"To contact a veterinarian" means to get in touch with a professional who takes care of animals' health, usually for medical assistance or advice. Full definition
If you have any questions or concerns, please contact your veterinarian immediately for guidance. (vcahospitals.com)
If an undesirable weight loss occurs, please contact your veterinarian immediately so you can make an adjustment in your cat's feeding / diet plan. (pettao.com)
In a situation like this, you should immediately contact your veterinarian for advice. (loveyourpetuk.com)