Do not administer Yarvitan: • if your dog has impaired liver function. • if your dog is hypersensitive (allergic) to mitratapide or to any of the other ingredients. • if your dog is pregnant or during lactation. • in dogs less than 18 months of age. • if overweight or obesity in your dog is caused by a concomitant systemic disease such as hypothyroidism (this is due to a malfunction of the thyroid gland) or hyperadrenocorticism. (this is due to a malfunction of the adrenal gland).