Caterpillars are one of the features of this week’s Equine Science Blog, but first I’ll be talking about news of strangles in the UK, Swedish nutrition research and why British weather may be contributing to laminitis.

Every owner knows how serious strangles can be. A highly contagious disease, it’s usually recognised by abscesses under the horse’s jaw as well as nasal discharge and general lethargy.

Caused by the Streptococcus equi bacterium which gains entry to the horse through ingestion or inhalation, it can sometimes be fatal and easily spreads between horses on the same yard. Sadly strangles has now been confirmed at a racing yard in Lambourn, United Kingdom. According to reports on Horse&Hound Online, it has been confirmed that trainer Stan Moore has reported that a yearling filly he recently imported from Ireland has the infection. Strangles is not a notifiable disease in the UK but under racing rules Mr Moore was required to inform the British Horseracing Authority of the strangles case.

The filly has now been placed in isolation, the yard is currently under quarantine and any other yards that may have come into contact with the filly have all been informed. Hopefully this case will be an isolated one.

Onto the topic of nutrition now and Swedish researchers have discovered that horses who are fed high-energy haylage have more stable gut bacteria than those who are fed more carbohydrates, such as those found in hard feed. The scientists from the Swedish University of Agricultural Science also discovered that those equines on the forage diet had less ‘undesirable’ bacteria in their guts.

The best diet they found was that of early cut timothy/meadow fescue haylage which even seemed to lead to lower counts of the Streptococcus bovis/equines bacterium complex. Further investigation is now needed to help owners and welfare workers develop the best feeding regimes to keep their equines happy and healthy.

The researchers also found that diets containing fermentable carbohydrates, which are usually given to increase competition horses’ energy, are associated with some disorders of the gut. They believe that this is because the micro-organisms in the gut undergo changes although the exact details are currently poorly understood. High levels of carbohydrate are responsible for several common equine diseases such as colic and laminitis.

Talking of laminitis leads on to the third news stories this week – the charity group World Horse Welfare has issued a warning to SE Britain after concerns that a warm autumn could lead to an increase in laminitic cases.

October isn’t a month that is usually associated with laminitis but World Horse Welfare told Horsetalk.co.nz that “this year is shaping up to be a very different story”. Warmer temperatures and the long-awaited rainfall in the southeast of the UK means that field grass will continue to grow longer than usual which in turn increases the risk of laminitis – in New Zealand laminitis risk has been increased because of the warm spring they’re currently experiencing. Any owners who suspect their horse might be suffering from Laminitis should contact their vet straight away.

Finally, caterpillars could be more harmful for horses than you might think…well to be more specific, a certain variety of caterpillars could be harmful for pregnant mares.

An image of a processionary caterpillar. Copyright of Quartl and licensed under the Creative Commons 3.0 Licence.

Researchers in Australia are reported on Horsetalk.co.nz to have found that processionary caterpillars (Ochrogaster lunifer) can caused abortions in mares. Mid-pregnancy mares that ate either whole caterpillars or their shed skins suffered abortions. Mares who were only in the first 35 days of pregnancy did not lose their foetus.

Whilst many people may think that their horses would not typically eat a caterpillar, what is worrying is that the caterpillar’s shed skin can also cause abortion and it’s quite possible that these skins could be carrier across fields and pastures by the wind where they could then be eaten. Further research into this area is currently needed, but the researchers told Horsetalk.co.nz that one possible idea is to remove trees such as eucalypt or acacia species from paddocks since these are natural sources of food for the processionary caterpillars.

Now for this week’s trivia question:

What is Spondylitis?
1. A fungal infection of the skin
2. Inflammation of the bones in the spinal column
3. A swelling of the fetlock
4. A disease of the teeth

Check to see if you got the right answer by visiting my profile page here.