Most worms that infect pets live in the gut, but a few end up in the skin. This guide covers three of them: the North American Guinea worm Dracunculus insignis, which lives under the skin; Pelodera dermatitis, an itchy rash caused by soil worm larvae; and hookworm larvae that get in through the skin. Maggots and bot fly larvae under the skin are fly larvae, not worms: see maggots and warbles in dogs and cats.
Guinea worm (Dracunculus insignis)
What it is
Dracunculus worms are large roundworms that live in the tissue just under the skin. [2] In North America the species is Dracunculus insignis. Its usual host is the raccoon, and it has also been confirmed in minks, fishers and river otters. It infects pet dogs and cats in the United States and Canada as well. [2]
It is a different species from the human Guinea worm, Dracunculus medinensis, which eradication programs have pushed back to a few countries in Africa. [3]
How dogs and cats get it
A mature female worm makes a swollen sore that opens in the skin. When the sore touches water, the worm releases its larvae into the water. [2] The larvae then grow inside copepods, tiny crustaceans that live in fresh water. [2]
Animals pick up the worm by drinking water that contains infected copepods, or by eating a frog, tadpole or fish that has swallowed them and carries the larvae. [2][3] In raccoons, researchers think eating frogs or fish is the more likely route, though this has not been fully tested. [2] How pets get infected is still being studied. [1]
Signs
- A swelling under the skin that turns into an open, ulcer-like sore where the worm comes out. [2]
- The sore is usually on the lower legs or feet, but worms have also been found on the chest, belly, head and flank. [1]
- In a dog from Spain with a related Dracunculus worm, the sign was an oozing sore on a hind leg. [3]
What one study found
Researchers looked at 62 new cases and 18 published reports of Dracunculus in pet dogs and cats in North America. [1]
- Infected dogs were between 7 months and 19 years old (median 4 years), and males and females were infected at similar rates.
- Most worms sat in the lower legs and feet, but some were in the chest, belly, head or flank.
- Most dogs had one worm. Three dogs had two or more, taken from several sores.
- Three new cases in cats, with similar sores, came from Alabama, North Carolina and Texas.
- Cases came from across eastern North America and from every month, but 72% were found between December and May.
- Every worm that could be tested genetically was D. insignis.
The authors used whatever case records were available rather than a planned sample. Even so, they concluded that the worm is widespread in the eastern US and Canada and that dogs get it more often than published reports suggest. [1]
Treatment
In published cases, the vet removed the worm from the sore. [3] Only female worms come out through the skin, and a lab can confirm the species from the worm if it is kept and sent in. [1][3] Do not try to pull a worm out yourself; let your vet do it and decide whether more treatment is needed.
Pelodera dermatitis (rhabditic dermatitis)
What it is
Pelodera strongyloides (also called Rhabditis strongyloides) is a small roundworm that normally lives free in rotting organic matter. Its larvae can, rarely, burrow into skin and cause a rash in several mammals, including dogs and people. [4] The dog is an accidental host, and the strong skin reaction shows the worm is poorly suited to living in dogs. [4]
Because the worm thrives in decaying plant matter, many affected dogs have a history of sleeping on damp straw bedding. [4] In a Finnish report of 11 dogs, all the hounds lived outdoors and slept on straw, and a litter of German Shepherd puppies got it from ground with a lot of rotting vegetation. [4] Most reported cases have been in short-coated dogs. [4]
Signs
The rash shows up on the skin that touches the ground or the bedding, such as the legs, belly and chest. [4] Typical signs are: [4]
- Red skin
- Hair loss
- Small crusty bumps
- Itching
In severe cases, clipping the hair can reveal deep, ulcerated sores. [4]
Diagnosis
A skin scraping looked at under a microscope is a quick, cheap and reliable way to find the larvae. [4] The authors of the Finnish report say vets should think of Pelodera in an outdoor dog sleeping on straw that has an itchy, hairless, crusty rash on the skin that touches the ground. [4] Other itchy, crusty skin problems can look similar; see sarcoptic mange (scabies) in dogs, ringworm in dogs and cats and pyoderma in dogs.
Treatment
In the Finnish cases, the first step was to replace damp or dirty bedding with clean, dry bedding; the authors say getting the straw out is essential for treatment to work. [4] The dogs were also treated by their vets. [4] Your vet will decide what treatment your dog needs.
Hookworm skin rash in dogs
Hookworms are best known as gut worms, but their larvae can also get into a dog through the skin, not only by being swallowed. [5] The larvae live in moist soil and die off when it dries out, and warm, humid weather helps them develop. [5]
Skin disease from hookworm larvae is uncommon. One Canadian case report describes hookworm dermatitis from Uncinaria stenocephala in a young greyhound, diagnosed with a stool test and a skin biopsy; it was the first case reported in Canada. [6] The Finnish Pelodera authors note that this hookworm usually does not get into dogs through the skin. [4] For other causes of sore paws and skin between the toes, see dog paw problems.
