Guinea pigs may look a bit like short-legged rabbits, but their digestive systems are actually quite different. To make life more interesting, guinea pigs are also often very fussy eaters – they decide what they like and refuse what they don’t, and their preferences can change from day to day!
How are guinea pigs different from rabbits?
Well, they have shorter ears… But being serious, the key difference is that, unlike most animals, guinea pigs cannot make their own Vitamin C (just like us, in fact).
What is Vitamin C?
Vitamin C, also known as ascorbic acid, is an antioxidant vitamin that is essential for the guinea pig to form connective tissue, and for their immune system to work properly. Most fresh greens are rich in Vitamin C, especially kale, cabbage, dandelion and parsley; however, it doesn’t survive storage very well and dried vegetation or out of date food is pretty useless as a source.
How much do they need?
Adult, non-breeding guinea pigs need about 10mg of Vitamin C per kg of bodyweight. If breeding, ill, or stressed, however, their requirement goes up to by 3 to 5 times (35-50mg/kg).
What happens if they don’t get enough?
Symptoms are often apparent in as little as two weeks, and include poor coat quality, lameness, limping, shuffling and joint swelling. Symptoms progress to pain when being touched, depression, loss of appetite and abnormal bleeding under the skin. The worse the deficiency, the more severe the symptoms; eventually, if untreated, their immune system will shut down, they will bleed internally and then they will die.
OK, that’s Vitamin C – so, I should just feed my guinea pig on greens, yes?
No, unfortunately, it’s not that simple! Although greens are great for vitamin C and other nutrients, they don’t have enough fibre to keep the guinea pig’s digestive system working properly. A diet consisting solely of green leafy vegetables is actually quite unbalanced (typically too low in protein and carbohydrate, as well as fibre).
Why do they need fibre? Do they constipated without it?
Unlike us, guinea pigs are adapted to live on grass – they actually ferment the fibre in their intestines, and get the vast majority of their nutrition through this process. If they are denied the fibre they need, they will get diarrhoea (which may prove fatal through dehydration) and their intestines will gradually shut down, leading to death from starvation.
In addition, a guinea pig’s teeth grow constantly throughout life. If not ground down (by chewing tough hay or dried grass), they will overgrow and stop meeting properly. As a result, the guinea pig will be first uncomfortable, then painful, and finally unable to eat at all.
So what’s the best type of fibre?
Dried grass – guinea pigs in the wild live high in the Andes Mountains of South America where the grass isn’t as long and lush as it is (usually!) in the UK, but tough and dried by the constant wind. As a result, hay is the best approximation of their natural diet (albeit supplemented with other foodstuffs). The best types for guinea pigs are Timothy or Grass Hays, and whatever else you’re feeding them, they must have an ad lib supply to keep their teeth and digestive systems healthy.
What about guinea pig food?
A properly formulated guinea pig food contains all the nutrients – including Vitamin C – that they need (although most are relatively light on fibre, so make sure you offer hay as well). There are a variety of different mixes and pellets available. However, there is a major problem with the muesli-type mixes – typically, a fussy guinea pig will only eat the bits they like the most, leading to an imbalanced diet!
But don’t animals select food based on what’s good for them?
Sadly, no. Just as many humans will eat junk food instead of “healthy” salads, many guinea pigs will pick the tastiest bits out of their mix, not the healthiest. If it’s hard to get people to make healthy food choices, what makes you think guinea pigs are any cleverer than we are?!
OK, that’s all very interesting, but what should I actually feed them?
Bottom line – feed a pelleted complete guinea pig food with ad lib hay. It may look boring to you, but it’s the best diet for a long and healthy life for them!
If you need advice about feeding or caring for your guinea pig(s), give us a ring!