The owner is required to supply all food for the stay. Remember to remind the owner to bring along enough wet and dry food to last the length of the stay plus an extra 2 days just in case. Wet Food = mince, tuna, or tinned pet food. Dry Food = Dry dog biscuits / kibble.
For long stays discuss options with the owner directly such as purchasing food. For this you should always photograph the receipts and upload into PetCloud as a message to the Pet Owner for reimbursement before the end of the stay to avoid the Pet Owner getting bill shock.