Hi there,
Hypothyroidism can indeed lead to Malassezia skin infections, as it affects the quality of the skin and its natural defences. In some dogs, these yeasts become very difficult to manage until the hypothyroidism is properly stabilised. If you haven't already done so, it might be worth checking with your vet to ensure the hypothyroidism treatment is correctly adjusted (by checking T4 levels after starting the medication). It is also important to look for other factors that could be sustaining the Malassezia, such as allergies (environmental or food-related), skin folds, or another underlying skin condition.
Depending on how widespread the lesions are, topical treatment (antifungal shampoos or mousses) might be enough, but some dogs also need oral antifungal medication for several weeks. I’d recommend discussing this with your vet.
All the best,
Inès
Translated from French
