Breeding a Laminitic Mare?

Q. Is it safe to breed a mare that is prone to laminitis?

Linda, via e-mail

A. There are several considerations that go into the decision to breed a mare that is prone to laminitis. Is the laminitis an occurrence that can usually be prevented by good dietary (pasture and supplemental feed) management? If so, then continue to practice these effective dietary manipulations, with due consideration to the needs of the fetus and foal during late gestation and lactation.

Is the laminitis secondary to a condition such as equine Cushing's (a metabolic disorder that involves excess glucocorticoids) that has many other medical implications that could affect the fetus? If so, then there are probably several reasons to not breed such a mare.

How severely affected has she been by the laminitis episodes in the past? I have seen horses that experience at least yearly mild episodes that can be acutely well controlled with no significant sequelae.

On the other hand, I have seen mares with severe and difficult-to-control episodes with coffin bone rotation and sinking. These mares truly struggled in a great deal of pain during gestation.

There are a plethora of medications used to treat laminitis, and we know very little about their potential effects on the fetus (via transplacental transfer) or newborn foal (through the milk).

Although many medications have theoretical risks, in practice they are used commonly with no apparent effect on the fetus or foal; the key is to use medications judiciously.

The importance of good foot care for this broodmare cannot be underestimated. Many horses that have had laminitis will tend to have excessive, abnormal growth of hoof wall that should be controlled with regular trimming by your farrier.

It can be difficult to estimate how a mare with laminitis might handle the entire gestation. I don't feel past episodes of laminitis necessarily condemn a broodmare to unemployment; however, the risks or pain associated with such an acute or chronic condition might not be justified.

About the Author

Nancy Diehl, VMD, MS

Prior to attending veterinary school, Dr. Nancy Diehl completed a master’s degree in animal science while studying stallion sexual behavior. Later, she completed a residency in large animal internal medicine at the University of Pennsylvania’s New Bolton Center and worked in equine practices in Missouri and Pennsylvania. Diehl also spent six years on faculty at Penn State, where she taught equine science and behavior courses and advised graduate students completing equine behavior research. Additionally, Diehl has co-authored scientific papers on stallion behavior, early intensive handling of foals, and feral horse contraception. Currently she is a practicing veterinarian in central Pennsylvania.

Stay on top of the most recent Horse Health news with FREE weekly newsletters from Learn More