Canine Haemorrhagic Pneumonia (CHP) Veterinary Update
The disease surveillance program operated by the Greyhound Board of Great Britain continues to identify cases of respiratory disease in racing greyhounds.
We wish to draw fellow practitioners’ attention to this uncommon disease which is primarily a problem for groups of dogs within kennels, but individual “pet dog” cases are possible. The infection is characterized by a sudden onset lethargy, pyrexia (above 39.5 ˚C / 103.1 ˚F) and tachypnoea. Coughing is not a consistent sign and its absence should not prevent the consideration of pulmonary disease, since CHP is a pneumonia, not a bronchopneumonia. A haemorrhagic oro-nasal discharge is seen as a terminal event.
The progress of the disease is extremely rapid, with death occurring within 6-10 hours of the first appearance of lethargy.
The diagnosis of suspicious cases should be done on clinical signs alone, and treatment must be vigorous and prompt, viz: intravenous fluids and intravenous antibiotics. The choice of antibiotics licenced for intravenous use in dogs is limited, but should be directed at Streptococci and E. coli. NSAIDs may be used to reduce the fever, but are not necessary. Any delays in treatment, or failure to use intravenous therapy, will worsen the prognosis.
Following timely aggressive therapy most cases will fully recover from the acute episode, and will then need 10-15 days of oral antibiosis. It is not necessary to medicate in-contacts.
Cases that fail to respond should be euthanased, since a poor response to therapy is strongly associated with death within a short period of time (<24 hrs). Bodies may be submitted to the DSMP for a PME examination funded by the GBGB, which is the preferred route. Should practitioners wish to perform a PME, marked pulmonary haemorrhage affecting the entire lung field will be seen. In about 50% of cases Streptococcus equi zooepidemicus can be isolated. This organism has zoonotic potential, so care is needed both in the hospitalization of cases and in PME examinations.
The usual principles of isolation, hygiene and staff awareness apply. Transmission is thought to be by close contact, whilst tonsillar carriers may explain persistence of Str. equi zooepidemicus in the greyhound population. In contrast to how this disease behaves in rescue kennels, multiple cases are rare in Greyhound kennels. Where second cases have occurred they have always been within 48 hours of the first (index) case.
Colleagues are encouraged to report any cases to the GBGB via the Helpline on 0207 822 0929. Specific veterinary advice sheets are available on the GBGB website here.
Dr Simon Gower BVSc MRCVS, GBGB Veterinary Director and Chair of the GBGB Veterinary Sub Committee;
Dr Richard Payne MA VetMB DProf AdvCertVPhys CertClinEd MRCVS, Vice Chair of GBGB Veterinary Sub Committee.