Tuesday, 30 April 2013

Coke, formalin, tea...save your horse from African horse sickness!

African horse sickness (AHS) is arguably the most lethal infectious disease of horses. Like Bluetongue virus, AHS virus is an Orbivirus in the Reoviridae family of dsRNA viruses. Also like BTV (and the bunyavirus Schmallenberg virus), it's an arbovirus that is spread between mammalian hosts by Culicoides midges. 

African horse sickness: the lungs fill with fluid and the horse essentially dies  by drowning.  If a horse develops the pulmonary form of the disease, the likelihood is the horse will die.

After recent experiences of BTV and Schmallenberg virus, it's not an unreasonable question to ask whether AHSV would be capable of a similarly large outbreak in Europe. Spain has previously experienced AHSV, but it's never persisted and spread to the extent of the recent BTV and SBV epizootics in Northern Europe.  Though an outbreak is a possibility, BTV and SBV are viruses of ruminants, particularly cattle and sheep, and whilst the midges which feed on cattle and sheep are competent to transmit these viruses, that's no guarantee that similar dynamics would be seen for AHSV. There are also many more sheep and cattle than there are horses, which would also make an AHSV outbreak harder to establish. Nevertheless, the devastating annual experience of AHSV in South Africa suggests that, given the right conditions, an outbreak could happen. Horse-lovers beware.

What can you do? Vaccination? There are both live attenuated and inactivated vaccines for AHSV, but because demand is low most pharmaceutical companies don't formulate them. The most commonly used are the South African live attenuated strains; unfortunately the efficacy isn't great, and if the horses are vaccinated during the midge season they can result in an outbreak.

That leaves therapy. Unsurprisingly people will try anything to save their horse, including some questionable as well the logical approaches (although I'm no pharmacist). I've come across the following, not all of them recommended by a vet:
  • Allergex tablets. 
  • Vitamin C.
  • Tioctan Vet.
  • Phosamine or any other Vitamin B Co-injectable.
  • Brewers Yeast (can use 2 teaspoons Marmite 3 x per day as a substitute).
  • A good probiotic.
  • Himalayan Rock Salt.
  • Colloidal Silver, a homeopathy classic
  • Coca Cola or liquid molasses added to the water to encourage drinking.
  • Hydrogen Peroxide 35% in the drinking water of all horses in the yard. 
  • DCA immune booster.
  • Immune boosting herbs.
  • The AHS herbal treatment kit.
  • Bute replacement herbs (containing cortisone).
  • Eco-Heal, Eco-Lung and Eco-heart.
  • Miracle mineral supplement (MMS).
  • Salix.
  • Dimethyl sulphoxide (DMSO).
  • Solal ribose.
  • Infrared lamp.
  • Oxygen blanket.
  • Bio-Electro-Magnetic_Energy_Regulation (BEMER).
  • Sub-cutaneous Dettol injections.
  • Essential oils (rubbed between the back legs).
  • Rooibos tea.

Coke: for AHSV maybe it works, maybe it doesn't, but it's still bad for their teeth. 

The 'cure' I find most concerning though is the intravenous injection of formalin. This seems to be based on historic rumours rather than anything else; one possibility is apparently that it stops the blood vessels from becoming leaky. On the other hand, it's toxic, and I find it surprising that this would even be considered.

Someone with more knowledge of therapies than me please explain, but looking around there doesn't seem to be masses of scientific support for many of these treatments.

At the end of the day though, I really don't blame the owners. If your horse is infected with a virus which is going to kill >90% of those it infects, surely anything's worth a shot!