Which logical fallacy is used in the text?
I can't believe you'd hire Tyler Khan to watch your dog! Did you know that his friend adopted a dog but then took it back to the shelter after just one week?

 - straw man: a misrepresentation of an opponent's position that makes it easier to argue against
 - guilt by association: a negative association intended to discredit someone or something
The text argues that Tyler must be an irresponsible dog owner, because his friend was an irresponsible dog owner. However, even though Tyler's friend was irresponsible, that doesn't necessarily mean that Tyler is also irresponsible. This illustrates a type of logical fallacy known as guilt by association.