Lungworm

What is a Lungworm?

Figure 1: Cephalic end of Dictyocaulus filaria L1.

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. However the group also colloquially includes species like Angiostrongylus vasorum – this species in particular may also inhabit parts of the heart. These parasites are exceedingly painful and deadly to both pet and livestock animals, but they are easily treated with modern antibiotics and analgesics.

As with most parasite groups, lungworm can greatly impact the productivity of your livestock, greatly diminishing weight gain amongst cattle, sheep and so forth. Hence it is of significance to the livelihood of formers and the agricultural industry as a whole – and we need to keep control of its spread.

What are the signs of lungworm?

Cattle:

  • Presence of ‘husk’ or parasitic bronchitis
  • Dry coughing
  • Increased dyspnea (elevated breathing rate/difficulty)
  • Rapid weight loss/body condition resulting in sudden death from 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
  • Anaemia 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 illnesses 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 have not been exposed to lungworm.

You may consider implementing a strategic anthelmintic dosing program to ensure your livestock is always covered. NADIS has some good advice on establishing 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 of 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 animal’s faces. In the case of a pet, your vet can take a blood sample for DNA analysis and a stool sample to look at the 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 before 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 vet’s 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 the 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

RRL is capable of lungworm at our facility. We have historically cultured D. filaria (an ovine lungworm) and 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 lungworms – RRL has compiled a set of articles that go into good detail about their lifecycles so that you can understand how transmission is interrupted:

Other Relevant species