
How to Transition Your Guinea Pig to New Hay, Pellets and Other Foods
How to Transition Your Guinea Pig to New Hay, Pellets and Other Foods
Hi everyone, I’m Dr Sam, a small animal veterinarian, and today I’d like to talk about how to safely transition your guinea pigs to new foods. This is something I often see guinea pig owners struggle with in practice. Whether you're switching to a different type of hay, introducing a new vegetable, or upgrading your pellets, a slow and careful approach is essential to keep your guinea pig happy and healthy.
Understanding What Guinea Pigs Eat
A healthy guinea pig diet is based predominantly on hay. In fact, hay should make up around 80% of their daily intake. It’s vital for keeping their digestive systems functioning properly and also helps wear down their ever-growing teeth. In my experience, the most common types of hay available in Australia include timothy, oaten and pasture hay.
Alongside hay, your guinea pig should also be eating a small amount of fresh vegetables daily (about 1 cup per adult guinea pig), and a specially formulated pellet designed for guinea pigs —particularly one that contains added vitamin C. Read more about choosing the best guinea pig pellet here.
Why and When to Transition Food
There are several reasons why you might need to change your guinea pigs food. Sometimes it’s as simple as your usual product being out of stock or discontinued. Other times, you may want to switch to a higher quality brand or a more nutritious alternative. You might also notice your guinea pig becoming fussy or uninterested in their current diet, or perhaps a health issue requires a dietary adjustment.
Whatever the reason, the most important rule to follow is to make any transition gradually. Sudden changes can easily upset their gut and cause more harm than good.
When introducing a new type of hay, start by mixing it with the old hay. At first, use just a small amount of the new variety. Over a week or more, increase the proportion of the new hay while decreasing the old. This allows your guinea pigs time to adjust to the change in texture, taste, and smell. Keep the hay fresh and clean, and try offering it in different parts of their enclosure to encourage natural foraging behaviour.
When changing pellets from one brand to another, a similar technique is used. Different brands may have a transition guide on the back of their packaging which is handy to follow, such as Burgess Excel. We recommend slowly transitioning pellets over a period of 14 to 28 days, starting with about 75% of old pellets mixed with 25% of the new pellets. Over the next week we recommend gradually reducing the ratio to 50% of each pellet, and week 3 adjusting the ratio again to 75% of the new pellet, 25% of the old pellet.
When adding new vegetables only introduce one new food at a time. For example, if you're adding capsicum to their diet, offer just a small piece at first and monitor them over the next 24 hours. You’ll want to look out for signs like soft stools, bloating, or any change in behaviour.
Also, make sure your guinea pigs have access to fresh water at all times.
One of the biggest mistakes I see as a vet is owners switching guinea pigs food too often and too quickly. This often leads to fussy piggies who are reluctant to eat the newly offered food, which is both frustrating as an owner and not ideal for guinea pig health if they are missing vital parts of their diet. Swapping food too quickly or too often can also lead to gut stasis, which is a serious condition that causes their digestive system to slow down or stop altogether as it has not had time to adjust to the changes in diet - this can become life threatening.
A great way to check how your guinea pig is coping with a food change is to watch their droppings. Healthy guinea pigs produce firm, oval-shaped poos. If you start seeing smaller, misshapen, or fewer droppings, it may mean their digestive system is struggling. Behaviour is also a key indicator—if your guinea pig is quieter than usual, less active, or not showing interest in food, it could be a sign something’s wrong.
Final Thoughts from Dr Sam
As a vet, I truly believe that taking your time when changing your guinea pig’s diet is one of the kindest things you can do for them. Moving slowly, watching closely, and keeping their environment consistent will help ensure a smooth transition. Whether it’s new vegetables, pellets, or hay, your efforts will be rewarded with a happy, healthy guinea pig.
If you're unsure at any point, reach out to your local vet for advice. It's always better to ask than to guess. And remember, keeping your guinea pigs well-fed, hydrated, and enriched will go a long way toward a long and joyful life together.