Calcium in Guinea pigs: everything you need to know

Calcium can be a tricky and worrying topic to get your head around but we’ve got the answers. 

Have you recently noticed white spots on your guinea pig's fleece liners and wondered why? Well, these mysterious white spots can indicate that your guinea pig has eaten a lot of calcium.

The white spots in themselves shouldn’t cause you alarm; they’re just how your piggy naturally passes unwanted calcium through their urine. You’ll usually see white marks a day after a heavy calcium meal.

While calcium is an essential mineral in your guinea pig's diet, an overload of it can be harmful to their health. However, it’s also crucial to be aware that it should never be removed entirely. That’s because a lack of calcium in your guinea pig's diet could also be detrimental. Confusing isn’t it! You may also be wondering just how much daily calcium intake your piggy should actually have. Here’s our easy-to-follow guide to guinea pigs and calcium, with helpful comments from Tara Richardson, who runs the Kavee Rescue.


    • Calcium is a critical mineral for guinea pigs 
    • Too much calcium can lead to bladder and kidney stones 
    • Only feed high-calcium food two to three times a week
    • White urine stains are normal unless the stain has a sludge or gritty texture, or blood - all of which can be signs of calcium excess
    • Phosphorus plays a critical role in the absorption of calcium
    • The ratio Calcium:Phosphorus must be kept between 1.3:1 to 1.6:1 for optimal health  
    • If you must closely monitor your guinea pigs' calcium intake:
      • Limit high-calcium food to once a week
      • Calculate the ratio in your guinea pigs vegetable using Guinea Lynx calculator 
      • Calculate the ratio in your guinea pigs nuggets using the nutritional analysis section 
      • Feed Timothy hay instead of Alfalfa hay 
      • Avoid guinea pig nuggets made with Lucerne

How much calcium does your guinea pig really need?

What exactly is Calcium? 

Calcium is a mineral which is essential for most animals, including humans and guinea pigs. It’s needed for several vital bodily functions such as regulating muscle contractions and heartbeat, and ensuring normal blood clotting. 

Calcium is also needed to help build bones and teeth in order to keep them healthy - and we all know just how important guinea pigs’ teeth are for their survival. After all, a piggy’s teeth never stop growing and they need them for munching yummy hay and fresh veggies!

What exactly is calcium? the importance of calcium in guinea pigs diet

What are the main sources of calcium for guinea pigs?

If you’re wondering where to find calcium, here’s the answer - calcium is in several different types of foods. You may be aware that, for us humans, dairy produce like milk and cheese are excellent sources of calcium. But how about guinea pigs who obviously CANNOT be fed dairy snacks such as cheddar or brie? 

Well, thankfully, calcium can also be found in the sorts of raw leafy greens and vegetables that guinea pigs love to eat. 

Some calcium rich foods include: 

  • Kale
  • Spinach
  • Dill
  • Parsley
  • Beetroot (particularly their leaves/greens)
  • Oranges

For a comprehensive list of high and low-calcium vegetables, please check the very useful lists provided by the Guinea Pig Forum as well as Guinea Lynx.

examples of vegetables and fruits with high good sources of calcium for guinea pigs

For a reminder of safe vegetables and fruits for guinea pigs, check our free care sheets for guinea pigs too.

How much Calcium do guinea pigs absorb?

The average human being absorbs about 30% of the calcium they ingest. But guinea pigs absorb more - about 50% - of the calcium they ingest. 

Just like in humans, vitamin D aids in the absorption of calcium, so try to give your guinea pig about 20 minutes of daily sunlight as long as it’s not too cold. (For tips on outdoor floortime for your guinea pigs, check our article, 'The Ultimate Guide to Taking your Guinea Pigs Outside on a Sunny Day). 

Other minerals are critical to the absorption of calcium, such as phosphorus. 

how do guinea pigs absorb calcium?

How does calcium work in your guinea pig’s body?

Right, now it’s time to get a little bit technical so read very carefully and try to concentrate! Here goes…

Calcium is stored in the teeth and bones, and is also found in cells and in blood. Your guinea pig’s body cleverly controls exactly where the calcium travels in order to keep everything healthy.

This ingenious process is known as calcium homeostasis (which is admittedly a bit of a tongue twister). Homeostasis is the technical term used to describe balance, which is what exactly happens within your guinea pig's cells. To achieve a nutritional balance, this process involves two hormones called parathyroid hormone (PTH) and calcitonin, along with vitamin D and another mineral called phosphorus as well as small amounts of the minerals, magnesium and potassium. Together, they control how and where calcium is stored within the body.

