Overview of Canine Lungworms
Lungworms are a type of parasite that can infect the respiratory tract in dogs. There are several different parasites that have been identified including: Paragonimus kellicotti, Capillaria aerophilia, Filaroides and Osleri spp.
Outdoor dogs 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.
The lung fluke (Paragonimus) is found near lakes that harbor the intermediate host (crayfish and snails) or the raccoons that eat them. Dogs that hunt and eat raccoon meat may be at risk.
The tracheal (windpipe) worm Osleri osleri is directly transmitted from the mother to pup.
Clinically important infections occur most often in younger animals, those less than two 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
Coughing is the most common sign of lungworm infection.
Diagnosis of Lungworms in Dogs
Veterinary care should include diagnostic tests and subsequent treatment recommendations. Diagnostic tests are needed to recognize lungworms, and exclude other diseases. Tests may include:
Treatment of Lungworms in Dogs
Home Care and Prevention
In addition to careful observation, you may be asked to medicate your pet 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 and are in the form of liquids or pills.
The only effective preventative is to control the roaming and hunting of dogs allowed out-of-doors. In the case of Osleri osleri infection, the bitch (mother) should also be treated for the tracheal worm.
In-depth Information on Lungworms in Dogs
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 include:
Veterinary care should include diagnostic tests and subsequent treatment recommendations.
In-depth Information on Diagnosis
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:
In-depth Information on Therapy
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:
Drugs recommended for the different parasites include:
Paragonimus kellicotti (dog lung fluke)
Capillaria aerophilia (the “fox lungworm” that can affect the dog)
Follow-up Care for Dogs with Lungworms
Optimal treatment for the dog with lungworms requires a combination of home care and professional veterinary care. Follow-up can be critical. Administer all prescribed medication and be certain to alert your veterinarian if you are experiencing problems treating your pet.
Minimize the chance of reoccurrence by eliminating exposure to host. Prevent your dog from hunting or scavenging infected crayfish or snails.
Repeat chest X-rays are suggested in about two and four weeks to assess improvement. Recheck a fecal sample to monitor for further development of larvae or ova in two to four 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.