Worming reminder

Discussion in 'Horse Management' started by wormwatch, Nov 18, 2008.

  1. wormwatch

    wormwatch Active Member

    This is a reminder to horse owners in the Perth area that if you are not treating your horses at the recommended intervals with an effective treatment OR testing regularly with worm egg counts and practicing good pasture management (manure removal at least twice weekly), then your horse is at risk of developing potentially harmful strongyle worm burdens.

    For worm egg counts performed by Worm Watch since June 2008:
    • approximately 67% of horses that were at least 2 weeks overdue worming had a positive worm egg count. This means that they had accumulated adult worms since the last treatment and were contaminating pasture with new worms
    • approximately 51% of horses that were at least 2 weeks overdue worming had worm egg counts high enough to indicate a treatment was required and were causing significant contamination of pasture
    • approximately 30% of horses that were at least 2 weeks over due for treatment had a worm egg count considered high enough that the horses are at risk of worm disease

    "2 weeks overdue" was defined as 10 weeks or more since the last treatment for ivermectin and abamectin treatments and 14 weeks since moxidectin treatment. Results for other treatments have not been included because of the risk of resistance and low numbers of horses treated/tested.

    These results are from local horses and show that if you are not treating regularly with effective treatments (or testing), then you are likely putting your horse at risk of worm-related disease. These test results are from horses who's owners have taken the time and effort to have a worm egg count test done and in many cases are practicing "best practice" pasture management (manure removal at least twice weekly), so the "risk" of not treating regularly for horses that are sharing grazing with other untreated horses or where pasture/manure management is less than ideal may be much higher than these figures suggest. None of these horses were being investigated for poor body condition, illness or colic.

    If you are relying on alternative methods of worm control such as herbs or colloidal minerals, it is important that you use regular testing to ensure that harmful worm burdens are not accumulating.

    Worm Watch offers a worm egg counting service for horse owners. Your vet is able to help provide advice on appropriate worm control for specific situations. If you are unsure of what the correct treatment interval is for the treatment you used last, then check the label, call the helpline for the manufacturer or check with your vet. Wormers given via stomach tube have the same treatment intervals as the paste version with same active ingredient. There is more information on the Worm Watch website and you can e-mail me to subscribe to the free quarterly newsletter.

    Effective worm control is an integral part of responsible horse management. Worm egg counts are not a "perfect" test and won't replace the need for effective treatments, but they will give you a tool to monitor how well your treatment programme and pasture management is working and allow you to make any changes necessary BEFORE your horse develops worm-related disease.

    Worm Watch
  2. retroremedy

    retroremedy Well-known Member

    That is rather concerning WormWatch because these are obviously the horses owned by people that put their hand up for a worm egg count so are being proactive!
  3. Ritadee

    Ritadee New Member

    Thanks WW, just out to de-poop the paddock AGAIN!!!. They're due for worming but I want to get an egg count done first,and then one again after worming. My friend should have been in touch with you today.:D:))
  4. ChillOut

    ChillOut Well-known Member

    Hi WW,
    I would like to ask you how long you need to spell a paddock to considerably reduce the worm eggs (I am a non-poop-picker) in hot and dry conditions and in cooler conditions.

    Thank you:)*
  5. wormwatch

    wormwatch Active Member

    Immature worms are able to survive longer inside manure balls/piles than outside manure on pasture.

    Based on studies performed in Australia and published in scientific journals, immature worms are able to survive in manure for 8 weeks in hot wet weather, 12 weeks in hot dry weather and 32 weeks in cool weather. Manure piles can become reservoirs of immature worms that are ready to emerge onto pasture once the rain (or reticulation) arrives.

    The immature worms are more susceptible to weather conditions outside of the manure pile, but worms can still survive for extended periods on pasture - 2-3 weeks in summer and 7-11 weeks in winter.

    So - if you are picking up poo and taking it away (not spreading it), then these studies suggest that paddocks need to be rested for at least 3 weeks in hot weather and 12 weeks in winter. If you are not removing the poo, then the required rest times are closer to 3 months in summer and 8 months in winter to consider the paddocks "safe".

    For those interested in some papers, here are some good references:

    English AW (1979) The epidemiology of equine strongylosis in southern Queensland. 1. The bionomics of the free-living stages in faeces and on pasture. Australian Veterinary Journal 55, 299-305

    English AW (1979) The epidemiology of equine strongylosis in southern Queensland. 2. The survival and migration of infective larvae on herbage. Australian Veterinary Journal 55, 306-309.

