Lungworms In Dogs (Oslerus Osleri)

There are several species of worms that can infect the airways of dogs and these are termed lungworms. One of these, Oslerus osleri (previously known as Filaroides osleri) is a parasitic worm with the adult worms found in the upper airways (trachea). Infection is not common in most of the UK and generally affects dogs in kennels (such as racing greyhounds).

Lungworms (Oslerus osleri) are parasitic worms that infect dogs.  These are true lungworms (in contrast to Angiostrongylus vasorum which is also known as lungworm) as the worms are found in the airways. The worms live and lay eggs inside the dog and immature forms pass out into the environment to infect other dogs.

The adult worms spend most of their lives in nodules in the trachea. The eggs laid by the adult female immediately hatch to immature worms (larvae). These are coughed up by the dog and then swallowed and pass out of the dog in the faeces
These larvae are swallowed by another dog either through direct contact, contact with infected faeces or a contaminated environment. Puppies can pick up the infection from their mother. Once back in a dog the larvae burrow through the wall of the gut and migrate through the dog’s body to the lungs. From here they pass up the airways to settle back in the trachea.

Many infected dogs show no signs of illness and signs do not develop until 5-6 months after infection. The nodules formed by the adults in the airways can result in a dry non-productive cough. Often the cough is mild but may become worse with exercise or excitement. Most affected dogs are less than 2 years old.
Since lungworm infections are not common in the UK there are far more common reasons for coughing in a young dog (such as kennel cough). Dogs with very severe infections may be off their food and lose weight. If your dog is unwell in any way make an appointment to see your vet.

It is unlikely that your vet will know straight away what is wrong with your dog and they will need to do a number of tests in most cases to make the diagnosis. If you live in an area where lungworm is common your vet may be more familiar with the disease and may be suspicious of the signs at an earlier stage. If there is a suspicion that your dog is infected your vet can do a test for lungworms in the faeces or in samples taken from your dog’s airways under general anaesthetic.

There is a relatively low risk of your dog being infected unless it lives in a kennel environment where the risk is somewhat higher. There is no specific preventative treatment available.
The aims of treatment are to eliminate the lungworm infection and this is usually relatively straightforward. There are a number of drugs that can be used to eliminate the worms and these are usually given over a period of several weeks. Most dogs go on to make a full recovery with appropriate treatment although in very severe cases signs may persist for sometime after treatment.

If you have several dogs living in the same household and one is found to be infected it is likely that the others will also be at high risk of infection. The common lungworm of dogs (Oslerus osleri) does not affect cats or people.