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Any questions?

Here’s a helpful list covering the most popular questions dog owners have about parasites and how they can protect their dogs.

For more information, please contact your vet practice.

Do I really need to protect my dog from parasites?


Yes - a wide variety of parasites can infect dogs, affecting their health and wellbeing. So it is important to make sure they are protected.

Which parasites should my dog be protected from?


Parasites can cause a number of diseases in dogs, and in some cases, even death. Important parasites to protect your dog against include fleas, ticks and worms (such as roundworms and lungworm).

Which parasites does NexGard Spectra® protect my dog from?


Your dog is protected from fleas, ticks, mites, lungworm and roundworms with NexGard Spectra®, some of the most common threats to your dog in the UK. That’s right…all that protection for your dog from just one tasty chew.

Can humans get parasites from dogs?


The answer is, unfortunately, yes. For example, roundworms can infect humans and cause major health concerns – they have been associated with epilepsy, asthma and reduced learning ability in children.1-4 They can also cause blindness. 

Where can my dog pick up ticks, fleas and worms?


Your dog can pick up ticks in their home or outdoor environment. For example, from other household pets or from gardens and parks. Fleas and roundworms can also be picked up these ways. Your dog can pick up lungworm by accidentally swallowing slugs and snails – or even their trails!6

Help! My home has become infested with fleas – how can I get rid of them?


This can be a concern: especially when you consider every single female flea can lay up to 50 eggs a day.7 Multiply that by the fleas on your dog and that’s thousands of eggs in a month – with most of these falling off your pet and contaminating your home and carpets!8 Thankfully, the good news is that flea infestations can be effectively managed by treating your home and dog. Your vet can provide more information on this.

Why are puppies particularly at risk from parasites?


Puppies by their very nature love to sniff, slurp, lick, and gobble up everything in their paths including dirt, rubbish, and (unfortunately) poo. These behaviours put them at risk of picking up worms. Also, through exploring their new environment, puppies can pick up fleas, ticks and worms lurking in homes, gardens and parks.

My dog doesn’t lick snail trails – do I still have to worry about lungworm?


Unfortunately, yes. Your dog might pick up lungworm accidentally by even just drinking contaminated water.6 Preventing disease caused by this parasite is important since lungworm is becoming increasingly common.9-12

Is lungworm a risk in my area?


Lungworm may be more common than you imagine: its numbers are on the rise9-12 and it is considered endemic within several countries in Europe, including the UK, Ireland, France and Spain. It is always best to check with your vet for more detailed information about your region.

What are the signs of worms in dogs?

FAQ 10

The signs of worm infections in dogs will vary according to the type of worm and it is worth pointing out that each worm can affect dogs differently. For example, roundworms in puppies can cause problems with growth and can even be fatal in the most severe of cases.7 Lungworm can also cause breathing difficulties. If you have any questions about worms or notice any in your dog’s poo, you should contact your vet.

Why is NexGard Spectra® given monthly?

FAQ 11

Since many parasites can be a threat to your dog all year round, continuous cover throughout the year is the best approach. Only monthly worming can prevent deadly lungworm disease and stop dogs shedding roundworm eggs into their environment. Some people find it easier to remember to treat their dog monthly than less frequently, for example seasonally. You might find setting a reminder to give your dog their next chew helpful.

Can my dog be bathed or go swimming once they have been given their NexGard Spectra® chew?

FAQ 12

Absolutely! Because NexGard Spectra® is a chew, you can stroke and cuddle your dog straight away, as normal, and swimming, bathing and shampooing won’t reduce its effectiveness either.

My dog is pregnant, breeding or nursing. Can I use NexGard Spectra®?

FAQ 13

Yes, Nexgard Spectra® can be used in pregnant, breeding and lactating bitches.


Please note that use in breeding male dogs is still a decision for the prescribing vet according to a benefit-risk assessment.


  1. Li, L. et al. (2014) Asthma and toxocariasis. Ann Allergy Asthma Immunol. 113(2), 187-192.
  2. Quattrocchi, G. et al. (2012) Toxocariasis and epilepsy: systematic review and meta-analysis. PLoS Negl Trop Dis. 6(8), e1775.3.
  3. Walsh, M.G. and Haseeb, M.A. (2012) Reduced cognitive function in children with toxocariasis in a nationally representative sample of the United States. Int J Parasitol. 42(13-14), 1159-1163.
  4. Overgaauw, P.A. and van Knapen, F. (2013) Veterinary and public health aspects of Toxocara spp. Vet Parasitol. 193(4), 398-403.
  5. Wright, I. (2012) Lyme disease: If you go down to the woods today are you in for a big surprise? Companion Animal. 17(6), 42-44.
  6. Helm, J. and Morgan, E. (2017) Canine and feline lungworm infections in the UK. In Practice. 39(7), 298-315.
  7. Beugnet, F. et al. (2018) Textbook of Clinical Parasitology in dogs and cats, Servet editorial - Grupo Asís Biomedia, S.L.
  8. Halos, L. et al. (2014) Flea control failure? Myths and realities. Trends Parasitol. 30(5), 228-233.
  9. Morgan, E. (2018) Lungworm in dogs: a local or national problem? Vet Times. 48(44), 16-17.
  10. McCarthy, G. et al. (2016) Geographical distribution of Angiostrongylus vasorum in foxes (Vulpes vulpes) in the Republic of Ireland. Parasitology. 143(5), 588-593.
  11. Morgan, E.R. et al. (2008) Angiostrongylus vasorum and Eucoleus aerophilus in foxes (Vulpes vulpes) in Great Britain. Vet Parasitol. 154(1-2), 48-57.12.
  12. Taylor, C.S. et al. (2015) Increased prevalence and geographic spread of the cardiopulmonary nematode Angiostrongylus vasorum in fox populations in Great Britain. Parasitology. 142(9), 1190-1195.
  13. ESCCAP. Worm Control in Dogs and Cats. ESCCAP Guideline 01 Third Edition 2017.

NexGard Spectra® contains afoxolaner and milbemycin oxime. UK: POM-V IE: POM. Advice should be sought from the prescriber. Further information available in the SPC or from Boehringer Ingelheim Animal Health UK Ltd., RG12 8YS, UK. Tel: 01344 746957. Email: NexGard Spectra® is a registered trademark of Boehringer Ingelheim Animal Health France SCS, used under licence. ©2023 Boehringer Ingelheim Animal Health UK Ltd. All rights reserved. Date of preparation: October 2022. UI-CAN-0129-2023. Use Medicines Responsibly.