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New Hendra Developments

24th October 2015

Hendra Vaccination has been a source of contention amongst the equine owner population. Some are for, some are against, some are on the fence. So I thought I'd put some information out from our perspective and open a (civil) discussion about this, so that everyone can be informed.

Firstly, Hendra is a new disease which isn't fully understood yet. It's still a bit of a mystery, but we do know it comes from bats (all bats? We don't know). It's rare, but if you get it you'll almost certainly die. It's transmissible between species (as evidenced by people and dogs contracting the disease, both of which had direct contact with infected horses), and presents in any way from colic, to runny noses, to vague lethargy, to full blown neurological signs.

Zoetis registered the Hendra Vaccine this year (previously it was on a permit) for 2 boosters initially in animals over 4mths, 3-4wks apart, and then 6 monthly. Registration is NOT for 12mthly boosters at this stage, so if you do boost every 12mths it cannot be guaranteed your horse will be covered against infection.


Well, we know here on the tablelands it's considered a low risk area, but as we don't know EXACTLY how Hendra is transmitted to horses there is still a risk. Firstly, for your own horses' safety - we know Hendra is 100% fatal in horses. Secondly, for everyone else in contact with the horse. There is no certain presentation for Hendra, so ANY unvaccinated sick horse we see we have to consider the potential for Hendra. This means we treat this horse as infected as we all have families that rely on us, that WE would like to see again tomorrow.... and if YOUR horse is the FIRST Hendra case in Armidale and we don't pick it up ('it's just colic') there's a good chance we'll be infected as we are the ones who deal with the body fluids during our examination (where the virus lives). Which means there's a good chance we will die. And we will have unwittingly exposed other animals and people to this horse by not quarantining it. So... what do we do? We are supposed to wear PPE gear and do a minimal examination, take samples and send them to the DPI lab and once it is confirmed negative we can proceed with our examination and treatment..... except this takes 2 days. So... in the meantime these horses receive NO treatment or thorough exam, and some might die (which is awful!) Just do the exam whilst waiting for the results? That's a good idea, except 3 vets in QLD are currently being sued for endangering lives for either not testing for Hendra in low-suspect cases (which turned out to be positive for Hendra - the horse had a runny nose), or engaging in treatment before results were in. So... a bit damned if you do and damned if you don't eh?


In my experience it's because it's a bit pricey, and must be administered by a vet (for now anyway). Also, Hendra does sometimes cause a localised swelling which can be sore, but it's short lived and will resolve. Vaccines cause swelling and soreness in people too... it's a pretty normal side effect and shouldn't cause undue alarm. There are reports of horses dying after being vaccinated by the Hendra vaccine, but if you look into the timelines, there is often weeks or months between vaccination and the death, making it hard to link the two events, especially when the horse is normal between times. It's another vaccination to remember too... and you have to be timely as it's all monitored on the Zoetis register so if you're even a day over 12mths since your last booster you have to start the course again.

So, if we can be assured your sick horse is Hendra free we can merrily perform a full examination and begin treatment. The lines are being drawn for us both from an infection point of view, and now a litigation point of view so we have our hands tied a bit when it comes to unvaccinated horses. It's worthy to note as well that REFERRAL HOSPITALS ARE NO LONGER ACCEPTING INVASIVE SURGERIES (such as colics) from unvaccinated horses either as the surgeons contact a LOT of body fluids during a surgery, and in the post operative management period. 

In the end, the choice is up to you, and it seems to have totally polarised people, but hopefully this can help you understand it from our end. I'm happy to answer questions from people and there's information as well on the Zoetis website.

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