Introduction

Classification

Taxonomy

• Family: Coronaviridae.
• Genus: Coronavirus.
• Group 1 coronavirus: Type 1 canine coronavirus and Type II canine coronavirus.
• Group 2 coronavirus: Canine respiratory coronavirus.

Etymology

• L: corona - crown: refers to the large club-shaped glycoprotein peplomers in the envelope of the virus.

Active Forms

Clinical Effects

Epidemiology

Habitat

• Can replicate in dogs without clinical signs.
• Dogs can shed group 1 coronaviruses for weeks or months post-infection.
• Canine respiratory coronavirus detected for up to 10 days post infection. 

Lifecycle

• Inapparent or persistent infections occur → virus maintenance.

Transmission

Group 1 coronavirus

• Fecal-oral.
• Ingestion of virus contaminated material.
• Highly contagious.

Canine respiratory coronavirus 

• Highly contagious. 
• Most likely spreads through aerosols. 
• Feco-oral transmission remains to be determined. 

Pathological effects

Group 1 coronavirus

• Re-infection common; pre-existing immunity does not give good protection.
• Incubation period 1-4 days.
• Infects cells of the duodenum and progresses through the small intestine.
• Spreads to mesenteric lymph nodes, liver and spleen.
• Present in the feces within 1-2 days of clinical disease.
• Can act synergistically with other agents.
• Certain strains can spread systemically and cause severe disease especially in puppies; isolated from lungs, liver, spleen, kidneys.

Canine respiratory coronavirus 

• Earliest histopathological changes detected at 3 days post infection. 
• Mostly upper respiratory tissues affected. 
• Shortening, clumping and loss of tracheal cilia observed. 
• Pathological changes in lungs less significant.

Control

Control via chemotherapies

• Group 1 coronavirus: treat dehydration and supply electrolytes. 
• Canine respiratory coronavirus: usually self-limiting. Treat as for infectious tracheobronchitis Lung: bacterial pneumonia. 

Control via environment

• Attention to hygiene.
• Avoid poor management conditions, eg overcrowding or stress.
• Isolate infected individuals.

Vaccination

• Inactivated vaccines available in UK.
• Inactivated and live attenuated vaccines available mainland Europe and USA (2 doses 3 weeks apart and annual boosters).
• No vaccine for canine respiratory coronavirus available yet, but may be available soon. 

Diagnosis

Further Reading

Publications

Refereed papers

• Recent references from PubMed and VetMedResource.
• Priestnall S L, Mitchell J A, Walker C A, Erles K, Brownlie J (2014) New and emerging pathogens in canine infectious respiratory disease. Vet Pathol 51 (2), 492-504 PubMed.
• Erles K & Brownlie J (2008) Canine respiratory coronavirus: an emerging pathogen in the canine infectious respiratory disease complex. Vet Clin North Am Small Anim Pract 38 (4), 815-825, viii PubMed.
• Buonavoglia C, Decaro N, Martella V et al (2006) Canine coronavirus highly pathogenic for dogs. Emerging Infectious Diseases 12 (3), 492-494 PubMed.
• Erles K, Toomey C, Brooks H W et al (2003) Detection of a group 2 coronavirus in dogs with canine infectious respiratory disease. Virology 310 (2), 216-223 PubMed.
• Tennant B J, Gaskell R M & Gaskell C J (1994) Studies on the survival of canine coronavirus under different environmental conditions. Vet Microbiol 42 (2-3), 255-259 PubMed.
• Tennant B J, Gaskell R M, Jones R C et al (1993) Studies on the epizootiology of canine coronavirus. Vet Rec 132 (1), 7-11 PubMed.
• McArdle F, Bennett M, Gaskell R M et al (1992) Induction and enhancement of feline infectious peritonitis by canine coronavirus. Am J Vet Res 53 (9), 1500-1506 PubMed.
• Tennant B J, Gaskell R M, Jones R C et al (1991) Prevalence of antibodies to four major canine viral diseases in dogs in a Liverpool hospital population. JSAP 32 (4), 175-179 VetMedResource.