Tuesday, September 04, 2012

Autumn Laminitis: Prepare to Prevent--Instead of Treat--Seasonal Flair-Ups of Endocrine Conditions in Horses

This is what a foot looks like after laminitis...could this damage and deformation have been prevented? In Great Britain, a study found that 43 percent of horse owners waited more than a week after suspecting laminitis before seeking veterinary intervention. (Boehringer Ingelheim photo)

If Labor Day is over, can autumn laminitis season be far behind?

This summer's drought has been relieved in some states, but many of the horses in the United States are standing in parched pastures, munching on hay, as they have been all summer. The drought put a quick end to the grazing season in many states, and horse owners have been saddled with increased hay bills.

Horse owners who grow their own hay found that they were feeding it as soon as they baled it. Second cuttings were poor in many areas. And a third cutting probably isn't even going to happen.

Fall rains usually send a dark green growth spurt up through brown pastures and with this signal comes the warning to horse owners that the fall can be just as dangerous as spring for horses to develop laminitis as they gorge on the grass.

This video from the British Veterinary Association's Animal Welfare Foundation is a quick primer on the general disease of laminitis and features veterinarian Ben Mayes, president of the British Equine Veterinary Association.

Recent research has shown us that the lush grass does not, by itself, cause laminitis. If two horses had a grazing contest, it's possible neither of them would develop laminitis no matter how much they eat.

But if one or both horses has an endocrine system vulnerable to cycling hormones that may cause laminitis when and if they are pushed, the results can be a stretched white line, hoof rings, a gimpy gait, or full-fledged laminitis.

The time to be vigilant is now, while it is still technically summer and the nights are still pretty warm. But across the country, night-time temperatures are dipping, and snow will soon be showing up on high peaks of the mountains.

Laminitis is a wholly preventable disease, and in the case of endocrine-related laminitis, it is part of a larger syndrome that indicates the horse may have a problem in the way the body processes glucose, in that the condition of insulin resistance prevents normal glucose metabolism or that circulating hormones are elevated by pituitary pars intermedia dysfunction (PPID).

Is this your perception of a horse with Cushings syndrome (PPID)? While there are still plenty of older horses with the problem out there, the obvious change in hair coat is not seen in the early-teens horses whose blood tests yield information about high levels of the pituitary hormone ACTH. (Photo © Dr. Christian Bingold, Pferdeklinik Gro├čostheim, used with permission)

Some of the recommended management suggestions include evaluating a horse's weight and condition and stepping up the exercise for horses kept at pasture during the fall months when risk is increased.

Another simple thing that horseowners can do is get their hay tested. Some hay can have as much or even more sugar than pasture grass. Soaking hay or feeding lower calorie hay to horses with higher laminitis risk quotients may be helpful.

Additionally, horse owners can ask for help from farriers this time of year. Ask to see or photograph the horse's feet after they have been trimmed--is the white line tight or is it stretched? Are there red spots in the line? Ask the farrier if the hoof wall is smooth and healthy or if it is ridged and has "fever rings" that are telltales of some disruption in the horse's diet or metabolism in recent months.

Finally, testing a horse's ACTH levels is now recommended to be done in the fall. Boehringer Ingelheim, manufacturers of the PPID medication Prascend, has recommended that the testing for Cushing's be done in the fall, when differences in test results would be most evident.

Dr. Don Walsh of the Animal Health Foundation explains the basic tenets of laminitis prevention, including insulin resistance and Cushings syndrom (PPID) in this brief video.

Current thinking and evidence suggests that 90 percent of laminitis cases occur as a result of an underlying hormonal condition(1,2) such as Cushing’s disease (PPID) or Equine Metabolic Syndrome. With this in mind, owners - particularly those with a horse over 10 years of age - are being urged to get their horses tested for Cushing’s as soon as possible if they suspect that the horse may be suffering from laminitis, or even if it simply appears a little foot-sore.

Despite the severity of laminitis, only two-thirds of laminitis cases reported by owners in Great Britain were treated by a veterinarian (3) and, in one study, 43 percent of horse owners waited more than a week after suspecting laminitis before seeking veterinary intervention (4).

Boehringer Ingelheim Vetmedica's data shows that one third of laminitic middle aged horses (defined as between the ages of 10 and 15 years) test positive for PPID (Cushing's)(5).

Over 3,100 horses were tested for Cushings as part of the company's Talk about Laminitis campaign in Great Britain during the spring of 2012. The pharmaceutical company is offering free testing for Cushing's in Great Britain again this fall, thanks to the Redwings Horse Sanctuary, which is providing funding.

Horse owners may have to pay for the ACTH and insulin resistance tests in the United States, but there is no price that can be put upon the peace of mind of knowing more about a horse's potential risk for laminitis.

To learn more:
Visit the Animal Health Foundation laminitis web site and watch more videos there.
Boehringer Ingelheim's "Talk About Laminitis" web site is meant for British horse owners, but most of the information is relevant worldwide; Prascend is available in the USA.
Read "Six Steps to Prevent Autumn Laminitis".
Plan to attend the Laminitis West conference in Monterey, California in November 2012.

References from the text:

  1. Donaldson, M.T., Jorgensen, A.J.R and Beech, J. (2004) Evaluation of suspected pituitary pars intermedia dysfunction in horses with laminitis.  Journal of the American Veterinary Medical Association 224, 1123-1127.
  2. Karikoski, N.P., Horn. I., McGowan. T.W. and McGowan, C.M. (2011) The prevalence of endocrinopathic laminitis among horses presented for laminitis at a first-opinion/referral equine hospital. Domestic Animal Endocrinology 41,111-117.
  3. Ireland, J.L., Clegg, P.D., McGowan, C.M., McKane, S.A., Pinchbeck, G.L., 2011.  A cross-sectional study of geriatric horses in the United Kingdom Part 2: health care and disease.  Equine Veterinary Journal 43, 37-44.
  4. Knowles, E.J., Withers, J.M. and Mair, T.S. (2012) Increased plasma fructosamine concentrations in laminitic horses. Equine Veterinary Journal 44, 226-229.
  5. Boehringer Ingelheim Vetmedica. Resting ACTH results of 724 horses aged 10 to 15 years. 
Do you know your way around the inner hoof wall? This wall chart will remind you of the layers of sensitive and insensitive tissue that make up the hoof capsule. Click this text to go to the ordering page.

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