Noteworthy Research: 08/03

We may soon have a safe, effective vaccine for equine infectious anemia, the disease detected by your Coggins test. Vaccination with a genetically modified strain of the EIA virus, which has limited ability to reproduce in the horse’s body, provided 100% protection in challenge studies, compared to 100% induction of the disease in identically exposed unvaccinated controls.

Prior experimental vaccines provided either limited protection or actual worsening of disease in exposed horses. The study was done by researchers at the University of Pittsburgh and the University of Kentucky Gluck Equine Research Center and was published in the July 2003 Journal of Virology. With any luck, we may soon be able to trade in our Coggins tests for an effective vaccine.


Tendons And Jump Size
The greatest strain on front legs when landing from a jump is on the superficial digital flexor, according to a University of Utrecht, Netherlands, study. The finding fits clinical observations that superficial flexor injuries are the most common in jumpers.

Next in line in terms of stress were the suspensory and the check ligament. As might be expected, higher jumps and harder landings greatly increased the stress placed on the superficial flexor. Interestingly, higher jumps had little effect on the stretch of the check ligament or suspensory.


Risk Of Fatal West Nile
A survey in Coahuila, Mexico, which borders Texas, showed 15 of 19 horses tested positive for West Nile virus.?? Of the 15 positives, five had symptoms, while 10 did not.??A similar study conducted in New York in 1999 showed about 50% of West-Nile-positive horses were asymptomatic.

Surveys involving larger numbers of horses are needed to confirm these percentages, but it appears your horse has a 30 to 50% chance of becoming ill if he is infected with West Nile. Since fatality rate in horses showing symptoms is about 25%, the chance of a fatal outcome overall after infection with West Nile is about 10%.


Mule Clone And Cancer
The first cloned member of the horse family, a mule named Idaho Gem, was born May 4. It’s also the first clone of a hybrid animal. Cloned by a University of Idaho-Utah State University research team, the foal’s DNA comes from a fetal cell culture first established in 1998. The mule is a full sibling of a champion racing mule owned by Idaho businessman Don Jacklin of Post Falls.

Research-team member Gordon Woods said he believes the breakthrough understanding of cellular biology necessary for horse cloning may offer new insights into cancer development in humans.


Dewormers And EPM
Many owners of EPM horses say their horses worsen after a deworming with ivermectin or moxidectin. On the flip side, in some racing circles, the newest craze in EPM treatment is ivermectin for three consecutive days at the usual deworming dose. Other people believe the daily dewormer pyrantel tartrate prevents EPM or keeps relapses at bay. While all this remains unproven, the anecdotal evidence continues to mount.

In the case of pyrantel tartrate, the reports were strong enough to spur a study in mice, but it showed no protection with the drug. We found no studies concerning moxidectin.

However, the situation with ivermectin and praziquantel, the new anti-tapeworm ingredient approved for Merial’s Zimecterin Gold, shows promise. Both these drugs are effective in treating protozoal intestinal-tract infections, such as Giardia, Cryptosporidia, Eimeria and Entamoeba. Although we’ll have to wait for studies to prove they also have activity against EPM organisms or protozoa living in the body tissues, if you feel your horse shows a change in EPM symptoms after a deworming, there may be a reason. Discuss it with your veterinarian.


Ulcer Research Agrees With Our Trials
A recent study at the Veterinary School of the University of Milan, Italy, showed positive results in nine of 10 Standardbred racehorses with gastric ulcers treated by a combination of pectin and lecithin. After 30 days, three of the horses had healed completely, with significant healing noted in six others.

Pectin is a soluble fiber, high in apples and beet pulp. It’s also an active ingredient in our favorite non-drug ulcer supplement, U Gard from Equine America ( 800-838-7524 see October 2000). Lecithin is a phospholipid that’s found in all living cells. Rich sources include egg yolk, soybean, rice and grains.

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