Hookworms – Prevalence, Symptoms and some Treatment Notes Including Resistance

   2025-08-19  Posted in Cases & Recs, Dog Health, Parasites Inside n Out, Vet Notes, Vet Topics

Companion Animal Parasite Council – Hookworms

Source:

https://capcvet.org/guidelines/hookworms

  • Suggested treatments include one of the following combinations given monthly:
    • Febantel (25mg/kg) + Pyrantel pamoate (5mg/kg) + praziquantel (5mg/kg) + topical moxidectin (2.5mg/kg) given on the same day. (Drontal and ProHeart/Midamox)
    • Fenbendazole (50mg/kg daily for 3 days) + pyrantel pamoate (5mg/kg) + topical moxidectin (2.5mg/kg) given on the same day (with fenbendazole continued for an additional 2 days).

Treatment

  • In severely affected animals, anthelmintic treatment must be combined with supportive therapy to keep the animal alive until the drugs can kill the worms. In addition to keeping the patient warm, supportive treatment can include electrolyte and fluid therapy, iron supplements, a high-protein diet, and when clinically indicated, blood transfusions.
  • Routine anthelmintic therapies do not kill arrested third-stage larvae in tissues.
    • Fenbendazole, milbemycin oxime, moxidectin, and pyrantel pamoate are approved for adult  A. caninum; pyrantel pamoate, fenbendazole, and moxidectin are approved for adult  U. stenocephala; and pyrantel pamoate is approved for adult  A. braziliense.
    • Moxidectin is approved for fourth-stage and young adult  A.caninum  and  U. stenocephala  in the intestine.
  • Ancylostoma caninum:  The following products are approved for the treatment (and in some cases control*) of adult  A. caninum  infections in dogs:
    • Advantage Multi® Topical Solution for Dogs (imidacloprid + moxidectin)  (Elanco)*
    • Drontal® Plus Tablets (praziquantel/pyrantel pamoate/febantel) (Elanco)
    • Drontal® Plus Taste Tabs® (praziquantel/pyrantel pamoate/febantel) (Elanco)
    • HEARTGARD® Plus Chewables for Dogs (ivermectin/pyrantel)  (Boehringer Ingelheim)*
    • HeartShield™ Plus Flavored Chewables (ivermectin/pyrantel) (TruRx)*
    • Imectro™ (ivermectin, pyrantel pamoate and praziquantel) (Ceva)
    • Interceptor® Flavor Tabs® for Dogs & Cats (milbemycin oxime)(Elanco)*
    • Interceptor® Plus (milbemycin oxime/praziquantel)(Elanco)*
    • Iverhart Max® Chewable Tablets (ivermectin/pyrantel/praziquantel) (Virbac)*
    • IVERHART PLUS® Flavored Chewables (ivermectin/pyrantel) (Virbac)
    • MilbeGuard™ for Dogs (milbemycin oxime) (Ceva)
    • Panacur® Granules 22.2% (fenbendazole) (Intervet/Merck Animal Health)*
    • PetTrust™ Plus Chewable Tablets (ivermectin/pyrantel) (Sergeant’s)
    • ProHeart® 6 (moxidectin) (Zoetis) *indicated for treatment of existing larval and adult hookworm infections
    • ProHeart® 12 (moxidectin) (Zoetis) *indicated for treatment of existing larval and adult hookworm infections
    • Sentinel® Flavor Tabs® (milbemycin oxime/lufenuron) (Merck Animal Health)*
    • Sentinel® Spectrum® Chewables (milbemycin oxime/ lufenuron/praziquantel) (Merck Animal Health)*
    • Simparica TRIO® (sarolaner, moxidectin and pyrantel): dogs (monthly oral) (Zoetis)
    • Trifexis® (milbemycin oxime/spinosad) (Elanco)*
    • Tri-Heart® Plus Chewable Tablets (ivermectin/pyrantel)  (Intervet/Merck Animal Health)*
  • The following products are also approved for fourth-stage larvae (L4) and/or young adult  A. caninum  in dogs:
    • Advantage Multi® Topical Solution for Dogs (imidacloprid + moxidectin)  (Elanco)
    • ProHeart® 6 (moxidectin) (Zoetis) *indicated for treatment of existing larval and adult hookworm infections
    • ProHeart® 12 (moxidectin) (Zoetis) *indicated for treatment of existing larval and adult hookworm infections
    • Simparica TRIO® (sarolaner, moxidectin and pyrantel): dogs (monthly oral) (Zoetis)
  • Ancylostoma braziliense: The following products are approved for the treatment (and in some cases control*) of adult  A. braziliense  infections in dogs:
    • HEARTGARD® Plus Chewables for Dogs (ivermectin/pyrantel)  (Boehringer Ingelheim)*
    • HeartShield™ Plus Flavored Chewables (ivermectin/pyrantel) (TruRx)*
    • Imectro™ (ivermectin, pyrantel pamoate and praziquantel) (Ceva)
    • Iverhart Max® Chewable Tablets (ivermectin/pyrantel/praziquantel) (Virbac)*
    • IVERHART PLUS® Flavored Chewables (ivermectin/pyrantel) (Virbac)
    • Tri-Heart® Plus Chewable Tablets (ivermectin/pyrantel)  (Intervet/Merck Animal Health)*
  • Uncinaria stenocephala: The following products are approved for the treatment (and in some cases control*) of adult  U. stenocephala  infections in dogs:
    • Advantage Multi® Topical Solution for Dogs (imidacloprid + moxidectin)  (Elanco)*
    • Drontal® Plus Tablets (praziquantel/pyrantel pamoate/febantel) (Elanco)
    • Drontal® Plus Taste Tabs® (praziquantel/pyrantel pamoate/febantel) (Elanco)
    • HEARTGARD® Plus Chewables for Dogs (ivermectin/pyrantel)  (Boehringer Ingelheim)*
    • HeartShield™ Plus Flavored Chewables (ivermectin/pyrantel) (TruRx)*
    • Imectro™ (ivermectin, pyrantel pamoate and praziquantel) (Ceva)
    • Iverhart Max® Chewable Tablets (ivermectin/pyrantel/praziquantel) (Virbac)*
    • IVERHART PLUS® Flavored Chewables (ivermectin/pyrantel) (Virbac)
    • Panacur® Granules 22.2% (fenbendazole) (Intervet/Merck Animal Health)*
    • PetTrust™ Plus Chewable Tablets (ivermectin/pyrantel) (Sergeant’s)
    • ProHeart® 6 (moxidectin) (Zoetis) *indicated for treatment of existing larval and adult hookworm infections
    • ProHeart® 12 (moxidectin) (Zoetis) *indicated for treatment of existing larval and adult hookworm infections
    • Simparica TRIO® (sarolaner, moxidectin and pyrantel): dogs (monthly oral) (Zoetis)
    • Tri-Heart® Plus Chewable Tablets (ivermectin/pyrantel)  (Intervet/Merck Animal Health)*
  • The following products are also approved for fourth-stage larvae (L4) and/or young adult  U. stenocephala  in dogs:
    • Advantage Multi® Topical Solution for Dogs (imidacloprid + moxidectin)  (Elanco)
    • ProHeart® 6 (moxidectin) (Zoetis) *indicated for treatment of existing larval and adult hookworm infections
    • ProHeart® 12 (moxidectin) (Zoetis) *indicated for treatment of existing larval and adult hookworm infections