People. Dog and cat hookworm larvae can get into human skin from soil contaminated with animal feces, often at beaches and in sandboxes, and cause cutaneous larva migrans: very itchy, winding red tracks in the skin. [7] The dog and cat hookworm Ancylostoma braziliense is the classic cause. [7] Ask your doctor about any itchy, creeping skin rash of your own.
When to see your vet
- A swelling or open, oozing sore on a leg or foot, especially in a pet that has been around ponds, streams or other fresh water, or that eats frogs or fish. [1][2][3] Do not try to pull a worm out yourself.
- A red, hairless, crusty, itchy rash on the legs, belly or chest of a dog that sleeps outdoors or on straw. A skin scraping can find the cause. [4]
- Sore, inflamed skin on the feet of a dog, so your vet can check for parasites and other causes. [5][6]
FAQ
Can my dog get worms in its skin?
Yes, but it is uncommon. The main ones are the Guinea worm D. insignis in North America, Pelodera larvae from damp straw or rotting plant matter, and, rarely, hookworm larvae. [1][4][6]
Can cats get worms under the skin?
Yes. D. insignis has been found in pet cats in North America, with sores like those seen in dogs. [1][2]
Can I catch these worms from my pet?
Dog and cat hookworm larvae in contaminated soil or sand can get into human skin and cause cutaneous larva migrans. [7] Pelodera larvae can rarely cause a skin rash in people too. [4] The Guinea worm in North American pets is a raccoon worm, a different species from the human Guinea worm. [2][3]
Will Pelodera dermatitis go away?
In the Finnish cases, the dogs first got clean, dry bedding in place of the damp straw, along with treatment from the vet. [4] Ask your vet what your dog needs.
The bottom line
A few worms affect the skin of dogs and cats. The North American Guinea worm, Dracunculus insignis, causes a swelling and an open sore, usually on the lower legs, and pets likely pick it up from water or from eating frogs or fish; a vet removes the worm. [1][2][3] Pelodera dermatitis is an itchy, crusty rash from larvae in damp straw or rotting plant matter, found with a skin scraping, and clean, dry bedding is the first step. [4] Hookworm larvae can also get in through the skin, and in people they cause itchy, creeping tracks. [5][6][7]
This article is for general information and is not a substitute for a veterinary exam. If you are worried about your pet’s skin, see your veterinarian.
Sources
- Williams BM, Cleveland CA, Verocai GG, et al. Dracunculus infections in domestic dogs and cats in North America; an under-recognized parasite? Vet Parasitol Reg Stud Reports. 2018;13:148-155. PMID 31014864 (abstract). https://pubmed.ncbi.nlm.nih.gov/31014864/
- Cleveland CA, Garrett KB, Cozad RA, Williams BM, Murray MH, Yabsley MJ. The wild world of Guinea worms: a review of the genus Dracunculus in wildlife. Int J Parasitol Parasites Wildl. 2018;7(3):289-300. CC BY-NC-ND 4.0. https://pmc.ncbi.nlm.nih.gov/articles/PMC6072916/
- Diekmann I, Alnassan AA, Globokar M, et al. Canine Dracunculus nematode infection, Toledo, Spain. Emerg Infect Dis. 2020;26(8):1860-1863. CDC, public domain. https://pmc.ncbi.nlm.nih.gov/articles/PMC7392431/
- Saari SA, Nikander SE. Pelodera (syn. Rhabditis) strongyloides as a cause of dermatitis: a report of 11 dogs from Finland. Acta Vet Scand. 2006;48:18. CC BY 2.0. https://pmc.ncbi.nlm.nih.gov/articles/PMC1569853/
- Sönmez Hİ, Madak E, Karaer MC, Sarımehmetoğlu HO. Anthelmintic resistance in Ancylostoma caninum: a comprehensive review. Vet Med Sci. 2025;11(4):e70434. CC BY 4.0. https://pmc.ncbi.nlm.nih.gov/articles/PMC12118500/
- Chu S, Myers SL, Wagner B, Snead EC. Hookworm dermatitis due to Uncinaria stenocephala in a dog from Saskatchewan. Can Vet J. 2013;54(8):743-747. PMID 24155473 (abstract). https://pubmed.ncbi.nlm.nih.gov/24155473/
- Osman S, Tarnari N, Ahsan A, Ahmed KAHM. Cutaneous larva migrans (CLM) may not be easy to diagnose: a case report and narrative review. Oxf Med Case Reports. 2024;2024(4):omae025. CC BY 4.0. https://pmc.ncbi.nlm.nih.gov/articles/PMC11049579/