Hookworm Symptoms in Puppies

Left untreated, hookworms can kill puppies.
German shepherd puppies image by csaba fikker from Fotolia.com

Hookworms are among the most dangerous canine parasites, and are particularly risky for puppies, who don't have well-developed immune systems. They burrow into the intestinal wall of dogs and suck blood, resulting in anemia, secondary infections and, in severe cases, death. All puppies should begin treatment for hookworms at 2 weeks, and puppy owners should carefully monitor their dogs for symptoms of the parasite.

Behavioral Symptoms

Because hookworms suck blood and deplete energy, the most common symptom of an infection is depleted energy and lethargy. Puppies may lose their appetites, and nursing puppies may nurse infrequently or struggle to find a nipple. Sometimes puppies become extremely restless and seem uncomfortable, with no visible cause of the discomfort.

Physical Symptoms

Hookworms can quickly cause anemia, so one of the most common symptoms of an infection is pale mucous membranes, especially along the gums. Puppies may also develop severely dry, flaky skin or begin losing their hair. In advanced cases of infection, puppies may develop open sores along the pads of their feet or in their mouths. Diarrhea and constipation are also common, and dogs may develop a tarry, black stool. Unlike other worms, hookworms are too small to see in feces.


Veterinarians often treat puppies for hookworms even without a firm diagnosis because the infection is so dangerous. To detect hookworms, vets typically look for microscopic eggs in a sample of the dog's feces. Eggs almost always show up in feces, but if your dog has symptoms and eggs do not show up on examination, your vet may request another sample and test again.


Preliminary treatment for hookworms focuses on killing adult worms to prevent further damage to your dog. Your veterinarian will administer an oral dose of a de-wormer or may give your dog an injection of a de-worming agent. When the adult worms have all died, your veterinarian will administer a different de-wormer to kill eggs. After treatment, your vet will retest your dog for hookworms.


  • Biology: Life on Earth with Physiology; Gerald Audesirk et al.
  • Dog Owner's Home Veterinary Handbook; Delbert G. Carlson et al.
  • The Complete Healthy Dog Handbook; Betsy Brevitz

About the Author

Brenna Davis is a professional writer who covers parenting, pets, health and legal topics. Her articles have appeared in a variety of newspapers and magazines as well as on websites. She is a court-appointed special advocate and is certified in crisis counseling and child and infant nutrition. She holds degrees in developmental psychology and philosophy from Georgia State University.

Photo Credits

  • German shepherd puppies image by csaba fikker from Fotolia.com