Strongyloides spp

From Dog
Adult Strongyloides spp
Eggs of Strongyloides spp

Strongyloides spp are a parasitic nematode of dogs worldwide.

Pathogenic species include:

  • Strongyloides stercoralis[1]
  • Strongyloides ratti[2]
  • Strongyloides felis
  • Strongyloides planiceps
  • Strongyloides tumefaciens

Lifecycle involves adult females in the anterior half of the small intestine, where female worms lay embryonated eggs which are passed in the feces. Only female Strongyloides spp are parasitic.

Larvae hatch before being passed in the feces and females develop into infective filariform larvae which either penetrate the skin or infect the host via the oral cavity. Transmammary transmission is possible. The lifecycle is relatively short with a prepatent period of less than one month. Autoinfection can also occur.

Clinical signs usually relate to heavy burdens, and weight loss, polyphagia[3], diarrhea, myositis[4] and dyspnea if visceral migration occurs.

Diagnosis is based on demonstration of larvae in fresh faeces, which is best made by Baermann technique[5]. ELISA assays are also available[6].

Treatment is usually effective with ivermectin (0.2 mg/kg, SC or PO, once, with a second dose required in some animals; 0.8 mg/kg, PO, once), fenbendazole[7] or thiabendazole (100-150 mg/kg, PO, sid for 3 days, repeated weekly.


  1. Martins CM et al (2012) Dog parasite incidence and risk factors, from sampling after one-year interval, in Pinhais, Brazil. Rev Bras Parasitol Vet 21(2):101-106
  2. Sakura T & Uga S (2010) Assessment of skin penetration of third-stage larvae of Strongyloides ratti. Parasitol Res 107(6):1307-1312
  3. Mandarino-Pereira A et al (2010) Prevalence of parasites in soil and dog feces according to diagnostic tests. Vet Parasitol 170(1-2):176-181
  4. Snook ER et al (2009) Verminous myelitis in a pit bull puppy. J Vet Diagn Invest 21(3):400-402
  5. Dillard KJ et al (2007) Strongyloides stercoralis infection in a Finnish kennel. Acta Vet Scand 49:37
  6. Gonçalves AL et al (2007) Evaluation of strongyloidiasis in kennel dogs and keepers by parasitological and serological assays. Vet Parasitol 147(1-2):132-139
  7. Itoh N et al (2009) Fenbendazole treatment of dogs with naturally acquired Strongyloides stercoralis infection. Vet Rec 164(18):559-560