Topline Equine Veterinary Care
The following information is from:
PREDICTION OF FOALING by Patrick M. McCue DVM, PhD, Diplomate American College of Theriogenologists
Clinical signs of impending foaling begin subtly a month or so prior to the expected due date. Changes become more dramatic and occur more rapidly as day of foaling approaches.
2-6 Weeks Before Foaling
The first noticeable change is in the mammary gland, which begins to enlarge 2 to 6 weeks prior to term. Some mares may develop a large amount of edema around the udder before the gland itself becomes enlarged. Mammary gland development will be much more pronounced in mares that have previously had foals than in maiden mares.
1-3 Weeks Before Foaling
In the last 2 to 3 weeks of pregnancy, the abdominal muscles relax causing a pronounced ‘dropping’ of the abdomen, which is especially noticeable in older mares. During the last week prior to foaling, the ligaments, muscles and other structures surrounding the mare’s pelvis and perineum soften in preparation for birth.
7-10 Days Before Foaling
The teats or nipples will remain relatively flat until the last few days prior to foaling, at which time they will fill with milk. The secretion by the mammary gland changes from a clear straw-colored fluid to a more turbid milk-like substance as the due date draws near.
48-72 Hours Before Foaling
The mammary secretion becomes thick and honey-like as colostrum develops within the last day or two prior to foaling. A thick, waxy exudate is often observed to accumulate at the ends of the teats 24 to 48 hours prior to foaling. ‘Waxing’ of the teat ends is a classic sign that foaling is imminent. The extent of waxing can range from tiny droplets to elongated candlewax-like formations that project an inch or more from the teat ends. However, not all mares will wax up and the duration from onset of waxing to foaling can be quite variable. In addition, some mares will transiently develop wax at the teat ends 1 to 2 weeks prior to foaling.
12-24 Hours Before Foaling
The behavior of the mare often changes during the last few days or hours preceding foaling. Mares near term may tend to isolate themselves, go off feed and pass small amounts of manure or urine frequently. In addition, milk may begin to drip from the mare's udder.
0-24 Hours Before Foaling
The vulva becomes relaxed, elongated and edematous in the hours immediately prior to foaling.
During the first stage of partuition, mares typically exhibit the following behaviors:
Appears restless, indicated by frequent interruptions in eating, may stop chewing feed already in her mouth or may pace the stall.
Pawing the bedding or ground in different places as if looking for something.
Switching the tail.
Getting up and down frequently.
Sweating in the flanks.
Urinating frequently.
Timeline of Changes and Clinical Signs of Impending Foaling
