Clive Hamblin Bvet med MRVCS, NTF Veterinary Adviser, explains Equine Influenza

To help communicate the seriousness of the recent cases of Equine Influenza, our Veterinary Adviser, Clive Hamblin, has written an explanation of the disease and its transmission. He concludes with advice on biosecurity and vaccination. Below his account, we have inserted a link to a scientific paper by Dr Richard Newton (of the Animal Health Trust) and colleagues, demonstrating the increased immunity provided by vaccinating against equine flu at six monthly intervals.

Clive Hamblin writes:

On the eve of our return to racing, I would like to stress that we are not out of the woods yet, although we can perhaps see the odd patch of green between the trunks. It has been a fraught time for all concerned with airtime and column inches normally given to our sport of British horseracing, having to be filled with opinions from many people, some more informed than others.

The simple fact is we have seen an escalating problem with a mutation of a variant of equine influenza, initially seen on the continent and also in Ireland and now Great Britain. It has been reported in a number of individual outbreaks, across the land, most of which have been in unvaccinated horses, then more alarmingly in vaccinated horses and then with entry into the racing population, as you well know.

There is a wide range of pathogens affecting the respiratory tract of the racehorse, seen at intervals, across the spectrum of yards, many of which are viral and many bacterial, but make no mistake, these are not Equine Influenza. This latest outbreak is!! No, it is not Ebola, but it has the potential to bring racing to a coughing and spluttering halt and not just for 6 days.

I would like to commend the BHA and its officers, the Animal Health Trust and my fellow members of its Veterinary Committee for their prompt and sensible action. This break has enabled us to take stock and properly assess the situation prior to making an evidence-based programme for the recommencement of the sport, maintaining the best health of the national racehorse herd and with the least risk of further spread of this potentially debilitating disease.

It is perhaps of value to know how the disease progresses. Virus particles from an infected horse are discharged in a spray of water droplets when breathing, coughing or snorting and are inhaled by our horse. The virus gains access to the cells of the airway and rapidly multiplies, this is the period we call “incubation”, 48 hrs to 4 days in duration. This is then followed by the period when clinical signs are apparent although they may be subdued in vaccinated horses, particularly if that has been recently carried out. This is the period when the horse may be “shedding” virus (can be up to 10 days) and is the optimum time for swabbing (inserting a long swab through the nose and collecting mucous from the throat region ready for transporting to the laboratory). The laboratory will carry out PCR on this sample where any viral RNA (this virus’s equivalent of DNA) is multiplied many, many times and can then be identified. The immune system of our horse now is in full flight combating the virus invasion, the horse stops shedding and is now no longer infective to the rest of the population. Damage done to the respiratory tract will gradually repair allowing a return to training in due course.

The equine influenza virus cannot live for long outside its infected host but can live for short periods in secretions in a stable, lorry or on a groom’s clothing, providing another source of infection. The main source though is a newly infected horse and more often than not, a horse newly introduced into the herd. That could be from overseas, the Sales or perhaps a breaking or livery yard or a new intake horse from shared transport.

In the light of this new influenza outbreak we have two major weapons in our armoury, namely vaccination and biosecurity. There are quite a number of scientific papers supporting the evidence that vaccinating at 6 month intervals gives superior protection against equine influenza virus and hence the BHAs approach to resuming racing if the participants have been so protected. This was never going to please every owner and trainer, but the advice of world experts would be ignored at our peril.

With regard to biosecurity, the watchword is all new inmates should have a period in a quarantine unit, preferably some distance from the training yard. For those looking for a cracking good read, I refer you to the NTF Code of Practice for Infectious Diseases of Racehorses in Training booklet (or via the NTF website, https://www.racehorsetrainers.org/publications/pdfs/cop.pdf . Please, please pay particular attention to the sections on biosecurity……pages 3-11 and try and orchestrate the best arrangements you can.

Clive Hamblin Bvet med MRVCS

12th February 2019

Dr Richard Newton et al paper on

Optimising vaccination strategies in equine influenza.”

 

and the layman’s explanation on the BHA website

 

 

Equine flu – Statement from Donald McCain

NEWS RELEASE

7 February 2019 -For immediate release

STATEMENT FROM DONALD MCCAIN CONCERNING HORSES AFFECTED BY EQUINE FLU

The National Trainers Federation is issuing the following statement from trainer Donald McCain to provide some background information about the cases of Equine Influenza at his Bankhouse premises in Cheshire.

