Common causes of wheezing in puppies, including Yorkies, are allergies, upper respiratory infections and heart worms, according to Natural Dog Health Remedies. Although these conditions can be dangerous if untreated, there are treatments available for all of them.
A dog's airways are very fragile, and when healthy, expand and contract to allow just enough oxygen through to the lungs, explains Natural Dog Health Remedies. However, when these airways contract too much, the oxygen has to force its way through, causing the wheezing sound.
The most common cause of wheezing is allergies, which can be triggered by airborne allergens such as pollen and dust, notes Natural Dog Health Remedies. Dogs can also suffer from upper respiratory infections such as kennel cough, asthma and bronchitis, all of which can cause wheezing. Another possible cause could be the presence of heart worms. These heart worms are usually transferred to a dog through mosquitoes, and can make the dog very sick. Veterinarians have access to medicines that can treat all of these conditions and prevent wheezing.