Plague in Dogs

Plague is a sudden and sometimes fatal disease caused by Yersinia pestis bacteria. It is mainly spread through fleas that live on rats and other rodents. This is the same disease known as the black death, which caused massive outbreaks in Europe and Asia during the 14th century.

Although antibiotics can now treat plague, it still exists today. Small numbers of cases occur in wild animals in parts of the western United States and in regions of Eurasia, Africa, and both North and South America. In the United States, about 10 cases in people are reported each year, mostly in New Mexico, California, Colorado, and Arizona. Infection in dogs is very rare.

The bacteria circulate in nature between rodents (including squirrels an wood rats) and their fleas. Dogs are usually infected by eating infected rodents or rabbits or by being bitten by infected fleas. Infected fleas can also be brought into homes.

Dogs are naturally quite resistant to plague and often show few or no signs compared with cats. When illness does occur, signs can include fever, lack of energy, swollen lymph nodes under the jaw, pus-filled lesions along the jaw, mouth sores, and coughing.

Because the disease can develop quickly, treatment and infection control should begin as soon as plague is suspected, even before the disease is confirmed with laboratory testing. Antibiotics are the main treatment.

Strict precautions are also important to protect people and other animals from infection. Animals suspected of infection should be isolated, and cleanliness and infection-control measures must be followed to prevent spread.

To decrease risk, keep pets from roaming, hunting, and having contact with dead rodents or rabbits in areas where plague occurs. Treat your dog regularly for fleas using products your vet recommends.