Early spaying causes the leg bones to grow unevenly. This leaves your dog more vulnerable to hip dysplasia and torn ligaments. Early spaying triples the risk of bone cancer, a deadly cancer that mostly occurs in large and giant dogs. Early spaying causes urinary incontinence in up to 20% of spayed females.
An average horse should live around 25-30 years old, that is if it is healthy. If you are lucky, your horse will live longer! The oldest horse was 62 years old! I have known horses to live for over 30 years! The oldest I have known was 32 and was still being used in a riding school for 1 hour a day!
Thoroughbreds mature slightly earlier than quarter horses and other similar breeds. They are broken to ride starting around 18 months of age so that they are ready to race as 2 year olds. Warmbloods and draft horses mature later than average and may not be broke to ride or pull wagons until they are 3 to 4 years old.