My dog has the same case. Wheezing.
A dog's wheezing or "snorting" sounds similar to a person who is having an asthma attack. It is, therefore, understandable, that many dog owners find it very alarming.
A dog's airways are extremely delicate and sensitive. In a healthy dog, the airways expand and contract in such a way that the right amount of oxygen can get to the lungs. However, when there is a problem with the airways, causing them to contract too much, oxygen has to squeeze its way through, making a high-pitched wheezing sound.
Common causes for this wheezing are: allergies, upper respiratory problems (Kennel cough, asthma, bronchitis), and heartworms.
Kennel cough: a dry, hacking cough.
Asthma: not as frequent as in cats - wheezing, coughing, and sneezing.
Bronchitis: a dry, hacking cough, which may be accompanied by wheezing and gagging.
More than often, however, it is nothing serious.
Occasional wheezing that stops within 20 to 30 minutes is not serious. It probably is caused by something that is irritating the dog's airways. However, if the wheezing lasts longer than 30 minutes, or if the dog has been wheezing on and off rather frequently, it is likely that something more serious is going on with your dog's health. It is, therefore, important to find out and tackle the underlying cause.
Best advice: talk to your vet. My dog has had his wheezing problem from his puppyhood - he simply has allergies. :)