Internal and External Parasites of Dogs and Cats
Pose Threats to Children, Too
Michael W. Stephan, D.V.M.
Juno Beach Animal Hospital
Most people are aware of the fact that parasites are a potential threat to pets, but are you aware that many of those parasites can move from pets to people? Having your pets routinely checked and treated for parasites can help protect your entire family.
Roundworms and hookworms are the most common internal parasites of dogs and cats. The adult worms live in the intestines and shed their eggs through the pets stool. Children may ingest the eggs through contact with the pets or from a litter box or garden soil or sandbox. The egg hatches inside of us and the larva that is released from it will pass through the wall of the intestines and migrate through our bodies. In most cases, infected individuals show no signs of illness, but serious disease can occur if the number of worms is high or if they migrate to vital organs such as the liver, lungs, heart, eye, or nervous system.
Hookworm larvae usually enter a human host by passing directly through the skin. When bare skin comes in contact with soil contaminated by animal waste, the larva burrows painlessly through the skin and migrates into the body. In most cases, it tunnels in the skin and creates an intensely itchy lesion. Children and gardeners are at highest risk and the lesions most often occur on the hands, feet, knees, and elbows.
Eggs and larva of both of these parasites survive for long periods in moist soils. They can be killed by direct sunlight, drying, or freezing. Soils of the southeastern United States are considered to be highly contaminated with both of these parasites.
Fleas will move readily from pets to children, or, flea eggs in the environment may hatch out in presence of people and feed on them. In people who are sensitive to the proteins in the flea saliva, the bites can be intensely itchy and, especially in children, may become infected from scratching.
Sarcoptic mange mites may move from pets to people, by they generally do not survive on us for more than four days. If the dog or cat who is acting as host to the mites is not treated, new mites may move from the pet to family members so the rash may last considerably longer.
Ringworm is not actually a worm, but is a fungal infection of the hair. It is most common in kittens and Persian cats, though it also occurs in dogs and can spread from pets to people through casual contact. It will create a raised, red, itchy lesion, usually on the arms, face, or neck, but can be anywhere on the body.
Treating your pets for parasites depends first on accurately identifying which, if any parasites they have. Your veterinarian is trained to do this by collecting and examining samples of stool, hair, or skin. In most cases, examination of these samples through a microscope will give a quick diagnosis. In some cases, such as ringworm, a culture may be necessary. In any case, routine examinations of your pet by your veterinarian will help ensure the health of your pet and your family.