BC HealthFile #61, September 1997

The Role of Pets in Human Disease

• Personal and pet hygiene
• Litter box
• Look after your pet!
• Animal bites
• Your pet’s diet
• Adopting new pets
• Pets to avoid
• Turtles
• Farm animals

English PDF (156KB)

Everyone knows that pets make wonderful friends and companions. The role of pets in providing human companionship is even more important for people who are isolated from other people, through illness or age.

Animals, like people, interact with the world around them. Some of these interactions result in the transmission of infectious agents and parasites between animals, people, and their environments.

While it is true that people can catch diseases from animals, this does not happen very often, and the results of these infections are usually mild. Rarely does severe disease result, although it is possible.

Some groups of people are at higher risk of getting sick from illnesses passed from animals to humans. They include:

• people with HIV infection or AIDS;
  
• people who have been getting treatment for cancer (radiation therapy or chemotherapy);
  
• people who have had an organ or bone marrow transplant and are taking anti-rejection drugs.

Other people at increased risk include pregnant women (especially for toxoplasmosis carried by cats) and the elderly and young children.

These people in particular should try to follow the advice below to minimize their chance of infection. However, all pet owners should find the following advice of interest.

• Wash your hands, especially before eating or smoking.
  
• Keep your pet clean and well groomed.
  
• Keep your pet’s living and feeding area clean.
  
• Avoid any contact with your pet’s bodily fluids, such as vomit, faeces, urine or saliva.
  
• Don’t let your pet lick your face (or your child’s face). You don’t know where that tongue has been!
  
• Keep your pet’s nails trimmed short. Your veterinarian or groomer can show you how.
  
• If you use an insecticide (e.g. flea powder), be sure to follow instructions carefully. People with allergies or asthma should not breathe in or otherwise come into contact with these insecticides.

• Keep the box away from the kitchen and eating areas.
  
• Change the litter box daily. (Pregnant women should get someone else to do this).
  
• Use disposable plastic liners and change them each time you change the litter.
  
• Don’t dump! If inhaled, the resultant dust could infect you. Instead, gently seal the plastic liner with a twist tie and place in a plastic garbage bag for disposal.
  
• Disinfect the litter box once a month, by wiping it out and then filling it with boiling water and letting it stand for five minutes. No other disinfecting method seems to kill the toxoplasmosis organism.
  
• Always wash your hands after cleaning the litter box.
  
• You may want to have your pet’s feces checked by your veterinarian from time to time for parasitic diseases (e.g. toxoplasmosis) -- especially if your pet is outside a lot.
  
• Remember that animal droppings in flower beds or sand boxes present the same health risks as a litter box.

• Keep vaccinations current.
  
• Control internal and external parasites such as worms and fleas.
  
• At least once a year, take your pet in for a checkup. If your pet shows signs of possible illness, such as persistent coughing, sneezing, losing weight or diarrhea, contact your veterinarian right away.

Tend to any animal bite right away to help prevent infection. Rinse the wound with cold running water. Disinfect with a “tamed iodine” such as Betadine® solution (not Betadine® soap). This is available at drug stores. If the bite is serious or becomes infected, you should see your doctor. Cat bites are more likely to become infected than dog bites.

Rabies is extremely rare in B.C. and is normally only found in bats. If you are bitten, however, you should observe the animal’s behaviour so you can describe it to a health professional, who can assess the risk of rabies infection. (See BC HealthFile #07 Rabies )

The following are ways you can prevent your pet from catching diseases that may be passed on to humans:

• Feed your pet only reputable pet foods.
  
• Never feed your pets raw meat or unpasteurized milk.
  
• Don’t let your pet eat its own or other animals’ feces.
  
• Don’t let your pet drink from the toilet bowl, or rummage through the garbage.
  
• Don’t let your pet hunt other animals. Cats can catch toxoplasmosis from eating infected birds or rodents. If you have an outdoors cat, think about placing a double bell on the collar to help warn potential prey. If you have a farm cat who hunts rodents, you should have its feces examined regularly for signs of infection.
  
• Keep your dog on a leash to prevent scavenging.

New pets can often present more risk, especially if their health history is not well known. All new pets should be examined by your veterinarian, who may want to run some tests to screen for diseases and parasites. Puppies and kittens are more likely to be infected with harmful bacteria and parasites, especially if they have diarrhea or are strays. Be cautious around them. Wash your hands after petting them. Some infections or infestations may need more than one examination by your veterinarian to identify them.

Some animals have been found to be more likely to carry diseases which could spread to humans. Generally speaking, these include:

• Stray animals
• Animals with diarrhea
• Exotic animals
• Sick animals
• Wild animals
• Monkeys

Turtles (and other reptile pets, e.g., snakes, iguanas) are often infected with salmonella. There are many cases of young children catching this disease by handling turtles and then putting their fingers in their mouths. Some municipalities do not allow the sale of turtles. Check with your local Environmental Health Office.

(See also BC HealthFile #17 Salmonellosis )

People whose immune systems are weakened should not keep a reptile pet.

There have been cases of school children being infected with “Q” fever from handling newborn baby goats. Parents and teachers should be careful on field trips to farms to not let children touch or handle newborn animals or the byproducts of the birthing process (e.g. blood, afterbirth, manure, body fluids, etc.). Children visiting petting zoos should be warned not to put their hands in their mouths, and should wash their hands right after their visit, before they eat or handle food.

(See also BC HealthFile #43 Toxoplasmosis ).

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