How to Prevent Contagious Diseases in Pets


All pets have the potential to spread disease; however the good news is that the risk is small that you will get sick from your pet. Pet diseases that are transmittable to humans are known as “zoonotic diseases”, and those with a compromised immune system should be careful, including infants, toddlers, the elderly, cancer patients, pregnant women or anyone dealing with an autoimmune disease. If you fall into any of these categories, you should avoid contact with baby chicks, ducklings and reptiles, including lizards, snakes or turtles. Viruses, bacteria, fungi and parasites are contagious pathogens that can be transferred from pet to human.


One of the most common contagious diseases is the spread of worms that can infect dogs, cats and other pets. In order to prevent worms from spreading, a de-worming program is essential when your dog or cat is young. Animal feces carry worm eggs or larvae that find their way into the intestines by hands, feet or food.

Here are some ways to prevent the transmission of worms:

• Wash your hands often, especially after playing with your pet

• Clean defecation sites and litter box regularly

• Avoid walking barefoot

• Do not put your hands in your mouth

Be careful walking barefoot on infected soil or grassy areas, as hookworms can penetrate the skin. Roundworms have the potential to migrate beyond the intestines, damaging internal organs and tissues. Children playing outside in or near infected areas can track worms onto the floors, so it is smart to designate a playing area away from where your pet defecates.

If you own a cat, enjoy gardening or do not wash all produce, then you may be at risk for toxoplasmosis. This is an infection caused by a parasite that can live dormant in the body forever. It rarely causes any symptoms, especially if your immune system is healthy. Over 30% of the world’s population carries this parasite in their muscle and nerve tissue. Cats can carry the parasite that causes toxoplasmosis; however most do not show any symptoms.

Some people do experience flu-like symptoms, including headache, fever, fatigue and body aches. A healthy immune system helps keep them in check so no treatment is needed. It is important to take special precautions during pregnancy because toxoplasmosis can cause premature births, miscarriage and birth defects. Pregnant women should:

• Not change a cat’s litter box

• Make sure the person who does change the litter disposes of the cat’s waste in a plastic bag

• Make sure a children’s sandbox is covered when not in use


Ringworm is actually a fungus, not a worm, and is transmitted by touching the fur or skin of an infected animal, especially cats, though ringworm can also infect dogs, horse, ferrets, rabbits and guinea pigs. Symptoms include fur-less patches or areas of baldness; however some symptoms are not visible. The ringworm fungi grow in contaminated bedding and dirt, so it is important to wash and clean bedding regularly. Both people and pets can be treated with oral or topical medications.


Fleas can transmit bacteria that cause cat scratch fever; however many do not show any signs or symptoms. Be proactive with a flea control system for your cat, keep claws trimmed and try to avoid being scratched by your cat. The bacteria can invade the skin.


Rabies is transmitted through saliva and is a viral, deadly disease. Some farm animals, horses, ferrets, dogs and cats may be vaccinated. Make sure you keep vaccinations current for your pet, and make sure they avoid raccoons, foxes, skunks and bats. See your veterinarian right away if you suspect your pet has been exposed.


Fleas and ticks can be transported into the house and are responsible for a number of diseases, most notably Lyme disease. Control fleas and ticks as much as possible to prevent them from spreading. Check your pet for ticks after playing outside, especially in the woods.


Keeping a rodent as a pet, like hamsters, mice or rats, can cause a viral disease known as LCM. You can get LCM from inhaling airborne particles of the virus from contaminated rodent feces, urine saliva or food that is contaminated with the virus. A bacterial illness known as Rat Bite Fever can be transmitted through a scratch, bite, rodent feces or contaminated food and water. Both of these diseases cause flu-like symptoms including headache, fever and muscle aches. Notify your doctor immediately if you have had any contact with a rodent, as it can escalate to muscles weakness or paralysis. Antibiotics are usually prescribed; however there is no specific drug for LCM or Rat Bite Fever. If you own a hamster, avoid direct exposure to their droppings and clean their cage regularly by disinfecting the area inside.


Reptiles, baby chicks and ducklings can transmit contagious bacteria known as Salmonella through their feces. Salmonella is normal for reptiles to carry on their skin, but if they are allowed to roam around your house, they can spread it everywhere, including their cage.


Fish (and their aquarium) may contain a contagious germ known as Mycobacterium. Prevent contracting mycobacterium by wearing rubber gloves when it is time to clean the fish tank. Never put your hand in the tank and do not let your cat drink from it – make sure to keep the lid on.


Birds carry disease caused by bacteria known as psittacosis. It is found in the nasal discharges and droppings, and infection can occur by inhaling particles from these secretions or droppings. Symptoms include chills, fever, headache, muscle aches and cough. See your health care provider immediately to avoid other health problems including pneumonia. Here are some precautions to take when handling your bird:

• Wash hands immediately after handling your bird

• Do not allow your bird to fly around your food areas, especially the kitchen and dining area

• Wear a mask when it is time to clean their cage


Reviewed and Approved by Dr. David L. Roberts, DVM

Photo:  Courtesy of Vall d’Hebron Research Institute (VHIR) via Flickr (CC by 2.0)

Sherry is a Nutritionist, Writer, National Speaker, Ghostwriter of books for Natural Medicine Doctors and an Author of 2 healthy cookbooks. She is a Nationally Certified Fitness Instructor and Personal Trainer in Pilates, Yoga, Body Pump, STEP and Aerobics with over 20 years experience. She served as the On-Air Nutritionist for QVC television in the United States and the UK and hosted her own weekly “Healthy Living” segments for PBS. Sherry is passionate about helping animals and worked with “Helping All Animals” in Palm Springs, CA. in their rescue efforts, and is a member of the ASPCA and the Humane Society of the United States. Her experience working as a Veterinarian’s Assistant for many years’ aids in her passion for helping animals lead healthy and happy lives. For more information on Sherry, visit or write to Sherry at - call 517.899.1451