Udder problems are not terribly common, but if you own or manage a broodmare you should be aware of the following issues. | Photo Credit: Anne M. Eberhardt/The Horse

Take any swelling, asymmetry, or other abnormality of your mare’s udder seriously.

A few days after weaning your foal, you notice his dam’s udder is hot and tender. While this veteran broodmare’s udder has been quite large at weaning time before, she’s never been so grumpy about having it touched. A veterinary examination confirms your suspicions: The mare has mastitis. Udder problems such as this are not terribly common, but if you own or manage a broodmare you should be aware of the following issues.

Mastitis

The most serious udder problem in mares is acute mastitis, which is an infection of the mammary gland that occurs most commonly after weaning. “This can be life-threatening but is usually treatable, especially if the owner realizes what’s happening early on,” says Jon Palmer, VMD, associate professor of medicine and director of the Neonatal and Perinatal Programs at University of Pennsylvania’s New Bolton Center Connelly Intensive Care Unit, in Kennett Square. “If the veterinarian does a physical exam it becomes obvious that the mammary gland is infected.”

Clinical signs of acute mastitis include depression and high fever, although Ahmed Tibary, DVM, professor of theriogenology at Washington State University’s Department of Veterinary Clinical Sciences, notes that signs can be variable. The udder might be slightly enlarged or very tight and painful to the point the mare is lame and reluctant to move. “There may be asymmetry (one side larger than the other), or some exudate (pus) or lesions on the udder,” he says. Another sign of mastitis in a mare whose foal is not yet weaned is reluctance to let the foal nurse–for example, kicking at the foal