Some people worry about how old an animal should be to fix them. Depending on the breed, a dog or cat will be reproductively active at about 6 months to 1 year old. It is not necessary to wait for a pet to go through their first heat. Many animals are fixed before 6 months of age, and it does not cause them excessive discomfort.  Millerstown Veterinary Associates recommends that owners have their pet spayed or neutered between 6 and 12 months of age.   Their growth development will not be impacted, and their personality does not undergo dramatic changes. Some owners feel the cost of the surgery is too expensive, and think they can watch their pet to make sure nothing ever happens. However, the chance that they can slip away at the moment you do not notice or a roaming animal comes in contact with your pet is fairly great, which leads to unwanted litters and other complications. To avoid those issues, investing in spaying/neutering will save you from future related costs that could potentially end up costing more than what undergoing the surgery would have been originally.