I feel like some of the paragraphs could have been split into two or three paragraphs. Some of the sections could even have been split into multiple pages for readability. I first noticed this when I went to the pet store. The "Where to now?" page was an especially large text wall.
It was nice to see that the choices I made did have some bearing on the scenes, though I felt like some of them could have used a grammar touch-up.
I noticed that sometimes a pronoun would be capitalized in the wrong place. I don't know the exact way you formatted your variables, but did you have different variables for $they (he, she) and $theycap (He, She) or something similar to that?
I've never had a dog, so I can't really relate to a lot of the dog experiences, but the part about deciding whether or not to put down the dog made me cry -- we had to put down our cat earlier this month. That was completely accurate.