Mare Thyroid Condition Might be Linked to Foal Deaths

The rare condition–primary hypothyroidism–in mares could be behind a potentially deadly foal problem called CHDS.
Share
Favorite
Close

No account yet? Register

ADVERTISEMENT

Periodically since its discovery in 1979, an ailment called congenital hypothyroidism dysmaturity syndrome (CHDS) has caused newborn foal deaths in Western Canada and the northwestern United States. Since then, around 75% of foals born in affected herds have died, and the condition’s cause remains unclear.

Now researchers in Canada are making strides in understanding what could trigger CHDS. Mariana Diel de Amorim, DVM, DVSc, Dipl. ACT, and colleagues recently became the first to identify primary hypothyroidism in a herd of mares with a history of producing CHDS foals. She presented their findings at the 2015 American Association of Equine Practitioners convention, held Dec. 5-9 in Las Vegas.

Diel de Amorim is an associate professor of theriogenology at the University of Prince Edward Island’s Atlantic Veterinary College, in Charlottetown. She worked on the study with senior investigator Claire Card, DVM, PhD, Dipl. ACT, at the University of Saskatchewan’s Western College of Veterinary Medicine, in Saskatoon.

Foals with CHDS are born to mares that appear healthy, but after a prolonged gestation (often more than a year) and sometimes dystocia (a difficult birth). Affected foals can have umbilical hernias, contracted front legs and other flexural deformities, cubital bone dysgenesis (inappropriate bone formation), mandibular prognathism (their lower jaw sticks out beyond their upper), and poor muscling. Diel de Amorim said researchers believe contributing factors include a mare’s excessive consumption of nitrates, endophytes, and goitrogens (goiter-causing substances), and deficiency in trace minerals, such as selenium

Create a free account with TheHorse.com to view this content.

TheHorse.com is home to thousands of free articles about horse health care. In order to access some of our exclusive free content, you must be signed into TheHorse.com.

Start your free account today!

Already have an account?
and continue reading.

Share

Written by:

Erica Larson, former news editor for The Horse, holds a degree in journalism with an external specialty in equine science from Michigan State University in East Lansing. A Massachusetts native, she grew up in the saddle and has dabbled in a variety of disciplines including foxhunting, saddle seat, and mounted games. Currently, Erica competes in eventing with her OTTB, Dorado.

Related Articles

Stay on top of the most recent Horse Health news with

FREE weekly newsletters from TheHorse.com

Sponsored Content

Weekly Poll

sponsored by:

When do you vaccinate your horse?
190 votes · 190 answers

Readers’ Most Popular

Sign In

Don’t have an account? Register for a FREE account here.

Need to update your account?

You need to be logged in to fill out this form

Create a free account with TheHorse.com!