Lungworm, caused by Angiostrongylus vasorum, also called the French heartworm, is a potentially life-threatening worm spread by slugs and snails. We diagnosed it for the first time in 2010, in a dog that had recently been to Crufts – it had been wormed but not with a wormer that killed lungworm.
Lungworm affects dogs and foxes, and traditionally has only been found in the south/south west and Wales but cases have been recorded all over the UK. At Alfreton Park Veterinary Hospital, we have had cases in dogs all around our 'patch', including South Normanton, Newton, Alfreton and Kilburn, very sadly including one fatality.
Recently it has been shown that the slime trails left by slugs and snails can contain active lungworm larvae, which can survive for at least 15 days on vegetation. This makes slime trails an important source of lungworm infection for dogs.
Foxes are increasingly becoming infected with lungworm, and their faeces is therefore a source of infection. Overall, 18% of UK foxes have lungworm, up from 7% in 2008, with 50% of foxes in the south-east now thought to be infected.
How does my dog become infected?
An infected dog will have adult worms present in the arteries of the lungs and in the heart. These animals will pass worm larvae out in their motions. Slugs and snails will eat these larvae, which then develop within the slug or snail. Dogs and foxes become infected when they eat the slug/snail, and can also be infected by licking slime trails that contain the larvae. Frogs can also harbour the larvae.
Once the dog or fox has eaten the larvae, they travel across the gut, via the liver to the heart and lungs where they develop into adult worms. The time taken to complete the lifecycle is 38-57 days.
Spread will be greater if the fox population is affected. The vet school at the University of Nottingham recently found Angiostrongylus worms in a fox at post mortem – so we know foxes in this area are affected.
Which dogs are at risk?
A recently published study looked into patterns of infection in the UK. The risks are highest for dogs under 18 months old – 8 times higher than dogs over 8 years old; for dogs aged 18 months-8 years, the risk are 4 times higher than for the over 8s. So – the younger the dog, the greater the risk. This probably reflects their greater tendency to play with or eat slugs and snails.
What are the signs of disease?
These fall into several categories:
· Respiratory signs (coughing, breathing heavily, reduced ability to cope with exercise)
· Nervous signs (the brain and spinal cord become involved, which can result in a variety of signs such as being unsteady/wobbly, fainting, knuckling of limbs)
· Blood clotting problems, which may lead to coughing up blood, bleeding after an operation, nose bleeds)
Because of the wide variety of symptoms, this disease can be very difficult to diagnose. Some dogs show minimal clinical signs or generally unwell. Our most recent case presented with a blood shot eye!
How is the disease diagnosed?
There is a very accurate blood test, which can give results in just a few minutes.
Lungworm can also be diagnosed by examining the dog’s motions for the presence of larvae.
Can it be treated?
Yes – happily many dogs with A.vasorum infection make a complete recovery, but it is important to remember that this condition is potentially life-threatening, and sadly not all cases will recover. We have had one fataility, the dog's symptoms were too severe by the time he was brought to the surgery, and sadly he could not be saved.
Angiostrongylus can be treated using worming products, currently there are only 3 wormers that are known to work, using a specific worming schedule.
Other treatments are sometimes needed, such as medication to improve breathing, stop any bleeding etc.
How can it be prevented?
This is the question that all responsible dog owners should now be asking themselves!
The answer is YES - by worming your dog with a tablet EFFECTIVE AGAINST LUNGWORM.
There is a worming tablet that is routinely prescribed by this practice that reduces the numbers of worms. If this is used monthly, this should prevent A.vasorum infections.
There is also a spot-on product which also kills fleas, other roundworms, ear mites and lice – this is NOT available in the shops over the counter.
Both of these products are recommended to prevent A.vasorum. Very few other wormers are effective against this worm. Please ask us at the surgery for advice about the best way to prevent A.vasorum in your dog.
How common is it in Derbyshire?
Probably not common at the moment, but it is almost certainly under-diagnosed, mainly because vets haven’t previously seen it, so don’t always consider it a possible diagnosis. A recent study showed 16% of coughing dogs had A.vasorum! We expect numbers of confirmed cases to rise in the future. We have had one fatality, from a dog living in Alfreton, and know that one dog treated at a nearby practice has also died. We have diagnosed cases in various local areas, including Newton, South Normanton, Ripley and Kilburn.
Are cats also at risk of Angiostrongylus?
Although cats can get lungworm, they aren't affected by Angiostrongylus vasorum.