Everything you should know about lungworm in cats
The parasitic infection is becoming an increasing concern for cats in the UK, just as it is in dogs. Until a few years ago, cases here were relatively rare but incidences are now being reported across the UK. Lungworm in cats is a horrible parasite that can lead to serious lung damage, and can be potentially life-threatening if it is not treated early on. Here’s everything you need to know about lungworm in cats, so you can help keep your cat healthy.
As the name suggests, lungworm is a type of parasitic worm that likes to live in the lungs and small airways of cats. The hair-shaped adult worms grow to 5-12 mm long. They produce eggs that hatch into larvae and burrow through the lung tissue. This causes damage to the lungs, and it’s often signalled by a symptomatic cough. There are several types of lungworm that affect cats but two are particularly common. Aelurostrongylus abstrusus is the specific species that causes feline lungworm and it’s different from the lungworm parasite that affects dogs (Angiostrongylus vasorum). The second is Eucoleus aerophilus (sometimes called Capillaria aerophila), which is actually found in both cats and dogs. The problem with diagnosing lungworm in cats is that symptoms are similar to other common lung conditions, such as feline asthma. Although a recent study found feline lungworm prevalence was significantly higher in cats living in the south-east of England, it’s more likely that lifestyle is a greater risk factor than geographic location.
Lungworm is different from other worms your cat might contract and it’s not treated by standard worming treatments.
Cats become infected by:
- Eating infected slugs or snails
Just as in the case of dog lungworm, the cat lungworm parasite is carried by infected slugs and snails. Although unusual, cats may accidentally eat a slug or snail while on their adventures around the neighbourhood.
- Eating other animals that have eaten infected snails
Many outdoor cats enjoy roaming and hunting. The trouble is they can be exposed to cat lungworm if they eat rodents or birds that have eaten infected slugs or snails. This is often the most likely way cats will catch lungworm.
When a cat swallows lungworm larvae and it reaches the intestines, the parasite then migrates out of the intestines through the body and into the lungs, where it develops into an adult worm. It’s here they become fully grown and can reproduce, laying eggs in the cat’s lung tissue, the eggs then release larvae causing the cat to cough. Once the larvae are coughed up and swallowed, they are passed in the faeces.
Infected cats pass the parasite in their poop and in order to complete their lifecycle the lungworm larvae need to be taken up by the intermediate host, a slug or snail, to develop further. Any snails that come into contact with the infected cats’ faeces will become infected, ready to pass on the parasite to any rodents or birds – the favourite prey for a cat. The lifecycle can then continue once more inside the cat.
The trouble is some cats with lungworm won’t show any obvious signs something is wrong. However, common symptoms include:
- a mild to moderate chronic cough
- shortness of breath, wheezing, or difficulty breathing
- lethargy or reluctance to exercise
- weight loss
- nasal discharge
These signs can be indicators of other diseases, so it’s not always easy to tell if your cat has lungworm. If your cat is displaying anything listed above, it’s important to take them to the vet.
Symptoms are often mild in adult cats, but the disease can be more serious in kittens and cats with compromised immune systems. It can lead them to develop bronchitis, pneumonia and even respiratory failure.
Senior cats and cats that are otherwise unwell are also at higher risk of lungworm causing serious consequences if they pick up the lungworm parasite.
Your vet will carry out a number of tests to find out if your cat has lungworm. These might include:
- Physical examination
Your vet will listen to your cat’s chest to check how they’re breathing and any sounds being produced by the lungs.
- Faecal examination
The most common way to confirm a lungworm infection is to test the cat’s faeces for lungworm larvae. However, this isn’t always straight-forward because it can take more than a month for the parasite to show up in the cat’s stools, so multiple tests may be required.
- Complete blood count (CBC)
Your veterinarian will likely take blood tests to check for any other diseases.
A chest X-ray will enable the vet to look at the condition of your cat’s lungs and rule out any other causes.
- Tracheal wash
This is performed by passing a sterile fluid into the airways of the lung and examining the fluid once it has been recovered for any parasites.
The vet may use a camera to look inside the cat and check their airways.
Treatment is available for cat lungworm and when the disease has been caught in its earlier stages cats can make a full recovery. Some cats however may suffer lung damage if they are not treated in good time, which is why it’s important to speak to your vet as soon as you notice any signs in your cat.
If your cat is diagnosed with lungworm, your vet will recommend the best treatment for them.
- Lungworm wormer
Not all routine worming products will treat for lungworm, so it’s best to speak with your vet to find out the best treatment options for your cat.
Cats cannot pass lungworm from cat to cat, and cat lungworm can’t affect dogs; they have their own species of lungworm that poses serious risk to them.
However, a cat infected with lungworm will pass lungworm larvae in its faeces, contaminating the environment and infecting the local slugs and snails. Other cats may then pick up the disease by eating these molluscs, or by eating another small animal (such as a rodent or bird) that has eaten the mollusc.
It can be difficult to control what mischief your cat is getting up to when they roam outdoors but you can help to reduce the threat of lungworm for your ball of fluff.
- Discourage your cat from hunting
Help to satisfy your cat’s natural hunting instincts by taking the time to play with them, reducing their appetite to find rodents and birds, which could be carrying lungworm.
- Treat with a preventative product
There are preventative cat lungworm products available. Ask your vet for more information.
- Clean up after your cat
By picking up your cat’s poop from the garden, you’re helping to prevent the potential spread of lungworm to the surrounding environment and wildlife.
Don’t eat slugs. That might seem obvious, but an Australian man ate two for a dare and contracted meningitis from the rat lungworm hiding within. Thankfully, he recovered fully, but it took five months. Further evidence that you should always choose ‘truth’.