Plague Found In New Mexico and Arizona

Another outbreak of plague has been found in New Mexico and Arizona. From January to July 2017, New Mexico has three confirmed cases of Yersinia pestis.  This bacteria causes plague in humans. Arizona prairie dogs in Cocinino county near Williams, Arizona suddenly started dying this summer. Testing revealed Y. pestis bacterium caused their deaths. Now, fleas in Navajo county have tested positive as well. Plague often occurs in the desert southwest states from May through October.

People develop plague after being bitten by a flea infected with Y. pestis within 2 to 6 days. If the bacterium is inhaled, the onset of clinical signs is only 1 to 3 days. Unlike people, cats contract the plague after eating infected rodents. Clinical signs in animals and people include swollen lymph nodes, fever and general malaise. Plague has three different syndromes in humans and cats.  Dogs are naturally resistant to the plague. Bubonic plague is the first stage that occurs when the bacterium settles into the lymph nodes of the head and neck. With time, the glands may rupture and drain a bloody material. Pneumoic plague occurs when the bacterium spreads from the lymph nodes to the lungs. Septicemic plague occurs when the bacterium enters the bloodstream and spreads throughout the body. This form is rare in cats.

Intensive treatment with antibiotics and fluids must be started early to prevent death. Infected patients, animals as well as humans, are quarantined to prevent infecting others. Because of the extremely poor prognosis and rapid progression of the disease, treatment is often started before an actual diagnosis is confirmed. If plague is suspected, start treatment.

Avoiding the bacterium is the key to prevention. Keep cats indoors to prevent exposure to rodents. For the benefit of humans and cats who live with dogs, routinely use flea control products on the dogs. Clear out rodent habitats around homes. Humans should wear gloves when handling wild animals. Most human deaths are in either hunters who were bitten while handling their prey or veterinary professionals who were exposed when treating a sick cat.  This happens to vets and staff because draining buboes on the head and neck look similar to cat fight abscesses. More information can be found at the Centers for Disease Control.


-Hafner, John. ‘Plague in Arizona: fleas found carrying the infectious disease.’ USA TODAY Network, Published 8/16/17.

-Morrison, Wallace. ‘Plague’. Balckwell’s Five-Minute Veterinary Consult, Canine and Feline, 5th edition, Wiley-Blackwell Publishers




H3N2 Dog Flu Hits Arizona

H3N2 dog flu has come to Arizona.  In 2015, a new strain of canine influenza hit the Midwest sickening more than 1,000 dogs.  At first, the outbreak was attributed to Influenza A H3N8, a virus that was first observed in the United States in 2004. But further testing by researchers at the University of Wisconsin and Cornell University identified a new virus, H3N2. This avian virus was first found in 2007 in Korean dogs.  The H3N2 canine flue virus has also infected cats. So far, this influenza has not spread to humans. The virus spread across the United States until it finally came to Arizona. Now, two years later, two dogs at Maricopa County Animal Care and Control tested positive for the virus. Both are responding well to treatment.

Clinical signs range from mild malaise to anorexia, coughing, fever and a runny nose to severe pneumonia. Coughing lasts 10 to 30 days and fevers range from 104 to 106. The normal range for dogs and cats is 100 to 102.5. Deaths are rare but seen most often in brachycephalic breeds such as Shit tzus, Pekinese and pugs. Treatment is supportive as there is currently no cure available. Severely affected dogs and cats are placed in hospital isolation wards and treated with fluids, antibiotics and nebulization. The goal is to prevent a secondary bacterial pneumonia which can be life-threatening.

Since no specific treatment is available for this virus, prevention is the key to protecting both dogs and cats. I recommend vaccinating all brachycephalic breeds of dogs, immune suppressed and dogs who frequent dog parks, pet stores, boarding facilities and shelters. Since this is a new virus, dogs do not posses a natural immunity against it. There are two types of vaccines available for canine flu, one for H3N8 and one for H3N2. It is important to get the H3N2 vaccine because the H3N8 does not cross protect.  Take precautions to avoid accidental transfer of the virus from sick animals to your pets. Disinfect clothing, equipment and hands after interacting with other animals.


-Brooks, Wendy. “Canine Influenza (H3N8)”. The Pet Health Library, VIN, Published 10/24/2005, Reviewed 4/30/2014.


-‘Key Facts about Canine Influenza (Dog Flu)’. Centers for Disease Control and Prevention.

-Rishniw, Mark. ‘Canine Influenz’. VIN: Veterinary Partner, published 04/17/2015, reviewed and revised, 06/19/2017.

-Schwartz, Joe. “Midwest Canine Influenza outbreak caused by new strain of virus”. April 12, 2015.