Using Hot Compresses at the Base of the Penis
as an Aid to Semen Collection in Stallions

Sue M. McDonnell, PhD

Equine Behavior Laboratory at New Bolton Center
University of Pennsylvania School of Veterinary Medicine, Kennett Square, PA 19348
610-444-5800 x2221       Fax 610-925-8124

Fig 1

Fig 2

Fig 3

Rationale: this simple procedure provides additional stimulation similar to the natural heat and pressure of the vulva of the mare during natural cover.  The target is a portion of very sensitive spongy tissue at the base of the penis that anatomically corresponds to the vulva of the mare.

  • Works best with a Missouri AV, but can be done with any AV.  It can be attached or free in the spare hand.
  • Towels:  soft, non-abrasive, lint free (terry cloth is usually too abrasive).  We typically use either lint-free disposable towels (Bulky Wipes from CCP Industries) or thin sheep sponge material (8" squares, 2 per packet) available from the kitchen department of Target stores.
  • With Missouri AV, to attach to the AV by insert the towel between leather cover and rubber liner as shown in figure 1 (about 6 thicknesses of fine tea towel or disposable cotton towels)
  • Just as the horse is ready to mount, dip towels into bucket of very hot water (50-55 degrees C = 120-130 degrees F - too hot to touch) as shown in figure 2.
  • AS you approach the stallion, wring out excess water as in figure 3 and allow towels to dangle in air as you immediately place the AV on the stallion (water is toxic to sperm, so avoid getting water into the AV lumen).  The towels will cool rapidly as they dangle, so start out hotter than you need when you get to the horse.
  • AS you place the AV on the shaft, sweep the free hand under the towels and grasp the base of the penis high up next to the belly wall with a firm handshake squeeze.  The hot towels will be between your palm and the penis.  Just hold firmly and squeeze with each thrust.  No stroking motion is needed and it might be counterproductive.
  • If the towels cool off, they are often off-putting to the horse.  If they are too hot, they can scald the horse.  The most effective will be hotter than the AV lumen when they touch the horse.