Lumps under the skin can be a sign of tumors. Your vet will be able to tell you if they are a concern. Melanomas a common on light colored horses and may be evident fairly early in life. Have your vet check them and give you advice.
Some older horses don’t shed out quickly in the spring. If your horse doesn’t shed out, and the hair appears curled, this could be a sign of Cushings Disease, a dysfunction of the pituitary gland. Your vet can advise you on treatment and diet.
Older horses may be more susceptible to colic. Some people believe that even changes in air pressure can cause some older horse to have mild spasmodic colic. Easily digestible feeds, regular routine and a regular de-worming schedule may help prevent spasmodic colic. Small, frequent meals are easier for the horse to digest with its small stomach and very long digestive system.