Updated September 25, 2026. Fact-checked against veterinary sources; review by a licensed veterinarian is in progress. See our editorial policy.
Quick answer: Many behavior problems, such as new aggression, house soiling, anxiety, or confusion, have medical causes like pain, thyroid disease, urinary problems, or cognitive decline. A vet exam is the best first step, especially for sudden changes. Treatment usually combines management, reward-based training, and sometimes medication.
Signs to watch
- New aggression or irritability
- House soiling in a trained dog
- Anxiety, pacing, or destructive behavior
- Nighttime restlessness or confusion in older dogs
- Excessive barking or clinginess
Common causes
- Pain from arthritis, dental disease, or injury
- Hypothyroidism or other illness
- Urinary infections
- Canine cognitive dysfunction in seniors
- Fear, anxiety, or lack of enrichment
Go to a vet or emergency clinic right away if
- Bites or serious aggression, especially toward children
- Sudden confusion, circling, or seizures
- Self-injury
Safe home care while you arrange a visit
- Manage triggers and use gates or leashes to prevent incidents
- Increase exercise and enrichment
- Keep a log of when problems occur
What to avoid
- Punishment, which increases fear and aggression
- Human sedatives
Can you ask a vet online about this?
Online vet services can be helpful for deciding how urgent a problem is, getting general advice, and follow-up questions. But they have limits:
- A vet can’t examine your dog, listen to the heart and lungs, or run tests over video
- In many US states, a vet must have examined your dog in person before prescribing medication. Rules vary by state and are changing
- For any emergency sign listed above, go directly to an emergency clinic rather than waiting for an online reply
Have your dog’s age, weight, medications, and photos or video of the problem ready to make any consultation more useful.
More: treating behavior problems.
Sources
- American College of Veterinary Behaviorists: Resources
- AAHA Canine and Feline Behavior Management Guidelines. 2015
This article is for general education and is not a substitute for care from your own veterinarian. Learn about The Pet Vet and our editorial policy.