- Throughout their lives, goats are very susceptible to worms in their stomach and intestines.
- Big worm burdens cause ill-thrift, weight loss, diarrhoea and even anaemia and deaths.
- Anthelmintics can get rid of worms, but it is important to give the correct type of anthelmintic, to give the correct dose and to drench at appropriate intervals.
- Giving too little drench is ineffective and will encourage the worms to become resistant to the drench.
- Giving too much can cause poisoning, especially if selenium has been added to the drench.
- A degree of worm control can be achieved by pasture management, as well as by giving regular effective anthelmintic drenches.
- Grazing goats with cattle or horses (which don't share the same worms) can help prevent the build up of worm larvae on pasture.
- Grazing long pasture can help control worms, because larvae tend to be concentrated at the base of the sward.
- Feeding browse is good too, because shrubs and trees are generally not contaminated by faeces that might contain worm eggs and larvae.
- Cutting grass and carrying it to goats from faeces-free areas might be laborious but it helps keep worm burdens down (as long as you don’t give too much at once and cause digestive problems!).
- Efficient drenching involves giving an effective anthelmintic at strategic intervals to keep worm burdens in goats down to a level that is doing no harm.
- Read the instructions on the drench container, and give each goat the correct dose for its weight.
- If commercial animal scales are not available, then use bathroom scales.
- Weigh yourself, then pick up a goat and weigh yourself and the goat - the difference is the goat's weight.
Do this for a representative number of animals to make sure you know the weight of each goat before you drench it.
- There are three types of drench - white, clear and third generation ivermectin types.
- Only some of the white drenches, including Axilur 10, Bomatak-C, Bomatak-S and Oxfen are licensed for use in goats.
- If one of these is used it should be given at regular intervals of about 4-5 weeks throughout the summer and autumn months.
- The clear drenches based on levamisole, eg Nilverm, are not particularly effective in goats, they are not licensed for use in goats and are NOT recommended.
- Note that at twice the sheep dose rate, they can cause poisoning in goats.
- The third generation drench Ivomec Liquid for Sheep and Goats can be given at regular intervals of about 8 weeks throughout summer and autumn.
- There are many other types of pour on, ruminal bolus and injectable anthelmintics on the market for various livestock species, but not many are licensed for use in goats.
- This is why it is best to consult a veterinarian for advice if planning to use any anthelmintic other than the Ivomec and white drenches listed above.
Faecal egg counts
- If a drench is effective, egg counts will be zero in faecal samples taken from the goats 7 to 10 days later.
- Your vet can arrange for tests of faecal samples taken at that time to confirm nil egg counts.
- If egg counts are not zero, your drenching was not effective.
- The dose rate may have been wrong or the drenching technique (eg the drench gun) may have been faulty.
- Alternatively the worms may be resistant to the drench used, in which case you will need your vet's help to select an effective drench in future.
- Drench resistance means that some or all of the worms in the goats are not being removed by the drench used.
- Once you have drench resistant worms in pasture and in livestock on your farm, it is very difficult or impossible to get rid of them, and you must change to an effective drench.
- It is wise to test for drench effectiveness from time to time (as described above), to maintain good worm control.
Withholding times in dairy goats
- In dairy and meat goats, withholding times must be observed, and these are clearly shown on the anthelmintic label.
- The withholding time is the time that you should allow to elapse before milk or meat from that animal is used for human consumption.
- For some of the long acting third generation drenches, the withholding time is remarkably long, so you have to take this into account when planning the drenching programme.
- For example, Ivomec should not be used at all during lactation or in the last 28 days before kidding if the milk is to be drunk by humans.
- It can seem complicated - which is why it is important to get advice from a veterinarian if you have any doubt about choosing a drench for dairy or meat goats that is effective in controlling worm burdens.