Last program we discussed diagnosis and treatment of uterine infections in mares.  Today we will look at problem mares, or those mares with chronic infection or inflammation, and what we can do to get them in foal.  As with all brood mares, it is important to make sure to repair, if possible, any anatomical abnormalities that may be present.  Certainly a culture and cytology is important to determine if infectious organisms are present.  This tells us what organisms are involved and what medication is needed.  A biopsy is mandatory as it will determine the uterine damage present and the chance of the mare becoming pregnant and carrying a foal.  A category 1 uterus is considered normal and indicates an 80% to 90% chance of pregnancy, a category 2A is a 50% to 80% chance, a category 2B is a 10% to 50% chance, and a category 3 is a less than 10% chance of pregnancy. 

It is sometimes possible to raise the biopsy score of mares with chronic infection with uterine lavage and antibiotic therapy.  We usually lavage and treat for 3 days with a category 2a uterus, for 5 days with a category 2b uterus, and for 7 days with a category 3 uterus.  We also will ultrasound and breed these mares one time artificially to decrease the contamination as well as inflammation that can develop from the semen itself in some mares.  As sperm have been shown to be at the oviduct in 2 to 4 hours, the uterus is again lavaged at 4 hours post-breeding to remove any excess fluid and oxytocin is given to help empty the uterus.  This lavage and oxytocin is repeated up to 2 days after breeding if excess fluid is still present since the embryo does not enter the uterus until day 5.  Many veterinarians routinely start problem mares on Regu-Mate, an oral form of progesterone, 2 to 4 days after ovulation, in hopes of maintaining the pregnancy.  Whether Regu-Mate actually helps prevent abortion in mares is debatable.  Our next program will cover options for mares with severe uterine damage that can not support a pregnancy.