Why teeth and weight belong in the same routine
A guinea pig's teeth grow throughout her life and are worn down by chewing hay and fibrous food. When wear goes wrong, the first measurable sign is often on the scale, as eating becomes slower and less effective while appetite still looks keen. That is why teeth and weight are checked together, on the same day each week: the front teeth you can see tell part of the story, the weight trend tells you whether the whole system, including the back teeth you cannot see, is coping. Either check alone misses cases the other one catches.
The weigh-in: same scale, same setup, written down
Use a kitchen scale with a bowl, box, or carrier your guinea pig will sit in calmly, and weigh the container first or use the scale's zero function with it in place. Weigh at roughly the same time of day, because a guinea pig full of breakfast weighs noticeably more than the same pig before it. Write the figure down with the date, every week, in the same place. Individual readings bounce around with gut fill and mood; the pattern across four to six weeks is the information. A pig whose line drifts steadily downward is losing condition even if every single week looked like a small change.
The front teeth: what you can actually see
With your guinea pig supported on your lap or a towel, gently lift the upper lip with a thumb. The four front teeth — two up, two down — should be visible without forcing her mouth open. Look for even meeting edges, similar length left and right, and a clean, straight alignment. Warning signs are a slanted wear line, one tooth clearly longer than its partner, a broken or discoloured tooth, teeth crossing or splaying, or the lower teeth growing up behind at an odd angle. Also notice wetness: a damp chin, dribbling, or a pig who chews eagerly then drops food is flagging mouth discomfort that a normal-looking front view does not rule out.
The honest limit: molars hide at the back
The teeth that do most of the chewing sit far back in a guinea pig's mouth, behind cheeks that make them impossible to inspect properly at home without instruments — and attempting to force a view risks injury and real distress. So treat the home check as screening, not clearance. A guinea pig can have painfully overgrown or spurred back teeth while her front teeth look respectable. That is exactly why the weight record matters so much: it is your window on the teeth you cannot see. Drooling, selective eating where soft food is favoured over hay, smaller droppings, and weight loss are the back teeth asking for a vet's examination, where the mouth can be looked at properly.
Habits that keep the wear even
Home checks work alongside the daily conditions that wear teeth correctly. Unlimited hay is the main tool — the long side-to-side chewing action on coarse stems is what grinds the whole tooth row down evenly, and a guinea pig filling up mainly on pellets does far less of that chewing. If you notice her eating pattern change — slower, messier, preferring one side — move the next check forward instead of waiting for the weekly slot.
When the home check sends you to the vet
Book a vet visit if the weight drifts down across successive weeks, a front tooth is broken, slanted, or overlong, or you see drooling, dropped food, or reduced droppings — even if she still seems bright and hungry. Take your written weights with you; a six-week trend on paper is far more useful to the vet than a memory of her seeming lighter. In KinsLe, her Pet Passport keeps those weekly weights and dental notes together with her other health records, so the history is complete and ready at the appointment rather than reconstructed in the waiting room.