Natural Horse World

Health News

Hendra Virus Overview

by Donna Anderson

HeV kills 75% of the horses that get it and you are not allowed to keep a horse that gets the virus and recovers. It must be put down (in case it passes HeV onto humans at a later date I presume.) The fatality rate in humans is currently 57%. Survivors may have to rehabilitate if it gets to the Central Nervous System.

Usually there are 2 unrelated outbreaks in a year. THis year is unprecedented. We are up to at least seven. Scientisits know that 10% of the bat population carries HeV at any time.
Presently it’s at 30%. Nobody knows why. If the bats are stressed and unwell (thru loss of habitat/ environmental toxin whatever) then immune systems are down and viral loads could increase.
Northern NSW and SE Qld is bat central -the hub of the bat network. All four native breeds will mix/intermingle in this area. This crossover does not occur anywhere else in Australia. Having said that the experts think it is only a matter of time before HeV turns up in other states. It will just be rarer than at ‘Bat Central’.

A vaccine is being developed but it will still be 2 yrs before its widely availale for vaccination. Interestingly, they cannot take an infected bat and transmit it to a horse in the lab. They’ve only been able to infect cats, guinea pigs and pigs. The other animals do not seem to be able to pass the HeV on. It stops there with that one animal (in the lab) although recently a dog was found to be infected after a horse on the property had the virus.

If your horse caught HeV you won’t see symptoms for 2-3 days. By the time symptoms occur – rapid onset, increased heart rate, fever, maybe colic, depression, swollen/pain in all four feet – turning to respiratory problems or neurological problems – the horse is heavily shedding the virus through his excretions by this stage – so avoid contact with any fluids – manure, urine, sweat, blood, and nasal. If the horse actually has HeV the horse is usually dead within two days after the onset of symptoms. (Many viral infections start out the same and won’t be HeV). Other horses and people have to be in contact with the body fluids of the infected horse to catch it.

From another aspect – vets were harder to get out when we lost our own local vet to Hendra in 2009. These days we are lucky as vets are more informed and feel more confident in attending sick horses.

Latest Update from ABC News:

New South Wales north coast horse owners concerned about the spread of the hendra virus are being urged to discuss the situation with their regular vet.
Four horses have died on three separate properties in the Mullumbimby and Ballina areas this week. Nine horses in the region have died from the virus in less than two months.

The senior vet with the Department of Primary Industries, Ian Roth, says horses owners should keep their animals away from fruit trees and flying foxes.
“It’s not going to eliminate the risk completely, that’s for sure, but it’s certainly going to be a great help,” he said. “A couple of these properties, there doesn’t appear to be large fruit trees in the immediate paddock and so we need to assess what’s in the other paddocks and as I say, this is where the bat ecologists are invaluable.

“There’s a lot of work being done at the Australian Animal Health Laboratory in Geelong and also there’s the Hendra Taskforce, and that will help with research.
“So it will help with identifying projects that need to be done, accelerating projects and new areas of work.”

Vaccinate Horses for West Nile Virus Now

– A reminder from N. C. Hinkle, Ph.D. Univ. of Georgia

West Nile Virus is showing up early this year.  Horses are highly vulnerable to this disease, and over a third of horses that get West Nile die.  There is no treatment.  If your horse has not already been vaccinated this year, call your veterinarian now and make an appointment to get the West Nile (and Eastern Equine Encephalitis) vaccination.

There is no West Nile vaccine for humans, so disease prevention must rely on avoiding mosquitoes.  Wear long sleeves, long pants, and insect repellent when outdoors.  Encourage your neighbors to pour out any standing water in the community (mosquito larvae can complete their development in less than a cup of water in a tin can).  Standing water that cannot be drained (ditches, for instance) can be treated with “mosquito dunks” or “mosquito donuts” (containing the non-toxic mosquito larva killer Bti).  Cut back bushes and shrubs to increase air flow around the home and discourage mosquito flight.

A third of horses infected with West Nile Virus will die; a third of those that survive will be paralyzed or have to be euthanized. For more info read this article featured on or get 10 tips for reducing your horse’s your horse’s West Nile risk here.

2 thoughts on “Health News”

  1. This WNV article is based on fear. Sure, in conventional vet medicine, there is no treatment, but there are great results using various alternative therapies. We live by a creek and do not and have not ever vaccinated for WNV. Our horses have a natural immunity due to exposure which is longer lived than vaccinating. For your site, Natural Horse World, I am confused why you are running this type of fear based article based on conventional vet med.

    1. Cynthia

      Hi Lisa,
      Yes the fear factor got me in and as I’m not familiar with West Nile Virus I thought I was being responsible by following a vet’s advice to alert horse owners. I am glad to hear there are alternatives to vaccination and for the treatment of this disease. There are many issues surrounding vaccination so it looks like the other side of the story needs to be told. Thanks for your input, Cynthia.

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