People have shared their homes with dogs for thousands of years. In the United States, there are approximately 83.3 million pet dogs, and almost half (46 percent) of all households own at least one dog.
Dogs make wonderful companions, but they can also carry diseases that can make people sick. Some of these diseases such as campylobacteriosis, leptospirosis, and salmonellosis cause signs of disease in dogs, while others, such as brucellosis, can be carried by apparently healthy dogs without signs of disease.
What dog-related diseases are of concern in Ohio?
Animal bites: dogs
Dog bites account for approximately 75 percent of all bites to people reported in Ohio each year.
Dog bites can not only transmit rabies, but can result in bacterial infections and damage to tissues. Dogs carry a number of different types of bacteria in their mouths. Of particular concern is the bacteria, Capnocytophaga canimorsus. These bacteria can cause serious life-threatening infections in immunocompromised people.
If you have been bitten by a dog, consult with your healthcare provider regarding the need for antimicrobial treatment, and report the bite to your local health department.
Brucellosis is caused by Brucella species bacteria. In dogs, the causative agent is B. canis. Dogs can be inapparent carriers of B. canis, although it can cause sterility and abortions in breeding animals.
People can become infected through contact with birthing materials and aborted fetuses. B. canis infection in dogs cannot be treated. Infected animals should be spayed or neutered to reduce the risk of transmission.
Campylobacteriosis is a gastrointestinal illness of humans and animals caused by Campylobacter bacteria. It is a common cause of diarrhea in kittens and puppies.
Campylobacter bacteria are commonly found in the feces of infected animals and in food products contaminated with the bacteria during processing or preparation. Eating raw or undercooked chicken and consuming unpasteurized milk are two of the most common sources of human infection.
Hand washing and proper food handling techniques are important ways of preventing human infections.
A fact sheet on preventing Campylobacter infection from dogs and puppies is available for owners and pet store workers.
Cutaneous larval migrans (hookworm)
Cutaneous larval migrans is a skin disease cause by hookworm larvae. Humans become infected when their skin comes into contact with environments contaminated with hookworm larvae. The larvae penetrate the skin and cause an itchy red tract in the skin.
The disease is more common in tropical and sub-tropical climates. The best ways to avoid infection include:
- Deworming pets.
- Cleaning pet toilet areas regularly.
- Avoiding skin contact with potentially contaminated environments.
Leptospirosis is caused by Leptospira bacteria. It can infect people and a wide range of domestic and wild animals, including dogs. A vaccine against the most common types of Leptospira is available for dogs.
Leptospira is shed in the urine of infected animals. Transmission usually occurs through exposure to water or soil that has been contaminated with Leptospira bacteria, although transmission can also occur through direct contact with urine from an animal shedding the bacteria.
People, dogs, and horses are susceptible to infection. Dogs typically exhibit a fever and painful joints when infected. Lyme disease infections in dogs are not a significant risk factor for human infection because dogs (like humans) are considered to be "dead-end" hosts (i.e., humans cannot get Lyme disease from dogs). However, dogs can bring infected ticks into the home.
To reduce the risk of contracting Lyme disease, avoid tick bites by wearing protective clothing and using repellents when exposure to ticks is likely. It is also important to check your dog for ticks frequently and use repellents known as acaricides on your pet to kill ticks. A vaccine for Lyme disease is available for dogs.
If you think your dog may have Lyme disease or you are interested in vaccinating your dog for Lyme disease, consult your veterinarian.
Rabies virus can infect any species of mammal. It causes encephalitis and is almost always fatal once symptoms develop. It is spread when a person or animal is bitten by an infected animal or, less commonly, when saliva from an infected animal gets into an open wound or onto a mucous membrane.
Dogs are the most common domestic animal to transmit rabies to people in the world. All bites should be reported to the local health department.
Protect your pets by having them vaccinated for rabies. Even indoor dogs should be vaccinated because they can be exposed to a rabid bat. Rabid bats are often found inside homes.
Salmonellosis is a gastrointestinal illness of humans and animals caused by Salmonella bacteria. The most common source of infection for humans is through ingestion of food contaminated with Salmonella bacteria. There have also been outbreaks associated with pet food contaminated with Salmonella.
Dogs can become infected when they eat contaminated food and will shed the bacteria in their feces. Hand washing and proper food handling techniques are important ways of preventing human infections.
Spotted fever rickettsiosis
Spotted fever rickettsiosis is a group of several diseases caused by Rickettsia bacteria. Rocky Mountain spotted fever (RMSF) is the primary member of this group that infects dogs. In Ohio, it is spread by Dermacentor species ticks.
Infected dogs rarely develop signs of disease, although some dogs may develop fever, skin lesions, and nose and eye discharge.
To reduce the risk of contracting RMSF, avoid tick bites by wearing protective clothing and using repellents when exposure to ticks is likely. It is also important to check your dog for ticks frequently and use acaricides on your pet to kill ticks. If you believe your dog may have RMSF, consult your veterinarian.
Visceral larval migrans (toxocariasis)
Visceral larval migrans is caused by larvae of dog and cat roundworms migrating through a person's internal organs. Roundworm eggs are shed in the animal's feces and develop into infective larvae in 2 to 4 weeks in the environment.
The best ways to avoid this infection include:
- Deworming your pet.
- Cleaning pet toilet areas weekly.
- Avoiding areas likely to be contaminated by feces.