It used to be common practice for donkey owners to follow a worming calendar, administering a de-wormer, such as Ivermectin, every 4-13 weeks. This blanket approach to worming is now considered less effective and unnecessary.
Not all donkeys grazing the same pasture will have the same worm burden - 80% of worms are found in only 20% of animals known as ‘high shedders’. Also, donkeys can naturally tolerate a low-level worm burden without any detrimental effects to their health.
To avoid any unnecessary drug use, the first defence is maintaining a healthy immune system, proper nutrition and good management. We also recommend a targeted treatment strategy, identifying which donkeys are high shedders and monitoring their worm level. In order to do this, you need to conduct a faecal egg count with your vet.
Choosing a wormer for your donkey
No one particular wormer will control all types of equine worms and different rules apply to sick donkeys, pregnant and lactating mares, and foals. While there are only a few types of drug, there are many different brands and this can make choosing a de-wormer complicated. You should consult with your vet for the best course of action.
How to prevent resistance to wormers?
The easiest way to prevent a chemical resistance to worming products is to avoid using them as much as possible. The Donkey Sanctuary’s preferred method is for owners to conduct a faecal egg count. Your vet can then advise if worming is required.
If a worming product is recommended, you should take care to avoid under-dosing. If the dose is too small it may not be sufficient in treating all of the parasites. By leaving some worms exposed to a less than lethal dose they will be able to build up a self-preservation response to future dosing. Therefore, make sure you monitor your donkey's weight and calculate their dosage as correctly as possible.
Poor technique can be another factor of under-dosing. Worming pastes can be spilt, spat out, or may still be contained within the tube. Therefore, make sure to be extra vigilant when administering the wormer.
Faecal egg counts for donkeys and mules can be carried out by our in-house laboratory and submitted by owners using the forms available on this page. We do not charge for this service but donations are always greatly appreciated. A donation of between £5 and £10 per donkey is suggested to cover costs of running any laboratory tests.
Results are returned to your veterinary practice for them to advise on any necessary treatment. Please make sure samples are packaged in accordance with the guidance on the submission forms. You can read our ‘Guide to Worming’ for information on the most appropriate time to carry out a faecal egg count.