Hookworms in dogs

Health and Wellbeing

As a pet parent, you and your pooch will probably have a run in with parasites at some point in their lifetime. The idea of these creepy crawlies lurking around is enough to make your skin crawl, but it’s not only that, they can also cause serious damage to your dog’s health if left untreated.

Hookworms in dogs

Scientifically known as ‘Ancylostoma caninum’, hookworms are tiny little parasites that your dog can pick up from their environment, but they most commonly cause an infestation when your dog ingests infected faeces.

Keep reading to learn all about hookworms, what they are, what they do, how to detect their presence and how to eradicate them for good.

WHAT ARE HOOKWORMS?

Taking their name from their sharp, hook-like mouths that they expertly use to secure and stick themselves to the lining of your dog’s intestinal wall, hookworms might be small but they’re mighty.

In their adult stage, they only get to about 2-3mm long, so it can be relatively impossible to try and spot the worms with the naked eye in your dog’s stools or in the soil.

Despite the tiny size of these irritating insects, they manage to consume and steal excessive amounts of your dog’s blood so they can continue living and reproducing in the host body. The host is the living being that parasites feed from, in this case, your dog. Parasites need a host to survive, so they’ll constantly be on the lookout for their next target.

THE HOOKWORM LIFE CYCLE

As with many intestinal parasites, the hookworm has 3 life cycle stages to complete, starting as an egg, hatching into larvae and then fully maturing into an adult hookworm.

The cycle starts when teeny tiny, microscopic eggs are passed through the stools of an infected dog, where they then hatch into larvae. The larvae will infect the soil and they can survive in this stage for months before they infect another dog. They thrive in moist environments.

Once they’ve found their next target, they move throughout your dog’s body until they reach the intestine, where they hook on and grow into adult hookworms. The female hookworms will lay tons of eggs, which then pass through that dog’s stool and the cycle begins again.

Sometimes, the larvae can somehow accidentally travel towards the lungs and the trachea (windpipe) instead of towards the intestines, which will cause your dog to cough.

The larvae are likely to be coughed up and then swallowed down again, which is when they’ll attempt once more to reach the intestinal tract, where they can mature and get to work completing their full life cycle.

HOW DO DOGS GET HOOKWORMS?

There are a few ways in which dogs can become infected with hookworms, including:

  • Ingestion
  • Through the skin
  • From their mother

INGESTION

As much as we love our four-legged friends, a large amount of the canine population have the unpleasant habit of eating their own, or other dogs’ poo. There are many reasons for why they do this, with the major one being that they just like the taste of it!

Other than being totally disgusting, eating faeces poses the risk of ingesting hookworms if your dog eats a contaminated stool.

Also, as the hookworms can survive in the soil for many months, your dog can inadvertently consume hookworms by having a sniff around in the soil. Or, after a good old roll around in the dirt, your dog will probably lick themselves clean, where again they could ingest those horrible creepy crawlies.

THROUGH THE SKIN

The hook-shaped mouths of these pests make them pretty good at latching onto things. This means that they’re able to infect dogs by burrowing themselves into the skin.

As hookworms can linger in the environment for a relatively long time, your pooch might just be trotting along one day and unknowingly step on a hookworm which will then penetrate the skin and start its cycle, leaving your furry friend totally unaware that they’ve even been infected. The paw pads are the most likely place where this type of contamination will occur.

PASSED DOWN FROM THE MOTHER

Hookworms are one of the things you definitely don’t want passed down from pooch parent to pup. If the pregnant dog once had hookworms in the past, even if they were treated promptly and flushed out, there are usually some dormant larvae that get left behind.

Dormant larvae are still alive, but they’re essentially just ‘sleeping’, and the pregnancy can reactivate them.

Once they’re back to life, they can infiltrate the pregnant pooch’s bloodstream and infect the unborn litter of puppies, which is referred to as prenatal infection. Also, when the pups are born and begin nursing, the hookworms can infect the puppies when they drink their mother’s milk, which is called transmammary infection.

WHERE ARE HOOKWORMS MOST COMMONLY FOUND?

Typically, hookworms are rife in locations that are overcrowded, such as dog kennels and shelters that are densely populated with pooches. To be quite frank, more dogs in one area equals more dog poo, allowing for infection to spread fast through the contaminated dog poo.

HOW WILL HOOKWORMS AFFECT MY DOG?

