McKee-Pownall Equine Services | Reproduction

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The veterinarians and staff at McKee-Pownall Equine Services provide reproductive services. We take great pride in continuously updating our skills to provide our clients with the most current and innovative techniques and equipment. Reproductive work can be scheduled on-farm.

  • Breeding soundness examination
  • Ultrasound examination
  • Estrous synchronization
  • Instruction on requirements for importation of semen
  • Infertility diagnostics (uterine culture/sensitivity, cytology, and endometrial biopsy)
  • Treatment of the infertile mare
  • Vaginal speculum examination and endoscopy
  • Hormone analysis and manipulation
  • Evaluation of pregnancy and strategies for maintenance of pregnancy
  • Pre-foaling preventative health care
  • Foaling assistance/Dystocia management
  • Post-foaling preventative health care
  • 24-hour emergency service

Breeding Time line


  • Breeding soundness exam, synchronize estrus and monitor uterine structures and conditions
  • Deworm – All stages of encysted small strongyles
  • Vaccinate for Rabies (now or at month 5 of pregnancy)
  • Dental care (now or second trimester)

1st Trimester

Monitor progesterone levels in at risk mares

Day 0 – Breeding date

Day 14-17 – Rectal ultrasound to confirm pregnancy and rule out twins

Day 25-29 – Rectal ultrasound to re-confirm viable pregnancy and rule out twins.  Check fetal heartbeat.

Day 60-70 – Ultrasound fetal sexing

Day 60 – First deworming

2nd Trimester

-Maintain hoof care, feed for growing foal

Day 150 – Second deworming

Initiate Herpes vaccination (EHV-1)– Month 3, 5, 7 and 9

3rd Trimester

Open Caslisks at day 300 or later, rising plane of nutrition, monitor for signs of placentitis

Day 270-300 -  9 Months vaccination for EHV-1.  Vaccinate for EWT, FR, WN, and PHF

Day 310 - Third deworming

Day 330-340 – Foaling

Reminder – like women, horses foal within a normal window and normal foals can be born anywhere from 300-360 days. Do not rely on a due date!


Rule of 3:  Foal should be standing in 1 hour, nursing in 2 hours, mare should pass the placenta by 3 hours

Post Foaling Exam

  • Veterinary exam within 24 hours of foaling
  • Test for serum IgG concentration within the first 12-18 hours
  • Deworm mare 24-48 hours after foaling
  • Dip umbilical stump – 3-4x daily for 2-3 days
  • Enema
  • Monitor nursing, meconium passage, body condition and conformation

Foal Care

First week of life– mange flexural limb deformities, dip umbilicus and monitor temperature and overall health

2-4 weeksinitiate therapy for moderate to severe angular limb deformities (often working with farrier)

6-8 weeksof age: Deworm for roundworms (ascarids)

6-8 weeks later:  Deworm again

4-6 months of age: Initiate vaccination series  for WNV, EHV-1/4, EWT, Rabies.  In epidemic areas, vaccinate for PHF and Strep equi

5-7 months of age:  Booster vaccines 

9-10 months of age:  Booster EHV-1/4 and EWT.  Vaccinate for influenza.

11-12 months of age: Deworm all stages of encysted small strongyles

Follow this link for more information on What do do when your mare is foaling?

Timeline For Artificial Insemination

The first step, once you have decided to breed your mare, is to select a stallion and contact the stallion owners. You should find out which days the stallion is collected, how the semen is shipped and time frame for shipping. In addition, for international shipping, you must find out what import regulations exist. This information can be obtained from our vet offices, CFIA office, or online on the CFIA website.

Next, your veterinarian needs to perform an initial assessment, including ultrasound examination, and other diagnostics depending on the mare's reproductive history. The initial ultrasound exam can provide information on when the mare is predicted to be in heat, and her potential timing of ovulation. Once the mare is in heat, she needs to be followed closely to predict the time of ovulation. For fresh chilled semen, the semen needs to be inseminated prior to the mare ovulating, and will generally remain viable within the uterus for up to 48 hours. For frozen semen, the mare needs to be inseminated within 4-6 hours after ovulation, and requires much more diligent monitoring of the mare through ultrasound. Once the mare is bred, medications are often administered to promote ovulation. Ovulation is confirmed after insemination, and the mare is checked 14-16 days after ovulation for pregnancy.