Is your guinea pig eating cardboard and wondering if this is good for it or whether it is an unhealthy habit that could put your pet at risk? Find the answer to this question below in this article.
Guinea pigs are great companions for anyone who likes small pets. They are not very expensive, have an easy diet, do not require a lot of attention, and do not get sick very often.
Although they are generally great pets, guinea pigs have a habit that many would consider disturbing - they like to chew anything. However, the passion for chewing is one of the traits of all rodents. Hence, if you don't like the idea that your animal can gnaw everything in its enclosure, you shouldn't get a rodent as a pet in the first place.
These animals will try to chew everything in their path. The material is not very important to them, as long as it is somewhat soft that they can stick their teeth in it. From textiles to wood, rubber, paper, and even solid plastic, they will nibble anything. Guard your furniture, wires, carpets, and other items if you let these pets freely in your house from time to time. Anything is potential gnawing stuff for a guinea pig.
Even though this habit of chewing anything is perfectly normal for rodents, it can sometimes be dangerous for the animal. For example, they may gnaw things they should not gnaw, such as power lines, cleaning solution containers, or any toxic materials they find in your house.
One cause for concern for many guinea pig owners is also cardboard. This material is not only often found in our homes, but even in their cages as owners often buy various toys or hiding places made of cardboard for their guinea pigs.
Is eating cardboard dangerous for your guinea pigs?
In general, cardboard does not pose a risk to guinea pigs, but there are certain situations when your pet may develop health problems because of it.
First of all, cardboard is a soft material. So there is no risk of your guinea pig breaking its teeth in it. Shredded cardboard is also used for some animals' bedding as it is a good insulator and absorbs moisture.
If your pet just loves to gnaw on the cardboard objects around him, this is not usually a problem. However, problems can occur if the animal not only gnaws the cardboard but also swallows it.
Even occasionally swallowed pieces of cardboard, in most cases, will not make your guinea pigs sick. Their digestive system enables them to process wood and wood-based items, such as cardboard or paper.
However, if your pet gets used to chewing cardboard frequently and swallows large amounts in a short time, this can cause a bowel obstruction . This is a life-threatening condition, and in the unfortunate event that this happens, you have to take your animal to the nearest vet urgently.
Another risk factor is the type of cardboard that the animal swallows.
Cardboard is most of the time made up of recycled paper, sandwiched between two liners. These are made up of a considerable amount of recycled content, obtained from old cardboard or other sources of second-hand paper. 
During the manufacturing process, various solvents and synthetic resins are many times added to increase the final product's resistance or make the cardboard more water-resistant. Additionally, because most of the paper is obtained from recycled newspapers, it carries toxic mineral oils left from the ink. 
So, even if a piece of cardboard may seem harmless to guinea pigs, may contain numerous toxic chemicals that, once ingested, can trigger various diseases.
Consequently, if your guinea pig is used to not only gnawing but also swallowing the resulting pieces of cardboard, you should avoid giving him any more containers, toys, or anything made of this material.
Why do guinea pigs eat cardboard?
The "passion" for chewing is common in guinea pigs. The reason behind this is that their front teeth grow continuously, and chewing is a way to keep them shorter and in good shape.
Many guinea pigs will just gnaw on the cardboard boxes, without consuming the resulting fragments. However, there are also some that choose to swallow them.
This behavior may differ from one specimen to another, but at the same time, if your guinea pig eats cardboard, it could be a sign of an inappropriate diet.
The nutrition of guinea pigs should be composed of fruits, plant leaves, root vegetables, guinea pigs pellets, and especially high-fiber grasses. They also need plenty of hay to help shrink their continuously growing teeth and keep the level of food-fermenting bacterias in their intestinal tract at the optimal level. 
If the diet it's not the source of the problem, maybe they need more things to chew on. Hence, you may keep them busy and satisfy their cardboard-eating craving by giving them other, but more healthy things to gnaw.
For instance, they love to chew young tree branches. These are nutritious and contain fibers that keep your guinea pigs' digestive system healthy.
Thus, if you grow any trees in your hard, you can from time to time collect a few branches and give them to your piggies to nibble. They like to first peel the bark after the branches and later on will chew the wood as well.
Also, ensure that the trees were not sprayed with any fungicides or insecticides prior to collecting the branches. It is also advisable to wash them thoroughly with water before handing them to your pets.
If you don't have any trees around or you want to make sure that you are not mistakenly poisoning your piggies, you can even find some online. For instance, you can order these natural apple sticks from Amazon (affiliate link).