Introduction
Don't judge a book by its cover and don't assume your dog is healthy simply because they look well. Even dogs that appear active and healthy can be harbouring hidden parasites, including hookworms.
Hookworms are intestinal parasites that attach themselves to the walls of the small intestine and feed on their host's blood.1 In Asia, Ancylostoma ceylanicum, is among the most prevalent hookworm species, and has been reported in more than 40% of domestic dogs, according to studies.4
Unfortunately, hookworms are also zoonotic, meaning they can infect both animals and humans. In dogs, hookworm infestations can lead to serious health complications, while infection in humans may cause uncomfortable skin conditions, resulting in intense itching and unsightly redness of the skin.
The Silent Attack of Hookworms
Dogs can become infected with hookworms through several pathways, with contaminated soil being the most common.
When they walk on contaminated ground, hookworm larvae can penetrate a dog's skin or be ingested when dogs sniff, lick, or consume contaminated soil. Dogs may also become infected by eating tissues from infected animals that contain dormant hookworm larvae, which then travel to the small intestine where they mature, mate and lay eggs.
Puppies are also particularly vulnerable as hookworm larvae can be transmitted from infected mothers to their puppies through milk, potentially causing significant infections at a very young age.
Unfortunately, hookworms are often considered "silent” parasites because infections frequently cause mild, vague, or no noticeable symptoms during the early stages, especially among adult dogs. However, without treatment, a seemingly minor digestive issue can progress into far more serious complications, including:
Anemia1, caused by ongoing blood loss as hookworms feed on the intestinal lining.
Ischemic hepatopathy3, where significant blood loss reduces oxygen supply to the liver, resulting in liver damage.
Hemorrhagic enteritis5, caused by repeated biting and detaching of hookworms from the intestinal wall, leading to inflammation, bleeding, and fluid loss within the gut.
While adult dogs typically tolerate mild infections better, hookworms can be life-threatening for puppies between one and eight weeks old, as well as those that are weak, malnourished, or suffering from other health conditions.5
Among humans, hookworm infections are most common in tropical regions with inadequate sanitation.15 Often due to exposure to contaminated soil, hookworm infestations in people can result in a condition known as cutaneous larva migrans (CLM), where migrating larvae create red, winding tracks beneath the skin and cause intense itching.6
Common Early Signs of Hookworms
Because hookworm infections in dogs often develop silently, it is important to recognise the early warning signs before the condition becomes severe. Some symptoms to watch out for include:
- Diarrhea and/or melena (dark, tarry stool) - Hookworms attach to the small intestine and feed on blood, which can cause internal bleeding and result in dark, tarry stools.12
- Weight loss or difficulty gaining weight - Chronic intestinal bleeding may reduce nutrient absorption, contribute to protein loss, and decrease appetite.12
- Lethargy, weakness, or low energy - Blood loss can reduce red blood cell counts, limiting oxygen delivery throughout the body and leaving affected dogs tired and weak. 12
- Pale gums - Pale, greyish, or white gums can be a sign of anemia caused by ongoing blood loss. 12
- A dull coat or poor body condition - Blood loss, protein loss, and inadequate nutrition from intestinal bleeding can leave the coat looking dry, rough, or lackluster.14
- Coughing - During part of their life cycle, hookworm larvae migrate through the lungs before reaching the intestines, which can cause irritation and coughing.12
- Itchy, red skin lesions - Larvae that penetrate the skin may cause irritation, redness, and inflammation, particularly around the paws and between the toes.12
Diagnosis, Treatments and Prevention
If your dog is showing any of these signs, consult your veterinarian as soon as possible. Early diagnosis can help prevent complications and speed up recovery.
To confirm a hookworm infection, your veterinarian may recommend one or more of these tests:
- Fecal flotation testing to detect hookworm eggs in stool samples.
- Fecal antigen testing to identify proteins produced by hookworms, even when egg shedding is low.
- Polymerase chain reaction (PCR) testing to accurately detect and identify specific hookworm species.
- Blood tests to evaluate anemia and assess your dog's overall health.
Once a hookworm infection is confirmed, your veterinarian may prescribe a deworming medication, or anthelmintic, to eliminate the worms.
Dogs with mild infections may recover with appropriate treatment and care at home. Severely affected dogs and puppies, on the other hand, may require hospitalisation and supportive treatment, such as fluid therapy, nutritional support and, in cases of severe anaemia, a blood transfusion.
That said, while veterinarians can successfully treat active infections, reinfection remains a risk if dogs are not protected consistently with vet-recommended parasite preventives such as NexGard SPECTRA®.
Offering the most complete parasite protection, NexGard SPECTRA® protects dogs against hookworms with its active ingredient, milbemycin oxime, which works by disrupting the parasite’s nervous system, leading to paralysis and death. Beyond hookworms, it also prevents other parasitic infections, including heartworms, lungworms, as well as fleas, ticks, mites, and more.
Stay Protected with PetCare Reminders®
While parasite preventives play an important role in protecting your dog from hookworms and other parasites, consistent monthly protection is key to ensuring continued protection. In fact, missing even a single dose may leave your dog vulnerable to infection and reinfection.
That said, keeping track of monthly treatments isn't always easy. Between work, family commitments, and busy schedules, it's understandable that reminders slip through the cracks.
That's why we created PetCare Reminders®, a FREE tool that syncs with your preferred calendar and helps you stay on track with your pet's treatments, medications, vaccinations, and veterinary appointments.
So what are you waiting for? Be a next-level paw parent by signing up for PetCare Reminders® today, so your furry friend stays happy and protected all year round.
References:
1. https://www.msdvetmanual.com/digestive-system/gastrointestinal-parasites-of-small-animals/hookworms-in-small-animals
2. https://link.springer.com/article/10.1186/s44149-024-00117-y
3. https://pmc.ncbi.nlm.nih.gov/articles/PMC3418564/
4. https://doi.org/10.1093/trstmh/trz115
5. https://www.vet.cornell.edu/departments-centers-and-institutes/riney-canine-health-center/canine-health-topics/hookworms-dogs
6. https://www.cdc.gov/zoonotic-hookworm/about/index.html
7. https://www.boehringer-ingelheim.com/animal-health/animals-we-support/dogs/what-are-hookworms-dogs
8. https://archive.cdc.gov/#/details?url=https://www.cdc.gov/parasites/resources/roundworms_hookworms.html
9. https://doi.org/10.3390/ani10112154
10. https://doi.org/10.1371/journal.pone.0142231
11. https://doi.org/10.1016/j.vetpar.2017.03.028
12. https://www.merckvetmanual.com/dog-owners/digestive-disorders-of-dogs/gastrointestinal-parasites-of-dogs
13. https://www.cfsph.iastate.edu/Factsheets/pdfs/hookworms.pdf
14. https://capcvet.org/guidelines/hookworms/
15. https://doi.org/10.2471/B09273