For several years, it has been noted that greyhounds adopted from racing facilities in Florida very often came with large hookworm infestations, of the species Ancylostoma caninum. These dogs would have undergone regular deworming during their racing careers; however, they would arrive at adoption facilities and be found to be shedding very large numbers of hookworm eggs in their feces. Even after adoption and multiple rounds of deworming, the numbers of hookworm eggs remained high.
While it is known that these greyhounds continue to shed due to larval leak syndrome, it is not definitively known why such great numbers of hookworms are able to persist and recur in this particular breed. Is it a result of their history of being in highly contaminated environments, such as greyhound breeding facilities and racing kennels? Is it a result of abnormally elevated dormant larvae encysted in their bodies? Do greyhounds have decreased immune function, leading to compromised ability to fight parasite infestations? Has the
hookworm developed a resistance to the deworming products that are routinely used in racing and breeding facilities?
Read more about Greyhound's Hookworm Resistance