Suspected drug resistant hookworms

  • Multi-anthelmintic drug resistant (MADR) Ancylostoma caninum infections have been observed and confirmed in several dog breeds around the USA, and are not limited to Greyhounds.
  • Cases of suspected MADR hookworms should be assessed using a combination of anthelmintics, in conjunction with a fecal egg count reduction test (pre and post-treatment quantitative fecal analysis, 10-14 days apart). See reference Jimenez Castro & Kaplan (2020) for diagnostic algorithm
  • Treatment may take months or years (depending on larval populations in tissues) and is also dependent upon environmental decontamination practices (e.g., removing feces immediately, avoiding dog parks when actively shedding ova) to minimize reinfection.

  • Suggested treatments include one of the following combinations given monthly:

    • Febantel (25mg/kg) + Pyrantel pamoate (5mg/kg) + praziquantel (5mg/kg) + topical moxidectin (2.5mg/kg) given on the same day.

    • Fenbendazole (50mg/kg daily for 3 days) + pyrantel pamoate (5mg/kg) + topical moxidectin (2.5mg/kg) given on the same day (with fenbendazole continued for an additional 2 days).

  • Worms that are not moxidectin-sensitive may not respond to the combination treatments. In those cases, extra-label use of emodepside may be considered. Dogs should be tested for heartworms (using an antigen test and modified Knott’s test) prior to being treated with off-label emodepside. Published studies show that, in vitro, emodepside has efficacy against many filarid life stages, which may result in adverse events in heartworm infected dogs.
  • PCR may be available to help identify drug resistant hookworms in dogs.

Safety of an extended-release injectable moxidectin suspension formulation (ProHeart® 12) in dogs – Parasites & Vectors – Full Text

Brands of topical Moxidectin

 

Author: Dr. Erik Johnson
Dr. Erik Johnson is the author of several texts on companion animal and fish health. Johnson Veterinary Services has been operating in Marietta, GA since 1996. Dr Johnson graduated from the University of Georgia College of Veterinary Medicine in 1991. Dr Johnson has lived in Marietta Georgia since 1976.