (8%), compulsive or repetitive behaviors (5%); and intraspecies aggression (5%). In senior cats, the primary complaint of 83 cats at 3 behavior referral practices was housesoiling (73%), followed by intraspecies aggression (10%), aggression to people (6%), excessive vocalization (6%), restlessness (6%) and overgrooming (4%). However, these cases do not represent the more tolerable or less serious behavior changes of older pets that would not necessitate referral. To identify some of these complaints, the VIN database was searched for behavior problems of 50 senior dogs (aged 9 to 17) and 100 senior cats (aged 12 to 22 years). In the dogs, there were 37 cases with multiple signs of anxiety (fear, vocalization, salivation, destructive, hypervigilant); 18 with separation anxiety; "wandering"; 11 night anxiety or waking; 9 noise phobias; 7 vocalizing; 2 with stereotypies; and 2 aggressive. Thirty-one dogs had signs consistent with the traditional categories of CDS commonly referred to as DISH (disorientation, interactions with family members, sleep wake cycles, and housesoiling). In the cat cases, 61 were vocalizing excessively (31 at night); 27 had inappropriate elimination; 22 were disoriented; 19 were wandering; 18 were restless; 6 were irritable or aggressive; 4 were fearful or hiding and 3 were more "clingy" with owners. While medical problems had been ruled out in many cases, cerebral disease, hypertension, sensory decline, pain, metabolic or endocrine disease, anemia, neoplasia, drugs or even infectious agents (e.g. FIV) first needed to be ruled out.
While these studies examined the problems that were serious enough for the owners to seek behavioral guidance, some of most common behavioral signs that arise in senior pets require a more pro-active approach on the part of the practitioner as often go unreported.
Senior care guidelines
In 2005, the AAHA senior care task force published guidelines which included annual wellness examinations and laboratory screening for middle aged pets and biannual screening for senior pets (defined as the last 25% of predicted lifespan).4 In addition, a critical component of the guidelines is the importance of questioning pet owners to determine if any changes have occurred in their pet's health or behavior and to advise them on the importance of promptly reporting any new changes. Early detection provides an opportunity for early diagnosis and treatment so that complications might be prevented, further decline might be slowed, longevity might be increased and welfare issues are promptly addressed.
Unless veterinarians are proactive in asking owners about these signs, they often go unreported, presumably because they are thought to be insignificant or untreatable. In one study of dogs aged 11-16 that had no medical signs, 28% of 11-12 year-old dogs and 68% of 15 to 16 year old dogs showed at least one sign of DISH (CDS). In a more recent study, 124 dogs over 7 years of age were evaluated and 22 were eliminated due to possible medical factors. Of the remaining dogs, 42 had alterations in one category and 33 had signs in 2 or more categories.6 In a study commissioned by Hills Pet Nutrition, 75% of owners of dogs over 7 years of age indicated that their pet had one or more signs when asked, but only 12% reported the signs to their veterinarians. In a prospective study of aged cats presented to veterinary clinics for routine annual care, 154 owners of cats aged 11 and older were asked to report any signs of cognitive dysfunction. After eliminating 19 cats with medical problems, 35% of the cats were diagnosed with CDS; 28% of 95 cats aged 11 to 15, and 50% of 46 cats over 15 years.
It is therefore the role of the veterinarian and staff to inform the clients of the importance of reporting these signs. Questionnaires, such as the ones available in the Handbook of Behavior Problems of the Dog and Cat can be used to quickly and extensively screen for problems at each visit. Handouts such as Senior Moments from AAHA, the handouts on the Lifelearn Client on line handouts ( http://lifelearncliented.com/) or those available from commercial companies that market products for senior pets can also be used to educate owners about the importance of regular geriatric evaluations.