Fortunately,senior dogs have relatively few disorders of the brain and spinal cord associated with the process of growing old. Arteriosclerosis, that bane of human aging and a primary cause of senility, is quite rare in dogs. Hence it is unusual indeed to meet a truly senile dog.
Cerebral hemorrhage, also called apoplexy or stroke, is likewise a very infrequent occurrence in senior dogs. Rabies is caused by a virus which is attracted specifically to nerve tissue and is transmitted by the bite of a rabid animal. However, there have also been rare reports in recent years of airborne transmission.
It has been traditionally believed for centuries that once symptoms of rabies develop, death is inescapable, and because of the hazard to other animals and people, senior dog are euthanized if they have not yet bitten anyone.
Recent reports of two human rabies cases which were treated successfully and survived the development of rabid symptoms, if confirmed, may possibly alter the present grim outlook for rabid dogs. With the extremely effective and safe vaccines available today to protect senior dogs, however, there is no excuse for you to ever have to worry about this disease.