Cognitive dysfunction syndrome (CDS) is a progressive neurodegenerative disorder of senior dogs. Since age-related behavioural changes may be useful indicators for early diagnosis and treatment, the first purpose of the present study was to investigate the prevalence of clinical signs of CDS in a general population of aged dogs. The second aim was to evaluate the use of a neuroprotective nutraceutical (Senilife (R), Innovet Italia srl, Rubano, Italy) using an open-label clinical pilot trial. Dogs were recruited from a geriatric population not referred for behavioural consultations. A questionnaire with a checklist of behaviours was filled out to evaluate behavioural items grouped in the following categories: disorientation (D), socio-environmental interaction (1), sleep-wake cycles (S), house soiling (H), general activity (A)-(DISHA). Each owner was asked to rate the frequency of the behavioural signs: never, rarely, often, or always. One hundred and twenty-four dogs were assessed in the first survey; 22 of the 124 dogs tested in the survey were ruled out based on exclusion criteria (clinically and/or sensory severe impairment), 42 dogs had alterations in one category and 33 dogs had signs in 2 or more categories. Consequently 75 dogs had signs consistent with CDS. Among this population eight dogs affected by CDS were enrolled for the second step of the project, an open-label clinical pilot trial with the neuroprotective nutraceutical Senilife (R). Senilife (R) contains 25 mg phosphatidylserine, 50 mg of standardized Ginkgo biloba extract, 33.5 mg/d-alpha tocopherol and 20.5 mg pyridoxine per capsule and is dosed at one capsule per 5 kg body weight. The investigator asked the owners to rate the frequency of behaviours referring to DISHA using a four point frequency scale (never, rarely, often, always). Post-treatment, the owners were asked to evaluate all the signs in each category on a five point scale (much better, slightly better, the same, slightly worse, much worse). At the time of the first visit (V-0) the owners were briefed verbally about the procedure; no behavioural advice was given throughout the study time and whenever appropriate therapy with Senilife (R) (was started. At V-0, V, (28 +/- 3 days), V-2 (56 +/- 3 days) and V-3 (84 +/- 3 days) a control visit was performed and the owners were interviewed. Dogs treated with Senilife (R) showed a highly significant difference at V-3 compared to V-0 (p < 0.001). Preliminary results from dogs on Senilife (R) showed a marked improvement of CDS related signs, even if the dogs failed to show a complete remission of symptoms. (c) 2006 Elsevier B.V. All rights reserved.