Ancylostoma caninum, commonly known as the canine hookworm, poses a significant health threat to dogs worldwide. Transmission of this parasite occurs through various routes, making accurate and timely diagnosis crucial for effective treatment and prevention. Understanding the diagnostic approaches for Ancylostoma caninum is essential for veterinary practitioners to safeguard canine health.
Infections are primarily transmitted orally or percutaneously, where infective larvae penetrate the skin or are ingested. A particularly important transmission route is galactogenic, through the milk of infected bitches to their puppies. This occurs due to the dissemination of larvae during routine infections and the reactivation of dormant somatic larvae in the mother at the end of pregnancy. Notably, galactogenic transmission can happen even when the bitch has developed immunity and shows no signs of patent infection. Existing immunity in the bitch provides limited protection against new infections or the migration of reactivated somatic larvae, and it can still allow for some larval accumulation in the host. Following percutaneous infection, dogs may develop dermatitis at the site of larval penetration, and the lungs can be affected by migrating larvae.
Intestinal stages of Ancylostoma caninum cause harm by feeding on the mucosa of the small intestine and consuming blood. The primary clinical signs of ancylostomiasis are mucous hemorrhagic diarrhea and anemia, which typically become apparent 8 to 10 days post-infection.
Diagnosis of Ancylostoma caninum infections involves methods for detecting both pre-patent and patent infections. For pre-patent infections, immunofluorescence and ELISA tests are effective. These serological methods detect antibodies against third-stage larvae, typically from the first or second week post-infection onwards.
Patent infections, where adult worms are present and shedding eggs, are readily diagnosed through fecal examination. This involves identifying the characteristic oval, thin-walled eggs containing few blastomeres under a microscope. Fecal flotation is a common technique used to concentrate these eggs for easier detection.
Prevention of galactogenic transmission and subsequent patent infections is crucial, especially in puppies. Regular treatment of the bitch with anthelmintic drugs like albendazole, fenbendazole, or oxfendazole during larval reactivation in the last trimester of pregnancy can be effective. Repeated treatments with ivermectin shortly before and after birth can also reduce larval transmission via milk. For puppies potentially infected galactogenically, early and repeated anthelmintic treatment is necessary to prevent patent infections and disease.
