Cytauxzoonosis is why I had to put our barn cat, Annie to sleep today. Until today I had never heard of this. It is passed by ticks that have bitten a bobcat then your domestic cat. Seed ticks are the worst culprit, they are too small and fast for most repellents used on our cats. There is no vaccine and it kills painfully, blood in the lungs and they drown. Annie was in the last stages and would have died in 24 hours. So we had her euthanized and she is no longer suffering.
We will keep the rest of our cats tick treated inside until the weather turns cooler and the ticks go away.