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10 Scary Diseases Your Pet May Be Exposing You To

PetMD Editorial
Updated: October 13, 2020
Published: December 04, 2014
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No Creepy Crawlers Allowed

Your pet is a wonderful companion, an excellent listener and possibly even your favorite family member. Unfortunately, if not properly cared for, he or she can also be a carrier of a whole host of diseases that can be transmitted to you. Some of these zoonotic diseases, as they are technically referred to, can even be deadly. We sat down with Dr. Anna M. van Heeckeren to discuss some of the scariest diseases your dog or cat may be exposing you to, as well as a few easy ways to prevent disease transmission in the first place.

1. Tapeworm

This parasite can be transmitted from accidentally ingesting a flea from your dog or cat. Symptoms of flea tapeworm infection include stomach aches, diarrhea, and an itchy butt.

2. Ringworm

Often confused with another zoonotic disease called roundworm, ringworm is a fungus that is fairly common in dogs and cats. It is often found in shelters and can be passed to people who pet an infected animal. It usually leaves people with an uncomfortable skin rash.

3. Roundworm

This parasite is found in almost every puppy and kitten. It is usually transmitted by their mother before they're born, or from drinking their mother's milk. The puppies and kittens then spread it through their poop. People can accidentally ingest roundworms if they handle dirt (or poop) containing nasty roundworm eggs and forget to wash their hands (or don't wash thoroughly) before eating. Fortunately, most people don’t get horrible symptoms, but for those that do, symptoms can include stomach problems, vision problems, and seizures. It can also lead to death, but it is rare.

4. Hookworm

Like roundworms, the hookworm is another parasite that can be spread through animal poop. It infects people through direct skin contact, like when walking outside in bare feet on contaminated dirt or sand. Because hookworms feed on blood in the intestinal tract, symptoms can range from gastrointestinal discomfort to blood loss leading to anemia and protein loss. In severe untreated cases, hookworm infection can result in stunted growth and cognitive dysfunction in children and in the developing feoteuses of pregnant women. In rare instances, hookworm infections can lead to death due to anemia and malnutrition.

5. Cat Scratch Disease

So called because the disease spreads when a cat that is infected with the bacterium Bartonella henselae bites or scratches a person hard enough to break the surface of the skin, or licks a person's open wound. According to the CDC, cats can get infected with B. henselae from flea bites and flea dirt (droppings) getting into their wounds. By scratching and biting at the fleas, cats pick up the infected flea dirt under their nails and between their teeth. For people, there's usually a mild infection associated with cat scratch fever where the injury occurs, but it can also cause swollen lymph nodes, fever, headache, and a poor appetite. The full impact of Bartonella infections in people is just beginning to be explored.

6. Leptospira

Leptospira bacteria can be found in the urine of dogs. People can develop many symptoms similar to that of a cold (fever, chills, headache, muscle aches, vomiting, diarrhea), after which they feel better and then get sick again with severe kidney or liver disease, or infection of the brain (Weil’s disease). People can die from severe cases of leptospirosis.

7. Toxoplasma

This bacteria is commonly spoken about when discussing cat litter and pregnant women. As pertaining to people, it can be contracted when handling contaminated feces from an infected cat. However, the Toxoplasma gondii bacteria can also be found "naturally" elsewhere, such as in undercooked meats or vegetables that have not been thoroughly washed. Symptoms can include swollen glands and muscle aches as if you have the "flu." Pregnant women should be especially careful because the bacteria can infect the developing baby and cause deformity or miscarriage. It is for this reason that doctors advise pregnant women not to clean cat litter boxes.

8. Plague

While you may think this is no longer a real fear, the plague is still around in some parts of the world — possibly even your backyard. It is caused by a bacterium (Yersinia pestis) that infects fleas, which commonly attach themselves to dogs and cats and are then brought indoors. If bitten by the infected flea, you, in turn, can also become infected. If left untreated, this can lead to death.

9. Rabies

Rabies is a fairly well known virus that is transmitted through the exchange of blood or saliva (typically, a bite) from an infected animal. People with rabies can display signs such as fever, headache, nausea, and vomiting. If left treated, it can even become fatal. Thankfully, it is no longer common in dogs or cats because of successful rabies vaccination programs.

10. Lyme Disease

Lyme disease, so called because it was originally discovered in Old Lyme, CT, is one of the most common tick-transmitted diseases in the world. It is caused by the bacterium Borrelia burgdorferi and is frequently brought indoors by our pets, unbeknownst to them. Clinical signs of Lyme disease include red, expanding rash, fatigue, chills, fever, joint aches, and swollen lymph nodes. If left untreated, it can lead to facial palsy, heart palpitations, and even meningitis. 

Prevention Tips

Just because our pets can be carriers of diseases doesn't mean we need to give them up. In fact, you are probably more likely to contract something from your friends and family than from your pet. However, it is still important that you and your family take precautions and care for your pet accordingly. Dr. Heeckeren recommends three simple rules: 1)Visit your veterinarian regularly to get necessary vaccinations and medications for your pet, including flea and tick preventives; 2)Pick up pet poop daily using gloves, seal it in a bag, and throw it in outdoor trash bin; and 3)Wash hands frequently and throughly, especially before mealtimes or after handling dog or cat feces.

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