Euthanasia should always be a last resort and only considered if you have tried other treatments. However, if a biting dog doesn’t respond to medication and behavioral therapy and continues to be a danger to people and other animals, euthanasia may be the only solution. When calling in outside help, ensure that the animal specialist is fully qualified and avoid anyone who believes that punishing the dog or administering cruel treatment will cure its aggression.
Consult your veterinarian. Ask if euthanasia is the only option. If you have arrived at this stage, you should have already explored alternative treatments with your vet. These include neutering a male dog to reduce dominant behavior and aggression toward other male dogs, and anti-anxiety medication if the aggression is triggered by fear or nervousness. The vet should also carry out tests to rule out medical causes for aggressive behavior. Ask your vet to put you in touch with a certified animal behavior therapist in your area, if she has not already done so. Behavioral therapists work closely with the dog's owner and the treatment may combine obedience training with praising the dog for submissive behavior, and gently exposing it to situations it finds threatening. For example, if the dog doesn't like its paws being touched, the therapist will work with the animal until it ceases to perceive this as aggressive human behavior.
Seek a second opinion. Talk to another vet or a reputable animal trainer. Someone else’s viewpoint gives a fresh perspective and he may be able to suggest treatment you haven’t considered. Even if you are still advised that the dog’s behavior cannot be changed and that it will always be dangerous, you will have peace of mind knowing that you did your best for your pet.
Explore other options. People who do not have the time or resources to invest in behavior modification therapy may be able to re-home the dog with someone who has. If so, ensure that the dog's potential new owner will treat the animal kindly and commit to a treatment program with a certified animal behaviorist. Dogs with behavioral problems often go from home to home where they lead a life of fear due to cruel treatment, which is why it is vital to ensure that the new owner is caring and responsible. Euthanasia may be a kinder option if you cannot find a suitable new home for the dog and you have exhausted all other avenues of treatment.