Ideally, the quicker you can spot the symptoms of a hookworm infection, the better, saving your dog a lot of discomfort. However, at first this can be tricky as the symptoms are often nonspecific and due to the tiny size of the pests and their firm attachment to your dog’s intestinal wall, they aren’t ever really visible in your dog’s stool. Some symptoms to look out for include:

  • Weakness
  • Weight loss
  • Bloody diarrhoea
  • Itchiness
  • Itchy paws if the worms burrowed in through the pads
  • Poor growth in puppies
  • Pale gums
  • Dull, dry coat
  • Coughing if the larvae travelled to the trachea
  • Anaemia

Anaemia refers to the tremendous, dangerous decrease in red blood cell count, which is because the greedy little parasites steal your dog’s blood for themselves, causing extreme internal blood loss. Significant blood loss like this can be a severe threat to our four-legged friends, even more so in younger puppies who have under-developed immune systems.

Quick treatment and a potential blood transfusion will be necessary for young pups to prevent the worst from happening. The first signs to look out for with anaemia will probably be pale gums and increased weakness.

HOW ARE HOOKWORMS IN DOGS DIAGNOSED?

Although it might be difficult for you to spot and detect hookworms yourself because of their small size and nonspecific symptoms, your vet will be able to confirm a hookworm infection pretty quickly with one simple diagnostic test.

Your pooch will need to supply a stool sample and then the vet will perform an examination using a technique named fecal flotation, which is effective and extremely reliable. The stool is combined with a solution that triggers the parasite’s eggs to float to the top and stick themselves to a glass slide which is placed on the surface of the stool solution mixture.

Hookworms produce eggs regularly and these eggs have a distinctive look to them under the microscope, so luckily the infection will be diagnosed quickly with little hassle.

HOW ARE HOOKWORMS IN DOGS TREATED?

Treating hookworms will require a course of medication, called anthelmintics, which will be provided to you by the vet. Typically, these drugs are administered orally, being totally effective and having little, if any, side effects for your dog.

However, anthelmintics will only work to kill the mature, adult hookworms, so it’s vital that your dog is given the drugs again in around 2-4 weeks after their first course to kill any newly matured hookworms that were only larvae when the first treatment was administered.

This should work to totally eradicate the pest from your dog’s body so they can go back to their happy, healthy self.

Although it’s rare, the pooches that are severely ill with anaemia may need a blood transfusion to replenish the significant amounts of blood they lost thanks to those little blood-sucking bugs. Hopefully, hookworm diagnosis and treatment is likely to be done fast enough so it doesn’t reach this stage.

Also, it’s super important that you immediately remove any dog faeces that remain in your garden, so the remaining larvae don’t get the opportunity to continue infecting their surroundings, and subsequently reinfecting your dog or other members of the pooch population.

CAN I PREVENT MY DOG FROM CATCHING HOOKWORMS?

Protecting your pup against parasites is fundamental in ensuring your pooch stays in good health, so make sure you’re always up to date with your dog’s parasite prevention medication.

Speak to your vet and figure out what’s the best for you and your dog. Also, it’s important to ensure that pregnant and nursing female dogs are dewormed to try and prevent the hookworm infection being transferred to their puppies.

Alongside this, try and ensure your dog’s environment is always clean. As we know, hookworm infections are typically rife in overcrowded places such as kennels and dog shelters, often due to unhygienic conditions and the sheer amount of faeces that isn’t instantly cleaned up.

Ensure that you pick up dog poo immediately, especially if they’ve recently had a hookworm infection to prevent reinfection and spreading the disease further.

CAN I CATCH HOOKWORMS FROM MY DOG?

Although it’s incredibly unlikely, humans can become infected with hookworms, however this won’t be through any direct contact with your dog. In a similar way to how hookworms can infect dogs, they’ll infect people by burrowing into skin.

Normally, this will occur when you’re barefoot and walking in the garden, unknowingly standing on an area where the hookworm larvae are residing. This may cause itching and irritation, a sensation referred to as ‘ground itch’.

It’s an unsettling thought that these creepy crawlies could infect you and your dog, however, try not to worry too much. Bathing and washing regularly, especially if you’ve been walking around the garden with no shoes on will help to prevent infection.

RECAP

Overall, a hookworm infection is easily treated so it shouldn’t cause you and your dog too much stress if you seek medical help quickly. Be aware of what to look out for with a hookworm infection alongside maintaining your dog’s parasite medication and you and your pooch should be absolutely fine.

Parasites are just one of those pesky things that you’ll most likely need to overcome in your time as a pooch parent, but with prompt treatment these pests will be just that, a minor pest.

Dr Andrew Miller BVSc MRCVS

Written by: Dr Andrew Miller MRCVS

Andy graduated from Bristol University in 2010 and sees nutrition as a foundation for our pet's wellbeing and takes a common-sense approach. We are what we eat, and it shouldn't be any different for our pets.

Sources
  1. Zoonotic Hookworm Parasites, Centers for Disease Control and Prevention
  2. Hookworms of dogs and cats The Veterinary Clinics of North America, Small Animal Practices, 17, (6), Nov 1987, 1341-1354, doi: 10.1016/s0195-5616(87)50005-5