A filly is the term used to describe a young female horse or pony. The female horse is considered a filly until about the age of four, when she then becomes a mare. This term is used regardless of the breed, coloring, or size of the horse. Young male horses are called colts.
Opinions on how to handle and care for a newborn horse vary greatly. It seems to depend on the type of horse, the environment, and future plans for the newborn when it becomes full grown. In spite of these differing approaches, most experts agree that when a horse is first born, unless health concerns exist, the care of the horse should be left to its mother for the first couple of days. The mother horse has basic instincts that will guide her in taking care of her newborn. This is an important time that should typically be set aside for the mother and her newborn to bond, though owners or trainers can assist if necessary.
After she is a few days old, most trainers suggest initiating some interaction with the filly. For instance, some experts advise putting the filly into a halter, and beginning some simple types of training. Studies seem to show that the younger the horse is when training begins, the less frightened it will be.
After the filly has worn the halter for a couple of days, it may be a good time to go ahead and get her used to being led. Training should be very gradual, only lasting for a few minutes, but can be repeated a few times per day. Most of the time, she will be sleeping and nursing, and during those times, she probably should not be disturbed. As a young horse gets older, the duration of training periods can be increased.
Some people have no reason to put their filly through extensive training. When that is the case, it is usually okay to leave her in the care of the mother for longer periods of time. Some horse owners do not even begin training until the filly is ready to wean.
Caring for a new filly also includes medical attention. Owners should probably have a veterinarian have a look at her to be sure she is in good health. During this visit, the veterinarian will advise on what immunizations will be necessary, and may also advise on care and feeding.