Allergic Pneumonitis in Dogs

Just like humans, dogs can suffer from allergic pneumonitis. The lungs overreact to an allergen that is otherwise harmless. It can be caused by an external source, such as an air freshener in your home, an allergen from outdoors, or can be caused by an external source, such as parasites. Typical symptoms include your dog developing a cough, getting tired more frequently, weight loss without you trying to get him to lose weight, wheezing, and anything else respiratory related. The veterinarian’s first step will be to determine the cause of the allergic pneumonitis. Then, treatment can begin in the form of corticosteroids, antibiotics, expectorant, and other supportive medications. If you notice your dog having any sort of respiratory distress, get him to a veterinarian immediately. The sooner you get him treatment, the easier his recovery will be. If you wait too long, his pneumonitis may become so severe, he may have to stay hospitalized until he stabilizes.

Allergic pneumonitis in dogs can be caused by a number of things. If your dog is experiencing symptoms such as shortness of breath, coughing up blood, or a bluish tinge to his gums, you should treat it as a medical emergency and get him to a veterinarian as soon as possible.

Symptoms of allergic pneumonitis can vary from case to case. Symptoms may include:

• Inflammation
• Cough - productive or dry (sometimes coughing up blood if has a productive cough)
• High white blood cell count
• Weight loss
• Rapid breathing
• Difficulty breathing
• Wheezing
• Exercise intolerance 
• Bluish tinge of the mucous membranes
• Fever 

Types

Allergic pneumonitis can be an acute or chronic allergic reaction. The lungs react to a parasite or other type of irritant leading to a reaction in the lungs and small airways. The underlying cause of the allergic pneumonitis can vary, but the symptoms are the same no matter the cause.

The cause of the allergy can be difficult to identify. Allergic pneumonitis is commonly associated with PIE syndrome, or what is known as pulmonary infiltration with eosinophilia. This can be caused by something viral, fungal, bacterial, or parasitic.

Diagnosis of allergic pneumonitis typically includes blood work and radiographs. The history and symptoms your dog is displaying will determine the exact tests the veterinarian will want to perform. 

If there is an increase in specific white blood cells, it is indicative of infection or inflammation. The veterinarian may want to run a heartworm test if she suspects heartworms as the parasite causing the reaction. She may also collect a fecal sample to check for intestinal parasites. Sometimes intestinal parasites can move to parts of the body they are not typically found, such as in the lungs, and therefore leads to the allergic reaction. 

A radiograph of the chest will be taken to look at the lung patterns. Certain findings can lead the veterinarian to the cause of your dog’s symptoms. Different lung patterns found on the image can be indicative of the cause of the allergic reaction.

Once the underlying cause of the allergic pneumonitis is properly identified, treatment can begin. If the allergen is external, removal of the offender is the first step. A course of corticosteroids can also help treat the problem. If a cause cannot be determined, your dog may need to remain on the corticosteroid for a longer period of time. 

If your dog’s airway is constricted and he is having breathing difficulties, the veterinarian may prescribe a bronchodilator to relax his airway and allow your dog to be able to get more oxygen. If your dog is experiencing severe respiratory distress, he may need to be put on oxygen therapy until he stabilizes.

If the cause of the allergic pneumonitis can be determined and removed, the recovery process goes very well. Even if the cause cannot be found, supportive therapies and medications can offer your pet relief until something more can be done. Medications to clear the lungs of fluid, antibiotics to combat infection, as well as other medications can help your dog on the road to recovery.

If you notice your dog having any sort of breathing difficulty, get him to a veterinarian as soon as possible. Low oxygen levels can be very dangerous and should be treated as a serious medical condition.