A baby guinea pig's first vet visit belongs in the first days to a week at home, booked while the pig is bright and eating — not saved for the first illness. It sets three things you will rely on for years: a confirmed sex, a trusted baseline weight, and a vet who has handled this animal while it was calm and well.
Sexing Is a Real Reason to Go
Even experienced sellers mis-sex baby guinea pigs, and the error surfaces weeks later as an unexpected pregnancy when two "sisters" turn out to be a pair. Have the vet confirm sex at this visit regardless of what the breeder or rescue said, and again at a follow-up if the baby was very small and the vet wants a second look. If you have a mixed group planned, this check comes before any introductions, not after.
What the Vet Examines
Expect a nose-to-tail once-over with guinea pig specifics in mind. The vet checks the incisors you can see and assesses the back molars as far as the mouth allows, since dental problems are common in this species and early signs are subtle. Eyes should be clear without discharge, the nose dry, breathing quiet — guinea pigs cannot afford respiratory infections, so any clicking or effort matters. Ears, skin and coat are checked for mites, lice and fungal patches, which often arrive with a new baby and are far easier to sort early. The vet listens to heart and chest, feels the belly, and looks at feet and nails.
One thing will not be on the list: vaccinations. Guinea pigs have no routine vaccination schedule, so if paperwork from elsewhere mentions keeping jabs up to date, that is a template error, not guinea pig care.
The Growth Baseline
The weigh-in is the point of the visit you will use most. A baby should gain steadily week to week, and the only way to spot a stall early is a baseline plus home weighing: same scales, same time of day, weekly, written down. Guinea pigs hide illness well, and a growth curve that flattens — or an adult weight that slides — is frequently the first objective sign something is wrong, days before appetite visibly changes. Ask the vet what weekly gain range to expect for this baby's age and frame, and what change should trigger a phone call rather than waiting for the next routine visit.
Diet Questions to Ask While You Are There
Bring the details of what the baby is currently eating: the hay type, the pellet amount, and which vegetables it has met so far. Guinea pigs cannot make their own vitamin C, so confirm the diet actually supplies it daily, that hay is unlimited and forms the bulk of intake, and that any food change is planned gradually — sudden switches upset a young gut. This is also the visit to ask about handling and floor time for a nervous baby, and when the next routine check should be.
Keeping the baseline weight, sexing result, diet notes and visit dates together in KinsLe's Pet Passport means the next vet — or an emergency clinic meeting your pig for the first time — starts from records, not guesses.