I have heard that children can get worms from dogs. Is this true?
Posted by admin in Dog Supplies Q&A, Dog Supplies Tips, tags: Diseases, Dog, Dog Advice, dog care, Dog Diseases, Dog Healths, Dog Operations, dog Q&A, dog supplies, dog supplies advice, Operations, Pet SuppliesI have heard that children can get worms from dogs. Is this true?
In the case of a few worms, it is correct that they can infect humans; usually children because their immunity is less. The worm which has received most attention is the roundworm, Toxocara canis. This is not the same as the threadworm (pinworm or seatworm) which is common in children. In its life cycle the infective larva, still inside the egg shell in which it has developed, may be eaten by a dog or by another species, often a rodent, which in turn may be consumed by a dog. At times, however, these infective eggs (i.e. containing the larvae) may be eaten by children. A number of factors contribute:
1. The outside of the microscopic eggs is sticky, so that they readily adhere to a dog’s coat, and to human fingers.
2. Young children, especially toddlers, have a habit of putting their hands and various objects, even contaminated soil, into their mouths.
3. The infective eggs can survive for two years or longer in the ground and will withstand all disinfectants, long-term freezing and even short periods in boiling water. Only the use of horticultural flame-guns on concrete runs effectively destroys the eggs.
4. The effects of wind, rain and human activity can spread the eggs over a wide area.
In humans the larvae hatch from the eggs, penetrate the wall of the intestine and disperse to the liver, kidneys, brain or eyes. They do not develop further but remain in those organs, and can cause damage leading sometimes to liver enlargement, blindness or convulsions. This disease, caused by migration or penetration of the larvae, is called visceral larva migrans, and it chiefly affects children between one and a half and three years old. It cannot be considered a common disease, although certainly more children become infected than ever show signs. Infection also seems to exacerbate existing illnesses such as asthma and paralytic poliomyelitis. At present there is no evidence that Toxascaris leonina can infect humans in a similar way.
It is also possible for a person, again usually a child, who swallows a flea infected with the intermediate stage of the tapeworm Dipylidium caninum to become infected with an adult tapeworm in the intestine, although this very rarely happens.
As previously mentioned, the extremely small tapeworm of the dog Echinococcus granulosus can infect a number of species, including man, which play the role of intermediate host. This parasite occurs in all the inhabited continents and the most common cycle is between farm dogs and sheep. Consequently most human infections are acquired in sheep farming areas where the worms are prevalent amongst dogs, and derive from eating worm eggs picked up from the dog’s coat or present on vegetables. In humans the eggs develop into slow-growing cystic structures (hydatid cysts) in the liver, lungs or other organs. These may eventually reach 6 inches (15 cm) or more in diameter, resulting in the severe, and sometimes fatal, illness hydatidosis. Rupture of the hydatid cyst may result in the numerous worm heads it contains being distributed all over the host’s body, each one of which can then give rise to a further hydatid cyst.
Entries (RSS)