Canine Distemper

Canine distemper (CD) is a highly contagious disease in young dogs, particularly those 3 to 6 months of age. It has a high morbidity and mortality rate. The disease can be spread by aerosol infection (Appel and Gillespie, 1972) and is characterized by a diphasic fever curve and acute rhinitis, and later by bronchitis, catarrhal pneumonia, severe gastroenteritis, and nervous signs.

The causative agent of the disease is a virus belonging to the genus Morbillivirus of family Paramyxoviridae. Since the canine distemper virus (CDV) can survive for a longer period of time in cold conditions, the disease spreads mainly in winter months. Although the disease is highly communicable, it is comparatively rare in many developed countries due to vaccination using the attenuated live virus, but occasional outbreaks of CDV infection can still occur in vaccinated populations of dogs. In areas with unvaccinated populations, CD is extremely widespread.

The host spectrum of CDV comprises dogs and many other carnivores and noncarnivores as well as marine mammals. Recently, a possible link between Paget's disease of bone in humans and CDV infection was shown by epidemiological studies and was substantiated by detection of CDV RNA in affected tissues (Gordon, et al., 1992; O’Driscoll, et al., 1990). CDV is also discussed as a candidate that might play a role in the initiation of multiple sclerosis (Rohowsky-Kochan, et al., 1995). Thus prevention of CDV infection in house dogs may have a direct impact on human safety.

Diagnosis of CD in acute or subacute form is usually based on clinical signs and history in unvaccinated puppies. But it has been difficult to differentiate CD from other diseases such as kennel cough in the early stage. Serologic detection of IgM antibody can be useful, but poses a problem in young puppies due to uncertainty caused by maternal antibody interference. Definitive diagnosis can be made through isolation of CDV, or through detection of CDV in epithelial cells after fluorescent antibody (FA) staining. However, virus isolation takes several days to weeks and is frequently not effective in the acute stage of the infection. In addition, FA testing is successful only during the first few days of acute signs of distemper.

CDV detection by PCR is the most rapid, sensitive and specific method for the diagnosis of this infection. It also helps to eliminate false negative and positive cases.

Utilities:

Confirm the disease causing agent
Ensure a dog population free of CDV
Early prevention of spread of this virus among a dog population
Minimize personnel exposure to this virus
Safety monitoring of biological products and vaccines that derive from dogs or other susceptible animals

References:
Appel, M. J. G., and Gillespie, J.H.(1972). Canine distemper virus, p. 1-96. In S. Gard, C. Hallauer, and K. F. Meyer (ed.), Virology monographs 11. Springer-Verlag, New York, N.Y.
Gordon, M. T., Mee, A.P., Anderson, D.C. and Sharp, P.T. (1992) Canine distemper virus transcripts sequenced from pagetic bone. Bone Miner. 19:159-174.
O'Driscoll, J. B., Buckler, H.M., Jeacock, J. and Anderson, D.C. (1990) Dogs, distemper and osteitis deformans: a further epidemiological study. Bone Miner. 11:209-216.
Rohowsky-Kochan, C., Dowling, P.C., and Cook, S.D. (1995) Canine distemper virus-specific antibodies in multiple sclerosis. Neurology 45:1554-1560.

Specimen requirement: 2 ml whole blood in EDTA (purple top) or ACD (yellow top) tube, or 2 ml fresh CSF, urine, saliva or tissue, shipped overnight at room temperature; or 1 ml frozen plasma, serum or tissue, shipped frozen.

For specimen types other than those listed here, please call to confirm specimen acceptability and shipping instructions.

For all specimen types, if there will be a delay in shipping, or during very warm weather, refrigerate specimens until shipped and ship with a cold pack unless more stringent shipping requirements are specified. Frozen specimens should be shipped so as to remain frozen in transit. See shipping instructions for more information.

Turnaround time: 2 business days

Methodology: Reverse transcription and polymerase chain reaction (RT-PCR)

Normal range: Nondetected