More formally known as cognitive dysfunction syndrome (CDS), senility can be described as an age-related mental decline that's not caused by hearing or vision loss, organ failure, or cancer. Dogs that are senile generally show it by wandering aimlessly, acting confused or disoriented, staring into space, changing their activity or sleep habits, or withdrawing from family members. Dogs can show signs of CDS as early as eight years of age.
Like any medication, the drug that helps with senility can have side effects. These include vomiting, diarrhea, hyperactivity, or restlessness. If you note these problems, tell your veterinarian so he can adjust the dose or recommend other changes that may help.
If you think your dog has CDS, don't assume nothing can be done. Take him to the veterinarian for a definitive diagnosis, first, to rule out health problems that can mimic CDS. These include kidney, thyroid, or adrenal gland disease. Then ask your veterinarian about medication that can help. You may also want to give your dog choline supplements, which are believed to help increase mental alertness. You can find choline supplements for dogs at holistic veterinary clinics, pet supply stores, online pet supply stores, and health food stores.