Canine Coronavirus Antibody Test (IFA)

Canine Coronavirus is a virus of the family Coronaviridae that causes highly contagious intestinal disease worldwide in dogs. It was discovered in 1971 in Germany during an outbreak in sentry dogs. The virus invades and replicates in the villi of the small intestine. Intestinal disease may be related to virus-induced apoptosis (programmed cell death) of cells of the epithelial mucosa of the small intestine. Canine Coronavirus was originally thought to cause serious gastrointestinal disease, but now most cases are considered to be very mild or without symptoms. A more serious complication of canine corona virus occurs when the dog is also infected with canine parvovirus. Coronavirus infection of the intestinal villa makes the cells more susceptible to parvovirus infection. This causes a much more severe disease than either virus can separately. However, fatal intestinal disease associated with canine corona virus without the presence of canine parvovirus is still occasionally reported. This may be related to the high mutation rate of RNA positive stranded viruses, of which canine corona virus is one.

The incubation is one to three days. The disease is highly contagious and is spread through the feces of infected dogs, who usually shed the virus for six to nine days, but sometimes for six months following infection. Symptoms include diarrhea, vomiting, and anorexia. Diagnosis is through detection of virus particles in the feces. It is also possible to detect antibody to corona virus in canine serum. Treatment usually only requires medication for diarrhea, but more severely affected dogs may require intravenous fluids for dehydration. Fatalities are rare. The virus is destroyed by most available disinfectants. There is a vaccine available (ATCvet code: QI07ADII), and it is usually given to puppies, who are more susceptible to canine corona virus, and to dogs that have a high risk of exposure, such as show dogs. IFA antibody titers of 1:25 and above are considered to be protective.

Our test for canine corona virus antibodies is an indirect fluorescent antibody (IFA) procedure and is carried out on Teflon matted glass slides which have corona virus (Black Strain 1981) infected cells fixed to their surface.

Dilutions of canine serum are placed on the slides and if antibody to corona virus is present it will attach to the infected cells on the slide. After washing in a buffer an IFA anti-dog conjugate is placed on the slide. The resulting antibody – IFA conjugate complex can be viewed with an ultraviolet microscope. Titers greater than 1:100 with concurrent clinical signs (diarrhea) are a good indicator of corona virus infection.