Dog Has Mass On Left Side Of Face And Sagging Lips. What Are Possible Problems?

Any growth on the lips of the dogs is not good sign. It is usually viral. Other causes of growth on the head of the dogs can be

1. Apocrine sweat gland cyst
2. Bee or wasp bite
3. Follicular cyst
4. Granuloma
5. Hematoma
6. Histiocytoma
7. Lipoma
8. Melanoma
9. Mast cell tumor

So, visit to a vet for differential diagnosis and treatment.