I was booked to take care of a dog while family was on vacation. They only need me to come in once a day but I don't feel like that's enough time per day. No one else will be around to make sure there dog is okay. She's also a very old dog.
These types of conversations are easiest handled in person.
I prefer to tackle it head on during the initial meet and greet. For example, I would ask their dog’s usual routine - when dog eats and walks, which includes how many times a day. If someone answered once or twice daily, I’d ask how the dog relieves itself in between. Some dogs do have indoor relief stations set up, which would explain that. If that’s not the case, I would raise eyebrows, question “really? My dog (who is a senior) relieves itself outside on average four times a day.” Pause long enough for them to respond. If it’s a budgetary constraint, you may choose to offer them a deal if it’s close by.
Your House Sitting rate is approx. the same cost as two visits rate. However, housesitting generally would tie you up for a 24 hour period, or much longer than 2 visits. If this person lives close to you, I would consider offering a price in between those two rates for at least two visits, using the cost adjustment field and document the revised arrangement in the messages.