Guinea pigs conceal illness skilfully, and their small size means lost condition shows quickly once it shows at all. A weekly hands-on check between vet visits counters both problems. Four checks in a fixed order, teeth, eyes, skin, and weight, take a few minutes during a calm lap session and produce exactly the observations a vet will ask about if you ever phone with a worry.
First Check: Front Teeth
Support him securely on your lap and gently lift the upper lip. A guinea pig's front teeth should meet evenly, appear straight, and show clean edges without one tooth outgrowing its partner, slanting, or sitting broken. Continuously growing teeth that meet badly wear badly, so even wear is the reassuring sight. You can see only the front teeth at home, since the cheek teeth sit far back in the mouth, and that limitation shapes the rest of your evidence gathering. Watch how he eats during the week alongside this check. Drooling that wets the chin, dropping food, favouring soft pieces, or taking longer over hay all suggest the back teeth deserve a professional look even when the front teeth appear tidy, and those eating notes belong in the record beside the tooth check.
Second Check: Eyes
Healthy eyes are bright, fully open, and clear. Look for discharge, cloudiness across the surface, crusting gathered at the corners, or one eye held partly closed while the other sits open. Guinea pigs produce a milky fluid used in grooming that briefly clouds the eye area before they wash it away, so judge persistent discharge or lasting cloudiness rather than a fleeting film you catch mid-groom. Note whether both eyes match, because a change on one side only often points to a local cause such as a poke from hay, and telling the vet which eye and since when focuses the examination from the start.
Third Check: Skin and Coat
Part the fur with your fingers along the back, sides, and belly, working down to the skin rather than skimming the coat's surface. Look for scabs, flaking, sores, redness, patches of hair loss, and any sign of parasites moving or debris at the skin. Feel gently as you go for new lumps under the skin, and note the size and position of anything you find with the date. Check the feet during the same session for sore or reddened soles, overgrown nails, or swelling, since a guinea pig resting on soiled bedding can develop sore feet that a coat-focused check would miss. Scurrying mites and other skin causes cannot be separated at home, so persistent scratching with flaking or hair loss goes to the vet as an observation, not as a conclusion you announce.
Fourth Check: Weight
Finish by weighing him, because weight gives you a figure that does not depend on impression. Place him in a light container he knows, set it on kitchen scales, and record the figure with the date, at the same time of day each week for comparability. A stable weight across weeks reassures. A downward drift, even a small one repeated across two or three weighings, deserves a vet call before appetite visibly changes, since guinea pigs that stop eating face rapid digestive trouble. An upward creep matters too, prompting a review of treats and pellets rather than celebration. Bring the weight run to every appointment, because vets weight-trend guinea pigs precisely because a single reading says so little.
When Weekly Checks Become a Vet Visit
Book promptly for weight loss across consecutive weeks, drooling, reduced interest in hay, a new lump, sore or broken skin, or an eye that stays cloudy or closed. Phone the same day if he stops eating, sits hunched and quiet, or breathes with audible effort, since a guinea pig off food deteriorates quickly and early help changes outcomes. Your four-part notes, offered in order, give the vet a head start that a general worry cannot.
His weekly weights and check notes belong together in KinsLe's Pet Passport, where the growing chart sits beside vet visit summaries and turns each home check into part of one continuous record.