Can female horses be spayed?
Yes a female horse (mare) can be spayed. It's a bit costly due to the nature of the surgery that must be preformed, but it can be worth it. Many mares really should be spayed to prevent them being bred, especially those with poor conformation or cross bred horses that can't be registered.
It depends but here is a general rule of thumb: Most of the time, it doesn't matter, especially if all dogs are neutered and spayed. If your female is already spayed get either a male or female. If your female is not already spayed get a female one IF NOT BOTH will need to be spayed BEFORE 6 months, or very close supervision and strict separation from the males when the female becomes in season.
They can get along, but they don't get along as well as two male ferrets. Female ferrets, after they get spayed, are much more territorial than before they get spayed. If you are thinking of getting two ferrets, I suggest getting one male and one female. Of course, you should get them spayed and neutered, first.