Coughing In Cats
By Rachele Baker, DVM – Some people think that the primary reason that cats cough is to cough up hairballs. However, coughing in cats can be caused by serious medical problems such as feline asthma, heartworm disease, or fungal infections. This post will discuss some of the more common causes of coughing in cats.
Feline asthma is caused by an allergic reaction to airborne allergens. Clinical signs of feline asthma include coughing, wheezing, and labored breathing. Airborne allergens that may cause clinical signs in cats with asthma include cigarette smoke, fireplace smoke, and dusty cat litter.
Feline Heartworm Disease
and Heartworm-Associated Respiratory Disease
Cats are susceptible to infection with heartworms. Clinical signs of heartworm disease are similar to those of feline asthma and include coughing, wheezing, and labored breathing. Heartworms are transmitted by mosquitoes. The prevalence of heartworm disease is higher in geographical areas with large numbers of mosquitoes. Although outdoor cats are at greater risk of infection, indoor cats represent approximately twenty-five percent of confirmed heartworm cases.
The map below from Antech Diagnostics shows the percentage of cats testing positive for exposure or infection with heartworms in 2014 in each state in the United States.
Diagnosing heartworm disease in cats is challenging and frequently requires a combination of tests including blood tests and chest x-rays.
Coughing in cats can also be caused by fungal infections with such pathogens as Cryptococcus and Histoplasma. Cats can become infected by inhaling airborne fungal organisms from the environment. Some fungal pathogens such as Cryptococcus neoformans are found worldwide, while others are found only in certain geographic areas.
Cryptococcosis is the most common fungal infection of cats. Cryptococcus neoformans is found primarily in bird (especially pigeon) droppings. After inhalation of the organism, cryptococcus infection is established in the lungs and then can spread to the lymph nodes, central nervous system, eyes, skin, urinary tract, thyroid glands, and abdominal organs. Clinical signs will vary depending on the organ system involved. A variety of tests may be used to diagnose fungal infections including blood tests and chest x-rays.
Aelurostrongylus abstrusus, the most common lungworm of cats, is found in many parts of the world including the United States, Europe, and Australia. Infection with lungworms can cause coughing, wheezing, and labored breathing.
The life cycle of the lungworm includes frogs, lizards, birds, and rodents as transport hosts of encysted larvae. When one of the transport hosts is eaten by a cat, the lungworm larvae migrate from the stomach to the lungs. The lungworms live in the lungs and release larvae into the lung tissue. The cat then coughs up the larvae, swallows them, and the larvae are passed in the stool.
Routine fecal examinations used to identify parasite eggs passed in the stool are not useful for identifying lungworm larvae. A special fecal test called a Baermann fecal is used to diagnose lungworm infection by identifying the lungworm larvae passed in the stool.
So if your cat is coughing – but is not coughing up hairballs when he or she coughs – the cough could be a sign of a serious medical problem. Your veterinarian can perform a complete physical examination, diagnostics such as x-rays and blood tests, and prescribe medications if indicated.