General management guide to reduce wormer resistance
- Good field management is very important.
- Poo pick your fields two to three times a week.
- Where possible rotate the fields with other species such as cows/sheep. Worms are species dependant, so rotating the field will break the worm life cycle.
- If possible, rest the fields for a period of time, try to have winter and summer fields.
- Ideally do not over graze the field, maximum two horses per acre.
- There is no need to worm prior to moving your horse to a new pasture as long as an adequate worm egg count programme is in place.
Worming programme for an adult horse (over 2 years old):
- Saliva test for tapeworm
- +ve: praziquantel (Equest Pramox) or pyrantel – double dose (Pyratape P).
- -ve: repeat saliva test in autumn.
- Worm egg count (WEC) for other intestinal worms
- +ve: treat with ivermectin (Eraquell) and wait one month for next WEC.
- -ve: wait three months until the next WEC.
- Worm egg count for other intestinal worms
- +ve: treat with pyrantel (Pyratape P) and wait one month for next WEC.
- -ve: wait two months until the next WEC.
- Saliva test for tapeworm and WEC for other intestinal worms
- +ve to both: treat with ivermectin & praziquantel (Equimax).
- +ve WEC, -ve tapeworm: worm with ivermectin (Eraquell) and repeat saliva test next spring.
- +ve tapeworm, -ve WEC: worm with praziquantel (Equest Pramox) or double dose pyrantel (Pyratape P).
- -ve to both: wait until January before worming.
December/January (ideally 2-3 weeks after the first frost)
- Treat all horses for encysted redworms (potentially life threatening)
- Treat all horses with moxidectin (Equest). Horses that were not treated for tapeworms in autumn can be treated with (Equest Pramox). It is especially important not to use this wormer more than once a year to minimise resistance.
How to take a worm egg count sample:
- Take a small sample, ideally one handful no more than 12 hours old – from three different droppings. All the faeces collected for the sample should be gently mixed and put in the same sample bag.
- The sample should be closed and kept refrigerated, unless it can be delivered in the next few hours to the practice.
- Label the bag clearly with your name, the horses name and the date taken.
- The sample MUST NOT be posted or kept in the car under high temperatures.
Bot Eggs (Gasterophilus)
The effective drug to treat them is ivermectin (Eraquell) or moxidectin (Equest).
The female flies lay their eggs on the chest and front limbs of the horse, where the horse may ingest them when licking itself/grooming. The eggs usually develop into larvae in the stomach where they get attached to the margo plicatus, laying dormant for up to 10 months. If the infestation is severe the horse can suffer from colic and gastric ulceration, however, it is common to see bot infestation in a horse with no symptoms. When the larvae detaches from the stomach they pass through the body, being eliminated in the faeces.
Management of bot infestation:
- Brush the front limbs and chest of your horse vigorously or use a bot knife, to detach the eggs from the hair.
- Give ivermectin/moxidectin wormer once a year.
- Poo pick your fields at least two to three times a week.
For further details in worming young stock and broodmares or general advice please do not hesitate to contact us 01344 426066.