Just thought I'd let you all know, 2 weeks ago my cav (Elliot) got very tired and was't eating that much, I noticed a tiny black spot on his belly(well hidden under his coat). Brought him to the vet, and he pulled out a huge tick which had completely burried itself into his belly. The vet was quite worried about it and warned me that tick bites can be very nasty and that he may develop sepsis as it had possibly entered the bloodstream. He was given an injection and put on strong antibiotics for a week and luckily (tg) he improved. I used the "spot on" treatment in May, and was told to keep using it during the summer months. He's fine now, however, im keeping a close eye out for those ticks!!! Just wondering what anybody else uses to prevent ticks, did'nt know that they could have such bad effects!