Over the past few years equine parasite control guidelines have been on a roller coaster ride. Many veterinarians now recommend owners focus their attention on horses with the highest parasite burdens, but how can you tell which horses are infected? Researchers recently tested whether a stall-side fecal test could identify horses with high internal parasite burdens.
At the 2014 American College of Veterinary Internal Medicine Forum, held June 4-7 in Nashville, Tennessee, Nicola Kerbyson, BVMS, Cert. AVP (EM), MRCVS, shared the study's results in a poster presentation.
Kerbyson, a PhD student at the University of Glasgow, in Scotland, worked with colleagues to determine if albumin contained in horses' feces was related to the otherwise healthy animals' parasite burdens; the team measured albumin levels via a commercially available fecal blood test, produced by SUCCEED.
The researchers collected feces from 21 mature horses of mixed breeds and ages to test for albumin and to perform fecal egg counts on. Prior to the study, all the horses underwent an annual ELISA test to screen for tapeworms. Then the researchers administered moxidectin (which targets small strongyles) to all horses and praziquantel (which targets tapeworms) to horses whose fecal egg counts indicated high tapeworm burdens. Two weeks after anthelmintic administration, Kerbyson and colleagues repeated the albumin tests, fecal egg counts, and tapeworm ELISAs.
The team determined that albumin was significantly more likely to be present in horses' feces prior to deworming than after deworming; 81% of the horses were positive for albumin prior to deworming while only 29% were positive after deworming. Of those horses, five were positive both before and after deworming, and one tested negative before deworming and positive after. However, there was no association between the presence of albumin and the severity of the horses' parasite burden.
Still, Kerbyson concluded, "This work indicates that parasite burden is associated with the likelihood of positive fecal albumin using the fecal occult blood detection kit."
Kerbyson told The Horse that fecal albumin is an indicator of disease anywhere in the large intestine caused by a variety of conditions (such as ulceration and inflammatory bowel disease), so it's not a specific indicator of a parasite burden. But she and colleagues are currently working to better understand colonic disease in horses and the types of pathologies that accompany it.
Kerbyson and colleagues are currently repeating the parasite burden study on a larger population of horses and are hoping to "identify associations between the specific parasite burden of an individual horse and the detection of fecal albumin," she said. "We are working with a welfare charity as we are keen to test horses with much higher burdens of parasites—something which is difficult to find in most well-managed populations. We hope to eventually establish something along the lines of, 'horses with a roundworm burden of more than X eggs per gram or a tapeworm burden of X (measured using the ELISA) are significantly more likely to have a positive fecal albumin than those without."
In the future Kerbyson hopes owners will be able to work with their veterinarians to use the test in their parasite control programs: "I think that this test will always be best utilized under the direction of the veterinarian, but it has the advantage of being a stall-side test (that takes 10 minutes to complete), so it may be able to give an early indicator that a horse has a significant parasite burden, prior to the results of fecal egg count testing or tapeworm ELISA being available."
Disclaimer: Seek the advice of a qualified veterinarian before proceeding with any diagnosis, treatment, or therapy.