Guinea Pig Health: The Problems Owners Catch Too Late

Weigh your guinea pig every week

Here's the single most useful habit in guinea pig care: a weekly weigh-in on a digital kitchen scale, recorded somewhere you can compare over time. Guinea pigs hide illness, but they can't hide weight loss, and a steady drop of 50–100g is often the first measurable sign of a dental or other problem long before the animal looks unwell. It costs nothing and catches most of the big issues early.

With that baseline in place, the sections below cover the specific problems to watch for and when each one needs a vet.

Vitamin C deficiency: the number one killer

Guinea pigs, like humans, cannot synthesise their own vitamin C. Without adequate daily intake, roughly 10 to 30mg per kg of body weight, they develop scurvy within weeks. Early signs include reluctance to move (joint pain), a rough coat, and bleeding gums. Many owners don't know that vitamin C degrades rapidly in water bottles and that supplementing via water is largely ineffective. An online vet can review your guinea pig's diet and recommend fresh food sources or chewable supplements that actually work.

Dental disease: a long slow problem

Guinea pig dental problems (overgrown molars forming bridges across the tongue) are insidious. They develop over months and the first obvious sign is often dramatic weight loss because the animal has been struggling to chew for a long time before you notice. Regular weight checks (a kitchen scale once a week) are the best early warning system. An online vet can advise on what to look for and when a dental examination is warranted.

Upper respiratory infections (URI)

URIs are common in guinea pigs, especially in newly acquired animals from pet stores or in multi-pig households. Bordetella bronchiseptica is the most common culprit and spreads easily between guinea pigs and from rabbits. Signs are sneezing, nasal and ocular discharge, and laboured breathing. URIs can deteriorate fast: an online vet can confirm whether antibiotics are needed urgently or whether supportive care is appropriate.

Bumblefoot (pododermatitis)

Bumblefoot is inflammation and infection of the footpads, caused by wire-floored cages, obesity, and inactivity. It's painful and can progress to deep tissue infection and bone involvement if ignored. An online vet can assess photos you send and advise on wound care, bedding changes, and whether systemic antibiotics are needed.

Ovarian cysts in sows

Unspayed female guinea pigs (sows) have a very high rate of ovarian cyst development as they age. Cysts cause bilateral symmetric hair loss (particularly along the flanks), irritability, and a distended abdomen. An online vet can advise on the options (hormonal implants, aspiration, or spaying) and help you navigate what to expect from each.

The social needs of guinea pigs: a health issue

Guinea pigs are genuinely social animals that get chronically stressed when kept alone, so much so that in Switzerland keeping a single guinea pig is illegal under animal welfare law. Chronic stress suppresses the immune system and feeds into the GI and skin problems above, so companionship is a health matter, not just a nicety. A vet can advise on safe introductions if you're thinking of adding a second pig.