Canine distemper is a highly infectious virus that is clinically known as a Morbillivirus in the Paramyxoviridae family. It is closely related to the measles virus. When an animal with the disease coughs, sneezes or expels any respiratory secretions, the virus is distributed as droplets into the air.
When another dog in the area comes into contact with the droplets, usually by breathing, the distemper immediately invades the respiratory tract. From here, it then passes along to the lymph nodes and other organs of the body, including the spleen, stomach, small intestine, and liver.
After eight or nine days of infection, the virus will have attacked the central nervous system. At this point, if the dog's immune system is able to kill the majority of the virus, then the dog will not become sick. If the dog's immune system fails to fight off the virus, then the distemper will be able to spread throughout the body, making the dog ill.
