Keep useful dog contacts where you can find them
Save a few useful details before travelling so that a weak signal or an unfamiliar postcode does not make a simple enquiry harder.

Keep the address complete
Save the cottage's full address, postcode, arrival directions and host's preferred contact method somewhere accessible offline. A picturesque property name may not be enough for someone trying to find it. If the building sits on a larger site, note the unit name and entrance instructions as well. Share the details with another adult in the group rather than leaving them only in the booking organiser's inbox.
Have your usual vet's contact details and any relevant existing care information available. Identify a veterinary practice near the destination and check how it handles out-of-hours enquiries before assuming that the nearest map result is available at all times. This is preparation for contacting a professional, not a reason to attempt treatment based on a holiday packing list.
Store information in a usable form
A short note on your phone, with a paper copy if useful, is enough. Keep it separate from a long collection of saved attraction links so the important details are easy to find. Do not leave sensitive personal or medical information displayed in a shared cottage. Carry what you need and keep it with your own belongings.
Add the host's instructions for reporting a property problem and the location of relevant house information. If a gate does not close or a facility differs from the description, knowing whom to contact can resolve the issue before it disrupts the routine. Use the channel requested by the host unless the situation requires an appropriate emergency service.
If more than one adult may take the dog out, ensure both can find the note and know the property address. A saved contact in the organiser's locked phone is less useful when that person has gone shopping. Keep the information current for this trip, removing details from a previous cottage that could be mistaken for the present location.
Check once, then leave it ready
Confirm numbers from official sources rather than copying an old review or directory entry. You need not compile a whole local address book. The cottage details, host contact, your usual professional contacts and a verified local veterinary option cover the practical purpose. On departure, remove any notes you placed in a drawer or beside a telephone so personal details do not remain for the next guests.