The veterinary, or vet for short, is located on the city map and offers a variety of services related to the health and breeding of horses.
At the moment, diseases have not yet been implemented in the game. Therefore your horses cannot get sick. However, the genes that determine if a horse is prone to an illness (called health stats) are already in the game. They can be found on a horse's profile under the Health tab. If a horse has never had a health check in its life, the Health tab will only say "This horse hasn't had a health check at the veterinary yet". The first health check will reveal the health stats.
The vet can test your horse's fertility and the result will show up on the health tab of its profile. You can only test the fertility of an adult horse. The failure rates of coverings are determined only by the stallion's fertility, but a foal's fertility is determined by the fertility stats of both parents.
If your mare is pregnant, the veterinary can perform an ultrasound examination. This will reveal the sex of the foal.
The ultrasound becomes available exactly 120 hours (five days) after the mare was covered. Note that the ultrasound icon will appear on the mare’s profile under the Summary tab earlier than that. The icon shows up at 00:00 HR time on the day when the 120 hours mark will be hit. This means that when the icon appears on the mare’s page at midnight, you can be sure that sometime throughout the next 24 hours you will be able to actually ultrasound her at the vet.
If your stallion reaches the age of seven, you can check if he qualifies for the “Clinical approved” predicate. Behind each health and fertility stat, there is a number associated with each rating. The better the rating, the higher the number, so for example, an excellent colic resistance stat will have a higher number than a good back problems stat. To earn this predicate, all five of his health stats and his fertility need to be 75+ points.
Hormone injections can be used to bring your mare in heat. As of now, that is only necessary if you want to artificially inseminate her using a semen straw. Using hormone injections does not increase your mare’s chances of a successful pregnancy.
The vet can collect semen of your stallion once every two days, the resulting semen straws will be stored in your freezer. You can use them to inseminate your mares after giving them hormone injections. Each straw can be used only one time.
Gelding (castrating) a stallion means that it will no longer be possible to breed with him. This operation is permanent – once you have done this, you can never change it back. Gelding stallions does not currently have any in-game advantages like performance boosts.