Amazon has Bayer Seresto Flea and Tick Collars, 8 month protection for $35.99, less with S&S. Choose from:
Large dog (18 pounds and up): https://www.amazon.com/Bayer-Sere…PDKIKX0D
Small dog (up to 18 pounds): https://www.amazon.com/Bayer-Sere…PDKIKX0D
Cat: https://www.amazon.com/Bayer-Sere…PDKIKX0D