By David Stoltz
Spring is the start of tick season in southwest Missouri, which means for cat owners, it’s a time to take extra precautions against a particularly deadly disease carried by ticks.
The disease is Cytauxzoonosis felis, more commonly called “bobcat fever” because its resource hosts are infected, wild bobcats. While not transmittable to humans or farm animals, this disease is particularly debilitating to domestic cats who spend time outdoors. And southwest Missouri is a hotbed for this disease.
Bobcat Fever was first documented in Missouri in 1976, and while it has been reported as far north of Pennsylvania and North Dakota, it remains particularly prevalent in this area.
The parasite is transmitted by the Lone Star tick, which is itself infected by, and carried, on a host bobcat. Cats living near heavily wooded areas in close proximity to ticks and bobcats are at highest risk of being bitten by this tick.
Onset of symptoms may occur quickly, and if not discovered immediately it can soon be fatal.
Buddy, a one-year-old tabby that belonged to Christine Clark of Branson, died from bobcat fever. Christine noticed her cat was lethargic. Two days later, Buddy was dead.
D. Rawls of Branson lost her 4-year-old Siamese named Gideon to bobcat fever in April 2018, despite his being outside for only two hours.
“We found him in the woods behind the house and he had one small tick on him. That next day he started acting sick, running a high fever,” Rawls said. “He passed away within a week despite all efforts by the vet.”
Besides lethargy, symptoms may include depression, anorexia, jaundice and dehydration and may last only 12-48 hours. Body temperature may rise as high as 106 degrees.
Emmett, a cat owned by Julie McAlister of Branson, escaped into the woods in May, 2018. When he came home, he started showing symptoms.
“His first symptoms were the day before he died, less than 24 hours,” she said. “He was weak and lethargic. The day he passed we noticed that he hadn’t been eating or drinking,” and he was meowing as if in pain.”
Ashley Hurst of Paws and Hands United, a foster-based animal rescue group, is familiar with bobcat fever.
“I hear more and more about it each year, it seems,” she said. “We no longer let any of our cats go outside at all, even for short amounts of time. It’s a very painful death and just an awful illness for cats.”
While this disease can sometimes be mitigated if caught early enough, usually by the time symptoms appear it is beyond that stage.
“Unfortunately, it is a very fast-moving disease so that by the time we notice a problem it is many times too late,” said Amanda McGinty, DVM, of Shepherd of the Hills Veterinary Clinic.
The best protection is to use a flea and tick preventative. Dr. McGinty said the only preventative on the market labeled to kill the Lone Star tick is Revolution Plus. But it may not be enough.
“Even with the tick preventative on board, it is still possible for the parasite to get transmitted to the cat before the medication kills the tick,” she said. “Once the cat becomes sick with bobcat fever the clock is ticking and fast, and sometimes even despite early intervention it is still too late.”
Keeping your pet indoors is among the safest and best prevention tools, but it is not always foolproof either. The tick could attach itself to another outdoor pet then transfer to a cat that it comes in contact with.
“Treatment is aimed at stopping the body from destroying its own red blood cells, giving medications such as Atovoquone or Immidocarb to kill the parasite in the body and in extreme cases a blood transfusion is needed to save the cat,” Dr. McGinty said. “A person can spend hundreds and even thousands of dollars and still may lose their feline friend.” The doctor said Immidocarb treatment is very easy and inexpensive to administer and is usually two injections given a week apart, but the success rate is about 20 to 30 percent.
“Atovoquone is a horrible-tasting pill or liquid that must be given three times a day for 10 days, but if done has up to an 80 percent success rate, but it is also much more expensive to purchase,” she said. “The mainstay of treatment is to keep the cat alive long enough for the antibiotics to kill the parasite.”
Forecasters from pests.org, a “resource hub for learning about specific aspects of pests and the threat they present,” predict that the “warm-weather months in the US will be a bad time for anyone who wants to avoid ticks, with tick populations likely to be larger than usual, and weather conditions likely to put ticks in range of people for much longer than average.”