Why does my rabbit have a dark spot in his fur?

A few days ago I pulled a tick of some sort of off my one year old holland lop it was by his neck but it didnt look like a deer tick or a wood tick. And now two days later he has about a quarter size patch of dark shorter hair compared to his light brown longer hair. He is acting the same and eating. I would take him to the vet but I don't have the money, if things get worse and he starts acting strange then I will.