Horses from Coast to Coast are Infected with Tapeworms

Equine parasites such as bot fly larvae, roundworms, large and small strongyles and tapeworms cause serious health problems in horses. For many years, the equine tapeworms were considered harmless and rarely associated with clinical disease. However, recent studies show that tapeworms pose a significant risk factor for colic.

In 2003 a groundbreaking study by Dr. Craig Reinemeyer of East Tennessee Clinical Research, uncovered the high prevalence of equine tapeworms throughout the United States. That original study indicated a lower risk of tapeworm exposure on the pacific coast compared to other areas of the country¹. To get a better representation of the prevalence of tapeworm exposure, the study was recently repeated, using over 300 farms and 600 samples from across the three western states. New data from Pfizer Animal Health shows tapeworm prevalence on west coast farms as 17.3% in California, 38.5% in Oregon and 25.3% in Washington².

These new figures confirm that the tapeworm poses a significant threat to horses all over the United States, not just the Eastern and Midwestern regions. It’s been five years since the original study was released and many horse owners still think their horses are not at risk to tapeworm infestations in their area. This new information clearly demonstrates that all horse owners need to take an effective approach to protect their horses from the tapeworm threat.

“This new research helps answer many questions about tapeworm prevalence in the western United States,” said Dr. Bobby Cowles, DMV, MS, MBA, Pfizer Animal Health. “Horse owners need to effectively protect their horses from tapeworm infections no matter where in the country they reside.”

Active tapeworm infection is difficult for veterinarians to diagnose. There are two approaches to tapeworm diagnosis (1) coprologic (fecal) testing using a centrifugation/flotation technique, and (2) serologic testing using an ELISA format to detect tapeworm antibodies as evidence of prior exposure. Both tests can be labor intensive and a poor indication of the actual tapeworm burden in the individual horse and in the herd overall^3,4. This limitation often contributes to an underestimation of the true prevalence of tapeworm infection in a herd, which in turn can encourage negligence in tapeworm control. In many cases, horse owners will simply resort to routine deworming instead of performing a diagnostic test that can confirm active tapeworm infection. Also, horse owners may mistakenly assume that broad spectrum dewormers such as macrocyclic lactones (avermectins), such as ivermectin alone or moxidectin alone, or benzimidazoles will control tapeworms, unaware that neither of these classes has any effect on the tapeworm parasite⁵.

Horse owners can ensure their herd is protected by incorporating a praziquantel dewormer into their deworming program⁶. This class of anthelmintic has been proven effective against tapeworm infections and is commercially available. Recent studies have shown praziquantel to be effective against the tapeworm species, Anoplocephala perfoliate, known to infect horses⁵. Praziquantel is available in the U.S. only in combination with ivermectin as a broad spectrum anthelmintic with efficacy against various worms, bots and tapeworms.

Pfizer Animal Health’s EQUIMAX^® (ivermectin 1.87%/praziquantel 14.03%) the only combination dewormer, with tapeworm control that is approved as safe in foals as young as four weeks of age. EQUIMAX also treats horses up to 1,320 lbs in one tube and is pleasantly-tasting apple-flavored.

www.equimaxhorse.com

References

1. C.R. Reinemeyer, A.W. Farley, S.A> Kania, B.W. Rohrbach and R.H. Dressler, 48th Annual Meeting of the American Association of Veterinary Parasitologists, Denver, CO, July 2003. Updated West Coast Farm prevelance of tapeworm infection data. Data on file. Pfizer 1nc. 2009.
2. Updated West Coast Farm prevalance of tapeworm infection data. Data on file Pfizer Inc. 2009.
3. Williamson RM, Beveridge I, Gasser RB. Coprological methods for the diagnosis of Anoplocephala perfoliata infection of the horse. Aust Vet J 1998;76:618-621.
4. Proudman CJ, Edwards GB. Validation of a centrifugation/flotation technique for the diagnosis of equine cestodiasis. Vet Rec 1992;131:71-72.
5. Lyons, E.T., Tolliver, S.C., Drudge, J.H., Collins, S.S. Vet 32: Tapeworms in Horses. University of Kentucky College of Agriculture. 1997; p. 6.
6. Slocumbe JO, Heine J, Barutzki D, et al. Clinical trials of efficacy of praziquantel horse paste 9% against tapeworms and its safety in horses. Vet. Parasitol 2007; 144; 366-370.
7. Farm prevalence data. Updated West Coast farm prevalence of tapeworm infection data. Data on file. Pfizer, Inc. C.R. Reinemeyer, A.W. Farley, S.A. Kania, B.W. Rohrbach and R.H. Dressler, 48th Annual Meeting of the American Association of Veterinary Parasitologists, Denver, CO, July 2003.

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