“I have been aware of the recent news about Equine Influenza outbreaks in France and Ireland, and over the last couple of days, I have been concerned about the health status of a small number of horses in the yard. Their welfare is at the front of our minds, so at my request, our veterinary surgeon has examined them regularly and we have followed his advice on testing and treatment. It was by following this protocol that the positive results for equine flu came to light yesterday evening. The BHA were contacted immediately and we are liaising closely with them about biosecurity and management of all the horses at Bankhouse.

“Bankhouse follows all the available advice on disease control and all our horses are fully inoculated. We are scrupulous about observing the health status of horses in our care and taking the necessary steps to treat any condition that may affect them. It follows we would never race any horses that we could have known were infected. Over the last 2 months, all potential runners have been scoped and their blood checked within 36 hours of their races to ensure that only healthy horses compete for the yard.

“When new horses arrive at our yard we, as much as possible, try to keep them separate but at this stage cannot know if the infection came from recent arrivals or from horses returning from racing. We have 3 confirmed cases and this morning have taken blood and swabs from all the others for testing.”

Comment from David Sykes, BHA Director of Equine Health and Welfare, “We would like to thank Donald McCain for his cooperation in this matter, and for the responsible manner in which he has dealt with this issue, under the guidance of his veterinary surgeon. He has acted professionally with the interests of the racing industry and the health of his horses as his priority.”

Mr. McCain will provide updates in due course.

Ends

The National Trainers Federation represents the interests of British licensed racehorse trainers.

For more information, please contact Rupert Arnold, NTF Chief Executive, on 01488 71794 or 07899 797010. E-mail: r.arnold@racehorsetrainers.org

For more information on the National Trainers Federation, please go to www.racehorsetrainers.org

Strangles can be eradicated – with the Thoroughbred industry leading the way

The Strangles Workshop recently held at the fabulous Animal Health Trust (AHT) Visitor Centre provided a fascinating insight into the complex and ground breaking disease surveillance and research underway into this disease. Strangles is endemic across most of the world, with evidence that more than 600 outbreaks are identified annually in the UK alone, but thankfully very few of these occur in British racehorses.

New research at the AHT, which was presented at the meeting, tracked the international spread of Streptococcus equi, the cause of strangles, through 22 countries from around the World. “Our results showed that European countries generously share their populations of Streptococcus equi, but we also saw exchange of strains in the UK with the USA, South America, Australia and the United Arab Emirates” explained Dr Andrew Waller, Head of Bacteriology at the AHT. “We believe that outwardly healthy persistently infected ‘carrier’ horses could be to blame for the international transport of strangles.” Recognising the risks of introducing strangles via the international transport of horses, the authorities in Dubai now insist on the mandatory testing of blood samples from horses for exposure to strangles pre-export. Dr. Waller said “Early findings indicate that this intervention has helped to identify carriers before they had the opportunity to introduce strangles to Dubai, preventing new outbreaks and breaking the cycle of disease.”

Although strangles is complex, the meeting consistently delivered this strong message “Strangles can be prevented.” Dr Richard Newton, Director of Epidemiology and Surveillance at the AHT described methods to prevent strangles from getting into a yard and to eradicate it should the worst happen. Dr Newton explained; “Although strangles is uncommon among racehorses in training, it is a disease, along with equine influenza and neurological equine herpes virus, which requires trainers to immediately notify the British Horseracing Authority (BHA) so that effective steps can be taken to prevent its spread through the racing network. The rarity of strangles in racing is undoubtedly linked to the zero-tolerance that the industry has to it, such that trainers, their vets and the BHA all work closely together to control and eradicate the disease when it occurs.” Dr Newton continued, “It is important that racing remains vigilant and in particular becomes open to adopting wider preventive strategies such as quarantining and screening batches of horses entering training for the first time and those returning from events, such as international meetings, where there may be a heightened risk of introducing a range of infectious diseases including strangles.”

 

For further information, please contact: Rebecca Calver, AHT press office, 01638 751000 ext. 1572

 

The Animal Health Trust (AHT) is the UK’s leading veterinary and scientific research charity, dedicated to the health and wellbeing of dogs, cats and horses.  It aims to improve the health and welfare of horses, dogs and cats through research, but also provides specialist referral services and continuous education to vets. Throughout 2017, the AHT is celebrating its 75th Anniversary – that’s 75 years of leading science and care for animals. Visit the website www.aht.org.uk