Overview of Feline Lungworms
Lungworms are an example of a parasite (“worm”) that can infect the respiratory tract of cats. There are several different parasites that have been identified including: Aelurostrongylus abstrusus, Paragonimus kellicotti and Capillaria aerophilia.
Outdoor cats in certain geographic areas of North America (and elsewhere) are predisposed to respiratory parasites. Infection typically occurs from exposure to the hosts that carry the parasite. For example, the cat lungworm (Aelurostrongylus) is found throughout the southeastern USA. Cats acquire the infection when they eat the snails or slugs that act as the intermediate host and (more likely) the birds or small mammals that eat the infected snails. Thus, a “hunting” or outdoor cat is most likely to be infected.
The lung fluke (Paragonimus) is found near lakes that harbor the intermediate host (crayfish and snails) or the raccoons that eat them.
Clinically important infections occur most often in younger cats (those less than 2 years old) that are heavily infested. The symptoms for lungworm infections depend on the specific parasite, the severity of the infection and the host response. Some pets with mild infections are normal, while other pets will exhibit a cough, lethargy, exercise intolerance and weight loss.
What to Watch For
Diagnosis of Lungworms in Cats
Diagnostic tests are needed to recognize lungworms, and exclude other diseases. Tests may include:
Treatment of Lungworms in Cats
Home Care and Prevention
In addition to careful observation, you may be asked to medicate your cat for this condition. This can be a challenge in some cases and you should ask for help at your veterinarian’s office if you need directions regarding proper medication techniques. A variety of medications may be prescribed depending on the exact parasite identified. Some are liquids, other pills.
The only effective preventative is to control the roaming and hunting of cats allowed outdoors.
In-depth Information on Lungworms in Cats
Infection of the respiratory tree is in some ways similar to infection of the stomach and intestines by gastrointestinal parasites like roundworms or hookworms, although it is less common. The lungworm injures the airways or lung tissue by inciting an inflammatory reaction. The parasites live and reproduce in the respiratory tissues.
Dogs acquire lungworms by eating one of the “hosts” that serve the lungworm during part of its life cycle. The life cycle of the different parasites can be complicated, involving both intermediate hosts and transport hosts.
The summary of specific lugworms parasites, the species each affects, the lifecycle of each and the geographical distribution of each is as follows:
The major symptom of lungworms is coughing. Of course, there are numerous causes of cough or other signs similar to lungworms. Some common examples in cats include:
In-depth Veterinary Care of Lungworms in Cats
Veterinary care should include diagnostic tests and subsequent treatment recommendations.
Diagnostic tests are needed to recognize lungworms and exclude other diseases. Tests may include:
Additional diagnostic tests may be recommended on an individual pet basis, including:
The principles of therapy for lungworms include killing the parasite and reducing tissue reaction if necessary. Most treatments are done on an outpatient basis or involve a very brief hospitalization. Treatments may include:
Aelurostrongylus abstrusus Treatment
Paragonimus kellicotti Treatment
Capillaria aerophilia Treatment
Home Care for Feline Lungworms
Optimal treatment for the cat with lungworms requires a combination of home care and professional veterinary care. Follow-up can be critical. Administer all veterinary prescribed medication and be certain to alert your veterinarian if you are experiencing problems treating your cat.
Minimize chance of reoccurrence by eliminating exposure to host. Prevent your cat from predatory (hunting) or scavenging infected crayfish or snails.
Repeat Chest X-rays are suggested in about two and 4 weeks to assess improvement. Recheck a fecal sample to monitor for further development of larvae or ova in 2 to 4 weeks.
The prognosis is good for full recovery, unless the problem has been ignored or untreated for many months (or years) in which case permanent lung scar tissue may form. If severe changes have occurred to the lungs, a residual cough may be present.