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Dear Veterinarian,
All veterinarians, throughout the state, should be on alert for cases of tularemia in cats, dogs, rabbits, squirrels, and other wild animals; and take appropriate precautions (such as wearing gloves) when handling suspect cases. Since April 2016, tularemia has been identified in nine Minnesota cats, one rabbit, and two people. Three of the nine cats and both people have recovered with treatment.
Tularemia is a zoonotic disease caused by the bacterium Francisella tularensis. Tularemia has been confirmed in cats from rural, urban, and suburban environments with zero to three cats reported in previous years. Outdoor animals that hunt are at highest risk but tularemia has also been identified in indoor cats, with no obvious exposure. Dogs can be infected with F. tularensis, but are often asymptomatic or have mild disease; livestock, particularly sheep, can also be affected. Please see the attached table and figure for description of the recent cases.
Diagnosis is confirmed serologically by a four-fold rise in titer, or by PCR and/or culture of clinical specimens. Every effort should be made to collect pre-treatment specimens from suspect cases. The MN Veterinary Diagnostic Laboratory (VDL) is able to perform cultures on diagnostic specimens; if the animal has died, submitting the animal to VDL for necropsy is the best option. If the animal is alive, whole blood, or swabs, biopsy, or aspirate from a lesion or lymph node can be submitted for culture at the MN VDL. Serologic testing is available at the National Veterinary Services Laboratory (NVSL) via reference laboratories such as Marshfield Labs or Antech Diagnostics and at the Wyoming State Veterinary Laboratory. PCR testing is available from the North Dakota State University Diagnostic Laboratory and the Colorado State Veterinary Diagnostic Laboratory.
The recommended treatment for suspected tularemia cases includes gentamicin, doxycycline, and fluoroquinolones. Beta-lactams are ineffective, including Clavamox®, Convenia®, and cephalexin. Two of the four surviving cats since 2015 were treated with IV doxycycline and/or enrofloxacin and transitioned to oral medication, one recovered cat was treated with oral fluoroquinolones. If single antibiotic therapy is not effective, consider adding a second agent. The condition of all three cats markedly improved within 24 hours of appropriate antibiotic administration.
People can also acquire tularemia through contact with infected animals or from ticks and biting flies. It is not transmitted person-to-person. Zero to three human cases are identified each year in Minnesota. The incubation period for tularemia in humans is generally 3-5 days (range, 1-14 days). Acute signs and symptoms include sudden onset of fever, chills, joint and muscle pain, headache, nausea, and lymphadenopathy. Please consult your healthcare provider and notify MDH if you have recently cared for a suspect tularemia patient and have symptoms consistent with tularemia. MDH follows up with people who have had contact with confirmed tularemia cases.
For more information, or to report suspect cases, please call the Minnesota Department of Health (651-201-5414) or the Minnesota Board of Animal Health (651-296-2942).
 
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