What are lungworms?
Lungworms are parasitic worms that live in the lungs and breathing passages of dogs, cats, foxes and other mammals. The most common lungworm species that infect dogs in the UK are:
- Angiostrongylus vasorum – also known as French heartworm
- Crenosoma vulpis – known as fox lungworm
- Eucoleus aerophilus – also known as capillaria aerophila
- Filaroides osleri – known as Oslerus osleri
These worms can cause serious health problems in dogs. Angiostrongylus vasorum is considered the most threatening lungworm species in the UK and Europe.
How do dogs get infected with lungworms?
Dogs can become infected with lungworms by ingesting larvae that develop into adult worms inside the body. The larvae may come from:
- Eating slugs, snails or frogs that act as intermediate hosts for lungworm larvae.
- Drinking contaminated water sources.
- Eating grass, toys or outdoor items contaminated with slug or snail slime that contains larvae.
- Eating the feces of infected animals like foxes.
The larvae migrate from the intestines into the bloodstream and ultimately end up in the lungs where they mature into adult worms. The worms reproduce and lay eggs inside the lungs that hatch into larvae. These larvae are then coughed up, swallowed and passed out in the dog’s feces, where they can infect other intermediate hosts and continue the lungworm life cycle.
What are the symptoms of lungworm infection in dogs?
The symptoms of lungworm infection can vary depending on the species involved, the worm burden and severity of infection. Some common signs to watch for include:
- Coughing
- Breathing difficulties
- Tiring easily during exercise
- Loss of appetite
- Weight loss
- Lethargy, depression
- Bleeding disorders – bruising, nose bleeds
- Pale gums
- Vomiting
- Diarrhea (sometimes bloody)
- Seizures and other neurological signs like circling, head tilt
In severe cases, especially with Angiostrongylus vasorum infection, dogs may develop right-sided heart failure, pulmonary hypertension, coagulopathies and other life-threatening conditions. Signs of lungworm disease can vary from mild to severe. If your dog has any of these symptoms, see your vet for diagnosis and treatment.
How do vets test for lungworm infection in dogs?
There are several ways vets can test dogs for lungworms:
- Fecal examination – Looking at a stool sample under the microscope to check for lungworm larvae.
- Blood test – A blood test called an ELISA can detect antibodies produced by the dog in response to lungworm infection.
- PCR test – This amplifies lungworm DNA in the blood to directly detect the presence of lungworms.
- Baermann fecal analysis – Using a special technique to isolate larvae from feces.
- Bronchoscopy/lavage – Taking fluid samples from the lower airways and examining for lungworm larvae.
- Biopsy – Taking lung tissue samples to check for signs of lungworm infection.
The most common and practical initial tests are fecal checks for larvae and blood antibody tests. Your vet may recommend doing multiple types of testing to increase the chances of detecting lungworms. Dogs should be tested annually for lungworms and any time symptoms warrant testing.
How are lungworm infections treated in dogs?
There are several deworming medications that can be used to treat lungworm infections in dogs:
- Fenbendazole
- Milbemycin oxime
- Moxidectin
- Ivermectin
- Levamisole
The specific medication, dosage and length of treatment will depend on factors like the type of lungworm involved and severity of infection. Most treatments are continued for 1-2 weeks but may be longer with severe infections.
Dogs are usually hospitalized and placed on intravenous fluids, oxygen therapy, bronchodilators, and other supportive care when lungworm disease is severe. Medications may be given to control vomiting, seizures, heart failure and coagulation disorders in complicated cases.
Steroids and anti-inflammatories are sometimes used short term to reduce inflammation in the lungs. The prognosis for full recovery is generally good if there is no permanent lung or heart damage. Follow up testing is done after treatment to ensure the worms have been eliminated.
How can I prevent lungworm infections in my dog?
Here are some tips to help prevent lungworm transmission and keep your dog protected:
- Use monthly heartworm preventatives that also protect against lungworms like milbemycin, moxidectin, or selamectin.
- Avoid areas where slugs and snails are common when walking your dog.
- Pick up dog feces promptly in your yard and dispose of it.
- Prevent your dog from eating slugs, snails, frogs or raw wildlife.
- Don’t allow your dog to drink from puddles, plant pots, birdbaths or other outside water sources.
- Clean up toys and bowls that have been left outside.
- Limit your dog’s access to compost or leaf piles where slugs/snails may live.
- Trim grass short around your home to reduce slug/snail habitat.
- Use fencing to prevent wildlife like foxes from contaminating your yard.
- Have annual fecal testing done to check for lungworm infection.
Taking these precautions along with using a good monthly preventative medication is the best way to protect your dog from lungworm disease. Be vigilant if lungworms are common in your area. Contact your vet with any concerns about your dog’s risk.
Conclusion
Lungworms can be serious parasites that dog owners should not ignore. Pay attention for any signs of respiratory illness, poor stamina or weight loss in your dog. Have your vet run tests to check for lungworms if concerns arise. Using dewormers and prevention year-round is crucial to avoid infection, especially if you live in an area where lungworms are endemic. With proper precautions and veterinary guidance, you can keep your dog healthy and lungworm-free for a long and happy life.
| Species | Geographic Distribution | Key Signs |
|---|---|---|
| Angiostrongylus vasorum | Europe, South America, Africa | Coughing, bleeding disorders, right heart failure |
| Crenosoma vulpis | Europe, North America, Africa, Asia | Coughing, breathing trouble, nasal discharge |
| Eucoleus aerophilus | Worldwide | Coughing, pneumonia, bronchitis |
| Filaroides osleri | North America, Europe | Coughing, pneumonia, tracheal nodules |
| Test | What it detects | Sample needed |
|---|---|---|
| Fecal exam | Lungworm larvae | Feces |
| Blood antibody test | Antibodies to lungworms | Blood |
| PCR | Lungworm DNA | Blood |
| Baermann technique | Lungworm larvae | Feces |
| Bronchoscopy/lavage | Lungworm larvae | Fluid from lower airways |
| Biopsy | Adult lungworms, eggs, inflammation | Lung tissue |
Key Points
- Lungworms are parasitic worms that live in the lungs of dogs and can cause respiratory illness.
- Dogs get infected by eating intermediate hosts like slugs/snails, or from contaminated environment.
- Symptoms include coughing, breathing problems, poor exercise tolerance, bleeding disorders.
- Diagnosis is made by fecal or blood tests looking for evidence of lungworms.
- Lungworms are treated with deworming medications often continued for 1-2 weeks.
- Prevention focuses on flea/tick preventatives, avoiding snails/slugs, cleaning the yard, and stopping dogs from eating wildlife.