I have a rider with my home owners insurance and it covers liability up to 100k. U can get separate policy's and I think depending on who you go to could be around 500-700 a year. Typically if not lumped with another plan, you pay it all at one time like apartment insurance. It all depends. I live near the ocean so I'm uninsurable with all carriers so I have to use the insurance for people who can't get insurance called the Massachusetts fair plan.
I am assuming u mean for liability not vet insurance?
State Farm did pull out of FL, but only for HO. There is only a small handful of companies that will write HO insurance with a Pit type dog. I am with Citizens and dog bite is excluded. I would have to purchase additional coverage through an independent company and it would run me about $500 a year. There are several companies out there. I suggest google dog bit insurance and shop the companies they list. If you are uncertain what it covers, an insurance agents job is to explain coverages. Call the companies and ask them. If they give you the run around, in some instances I can answer your questions for you. I have my 220 license and specialize mostly in auto and MC, but I do have a little HO experience.