A few minutes after we arrived, we walked around the backyard and discovered a large (~2in) black widow spider by the sliding door. Knowing the danger this presents to us and our dog, we contacted the host to ask them to hire an exterminator service to spray the property. They answered a few hours later, stating that "this is just part of life in the desert" and that they would not have the property sprayed. That evening, we found a much larger (~4in) wolf spider in our bedroom. This forced us to sleep on the couch that night and leave the next day, even though our checkout date was not until the day after that.
Fortunately, neither of us nor our dog ended up being bit, but it is only a matter of time before someone ends up hospitalized from this infestation.