Sounds like you should tell them ahead of time. But be sure to tell them in a light way..."just want to let you know ahead of time that I have a speech disorder. Takes me a little longer to say things, but it won't interfere with my work." This will be good because it takes some pressure off of you. And also, not that you have to use the word "disability," but they will know that it's not a good idea to not consider someone because of a disability. Yeah, I don't think they're going to ask you any hardcore interview questions with this job. They want someone reliable, and someone who likes animals. Of course you are nervous, more than nervous -- "this interview is literally the most terrifying thing to me right now" -- but this is a great job to start with. The place sounds nice, and, in this case, you won't have to convince anybody that you will be ok speaking to the public since you won't be doing that. Just be sure to get across that you love cats and would take the responsibility very seriously. Not sure there's any way to be less nervous beforehand? But it may go much better than you expect. I don't mean that you won't stutter...you will. But rather that they will not care nearly as much as you fear. Wishing you luck and I hope you post again after!