What is a Lungworm?
A lungworm is a member of the Strongylidae family of parasitic worms. Its primary lifecycle has its adult form situated in the lungs of any particular host animal, hence the ‘lung’ in its colloquial name. They may also inhabit parts of the heart in some related species such as Angiostrongylus vasorum. They are exceedingly painful and deadly to both pet and livestock animals, but they are easily treated with modern antibiotics and analgesics.
What are the signs of lungworm?
Cattle:
- ‘husk’ or parasitic bronchitis
- dry coughing
- increased dyspnea (elevated breathing rate/difficulty)
- rapid weight loss/body condition resulting in sudden death for severe infections
Sheep:
(Signs in sheep are typically less severe than in cattle)
- dry cough
- moderate dyspnea (shortness of breath)
- loss of condition
- lesions on the bronchi
- Anemia caused by undetermined pathogenesis
- secondary bacterial pneumonia
Dogs & Cats:
- Chronic coughing – one of the main indicators of infection
- Reduced stamina/energy with exercise
- Difficulty breathing
- Unusual bleeding
- Changes in behaviour (depressed, lethargic or more aggressive)
- Weight loss
- General illness such as vomiting or diarrhoea
If you suspect lungworm due to these signs, we strongly advise you to call your vet.
Methods of Prevention
Livestock
If you are letting your herd out onto a pasture previously known to be contaminated with larvae, it can be good practice to first vaccinate immature calves/lambs/kids. You can also vaccinate mature calves/lambs/kids if they have arrived from other farms and not been exposed to lungworm.
You may consider implementing a strategic anthelmintic dosing program to make sure your livestock are always covered. NADIS has some good advice on how to establish this type of program, specifically for cattle.
Dogs and cats
Not every dog or cat will show symptoms of lungworm – they may completely recover or not show symptoms but become infirm very quickly. Unfortunately in these cases there is not a lot pet owners can do, apart from regular testing or screening, as well as making sure that pets do not eat any snails, slugs, frogs, lizards, mice and rats that are intermediate/paratenic hosts of lungworm larvae.
Can I test my animal for lungworm?
There are multiple ways to confirm infection with lungworm, from post mortem to testing faeces, saliva, serum and milk. At RRL we can perform a lungworm test to confirm the presence or absence in your animals faces. In the case of a pet, your vet can take a blood sample for DNA analysis and a stool sample to look at larvae present. They may recommend a chest X-ray. This can be quite a costly process.
At RRL we provide a stool sample testing service wherein we can analyse faeces under the microscope and look for eggs or larvae, and also give an estimation to the severity of the infection. For more information on our testing services, click here – All you have to do is post a stool sample and we will do the rest.
Lungworm treatments
Livestock
If you have a ruminant with signs of infection, get a confirmation of diagnosis from the vet prior to treatment. You must then treat the entire grazing group or herd with an anthelmintic licensed to treat lungworm in the respective species as per your vets recommendations.
You may need to treat the symptoms caused by lungworm infection with anti-inflammation medication or antibiotics.
Removing your livestock (if possible) from the infected pasture to a clean pasture or barn will help to reduce chances of reinfection
Dogs and Cats
You may need to treat the symptoms caused by lungworm infection with anti-inflammation medication or antibiotics.
RRL In-house Culture

Figure 1: Cephalic end of Dictyocaulus filaria L1.
RRL is capable of lungworm at our facility. We have historically cultured D. filaria (an ovine lungworm) as well as D. viviparus to produce larvae for studies and are quite capable of en masse in vivo culture. Please note we DO NOT culture from pet animals.
As previously mentioned, we also offer identification services for lungworms.
Please get in contact with us if you require this service.
Lifecycles
Please have a look at our more in depth articles featuring lungworm – RRL has compiled a set of articles that go into good detail about their lifecycles so that you can understand how transmission is interrupted:
- Cattle: Dictyocaulus viviparus
- Sheep: Dictyocaulus filaria
- Canines: Crenosoma vulpis
- Felines: Aelurostrongylus abstrusus

