An Overview of Canine Coronavirus

Canine coronaviral gastroenteritis, also known as canine enteric coronavirus, or just canine coronavirus, is a highly contagious intestinal disease originally discovered in German military sentry dogs in 1971. This dog virus, which is similar to the virus that causes feline infectious peritonitis, was spread worldwide in dogs within ten years of the initial outbreak in Germany.

What Canine Coronavirus Is

Coronavirus is a genus of animal virus belonging to the family Coronaviridae. The virus envelope looks like a crown under an electron microscope, hence the name. Coronaviruses primarily infect the upper resiratory and gastrointestinal tract of mammals and birds. Human coronaviruses include the common cold and SARS, or Severe Acute Respiratory Syndrome.

Canine coronavirus is a highly contagious viral disease affecting the small intestine of dogs. Puppies younger than six weeks are especially vulnerable. The virus invades and replicates in the villi, small fingerlike extensions that come out from the wall of the small intestine. Villi is Latin for "shaggy hair." The virus damages the villi, and creates severe lesions. This affects the dog's ability to digest food, as the villi help the small intestine absorb nutrients by increasing the surface area of the lining of the small intestine.

Canine coronavirus has mutated into a second form, canine respiratory coronavirus. This mutation causes respiratory disease in dogs and was originally discovered in the United Kingdom in 2003 and has since spread to Europe, Japan and North America.

How the Disease Is Spread

This dog virus is spread through a fecal to oral pathway. The virus is not affected by the acidic environment of the stomach, and does not affect the colon: the surface epithelium of the small intestine is the target. The virus is present in the feces for six to nine days following infection, and dogs have occasionally still been shedding the virus in the feces for six months following infection.

Symptoms and Diagnosis

The incubation period of the virus is one to three days, and symptoms can come on suddenly. Vomiting, anorexia, diarrhea, depression and listlessness are all symptoms. The feces may be bloody and full of mucous, and have a particular fetid malodorous odor. Confirmation of the disease is done by examining fresh feces with an electron microscope, or examination of fresh small intestine from a deceased dog. The deepening of crypts as well as the atrophy and fusion of the villi in the small intestine will indicate coronavirus.

Dangers Related to Coronavirus

Dogs with coronavirus usually have mild symptoms, if any, and fatalities are rare. Puppies under six weeks are the most vulnerable. The real danger with coronavirus is that it makes the pup more susceptible to parvovirus, and a puppy with both diseases is in a life-threatening situation.

Treatment and Prevention

Coronavirus is not curable, per se, and the dog must recover on its own. Treatment for the diarrhea alone may suffice, or intravenous fluids may be needed for a more severe case. Prevention is done by keeping the kennel clean, as coronavirus is killed by most common disinfectants. There is a vaccine available, though a dog vaccinated against parvovirus is considered safe from the danger of dual infection. Breeders and show dog owners may consider the coronavirus vaccination an option because of a puppy's susceptibility, and a show dog's high exposure.