Your What do Lungworms look like in dogs? A Step-by-Step Guide

How Vets Diagnose Lungworms in Dogs

Your veterinarian will likely recommend chest x-rays if your pet has a history of respiratory concerns. They will also take a fecal sample and may recommend an airway wash if they can’t confirm the diagnosis.

On x-rays of dogs with lungworms, the vet might see small spots of inflammation within the lung tissue, or larger areas of inflammation with possible pneumonia. If the lung is damaged severely enough, it can break open and cause air to leak into the dog’s chest. This is called a pneumothorax.

One species of lungworm can produce thickening of the large trachea wall (windpipe) and/or trachea nodules (abnormal trachea growths), which your vet may be able to see on the x-rays.

X-rays alone cannot be used to diagnose lungworms in dogs, as other diseases can cause similar effects. However, your vet may have a suspicion of lungworm based on your geographical location and/or a history of recent travel with your dog.

Your vet will use fecal tests to look for lungworm eggs and larvae. They may have you bring multiple fecal samples from different days because the shedding of lungworm eggs and larvae in the feces comes and goes.

If your vet can’t diagnose lungworms with x-rays and fecal testing, they may recommend an airway wash such as a transtracheal wash (TTW) or bronchoalveolar lavage (BAL), both of which are performed under anesthesia.

The fluid obtained from your dog’s airways and lungs during the wash procedure may contain the lungworm larvae, eggs, and inflammatory cells that will lead to a diagnosis.

Treatment to get rid of lungworms in dogs involves a dewormer that’s usually administered orally for 14 days.

Your dog’s immune system will generate inflammation as a reaction to the dead worms and larvae, so your veterinarian may also prescribe a corticosteroid anti-inflammatory medication.

It is common for a dog to seem to get worse when first starting treatment, since this is the period when there will be the largest number of dead and/or dying worms.

If you are concerned with how your dog is doing or have any questions, call your veterinarian in case additional treatment is needed.

In more complicated lungworm cases, cysts can form in the lung tissue. If the cysts rupture, your dog can accumulate air that’s in the chest and outside the lung (pneumothorax).

If enough air accumulates to cause your dog to have difficulty breathing, your vet might need to remove the air and place a chest tube until the air leak seals on its own.

Rarely, surgery may be needed to close the sites where air is leaking from the lung tissue.

Untreated cases where there’s severe lung inflammation and/or lung damage can result in death.

Lungworm symptoms: How do I know if my dog has lungworm?

Unlike some other parasites that may cause your dog mild discomfort or illness, lungworm can prove fatal if the condition is not diagnosed and treated. But lungworm affects dogs differently. Often, dogs won’t show signs in the early stages of the disease, some dogs will display mild signs and others severe. The earlier you spot and treat a lungworm infection, the more likely your dog will recover, so it’s essential to know what to look out for.

A persistent cough is one of the more common lungworm symptoms, triggered by the presence of worms in the dog’s lungs. They may even lead pets to cough up blood. A cough like this should never be ignored or confused with more common respiratory infections, like kennel cough.

A dog with lungworm is likely to tire easily, even after gentle exercise. Fatigue could be one of the first physical changes you notice – especially in young, usually lively dogs.

If your dog bleeds persistently from a minor wound, it could be a sign they’ve contracted lungworm. Lungworm can lead to poor blood clotting, which can also make your dog more prone to nose bleeds, and can cause anaemia, which may make your dog’s eyes and gums look paler than usual. Lungworm may also cause bleeding in the whites of the eyes.

Your dog may experience other problems with bleeding too, including:

  • bloody stools
  • passing blood when weeing
  • vomiting blood
  • Changes in behaviour can be hard to pin down but if your dog is noticeably lethargic or depressed, or suffers from seizures, you should always contact your vet immediately.

    Lungworm can be associated with vomiting and diarrhoea but this is not always the case. The problem is that these signs are also the symptoms of many other common or temporary health problems – including food allergies and tummy upsets.

    If your dog has contracted lungworm, they may also have other non-specific signs such as weight loss or poor appetite. Lungworm can be present in your dog’s body for months without any obvious symptoms, and the signs are easily confused with other illnesses, which makes diagnosis tricky.

    What causes lungworm infection?

    A lungworm infection is caused by one of several parasitic roundworms. In North America, the parasitic lungworms that infect dogs are Eucoleus aerophilus (formally known as Capillaria aerophilus), Oslerus osleri (formally called Filaroides osleri), Crenostoma vulpis (fox lungworm), Eucoleus boehmi and Filaroides hirthi. Angiostrongylus vasorum (French heartworm) may also be considered a lungworm due to the lung damage it causes. It is an emerging parasite in North America, currently only seen in the Atlantic provinces of Canada and the eastern U.S.

    Eucoleus aerophilus is primarily known as a parasite of foxes but it has also been found in dogs, cats and other carnivores. The others are parasites that infect dogs and other related members of the canid family.

    The adult worms of Eucoleus boehmi live in the nasal cavity of dogs and related canids. Adult worms of Oslerus osleri and Crenostoma vulpis live in the trachea and bronchi. Filaroides hirthi adults live in the lungs. Angiostrongylus vasorum live in the arteries of the lungs.

    Lungworm infection in Dog|clinical signs|treatment