On the basis of current knowledge, the following overview and information should prove useful in managing canine respiratory disease:
Canine respiratory disease is essentially split into two syndromes, one of simple upper respiratory infection caused by viruses, and one of lower respiratory tract infection by secondary bacteria. It is thought that the primary stressor allows invasion of the lower respiratory tract by these bacteria, which include Strep.zooepidemicus, Strep.canis, Klebsiella, Bordetella, Pasteurella and E.coli. The streptococci may act as primary agents. The morbidity due to the primary disease agents is high, with over 50% affected, but the mortality rate is usually <5% - this being due to severe secondary bacterial pneumonia.
The primary phase of simple kennel cough may be missed, but is limited to malaise of 1-2 days with occasional coughing. There is usually, but not always, a high number of cases. Secondary bacterial infection may then become apparent in a few cases, defined by a sticky nasal discharge, moist cough, pulmonary rattles, pyrexia (fever), and depression.
Severe cases typical of Canine Haemorrhagic Pneumonia (CHP) present as a rapid collapse, poor circulation and pyrexia (fever). Typically there is a raised respiratory rate but no coughing. There is sometimes a bloody nasal discharge. The fever may be absent because of the blood-pressure-lowering effects of the bacterial toxins.
Some cases may develop CHP within a few days of racing or transport, with very few warning signs. Untreated dogs with CHP have a high mortality rate.
The clinical signs of "fever, panting and lethargy" indicate an advancing pneumonia and must be considered to be a medical emergency, warranting immediate veterinary attention and hospitalization, day or night.
Any suspicious cases should be reported to the GBGB or local greyhound racing stadium.
The clinical signs are enough to warrant immediate treatment without a specific diagnosis.
Pre-treatment tonsillar swabs in bacterial transport medium (ideally not Amies charcoal), and a serum sample can be sent to:
Animal Health Trust (Diagnostic Services)
for the attention of the Canine Flu Team. A convalescent serum sample can be sent 2-3 weeks later. Note that the prevalence of asymptomatic carriers is unknown, but is suspected to be high, and that the significance of this state is also unknown.
The GBGB area stipendiary steward, or the GBGB, must be informed at the earliest opportunity of any suspicious or actual cases.
The level of treatment is governed by the severity of the clinical signs.
The two most important treatments are:
- Intravenous antibiotics
- Intravenous fluids
with non-steroidal anti-inflammatory drugs for the pyrexia.
Good first choice antibiotics are augmented penicillins (eg "Synulox®" or "Noroclav®") and marbofloxacin ("Marbocyl®"). Marbocyl is available as an intravenous preparation licensed for use in dogs over 12 months. Response to treatment is usually rapid, with significant improvements seen within 12 hours, after which oral medication may be used.
The actual antibiotics used are to be decided by the attending veterinary surgeon. The full range of sensitivities is listed in a separate article.
Isolation and good biosecurity procedures must be used. In-contacts should be treated as well, although not necessarily as intensively as acute cases. All cases should be treated with antibiotics at the recommended dosage for a minimum of seven days.
Until the attending veterinary surgeon is satisfied that no further significant risk is involved, all greyhounds within the affected kennel are to be quarantined at that kennel. As a guide, the anticipated quarantine period is about three weeks, assuming one initial outbreak. Obviously if new cases are appearing, the quarantine period must be extended.
Extra vigilance is required at the tracks where possible contact has occurred, in addition to the routine biosecurity procedures already detailed in a previous document.
It is not believed that there is a greater risk for the kennel of origin when a greyhound is found to be diseased after being moved to a destination kennel. The attending veterinary surgeon should inform the kennels of origin, but attention should remain focussed on the destination kennel where the disease is evident.
As a general rule, all new entrants to a kennel should be quarantined for a minimum of seven days, and not presented at a race track, nor worked hard, during this time. Antibiotic prophylaxis is not required.
Action at Race Tracks
Broadly speaking, the track vet should be concerned with protecting the well-being of the healthy greyhounds at the track. Any greyhound that is presented as off-colour and/or coughing repeatedly should be examined away from the other greyhounds.
If the veterinary surgeon suspects that the greyhound may be suffering from contagious respiratory disease, then it must be removed from the paddock without delay, and sent home. The other greyhounds from the same trainer's kennels should also be examined for similar signs. If there are other greyhounds that give cause for concern, then the entire cohort from that trainer's kennel should be withdrawn and sent home. The track vet should try to resolve logistical problems on a pragmatic case-by-case basis, being mindful of the risks of contagion.
There is a similar, if not greater risk, from greyhounds from larger kennels, and as such they should all be handled in the same way, regardless of the impact of a mass withdrawal on the race card.
If a case of acute severe respiratory disease becomes apparent at the track, then that greyhound should be referred to a suitable veterinary practice without delay, where proper facilities for barrier nursing and intensive care are available.
The SGV Transport of Injured Greyhounds certificates can easily be used to aid the receiving practice, and to impress on the trainers the need for urgent treatment.
The track vet must be mindful of the duty to prevent the spread of disease to healthy greyhounds. As such, the track vet should ideally not be involved in the diagnosis nor treatment of acutely ill greyhounds. The duty of care of veterinary surgeons must take precedence, however, and any cases which need immediate therapy should receive appropriate care and treatment, prior to referral. In such cases strict biosecurity must be applied.
Direct in-contact greyhounds should be monitored closely for signs of disease over the next 48-72 hours. Any off-colour and/or pyrexic dogs should be treated without delay.
Bodily discharges must be dealt with to prevent contamination of the environment, as per the biosecurity and deep cleaning guidelines.
These include, but are not limited to:
- Long distance transport
- Close contact with other dogs with respiratory disease
- Shared air spaces
Other risk factors that may be involved are:
- Humans with Streptococcal sore throats
- Unpasteurized milk
- Raw horse meat
- Poor food handling hygiene
- Close contact with horses with Str.zoopepidemicus respiratory disease