Canine Coronavirus

About the Virus
Canine Coronavirus ties with Canine Parvovirus as the leading viral causes of diarrhea in puppies. Clinically, the 2 infections can be indistinguishable. But they are quite different in their final effect - Canine Coronavirus rarely kills the puppy while Canine Parvovirus often does. The virus appeared suddenly in Europe in 1971, and some scientists speculate that Canine Coronavirus may have mutated from another Coronavirus that causes a similar disease in pigs.

Canine Coronavirus is an RNA-type virus and a member of the Group I Coronaviruses. When the virus is viewed under an electron microscope the particles have a halo-like crown of projections or corona. Coronavirus is surrounded by a fatty protective coating which makes it rather easy to kill with detergent and solvents that dissolve fats. This is in contrast to Parvovirus, which is very tough and hard to kill. Coronavirus is spread from dog to dog through infected feces.

Worldwide Impact
Canine Coronavirus is widespread in the dog population worldwide. It invades the rapidly growing cells of the intestinal lining causing nausea, lack of appetite, vomiting, and diarrhea. It is primarily a disease of puppies. Coronavirus is shed in the feces of infected dogs for months after initial ingestion. It takes 1 - 3 days from the time the puppy is exposed to an infected dog's stool for it to become visibly sick.

Most dogs probably become infected with Coronavirus and recover without getting ill or after a sickness too mild for owners to notice. We know this because most adult dogs have antibody to this disease which indicates that they were, at one time, exposed to the virus.

Different Virus Strains
There are slight differences between Coronavirus strains isolated from puppies with diarrhea. So puppies and dogs immune to a particular strain of Coronavirus may not be immune other strains of the virus.

Canine Respiratory Coronavirus
We now know that a 2nd type of dog Coronavirus exists. This strain, known as Group II, affects the dog's respiratory tract rather than its intestine. It causes coughing, sneezing, and a nasal discharge. It is one of the organisms involved in what we call kennel cough or CIRD. When it is a problem, it is usually working in combination with other disease organisms. It is seen most often when large numbers of dogs are housed together such as in boarding kennel, animal shelters, dog shows, and dog race tracks.