There are many different reasons why our horses might walk a bit odd – usually it is because they are lame but occasionally it is due to nerve dysfunction. Shivers and stringhalt are two conditions that are easily confused as they both cause the hindlimb to be lifted high up to the belly (hyperflexion) as the horse walks.
With Stringhalt, the abnormality is most severe at a walk and the hindlimb snaps sharply up to the belly then forcefully stomps on the ground. Stringhalt is caused by a toxin in the plant catsear (also known as false dandelion or flatweed). We do have catsear in Central Otago and like its name suggests it looks very similar to dandelion. The main difference is that catsear has hairy leaves and a stem that branches to produce multiple flowers while dandelion produces a single unbranched stem. What’s the best way to get rid of catsear? Sheep and cattle can eat it without any issues, but if that isn’t an option, herbicides can be used.
Shivers also causes hindlimb hyperflexion but, unlike Stringhalt, is most severe when the horse is being backed up. Also, in addition to being held upz, the limb is often held out from the body and trembles. Shivers is caused by damage to special nerve cells in the brain and is a slowly progressive disease. Draft horses are most commonly affected but other breeds can get this disease too.