How to Transition Your Guinea Pig or Rabbit to New Hay, Pellets and Other Foods
by Dr Sam - Small Animal Veterinarian
Today we will discuss how to safely transition your guinea pigs or rabbits to new foods. This is something I often see small pet 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 critter happy and healthy.
Understanding What Guinea Pigs and Rabbits Eat
A healthy guinea pig and rabbit 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 or rabbit should also be eating a small amount of fresh vegetables daily (about 1 cup per adult), and a specially formulated pellet designed for guinea pigs or rabbits —particularly, for guinea pigs, one that contains added vitamin C.
Read more about choosing the best guinea pig pellet here.
Read more about choosing the best rabbit pellet here.
Why and When to Transition Food
There are several reasons why you might need to change your small pets' 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 critter 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 or rabbits 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 and rabbits have access to fresh water at all times.
One of the biggest mistakes I see as a vet is owners switching guinea pigs / rabbits food too often and too quickly. This often leads to fussy small pets who are reluctant to eat the newly offered food, which is both frustrating as an owner and not ideal for guinea pig and rabbit 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.
Monitoring Guinea Pig / Rabbit Health
A great way to check how your small pet is coping with a food change is to watch their droppings. Healthy guinea pigs produce firm, oval-shaped poos - rabbits should have round, firm, and dry fecal pellets daily, resembling compressed hay or "cocoa puffs". 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 or rabbit 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 or rabbit'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 critter!
If you're unsure at any point, reach out to your local exotics vet for advice (Find your nearest one here!). It's always better to ask than to guess. And remember, keeping your guinea pigs and rabbits well-fed, hydrated, and enriched will go a long way toward a long and joyful life together!
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