You should see your veterinarian immediately if your dog’s face is swollen, especially if the swelling developed rapidly. Do not delay seeking veterinary attention when your dog’s face is swollen, as allergic reactions can progress and can be deadly.
Signs that an allergic reaction is getting more serious include difficulty breathing and blue gums. For causes of facial swelling that are less urgent, such as abscess, it is still important to contact your vet, as your dog is likely in pain and demonstrating other sickness behavior like fever and inappetance.
Pro Tip: Contact your vet immediately if your dog’s face is suddenly swollen – this is a serious issue that can lead to a medical emergency.