Yeast (candida) is a normal part of the digestive Flora and, in a healty dog or person, is kept 'under control' by a strong proliferation of the beneficial bacteria. Your dog will have a yeast problem when the necessary bacteria is destroyed by outside factors, most frequently vaccination reactions. That same bacteria, when present in healthy amounts, also accounts for as much as 70% of immune function; therefore, its destruction can desimate much of immune system capabilities.
There are multiple underlying causes for dog skin sores including parasites (fleas, mites), poor grooming, dog skin infection (bacterial pyoderma, fungal), endocrine diseases, skin or hair follicle disorders disorders such as seborrhea, medication side effects (from corticosteroids) and allergy.
Mouth Sores in Arthritis Patients. Certian Arthritis Medication Can Cause Mouth Sores. Arthritis. It's not uncommon for arthritis patients to get mouth sores as a side effect from medications. Oral ulcers or mouth sores develop on the palate, under the inside of the lips or inside of the cheeks. Arthritis medications with mouth sores as a side effect include: NSAIDs.