Guinea pigs share one important trait with people: their bodies cannot manufacture vitamin C, so every bit of it has to arrive in food. When intake quietly falls short over time, the tissues that rely on that vitamin, especially joints, skin, gums and blood vessels, begin to suffer, and the resulting picture is what owners generally refer to as scurvy.
The signs most often described
Movement is frequently where it shows first. Affected guinea pigs may walk stiffly, hop with both back legs together, cry out when lifted, or simply stop moving around the pen and sit hunched in one spot. Joints can look swollen and feel tender, and a pig who once popcorned may become withdrawn and quiet. The coat often turns rough and dull, skin may heal slowly from small scrapes, and you might notice loose teeth, sore or bleeding gums, drooling, or a pig who wants food but struggles to eat it. Appetite commonly drops, weight slips, and young growing pigs may fail to thrive. Diarrhoea, general weakness and a tendency to pick up other infections can round out the picture. Each of these signs has other possible causes too, which is exactly why this is a pattern to take to a vet rather than a label to settle on at home.
How a shortfall usually happens
Understanding the route in helps you describe it accurately. Vitamin C fades in stored food, so an old bag of pellets kept open for months may deliver far less than its label once promised. A pig fed mostly hay and pellets with few fresh vegetables may simply never get enough, and a picky eater who leaves the vitamin-rich foods while filling up on favourites can drift into shortage while looking well fed. Illness, stress, pregnancy and growth all raise the body's demand at the same time as appetite may fall. None of this means a caring owner has failed; it means the daily diet deserves a fresh look, ideally with veterinary guidance about what this particular pig is actually eating and leaving behind.
What to do when you recognise the pattern
Book a vet visit rather than simply adding a supplement and waiting, because sore joints, dental trouble and other illnesses can imitate or overlap this picture, and a pig in pain needs the cause sorted, not just the diet. A guinea pig who has stopped eating, cannot walk comfortably, or is losing weight needs to be seen promptly, since pigs deteriorate quickly once food intake drops. Before the visit, write down exactly what your pig eats in a day, which vegetables are offered and eaten, how old the pellet food is, and when you first noticed the stiffness or quietness. That feeding history is the single most useful thing you can hand over.
Bringing that written diet and symptom timeline with you makes the appointment far more productive, and KinsLe's Pet Passport keeps your guinea pig's feeding notes and vet history together in one portable packet for visits like this.