    Hutchinson GW et al (1989) Seasonal translation of equine strongyle infective larvae to herbage in tropical Australia. Veterinary Parasitology 33 251-263

    Nielsen MK et al (2007) Climatic influences on development and survival of free-living stages of equine strongyles: Implications for worm control strategies and managing anthelmintic resistance. The Veterinary Journal 174, 23–32
    Last edited: Nov 18, 2008
  6. Trojane

    Trojane Well-known Member

    I'm interested in how our group will turn out since the last egg count (luckily very low load, but was on new pastures). Must get a collection organised soon!

    Thanks again for the excellent Worm Watch talk at Wallangarra Adult Riders! :)
  7. Golden Biscuit

    Golden Biscuit Well-known Member

    How do we get an egg count done? I would be extremely interested in doing one :D My boys are... oops a lil overdue :eek: thanks for the reminder
  8. Ritadee

    Ritadee New Member

    So does that mean I am doing more harm than good piling it into small piles? Should I be spreading it? (I haven't got a trailer to take it away)
  9. wormwatch

    wormwatch Active Member

    I just replied to your e-mail, but I'll copy part of the reply here in case anyone else is interested.

    Horses tend to avoid grazing the feed/pasture around manure. This is why paddocks develop roughs (long rank pasture around manure) and lawns (short heavily grazed pasture with no manure). Scientists have found that the number of worms on the roughs is 15 times higher than on the lawn areas. By avoiding grazing the roughs, horses are also reducing their own exposure to worms.

    If you are raking manure into a pile, it may spread the immature worms if you are raking the manure over the "clean grass" (lawns). If it is possible to rest the paddock after raking, that would help reduce the risk by allowing some of the worms on the pasture to die. In the US scientists suggest that paddocks are rested for 2-4 weeks after manure spreading during hot weather. In cooler weather months, the pasture can stay "infected" for several months. If you are moving manure into sandy areas, the risk of spreading worms will be lower because horses are unlikely to graze the "contaminated" spots.

    Pasture management needs to be reasonable and practical for your lifestyle. Pasture management isn't only about worms, but also about maintaining pasture, preventing weeds and erosion and so on. The worm egg count testing will help show if your current worm control is adequate and if it is not, then we can see what treatment options and pasture management options will be feasible and effective.
  10. Ritadee

    Ritadee New Member

    @)Thanks, much appreciated**):))
  11. wormwatch

    wormwatch Active Member

    Hi BEB:

    I offer a postal service, or you can contact me and we can see if we can organise to meet when we are in the same area. Basically you give me a sandwich bag of manure and I send you a report with the test results and some suggestions about what the results say about your current worm control and how it may be improved. Drop me an e-mail or PM if you want to organise a test.

    Your vet may also be able to offer worm egg counting services through a private lab. NSW Department of Agriculture also does a mail service. WA Department of Agriculture does horse worm egg counts, but the samples should go through your vet. I believe there is a lab in Kojonup offering a mail service too. So there are a few options out there :)
  12. LAURAmay

    LAURAmay Well-known Member

    hey WW
    at work we have about 50 paddocks with race horses on spell.
    they are always wormed and drenched before being put out.
    due to our hectic shedule we only rake the paddocks every second day.
    do you think that this is ok or would picking up the poo be better?
  13. wormwatch

    wormwatch Active Member

    There is no way of guessing whether worm control is adequate or not in that situation without doing any monitoring. In that situation, worm control may or may not be adequate. Indeed, it might be OK for some horses/paddocks and not OK for others.

    If worm egg count testing showed that horses were contaminating the paddocks with immature worms and picking up worms from the paddocks, then it would be up to the manager to determine what worming treatment protocol and paddock management options are feasible and whether they want to "invest" in ongoing monitoring or continue to assume that everything is OK.

    I'm not here to point the finger at everyone and say "thou must pick up every manure every day". "Ideal" paddock management for worm control is not always going to be feasible (or necessary). I put this post up to suggest that if you are not treating or testing regularly (ie every 8 weeks for ivermectin/abamectin, every 14 weeks for moxidectin), then you can't just assume that everything is going to be fine. By "regular treatment", having horses drenched/treated every 6 months is not always adequate for some horses.
    Last edited: Nov 19, 2008

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