Dear Critter Corner: My dog is generally very sweet, but lately he’s been acting differently, sort of withdrawn and irritable. He doesn’t want me to pet him and has even growled at me when I approach to pick him up. What is going on with this change in behavior?

Changes in a dog’s behavior can occur for many different reasons. When a normally friendly and approachable dog starts avoiding pets or objecting to being picked up, pain or another medical problem should be high on the list of possible causes. Dogs do not always display obvious signs of pain. Instead, withdrawal, irritability, or a change in how they respond to touch may be among the first signs that something is wrong.

Even mild pressure, such as a pet, can be uncomfortable if a dog has a painful area. Picking up a dog may also move or place pressure on the part of the body that hurts. A dog in pain may growl to stop an interaction that may cause discomfort. But your dog hasn’t suddenly turned against you. The growl is important communication indicating that they need you to stop and give them space. Do not punish the growl. Punishment will not address the reason your dog is uncomfortable and may discourage them from warning you in the future.

If you suspect your dog is in pain, it’s important to have them seen by a vet as soon as possible. A prompt examination by a vet can help identify the cause of their pain so that you can provide the most effective treatment for whatever injury or issue your dog is experiencing. Until then, avoid unnecessary touching or picking them up, and don’t test their reaction by touching the area you think may hurt. If you need to transport your dog and are unsure how to move them safely, call your vet for instructions. Remember that even a normally gentle dog may bite when frightened or in pain.

A dog’s behavior isn’t just random; there are reasons why they’re acting the way they’re acting. When a dog suddenly becomes reluctant to be touched or shows aggression during handling, it’s critical to have them assessed by a vet. Providing your furry friend with any medical help they may need gives them the best chance of feeling comfortable and hopefully returning to snuggling with you on the couch.

Barb Izzo is a Behavior Training Specialist for the Peninsula Humane Society & SPCA Behavior Department. For more information, please visit phs-spca.org, call 650-340-7022 x314 or email behavior@phs-spca.org.