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Zoonotic Diseases

All Creatures Animal Clinic, Ltd.

Mark Hale D.V.M.

1661 E. Mt. Gilead Rd.

Bolivar, Missouri  65613




            Pets have a very special place in our homes and in our lives.  It is estimated that more than half of U.S. families have a household pet.  Because of this close relationship between humans and animals, an understanding of zoonotic diseases is important.

            A zoonotic disease is a disease or infection that may be passed from animals to humans.  Rabies, for instance, is a zoonotic disease spread by saliva through bites or scratches.  Bacteria such as Pasturella and Staph can also be spread through bites.

            Some zoonotic diseases depend on an intermediate host such as an insect to spread.  These vector borne diseases include Lyme disease which is carried by ticks from wildlife.  Another familiar one is "cat-scratch disease" which is caused by the bacteria Bartonella and is carried by fleas.

            Still other zoonoses are spread by exposure to a contaminated environment.  These include bacterial causes of human gastrointestinal infection, of which Campylobacter jejuni is the most common.  These bacteria can be transmitted through contact with contaminated food or water or exposure to feces from pets or livestock.   Another too common infection is from exposure to canine and feline roundworms, hookworms and tapeworms.

            Roundworms (ascarids) are the most common intestinal parasite of puppies and kittens.  These may be passed from their mother even before birth or shortly thereafter through the milk.  These puppies may begin to shed eggs into the environment as early as four weeks of age.  These eggs are the potential source of infection for humans, particularly children whose play habits put them most at risk.  Soil or sand may become contaminated with thousands of these eggs which can survive for months to years in the right conditions.  The disease produced by these ascarids in humans can vary.  Most cases of ingestion do not produce disease, but when affected, signs such as permanent blindness, fever, edema and seizures may occur.

            Hookworms are also common parasites of dogs and cats.  The eggs from these may actually penetrate the skin of humans, as well as dogs and cats.  When people contact soil contaminated with feces from infected dogs or cats, they can develop a syndrome called cutaneous larva migrans or "creeping eruptions."  Most lesions are self-limiting, and the intense itching subsides within a few weeks.  In more severe cases, however, the larva may penetrate deeper into lungs, muscles and even the eyes.

            Prevention of these diseases relies on controlling the source of the infection in dogs and cats.  The Center for Disease Control recommends preventive deworming of young puppies and kittens, as well as routine diagnostic exams or periodic treatment of adults.  Puppies should be dewormed starting at two weeks of age, repeating at four, six and eight weeks of age.  Deworming of kittens should begin at six weeks of age and be repeated at eight and ten weeks of age.  Mothers should be dewormed concurrently since they often develop infections at the same time as their young.  In general, breeding animals should be dewormed frequently to prevent shedding of eggs.  Our office is able to perform fecal exams to check for these and other parasites.  Monthly heartworm preventatives are a good way to provide continual control of these parasites. 


The following tips will help you protect your pets and reduce your risk of exposure to zoonotic parasites:

v     Properly dispose of fecal material.  Eggs are shed in feces and contaminate backyards, parks, playgrounds, and public places.

v     Wear shoes as a barrier between your skin and the soil or sand.

v     Cover sandboxes when not in use.

v     Wash hands after handling animals or having contact with their feces.

v     Make sure new animals see a veterinarian as soon as they are adopted to begin tests and treatments for parasites.

v     Take your pets to your veterinarian for regular exams and proper preventive care.

v     Follow your veterinarian's recommendations for routine deworming of pets.