Text Box: Rase Veterinary Centre   Unit 1b Gallamore Lane Market Rasen Lincolnshire LN8 3RX   Tel:  01673 842448 Fax: 01673 844430

Text Box: Issue 4 September  2006

Text Box: Worming Worming allows horse owners to maintain their horses’ health whilst also significantly reducing the risk of colic. Worms can cause not only colic but also weight loss, poor performance, rough coat, a pot belly and also stunted growth. Therefore it is important to have an all year round worming programme. This, combined with good pasture management, should keep your horse free from worms. Tape worms and small red worms are the most common varieties that effect horses. Horse owners should be careful when worming their horses, as incorrect worming can lead to a resistance to future wormers, and can be expensive to horse owners if ineffective. The most significant worms for a horse owner to be aware of are the small strongyles worms. As the worms work their way through the horses’ gut, the damage causes can result in diarrhoea and weight loss. Tapeworms can also cause similar damage, so must be treated with a separate wormer. Other parasites to cause damage to the insides of a horse are stomach bots and large stongyles. But thanks to the effectiveness of modern wormers, these parasites are now not a problem.   The problem of worm resistance to the same wormer causes most traditional worming programmes using the same wormer at regular intervals to be ineffective. Care must be taken in applying the recommended dose of horse wormer. Parasites have the ability to build up a resistance towards wormers designed to kill them when the dosage administered is not large enough. Therefore it is important to rotate and vary the types of wormer a horse has and uses the weight of your horse.   Management of ones grazing is another effective method for reducing the risk of worms. It is hard for worming to be fully effective without adequate care of the pasture land. One must note though, that when a shared premise is relevant, everyone should worm their horses at the same time, using a common strategy. Droppings need to be rounded up every week as those types of conditions suit the spread of worms. Horse owners are advised to keep one horse per one acre of grazing. Another beneficial method for preventing worms is to cross graze horses with sheep and cows. As cattle and horses share none of the same major worms, cross grazing ensures that pasture is evenly grazed.  The pasture should not be overstocked and if possible rested periodically to allow worm eggs to reduce with time. Do not harrow pasture during damp weather. Harrowing done at this time will simply spread worm larvae over the pasture increasing the risk of consumption by horses. Dry, warm weather is the ideal time to harrow grazing to expose worm larvae to desiccation. The effectiveness of a worming programme can be monitored by submitting dropping samples to your veterinary practice for worm egg counts.   As well as horses, foals are also susceptible to worms, and in particular roundworms.  Foals can normally be wormed from 6 weeks of age, although not with Equest as it has serious side effects on foals under the age of 4 months. If a horse is already seriously infested with parasites owners should be very careful. A paste horse wormer, such as Equest and Equivalan, could conceivably kill too many parasites at once, thereby causing them to bunch up in the horse's intestines and colon. While this can kill a horse, more often then not it will just cause significant discomfort. In such cases using a  wormer such as Panacur would be more suitable.  The potency is far lower than the newer wormers. This lower potency allows for a slower and safer parasite kill and removal rate.