To worm or not to worm?
That really is the issue. Whether you have a single horse in an isolated paddock or are sharing a field with several other owners, what is the best policy?
Simply there is no PERFECT policy but what BEST in reality fits your particular situation.
Where do you start?
- Are you going periodically take Dung samples and treat ONLY if necessary?
Dung samples give an indication of the Adult round worm population living in your horses intestines. Levels are generally classified as so many eggs per gram (epg). You may decide to accept a low level of infestation, such as below 200 epg and only treat when above this level. Dung samples should be repeated every 8-14 weeks according to your confidence in the system.
HOWEVER!
- Tapeworm eggs are not reliably found in faeces. Horses should be treated once yearly (or twice in certain cases) using either a ‘Combined’ wormer, such as Equimax or use Double dose Pyrantel.
- Encysted Redworm are an increasing problem. Small redworm larvae migrate through the large bowel gut wall and then hibernate there for a period of time before exiting and maturing into adults. Whilst burrowing into and then out of the gut wall, damage is done that can lead to weight loss and diarrhoea. Larvae are causing the damage and not egg producing adults so there may be no rise in the faecal egg count.
- Bots over winter, attached to the stomach lining as a larval form and so not produce eggs in the faeces.
- Pinworm lay their eggs around the anus so will not be in the faeces.
2. Or are you going to reguarly Worm your horse throughout the year?
Regular worming requires a little thought into when to worm, against what and how often you should be dosing.
- Ensure an accurate estimation of Body weight is done using a Bodyweight Tape measure. Add about 10% to allow for any underestimation of Bodyweight.
- Each wormer type has a different interval between repeated treatments, Ivermectins about 10-12 wks, Pyrantel about 6-8 wks and Moxidectin 14 wks.
- Treat appropriately means Tapeworm, once/ twice yearly, Encysted redworm in Late Winter, Bots in Late Winter and Roundworms throughout the summer months.
BEWARE: resistance to wormers will occur if YOU worm TOO frequently, with TOO little wormer and use the WRONG product and the WRONG time of year!
We are told there will be no more new wormers so we need to protect what we have now for the future!
TESTING AND INTERPRETATION OF RESULTS
Originally we just had Faecal Egg counts, a ‘dynamic’ test of the ROUNDWORM burden within your horse. In simple terms you took a poo sample, got a result and if high enough to warrant worming, wormed your horse. A second sample 2 weeks later should show a ZERO worm count proving the wormer had been effective in a simple cause and effect action.
If the worm count 2 weeks later is not zero then consider that a degree of wormer resistance may be present along with, failed to worm horse properly, not enough wormer was given etc….
NOW we also have Tapeworm saliva testing and Encysted Redworm serum testing. These two tests deal in what we cant see or quantify as both parasites fail to reliably shed eggs!
The Equitape saliva test is an ELISA test so works on the presence of antibodies. In short a high level equals a high level of infection and negative result means absence of infection. Antibodies fail to respond to wormers quite like the ‘dynamic’ faecal egg count will, but deteriorate over time once the offending Tapeworms have been removed by an appropriate wormer.