Exploring Brucella canis, a Contagious Dog Disease that People Can Get

CNN recently reported on cases of Brucella canis (a bacterial disease) picked up in Marion County, Iowa by the Department of Agriculture and Land Stewardship.

While it’s very good to hear news outlets reporting on diseases that can affect both our pets and us, we would like to clarify a few things.

First: what is brucellosis?

Brucellosis is a bacterial zoonosis caused by bacteria from the genus Brucella. There are a few types of the bacteria that are more common than that carried by dogs (for instance, in sheep, goats, pigs), but they all have the potential to cause illness in humans and in their host animals (e.g., dogs, goats, etc.). While the disease caused in breeding animals can be devastating as it causes miscarriage and "contagious" spontaneous abortion, the disease in people who get it is usually mild.

FACT:

"Brucella canis can be trasmitted from dog to dog and dog to people."

The bacteria can be shed in a variety of body fluids, such as feces, urine, saliva, and discharge from the reproductive system (semen, vaginal discharge, afterbirth, and milk). It is normally transmitted from dog to dog either through breeding or oronasal contact (licking) of one of the body fluids noted. It is most often transmitted from dog to human by contact with canine afterbirth or miscarried materials (reproductive tissues tend to have the highest concentrations of the bacteria).

Once a dog acquires a brucellosis infection, it cannot easily be cleared with antibiotics because the bacteria likes to hide inside cells called macrophages. Moreover, it will be intermittently present in blood and then chronically and randomly shed from the dog.

On the plus side, the bacteria does not kill its host, and, for dogs, the disease is typically limited to infections of reproductive organs, along with occasional infections of the eye or spine.

If people acquire the infection, there is a broad, variable range of symptoms, and it is possible for the disease to become chronic (though infection from Brucella canis is usually mild). It does cause a fever in humans, but the fever is periodic and often nocturnal and is easily missed (or misdiagnosed) without blood testing (this is true for both dogs and people).

UNTRUTH:

"It can or will ONLY affect breeding dogs and not dogs who have never been bred before or are neutered or spayed dogs."

In fact, although breeding dogs still remain the most likely population to encounter the disease, even spayed or neutered dogs living with or kenneled near infected dogs can pick up the bacteria and then transmit it.

ALL breeding dogs should be screened for Brucella canis periodically whether they are currently breeding or not.

Dogs acquired from rescues and shelters with uncertain reproductive histories should also be screened prior to adoption.

SORT OF TRUE:

"Brucella canis is a significant risk to human health."

Brucella canis has a relatively low risk for potential to spread to healthy humans. Normal hygiene helps prevent infection. Individuals who are immunocompromised, including the very young, elderly, or sick, are at increased risk. 

If you would have more questions about your dog and Brucella canis, our doctors are happy to help you. Please feel free to contact us!