Flash Visual Evoked Potentials in Normal Pomeranian Dogs and Those with Canine Cognitive Dysfunction

Visual evoked potential (VEP) is a useful technique for evaluation of optic nerve pathway and diagnosis of human Alzheimer's disease. Canine cognitive dysfunction (CCD) is an age-related neurobehavioural syndrome which is commonly underdiagnosed in dogs. In the present study, VEPs were recorded from 28 Pomeranian dogs including 9 normal dogs aged between 1-8 years, 9 normal dogs aged over 8 years, and 10 dogs with signs of CCD. Brain atrophy in 8 CCD dogs was confirmed by CT scan. The other two dogs with signs of CCD had tumor which was confirmed by CT scan and cerebrospinal fluid. The VEP components of dogs over and under 8 years old were not statistically different (p>0.05). P2 and P3 of the dogs with CCD were longer than those of the normal dogs (p<0.05). The VEPs in dogs with CCD and tumor had different patterns. In conclusion, VEP is a promising tool for the diagnosis of CCD in aging dogs.