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May 2005

Liver Fluke

It would appear that recent warnings about high risk of liver fluke in cattle and sheep is causing concern in equine circles.  We are widely informed of the fact that the horse is not a natural host for fluke, though fluke still infect horses and can do a great deal of damage.

A more complete description of the problem exists elsewhere here, but some points need to be stressed. Firstly, egg-laying by fluke may be impeded; meaning a negative faecal sample might be misleading.  In such a case a clinical assessment is needed, remembering that anaemia, low-level jaundice and, possibly, intermittent diarrhoea might be seen.  Of course, affected horses will also be light in condition and usually dry in the coat. Heart murmurs are a common feature, be they coincidence or not.  

As far as treatment is concerned, there is always a possibility that the act of killing fluke within the confines of the liver will cause adverse consequences.  Therefore it is probably wiser to treat horses exposed to infection one at a time, or in small batches.  Some may react by going off food.

I quote here from a recent correspondence where three horses thought to be heavily infected were dosed. 

"The effect on them was almost immediate,
within 10 mins they were like they had been sedated, quite wobbly round the knees no interest in anything around them just standing, heads down, they were breathing heavier and appeared to be in some amount of discomfort.

I offered them water, but they weren't interested, Major worried me within 15 mins of dosing he laid down with his head up then 5 mins later flopped onto his side with his eyes closed and bottom lip drooping.

Goldie was the last to get back to normal; he still was not eating or drinking till about 24 hrs later."

These horses were treated with oxyclozanide/levamisole, fluke eggs having been found during faecal examination.

Despite this experience, adverse reactions are not inevitable and, in view of the damage fluke cause to the liver, treatment is essential for affected horses expected to perform in competitions of any kind.

Oxyclozanide and triclabendazole are both used for fluke in horses although not licensed for the species.  In cases of clinical necessity, affected horses are treated at a dosage to be gauged by your veterinary surgeon.

It is wise to be careful, but don't be afraid to treat when there is every reason to suspect fluke infestation is causing your horse clinical problems, not least of which might be lowered resistance to infection..

Foot Balance

The bulk of correspondence to this site suggests foot balance is an implicating factor in many lameness cases.  It should be stressed that foot and limb balance are inextricably linked and, ultimately, there is little point in having a foot perfectly balanced if that leads to the limb being compromised.

It might also be suggested that lame horses can have difficulty recovering from conditions like splints, sesamoid and fetlock strains, as long as the limb is out of balance.

This recent photo is of a horse diagnosed with a chronic foot problem.  While it is possible to make allowances for stance and ground, a vertical line from the centre of the toe should bisect the limb.  This, clearly, is not the case and it is natural to expect that such an imbalance will, ultimately, cause lameness, irrespective of what else might be going on in the limb.  Recovery from any lameness will be impeded and it is clear that structures like the pasterns, fetlocks, splint bones and knees are all at a disadvantage when under the influences of concussion in such a case.

Another comment worth adding: many farriers have difficulty balancing feet when using 'natural balance' shoes, as would appear to be the case here. Why this might be so, is unclear, but there are many reasons to be critical of this method of shoeing and it can be speculated that a certain amount of lameness can be attributed to it.  It is a subject that requires informed debate and, it can be suggested, constructive advice from appropriate teaching authorities. 

Peter Gray

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