In late October of last year, a two-year old Bobcat was admitted to our Animal Care Hospital, emaciated, dehydrated, and hypothermic. He had a severe dermatitis along his head, ears and neck, and a moderate dermatitis across the rest of his body, leaving him bald and crusty in several areas. He was given a physical exam and blood and fecal analyses, and was given medical treatments including fluids, antibiotics, and a gastrointestinal dewormer. A skin scrape examination revealed Notoedres cati, a mite that is the most common cause of mange in Bobcats.
Notoedric mange is caused by a reaction to the burrowing of mites into the skin, which leads to intense itchiness, and commonly, self-mutilation and bacterial skin infection. Such infestations are often so severe that they will lead to death of the animal if left untreated. Thus, this bobcat was started on a regimen of medications to treat his mite infestation, as well as Vitamin K.
Why the Vitamin K, you ask?
Interestingly, there is a strong association between mange infestations and anticoagulant rodenticides, commonly known as rat poison. Before 2002, mange was only reported in Bobcats as isolated incidents. From 2002 to 2006, a large-scale mange outbreak took place in California. According to one study it was so severe that it actually reduced the California Bobcat population, causing a genetic bottleneck. During an investigation into the decline, testing revealed that anticoagulants were present in 100% of Bobcats with mange. Furthermore, many animals were found to be exposed to three or more different anticoagulant rodenticides. In Bobcats, it is suspected that repeated small doses of anticoagulant rodenticides may harm immune function and increase their susceptibility to mange infestation.
Anticoagulant rodenticides disrupt the production of certain proteins involved in the blood clotting process that are dependent on Vitamin K for their synthesis. As these proteins are depleted the blood loses its ability to clot and the animal dies due to hemorrhaging (bleeding out). Treatment with Vitamin K allows the production of blood clotting proteins to resume, thus preventing hemorrhage and subsequent death.
After almost two months of treatment, our bobcat was mange-free. He began to regrow hair along his body and face, his skin irritation resolved, and his weight and energy level improved dramatically. He was released back to the wild on December 14th.
Riley SPD, Bromley C, Poppenga R et al (2007) Anticoagulant exposure and notoedric mange in bobcats and mountain lions in urban southern California. J Wildl Manag 71:1874–1884.
Serieys LEK, Armenta TC, Moriarty JG, Boydston EE, Lyren LM, Poppenga RH, Crooks KR, Wayne RK, Riley SPD (2015) Anticoagulant rodenticides in urban bobcats: exposure, risk factors and potential effects based on a 16-year study. Ecotox 24(4): 844-862.
Serieys LEK, Foley J, Owens S et al (2013) Serum chemistry, hematologic and post-mortem findings in bobcats (Lynx rufus) with notoedric mange. J Parasitol 99:989–996.