Quince is safe for dogs
Your dog can eat quince. Quince is low in fat and high in vitamin C. As with other fruits, it does contain sugar and so should only be given occasionally and in moderation. Both raw and cooked quince are safe. When cooking, avoid sweetening the quince since sugar is harmful. Make sure to remove the seeds since they contain nitriles, which can produce hydrogen cyanide and be toxic if large quantities are eaten.