Dogs vector of the major zoonotic diseases: an overview on Echinococcus granulosus
The dog has a high importance in the social life of the human population. These multiple and diverse functions make it an indispensable domestic animal, particularly for households in rural areas where the relationship between dogs and humans is very close.
Unfortunately, the risk of transmission of pathogenic agents from dogs to other animals, mainly mammals, is an issue of major concern. Dogs indeed can act as reservoirs of pathogens as they may transmit Leishmania spp. (leishmaniasis), Leptospira interrogans (leptospirosis), Toxoplasma gondii (toxoplasmosis), Neospora caninum (neosporosis), Dirofilaria immitis (dirofilaria/heartworm disease), Brucella canis (brucellosis), Sarcoptesscabiei (scabies), Echinococcusspp. (echinococcosis), Rickettsia rickettsii (Brazilian spotted fever). Various canine viruses (e.g. distemper virus, adenovirus, coronavirus, herpes virus, parvovirus), rabies virus, among other pathogens for both humans and wildlife [12, 13]. Especially, Echinococcus granulosus, is up to now one of the zoonosis with a considerable endemic situation upon human populations and livestock animals.Echinococcosis, the Echinococcus granulosus induced disease, is asymptomatic in dogs. Even with a high parasite load (from 1500 to 6000 worms per dog), this parasitosis may progress unperceived with no clinical signs. Moreover, due to the small size of the eliminated segments, no external signs can be seen. Nevertheless, anal pruritus can be induced following the penetration of gravid segments into the anal glands [14]. As the eggs are not visible by the human eye, there are no external signs of the infestation, explaining the danger of this parasite, which can easily spread and contaminate the environment, especially when dogs move from one place to another.
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