Does your dog make a whistling noise when they breathe? Is the whistling new or has it been happening off and on for a while? Whistling while breathing is a sign that your dog is wheezing. Dogs can wheeze for a multitude of reasons, some of them benign and some of them more serious.

Causes of Wheezing in Dogs

A dog will wheeze when they breathe because something in the trachea (windpipe) or further down the airway is blocking the flow of air. Sometimes, reverse sneezing is mistaken for wheezing, so watch your dog closely to figure out which it is. There are several possible reasons for wheezing in dogs:

Heartworm Disease

Heartworms are parasitic worms that are transmitted by mosquitoes. Almost every mammal is susceptible to them, including dogs and cats. Wheezing, while it can be a symptom of heartworm disease, is usually only seen in severe cases. A dog that is wheezing because of heartworm disease will have such a large burden of worms in the heart and blood vessels that they are literally blocking your dog's airway. Heartworm disease is easily diagnosed with a blood test. Additional tests, such as chest X-rays, may be needed to determine how severe your dog's heartworm disease is before starting treatment.

Airborne Allergens and Asthma

Pollens, mold spores, dust mites, and other airborne allergens can be a nuisance to your dog. They can cause irritation to your dog's airway and this irritation can cause wheezing. Airborne allergies usually occur seasonally, but a dog with asthma may be sensitive all year long. Dust mites and household allergens tend to be worse in the winter months when your furnace kicks in. Pollens and mold spores tend to be worse in the spring and summer months when things are in bloom.

Tracheal Collapse

A dog with tracheal collapse will have a trachea that narrows to an impossibly small diameter. This can create a distinctive wheezing, honking noise. Breeds that are susceptible to tracheal collapse are usually smaller breeds, such as Yorkshire terriers, shih-tzus, and malteses, but any dog can have a collapsing trachea. If your vet suspects that your dog's wheezing is due to a collapsing trachea, they'll take chest X-rays to visualize the trachea. Your vet will be able to visualize the narrowing of a collapsed trachea on the images.

Congestive Heart Failure

CHF, or congestive heart failure, is another illness commonly seen in smaller breed dogs, although some larger breeds are also susceptible to it. Although coughing and labored breathing are more common symptoms of CHF, it can also cause wheezing in dogs. CHF is commonly seen in chihuahuas, miniature poodles, Cavalier King Charles Spaniels, and Doberman Pinschers. Congestive heart failure is diagnosed with chest x-rays, blood work, and blood pressure checks. A dog with CHF will have an enlarged heart on X-rays, high blood pressure, and changes in their blood work.

Foreign Bodies

If your dog likes to chew on things, they may get a little too excited with their chewing and swallow down the wrong pipe. They can also inhale small objects while sniffing. Bones, toys, sticks, or grass awns may accidentally get stuck in your dog's airway and this can definitely cause a blockage and wheezing.

A foreign body in your dog's airway is typically diagnosed by chest X-rays and a sedated airway exam (usually dogs need to be sedated in order to physically examine their airway). Some dogs may need a bronchoscopy or a small camera guided down the airways to visualize what is happening. A good clinical history is also helpful in diagnosing a foreign body in your dog's airway, meaning you noticed your dog chewing on something and then they started wheezing.

What to Do If Your Dog is Wheezing

Wheezing should always be discussed with your pet's veterinarian if noticed. If your dog wheezes for a few seconds and then recovers, it is usually a non-emergency situation, although you should still schedule an appointment with your vet to have the wheezing checked out. However, contact your vet immediately if the wheezing continues, or if you notice any of the following:

• Frequent wheezing without improvement
• Difficulty breathing
• Blue, gray, or pale appearance to gums or other mucous membranes
• Loss of appetite
• Your dog seems panicky, anxious, restless, or lethargic

Treatment for Wheezing

Treating your dog's wheezing is entirely dependent on what is causing your dog's wheezing.

Heartworm disease can be treated, depending on the severity. Dogs are typically treated with three rounds of injections to kill the worms followed by strict rest. In severe cases, dogs may need surgery to physically remove the worms.

Allergies and asthma can be treated with medications to control symptoms.

Congestive heart failure is life-threatening and though it depends on the severity, many can still be treated with medications and sometimes diet changes.

Tracheal collapse is often controlled with cough medications as well as with adjustments to your dog's environment and exercise regimen. In more severe cases, surgery can be performed to place a stent in your dog's trachea to better open it.

Foreign bodies in the airway can sometimes be removed during a sedated airway exam. However, a bronchoscopy or surgery may be required.

How to Prevent Wheezing in Dogs

Congestive heart failure, tracheal collapse, and allergies, for the most part, cannot be prevented. They are something that your dog may or may not be predisposed to or born with. However, foreign bodies and heartworm disease can be easily prevented.

Environment control and proper enrichment can help prevent your dog from accidentally getting something lodged in their airway. Heartworm prevention is common, and there are countless preventatives on the market. Most treatments are oral chews taken monthly, but there are also topicals and injectables available. Your vet can help you determine what prevention is right for your dog.

Wheezing in dogs, even if not immediately urgent, is something that you should have checked out by your vet. Your vet can help determine what is causing your dog's wheezing and how best to treat it.