Why small mammals need this in writing
A boarding facility or sitter who finds a small mammal collapsed, bleeding or refusing food faces a problem a dog owner rarely creates: many vets will stabilise an animal in immediate danger, but ongoing treatment decisions belong to the owner, and an uncontactable owner plus an unsigned understanding can stall care. Small mammals also decline far faster than cats or dogs — a rabbit or guinea pig who stops eating is on a short clock. A clear written authorisation, left before you go rather than negotiated by phone from a departure lounge, removes the hesitation entirely.
What the document itself should say
Keep it to one page, in plain language. It should give your full name and the best number to reach you on throughout the stay, plus the name and number of a second person who can act if you are unreachable. Name the animal clearly — species, name, colouring — and name the carer or facility you are authorising. Then the operative sentence: that this carer has your permission to transport the animal to a veterinary practice and to consent to emergency treatment on your behalf if you cannot be contacted. Sign it. If the stay involves more than one carer, name each of them, because an authorisation that covers the facility owner may not obviously cover the weekend helper who actually finds the problem.
The health summary that travels with it
Attach a brief summary the carer can hand straight to the vet: your regular practice and any out-of-hours clinic you use, the animal's age if known, ongoing health issues, anything he is currently being treated for, and anything he has reacted badly to in the past. For a small mammal, add the daily baselines a stranger cannot judge — how much he normally eats, what his droppings normally look like, how active he usually is in the evening. Those baselines are often what turn a vague 'he seems quiet' into a decision to call the vet now. Avoid jargon; write it for a worried person at midnight, not for a clinician.
Decisions, limits and money — say it before you go
The hardest part to write is the part that matters most: what you want to happen if the vet presents serious choices and you genuinely cannot be reached. State whether the carer may agree to surgery in an emergency, whether there are treatments you would not want, and how the bill will be settled — many owners leave card details with their own vet in advance or arrange for the practice to invoice them directly. You do not need to predict every scenario; you need the carer to know they are acting inside your wishes rather than improvising with someone else's animal and someone else's money.
Where it lives during the stay
Give the carer the original or a clear copy, keep a photograph of it on your phone, and file it with the animal's other records rather than in a drawer at home. Stored in his KinsLe Pet Passport alongside his health summary and vet details, the authorisation arrives at the boarder's with the rest of his paperwork as one packet — and if a different vet ends up treating him, the whole background travels onward with him too.