Introduction
Porcine Respiratory Coronavirus (PRCV) is a coronavirus that is a deletion mutant variant, which is antigenically related to Transmissibel Gastroenteritis Virus of Pigs (TGEV). They differ by only one antigen of a spike protein. This virus is endemic in Europe and is thought to have 'replaced' TGEV, which is now rarely seen.
The virus replicates in the respiratory tract in epithelial lining cells, but replicates pooryl in the gastrointestinal tract, unlike TGEV.
Signalment
Pigs of any age
Clinical Signs
The virus does not usually produce any clinical signs in the respiratory or gastrointestinal tract. If complicated by secondary bacterial infections, or if present concurrently with an immunosuppressive virus e.g. porcine circovirus, then a mild- moderate pneumonia may occur and the animal may be seen to have an increased respiratory rate and cough.
Diagnosis
Usually this virus is an incidental finding- mostly when it confuses diagnosis of TGEV in serological tests. The virus can be isolated using ELISA.
Control
This disease rarely causes any clinical signs and is usually an incidental finding in the pig.
Emergence of this mutant virus has led to natural vaccination against the pathogenic Transmissable Gastroenteritis Virus of Pigs (TGEV), which has been almost absent since the emergence of this virus. This is better on the whole, as TGEV is much more severe than this disease.
References
Blood, D.C. and Studdert, V. P. (1999) Saunders Comprehensive Veterinary Dictionary (2nd Edition), Elsevier Science
Cowart, R.P. and Casteel, S.W. (2001) An Outline of Swine diseases: a handbook, Wiley-Blackwell
Jackson, G.G. and Cockcroft, P.D. (2007) Handbook of Pig Medicine, Saunders Elsevier
Taylor, D.J. (2006) Pig Diseases (Eighth edition), St Edmunsdbury Press ltd