Equine Influenza in the UK

In January of this year the British TBA alerted breeders to a number of outbreaks of Equine Influenza in Europe and recommended that people remain vigilant for the symptoms for horses in their care. Symptoms include a nasal discharge, elevated temperature and dry cough. If breeders observed these symptoms they were advised to follow the guidelines set by the Animal Health Trust’s Equiflunet.

By early February Equine Influenza had occurred in a small number of vaccinated horses in training in the UK. Racing was suspended in the UK whilst the outbreak was investigated and a controlled return to racing was implemented the following week.

The confirmation of EI cases amongst vaccinated animals presented a risk for stud farms, and breeders have since been advised to increase their biosecurity measures during this period and introduce 6 month intervals for flu booster vaccinations. Whilst infection has occurred in EI vaccinated horses, veterinary advice is clear that vaccination remains essential for disease mitigation as vaccination reduces the severity of clinical signs and decreases the time to recovery, thereby reducing viral shedding and reducing the risk for spread of infection. Young foals are most at risk from this disease.

The TBA veterinary advisors recommended the following actions:

  1. Breeders consult their veterinary surgeons regarding their risk and the preventive measures that they should take, including quarantine facilities for incoming horses.
  2. All horses should be fully vaccinated with a UK licenced EI vaccine and any horse that has not been booster vaccinated within the last 6-months, should receive a booster vaccination now, unless showing signs of EI infection or being kept in contact with horses showing signs of EI infection (i.e. may be incubating EI). Maximum benefit is always gained by vaccinating pregnant mares in the last 4 to 6 weeks.
  3. There should be at least a 7-day period of quarantine before horses out of training enter stud farms, during which time they should be monitored in quarantine for clinical signs (dullness, raised temperature, coughing, nasal discharge).  If horses show clinical signs they should be seen by a veterinary surgeon and tested for EI and maintained in isolation until they are shown to be no longer shedding virus.
  4. At the time of writing there is no evidence to suggest that EI is active on UK stud farms, but if you are travelling horses it is advisable to check for wellness, in particular for raised temperature, coughing and nasal discharge, before travelling.  If at all concerned, you should consult your veterinary surgeon.
  1.   For those studs standing stallions, it is recommended that mares should only be accepted for covering following receipt of evidence confirming a full EI vaccination history and confirmation that the mare has received a booster EI vaccination within the six months prior to covering.

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