Can Guinea Pigs Eat Hay?

In the last decades, the number of people that own at least one pet has grown a lot. However, more pets being adopted or bought is not an equivalent to helping animals because a lot of pet owners care for their little buddies just when it’s play time with them. This is not good and I encourage people to get a pet only if they really love animals. Getting a pet just because all of your friends have one or because it’s cool to have one is absurd – yes, there are people that think like this. 

These little but problematic things made me take the elephant out of the room and say that people need to be more caring with their pets. Becoming interested in their needs is what brings you closer to them. Pay attention to their favorite foods and give them what they need more often. When it comes to diet, some animals are more sensitive than others and this is the case with guinea pigs. Now we will talk about hay as food for the guinea pigs.

So, can guinea pigs eat hay? Yes, guinea pigs can eat hay. Hay is, along with water, is one of the things these little pets need to have on hand at all times. If you clicked on this article for the answer to this question (and not for some additional information), then this should be your first documentation on guinea pigs. They need water, hay, and pellets in order to survive with other raw foods such as vegetables, fruits, and herbs. 

Health Benefits of Guinea Pigs Eating Hay

The benefits are endless, but I will name a few: 

  • Hay prevents the teeth of guinea pigs to get too long 
  • It prevents illness 
  • Hay can be used as comfortable bedding. 
  • It regulates their digestive system. 

A little side-note: as we know, guinea pigs are really sensitive, so it’s no surprise their respiratory system is fragile. This is why the hay needs to have as little dust as it can have. 

Different Nutrition Facts and Types of Hay

1. Alfalfa 

This type of hay is not recommended for casual use. Young, pregnant or nurturing guinea pigs should eat alfalfa hay because it contains high levels of calcium, and in these stages of life, they need more calcium. 

Calcium is the mineral that you need to keep an eye on because of its immediate and drastic effects on a guinea pig. Calcium is very beneficial for the little pets if it is consumed in small amounts. Small amounts of calcium strengthen the bones, along with vitamin C. It also improves the teeth. 

2. Timothy 

Timothy hay is perfect for any adult guinea pig. You can start feeding them timothy hay after they stopped growing – at 12 or 14 months.  

Timothy hay is much more suitable because it has a low amount of calcium. The quantity of hay a guinea pig eats a day is huge comparing to other foods, so it makes perfect sense to give your little friend a low-calcium type of hay. 

Besides, timothy hay contains vitamin C as well. Vitamin C has a lot of benefits for guinea pigs. Vitamin C lowers the chance of getting a cold, it fixes the calcium in the bones, it prevents scurvy (a disease that it is practically a vitamin C deficiency). 

Too much vitamin C in a guinea pig’s organism is not a huge problem – the vitamin C is eliminated through urine, so it will flush out at some point. However, what happens if they don’t get enough vitamin C? 

The amount of hay with low vitamin C they eat daily is not enough for the 10 to 30 mg they need to gain during the day. Pellets contribute, but it still isn’t enough. Vegetables and fruits are the last part of the diet that completes the scheme. This is why a balanced diet is key. 

  • Scurvy

Scurvy is a vitamin C deficiency. The symptoms are very easy to recognize: diarrhea, lack of appetite, lack of energy, lethargy, weakness in bones.

Ultimately, scurvy can cause a sudden death of a guinea pig.

Don’t risk anything – take your little friend to the vet, at least twice a year – and prevent scurvy along with your pet’s death. Scurvy can be treated with supplements, but it is better prevented than treated.

Risks to Consider When Feeding Hay to Guinea Pigs

  • Too much calcium – the calcium to phosphorus ratio, determines if bladder or kidney stones will start forming. This is why alfalfa hay needs to be consumed just by the guinea pigs that have a temporary calcium deficiency.


  • You need to check hay you are going to feed your guinea pigs for any mold or high content of dust because they can get sick or get allergies. This is why it is very important to only buy well-established brands of hay.

Quick Facts

  • Also, hay is the main source of food for different domestic animals. 
  • The moisture content of baling hay should be less than 20% for it to be safe to eat by animals. 
  • Hay is usually harvested later than it should be. The later you harvested the hay, the more it loses its quality. 
  • Rain is pretty damaging for the hay, but it doesn’t compare to the amount of damage caused by late harvest. Rain causes increased microbial activity.

Related Questions

What are guinea pigs not allowed to eat?

Guinea pigs are not allowed to eat any cooked foods or meals – boiled, fried or baked – for several reasons. One of them is that their digestive system is adapted to this lifestyle and it cannot process cooked food.  

The second one is that it is simply not beneficial for them. Raw foods have the maximum nutrients they can have and once you cook them, they lose a lot of their properties, making cooked food not as healthy as raw food.

How much hay can you give to your guinea pig and how often should hay be fed to them?

You should know the answer by now, but I will say it again – hay needs to be fresh and guinea pigs need it at all times nearby.

What does a really healthy diet look like for a guinea pig?

A healthy diet for a guinea pig is very various. It should consist of vegetables, fruits, hay, water, and pellets. They eat hay and drink water all the time. The only concern about these two is to always be fresh. 

Pellets are not a big concern – a small amount daily (an eighth of a cup) is enough for their basic needs. Guinea pigs get the rest of the vitamins and minerals they need from the vegetables and fruits. The secret to their veggie-fruit diet is variety and small quantities. 

Before I let you go, one final thought on food. With food, you can’t ever be too careful which is why I get all guinea pig food from a reliable source such as Amazon. If you are not sure what to order but believe your little piggies deserve some great treats please check our Helpful Guide to the Best Guinea Pig Treats to get some ideas. We have also made a full list of foods that guinea pigs can and can’t eat (150+ Types of Foods). Be sure to also check our recommended products page for everything you will ever need to assure a happy life for your Guinea Pigs. Hope this information was helpful and you have found the answer you were looking for.

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