How can I protect my dog from Ancylostoma caninum?

Question

My dog was diagnosed with Ancylostoma caninum. His vet has been treating him, and she has apparently eliminated it from its system. But the parasite seems to habituate my garden, since my dog’s symptoms periodically persist. My dog lives inside the house, but he goes out to the garden everyday. I think the problem is the hookworm now lives in my garden. Does anyone know of a method to clean my garden? And how can I protect my dog from the parasite? Thank you very much for your time.

Answer 1

Ancylostoma caninum is a type of parasite commonly known as hookworm. To understand how to get rid of them, we first need to understand their life cycle.

Adult male and female hookworms mate in the dog’s intestine. The female worm then produces a large number of eggs per day (FIGURE 1B), which are shed in the feces into the environment. When shed, these eggs contain a morula and are not immediately infective. Within 24 to 48 hours, they develop to first-stage larvae (L1) and hatch. During the next week (5 to 10 days), L1 will molt to infectious third-stage larvae (L3). L3 can then infect a host through either ingestion or, more commonly, skin penetration. Source

That means, the best way to prevent a re-infection in your dog is to remove all feces from your garden every single day, for several months.

The larvae can survive for weeks or even months before infecting your dog. Source

If your dog pooped inside the house or if any tools came into contact with the feces, you should disinfect the surfaces with bleach.

Dogs should be treated for hookworms once a month. Puppies should be treated at 2, 4, 6, and 8 weeks of age.

Source: Hookworms in Dogs

Since dogs can also be infected by skin contact to adult hookworms, you should avoid taking him to places where many dogs frequent and defecate.

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There's another reason why the infection might reoccur in your dog: Some of the worms can actually make their way through the wall of the intestine and into the blood stream and muscle tissue. There they lay dormant in a capsule and simply wait. Most common treatments can only kill the adult worms in the intestine, but not the encapsulated worms. After a while they become active again and shed more eggs.

L3 can also undergo somatic migration, in which larvae reenter the alveolar blood vessels and travel to the muscles or organs, where they become encysted and their development is arrested.1,2,4 The arrested larvae may become reactivated under 1 of 2 conditions: larval leak or transmammary transmission to puppies.

Larval leak: When adults [hookworms] are eliminated, somatically stored larvae from muscle and intestinal wall migrate to the lumen of the intestine and develop into adults. Larval leak leads to refractory egg shedding and frustration that, despite anthelminthic treatment, hookworm eggs are still detected in the dog’s feces. Source

A repeated hookworm treatment 2 - 4 weeks after the initial treatment should take care of the remaining larvae. It's recommended to preventively treat dogs for hookworms on a monthly basis.

Please ask your vet for a suitable medication and make sure you treat your dog at the precise interval written in the information about the medication. Waiting just a few days too long can give the stored larvae enough time to cause severe symptoms again.

Most monthly heartworm preventatives include a drug to treat and prevent infections so additional deworming medications are usually not required if the dog is reliably treated with a heartworm preventive. Source