The small respiratory pathways of your pet’s lungs, called bronchioles, become inflamed when the allergen is inhaled or ingested. The body then produces extra mucous to try to expel the allergen. The combination of inflammation and mucous restricts the lung’s passageways, and makes breathing difficult.
In severe cases the muscles that surround these airways in the lungs can spasm, in what is called a bronchospasm, and further restrict breathing.
A pet who seems to be having trouble breathing should be taken the veterinarian right away, since a lack of oxygen can cause severe damage, or even death.
The Most At-Risk Groups
Cats get asthma more often than dogs, and all pets between 2 and 8 years old are more prone to asthma than pets of other ages. Siamese and Himalayan cats are more susceptible to asthma than other cat breeds and female cats are more likely to develop asthma than males. Finally, all pets that are overweight or obese are more at risk for asthma.
Finding the Cause of Asthma
Once you're at the veterinarian's office, they'll ask for a list of any possible irritants and changes in your household routine. When did you start using a new dog food? A new cleaning solution? Did you bring a new potted plant inside? Is the kitty litter a new choice? This list will help you and your vet pinpoint the most likely cause of your pet's allergic reaction.
Infections and Viruses
An infection or a virus can also cause an allergic reaction and asthma in your pet, in which case the infection or virus itself will need to be dealt with in order to stop the asthma attacks. Parasites, like heartworms, in the lungs can cause asthma symptoms.
Whenever you get a new pet or if you know your home will be exposed to new substances--like during a remodeling or spring cleaning--be on the lookout for possible symptoms of asthma. Most veterinarians also recommend having pets on heartworm medication year-round, such as Heartgard for Cats, to protect agains the many symptoms of heartworm.
More on Allergies in Cats and Dogs
Causes of Pruritus in Pets
What Causes Flea Allergy Dermatitis in Dogs