The Relationship between Signs of Medical Conditions and Cognitive Decline in Senior Dogs

SIMPLE SUMMARY: As dogs age, they develop conditions associated with old age, which include pathologies of the brain and the body. One of these conditions is canine cognitive dysfunction syndrome, a neurodegenerative disorder similar to the early stages of human Alzheimer’s disease. The goal of the current study was to investigate the relationship between cognitive dysfunction syndrome and other medical conditions in geriatric dogs, as reported by their owners, using an online questionnaire. The results indicated that dogs with greater cognitive dysfunction also had more signs associated with musculoskeletal and neurological problems, including pain and sensory decline. The relationship was similar, but weaker, for symptoms of digestive or metabolic disorders, and it was weakest for dermatological symptoms. The take-home message of the current study is that, in older patients, medical conditions should be carefully screened, and in cases of suspected cognitive dysfunction, the underlying cause should be cautiously assessed, especially for pain, sensory decline, and digestive and metabolic conditions. ABSTRACT: Canine cognitive dysfunction syndrome (CCDS) is a progressive age-related neurodegenerative disorder in dogs. Minimal research has been performed to investigate how clinical signs may be impacted by other medical conditions. A cross-sectional study was performed using the Canine Cognitive Assessment Scale (CCAS) to evaluate cognitive impairment as reported by owners. Owner-reported health-related measures included behaviour changes, the body condition score, and veterinary diagnoses of disease. The responses from 804 dogs in the last 25% of their expected lifespan were analysed. Factors were identified in the owner-reported behavioural signs of disease representing pathologies in four body systems: musculoskeletal–neurological, digestive, metabolic, and dermatological, with the items comprising these factors also compiled into a cumulative measure of health. The results showed a strong correlation between the CCAS score and both the musculoskeletal–neurological factor and the overall cumulative measure of health. Moderate correlations between the CCAS score and the digestive factor and metabolic factor were also observed. The correlation between the dermatological factor and the CCAS score was weak. This study highlights the need to screen dogs for concurrent diseases when using scales to assess cognitive impairment and to monitor dogs who have health conditions, particularly those that are painful, for the onset of cognitive impairment.