Strangles Vaccine FAQs
We explain what the Strangles is and why you should use the new Strangles Vaccine to protect your horses.
What is Strangles, and how does it affect our horses?
Strangles is a very contagious bacterial infection that is endemic in our horse population – that means there are always horses that have the disease in our area. These may be sick horses with clinical signs or ‘carrier’ horses with a silent infection that appear absolutely normal.
Between 2019-2023, voluntary recording in UK laboratories reported 1427 cases by 315 vet practices across 93 UK counties.
An active infection in our horses causes a very sick horse with a high temperature, difficulty eating and breathing, swelling and then rupturing of abscesses either under the jaw or at the back of the throat.
It is highly contagious and is transmitted between horses and also through people, yard equipment, water buckets, drinking troughs, tack and grooming kit.
- Strangles causes our horses significant illness
- Strangles causes possible long term health issues or complications in up to 10% of all clinical cases, which can include mortality
- Strangles can be very expensive to the horse owner
- Strangles can be very expensive to the yard with an outbreak – we know how ‘Lock Down’ works for ourselves – this has to happen for an infected yard as well. No yard income, horse movement or competitions for 3 months
- Strangles results in emotional distress for our horses (isolation) and for us (stigma for having a contagious disease)
It can take up to 3 months to recover from infection
Why is this new Strangles Vaccine different to the previous one?
There used to be a strangles vaccine that was given as an injection into the upper lip every 3 months. This was a live attenuated vaccine. Whilst it gave protection to horses, there was a fairly large number of adverse reactions.
This is a dead vaccine, injected into the muscles of the horse in the same way as the normal flu, tetanus or herpes vaccines. It can’t cause any clinical disease in horses as it is just a collection of inert proteins that the immune system recognises – the same as the other vaccines we use in horses.
Why should you vaccinate your horse against Strangles?
1. Welfare
Vaccinating will protect both your own individual horse, but importantly will also protect others on your yard from serious disease. If all horses on a yard are vaccinated, it will greatly reduce any risk of an outbreak for you all.
2. Finance
Individually, it costs a lot of money to treat your horse for strangles and it can be catastrophic for a competition yard, livery yard or sales yard from a business perspective if there is an outbreak. The cost of annual vaccination is a fraction of what it costs to treat the disease. In addition, it is also cheaper than having to perform pre-movement blood and guttural pouch wash testing.
Does the Strangles vaccine work?.
YES! There has been initial trials where the drug companies test how well it works which showed up to 94% protection from disease infection, but there is also now a huge number of horses that have been vaccinated in a ‘real world’ setting. Sweden in particular have vaccinated large numbers of horses and are sharing their results. Over 20,000 horses have already had the vaccination in Europe.
How often does the Strangles vaccine need to be give?
Like other vaccines (Flu and Tetanus) there is a starting course – the second injection is given 4 weeks after the first one. A booster should then be given every 6-12 months depending on the level of risk for that individual horse / yard environment. In cases of a nearby outbreak, bringing the interval down to 3 months will also give extra protection if needed.
Can it be given at the same time as other vaccines?
YES! Unlike the old live vaccine, this new vaccine can be given at the same time as your horse’s flu, tetanus and herpes vaccines
Can we still test horses for Strangles if they have been vaccinated?
YES ! This is one of the most important aspects of the design of this vaccine. The proteins that are used to stimulate the immune system are different from the ones tested for in the blood or wash samples that we send to the lab – so there is no cross-over at all. It is called a ‘DIVA’ vaccine (Differentiate Infection from Vaccinated Animals).
Are there any side effects?
Unfortunately we all know that we can get a sore arm after our COVID vaccine, or that we may have a temperature for a day or so afterwards. Out of the 20,000 vaccines given in Sweden, there have been a total of 5.6% of reported side effects. These can be:
- Localised heat, swelling or discomfort at the injection site – 2.5%
- Increase in temperature – 2.4%
- Dullness or reduced appetite – 2.5%
All reported side effects had resolved without treatment by 5 days.
Importantly, it CAN NOT cause any strangles disease as it is a collection of isolated proteins rather than a living vaccine.
Can it be used in a Strangles outbreak on a yard?
YES – It has been shown to markedly reduce the number of horses that are subsequently infected and ill in a herd / yard environment. Importantly, it also doesn’t interfere with any subsequent testing to monitor the spread of active disease if needed.
Can it be used on pregnant mares?
YES – Whilst there isn’t a license at present for this, it can be used in the same way that Herpes, Flu and Tetanus vaccines are given to boost the immunity of the foal – not during the first trimester, but at 5,7,9 months of gestation or alternatively as a single booster 4-6 weeks before foaling if already vaccinated.
Can the Strangles vaccine be used on foals?
YES – but it should only be used at the same time as the standard vaccinations – like with Flu and Tetanus, we have to wait for the maternal derived protection from colostrum to wear off before any vaccines are given. So we would normally give them at 5-6 months of age.
What about Pre-Movement Testing?
For many years we have been using a blood test, sometimes followed by a guttural pouch wash via an endoscope to make sure horses are free of infection before moving to a new yard.
THIS SHOULD NOT REPLACE THE NORMAL QUARANTINE PROCESS
We also know that there are limitations with the blood test. It gives us a ‘snapshot’ of the immune system and it’s exposure to the bacteria. This could be very recent and active or it could be many months ago and historic.
In addition, there are known ‘carrier’ cases that do not have a positive blood test. The strangles vaccine has the potential for providing better protection for a yard than the existing blood test. Vaccination could be used in place of pre-movement testing, on the proviso that horses aren’t moved within 7 days of the vaccination, and that it doesn’t replace the recommended quarantine advice, that also helps to protect against all other contagious diseases/illness.
Even stronger than this would be a stipulation that all horses currently at a competition yard or livery yard should be on a vaccination program similar to the flu vaccination programmes and all new horses coming onto the yard should be vaccinated as an alternative to the existing blood test.
If you would like any additional information please call us on 01577 841010.
