Last month, a dog in Rio Rancho, N.M., was diagnosed with bubonic plague. New Mexico health officials are warning pet parents to protect themselves and their animals against this disease.The Centers for Disease Control and Prevention (CDC) reports that cases of the plague – about 1,000 to 3,000 worldwide each year – are usually reported in rural areas. In the United States, the plague occurs in states west of the Great Plains. There has not been an urban plague epidemic since 1924 in Los Angeles.Most people get bubonic plague via a flea bite from an animal infected with the parasite Yersinia pestis, although one-fifth of cases are caused by people coming into direct contact with infected animals.
Fortunately, New Mexico public health veterinarian Paul Ettestad, DVM, told Veterinary Practice News (VPN) that dogs have not yet directly infected humans.“Maps of plague cases in animals vary by year,” he said. “There are some years where we will have over 30 cases in cats and over a dozen cases in dogs in New Mexico.”According to petMD.com, plague is rare in dogs because they are resistant to the bacteria.
Holly Edd, writes that there are three types of plague:
- Bubonic – The infected dog’s lymph nodes swell and drain.
- Septicemic – This type occurs more frequently in cats. Bacteria enter the bloodstream and can infect the internal organs.
- Pneumonic – This type also occurs most frequently in cats. Bacteria enter the lungs and can be transmitted to people via coughing.
While the plague killed millions of people and animals back in the Middle Ages, today it can be treated with antibiotics.
What Causes Bubonic Plague?
A dog can become infected with bubonic plague if he is bitten by an infected flea or eats an animal with infected fleas. The New Mexico dog reportedly had a history of eating sick rabbits.
What are the Symptoms of Bubonic Plague?
The incubation period for bubonic plague is from two days to a week after a dog has been bitten.Ettestad told VPN that the dog in New Mexico had “clinical signs of fever, lethargy and anorexia.”According to petMD.com, “The infection travels rapidly to the lymph nodes, where white blood cells are produced. The resulting reaction from the lymph nodes is a rapid multiplication of white cells, abnormal fluid build-up with swelling and possible skin breakage.
Dogs infected with plague will experience fever, inflammation, and excessive pain due to the lymph nodes being chronically swollen.”Edd notes that besides enlarged lymph glands, dogs rarely show any other signs of the disease.
How is Bubonic Plague Diagnosed?
Your vet will confirm a diagnosis either through “cultures of tissue specimens or fluids, through immunofluorescent testing methods which test fluid specimens, or through blood testing,” Edd writes.For the blood test, two samples are taken from your dog, 10 to 14 days apart.
“The blood test looks at a change in antibody level, and to be positive, the level must change by a factor of four over the two week period,” Edd notes. “If plague is suspected, the person or animal is often treated while awaiting the results.”When the infected New Mexico dog was first brought to a vet, blood tests were negative, but three weeks later, the dog tested positive for bubonic plague.If your dog has the plague, it must be reported to local, state and federal health departments.
How is Bubonic Plague Treated?
Dogs with bubonic plague are given antibiotics, such as Tetracycline or doxycycline.“Animals are generally treated for at least 21 days, far after any bubonic or pneumonic symptoms have resolved,” Edd writes.
How is Bubonic Plague Prevented?
If your house is heavily infested with fleas or if you live near a wildlife habitat, your dog is at higher of becoming infected, warns petMD.com.You should control the rodents and fleas in your dog’s environment, and clear out any garbage or woodpiles that could attract them.“Dogs and cats should be restricted from animal burrows and from eating any carcasses of dead rabbits or rodents,” Edd writes.Ettestad told VPN, “[W]hile plague cases in both dogs and cats are uncommon in most of the Western U.S., we encourage people to keep their dogs and cats from roaming and hunting, and to use a flea-control product recommended by their veterinarian.
”According to a study earlier this year, you also might want to change your sleeping habits:
It concluded that sharing your bed with your dog could contribute to the spread of infectious diseases, including bubonic plague.To prevent transmission to people, infected dogs must be kept in isolation. You should only handle them while wearing gloves, a gown and surgical mask.If you do become infected, you will be treated with antibiotics, just like your dog. A vaccine against the Yersinia pestis bacteria is available.