© Kirrawee Veterinary Hospital CANINE DISEASES
Roundworms
The roundworms which effect dogs are Toxocara canis and Toxascaris
leonia. They are large worms
3-5 cm in length that live in the intestine. Adult female worms
lay eggs (up to 20,000/day for T canis) which pass out in
the dogs faeces. These eggs then become infective larvae which
can survive in the soil for many months. Dogs become infected
by eating or licking material contaminated with the larva, or
by eating rodents, birds, and insects which have themselves become
infected. Most of the larvae migrate through the body to the intestine
where they grow to adult worms within a few weeks. Toxocara canis
larva also have the ability to form a dormant stage in muscles
and a variety of other tissues which can later reactivate and
continue to migrate eventually becoming adults. Some larva can
also cross the placenta or enter the mammary glands of a pregnant
bitch leading to infection of pups either before birth or via
the milk. For this reason it should be assumed all puppies will
become infected with Toxocara canis. Adult dogs generally show few signs when infected with roundworms,
however puppies can have a swollen abdomen, diarrhea, and vomiting
(sometimes with worms) from as early as 3 weeks of age. Severe
infections can completely block the intestine in these pups. Diagnosis of roundworms is by identifying the worm eggs from samples
of faeces using a microscope. A large range of effective worming
treatments are available. Puppies should be treated every two
weeks between 2 and 12 weeks of age. Adult dogs are treated every
three months. Roundworms also represent a potential health hazard to humans
especially children. The larva of T. canis can migrate into the
internal organs of humans causing a serious illness (visceral
larval migrans). Care should be taken to wash hands before eating
when around puppies |