Phosphorus is especially important in this process as it works together with calcium as a team to build healthy bones. When calcium levels rise, phosphorus levels fall - and vice versa. That's why it's important to have the right balance of both these crucial minerals in order to keep the body running smoothly. This can be achieved by providing your guinea pigs with a balanced diet!

What are normal levels for calcium and phosphorus in guinea pigs?

As stated before, phosphorus is important for the absorption of calcium, so really we should be looking at both of them instead of just calcium levels. A healthy guinea pig’s calcium level should be between 2-3 mmol/L of blood and their phosphorus level should be in the range of 0.68 - 2.3 mmol/L per litre of blood. 

This really isn’t something you can check at home. Your guinea pig’s calcium and phosphorus levels must be tested by a qualified vet. If you are currently searching for a vet for your guinea pigs, please consult our map of recommended cavy savvy UK vets.

However, your guinea pigs' calcium and phosphorus levels are not something you should worry about, unless you know for sure your guinea pigs are prone to calcium excess, in which case you should watch their intake - see sections below for further guidance. 

What are normal levels for calcium in guinea pigs?

When should I worry about calcium for my guinea pigs? And what are those white spots on my guinea pig’s fleece liner?

Guinea pigs expel excess calcium in their urine. These milky white calcium secretions are what you may see on your guinea pig's fleece liner or pee pad.

Tara explains:White powdery spots on your piggy’s fleece are nothing to be concerned about. Guinea pigs naturally pass unwanted calcium through the urine and so you will see white marks a day after a heavy calcium meal. The concern is when there is sludge, a gritty texture or blood.”

What are those white spots on my guinea pig’s fleece liner? kavee ivory fleece liners for guinea pig C&C cages

However, harder, grittier white stains on your guinea’s pig bedding may indicate a health issue. Why? Well, as guinea pigs’ urine is naturally alkaline, calcium can’t dissolve in it. Instead, it tends to form clumps otherwise known as uroliths or ‘urinary tract stones’. These hard stones can develop anywhere in your guinea pig’s urinary tract, bladder or kidneys and are more commonly found in sows.

These stones are sometimes tiny enough to pass when your piggy pees. However, larger stones may get stuck in the urethra or cause bladder irritation, bleeding or even prevent your guinea pig from urinating at all. Common signs to watch out for include hard, gritty white stains on your guinea pig's bedding or noticing them straining, squeaking or crying as they try to pee.

On the other hand calcium deficiency can lead to weak bones and teeth, which can be devastating for your piggy’s health.

What happens if your guinea pig has too much calcium? Signs of high calcium in diet

How can guinea pigs be treated for bladder and kidney stones?

Treatment for bladder stones can be risky, which is why it’s important to be aware of what you’re feeding your piggy in order to avoid this painful health issues in the first place.

Tara explains: “Treatment of stones will depend on your exotic pet vet. Many are managed with a low calcium diet and pain management. Antibiotics can be given in the event of stones causing an infection along with anti inflammatory medications and painkillers. Some piggies can pass the stones if they’re small enough. If not, surgery can be performed. As we all know, surgery brings its own risks but if the stones are severe and too large to be passed through the urethra this may be the only option. We recently lost a little boar to complications after treating bladder stones.”

How can guinea pigs be treated for bladder and kidney stones? guinea pig at vets

Why are Kavee fleece liners and pee pads useful for keeping an eye on your guinea pig’s calcium levels?

We’ve already talked about the white stains secreted by guinea pigs in their urine, indicating that their diet is too high in calcium. When these stains are harder and grittier, it may be a sign that things aren’t quite right with your piggy.

Now consider this: you’re unlikely to spot the tell tale white marks if your guinea pig is peeing onto wood shavings or white paper bedding, are you? However, if your piggy’s cage is lined in soft fleece liners and pee pads, it will be easier to spot suspicious white stains on the fabric and adjust your piggy’s diet as required.

Why are Kavee fleeces and pee pads useful for keeping an eye on your guinea pig’s calcium levels?

Should I be worried about feeding high-calcium food to my guinea pigs?  

If your guinea pigs are healthy, there is nothing to worry about. Just know which food are rich in calcium and only feed them two to three times a week (For a comprehensive list of high and low-calcium vegetables, please check the very useful lists provided by the Guinea Pig Forum as well as Guinea Lynx). 

Tara explains: “How often should you feed calcium rich foods? Well, the simple answer is that, as long as you're balancing the diet, it’s not something to worry about too much. Feeding high calcium foods two to three times a week is usually adequate to allow for a good variety of foods throughout the week. Keep a close eye on your piggy’s wee and poo - it’s often one of the first signs that something is wrong. Always consult an exotic vet if you're worried, feed a balanced, varied diet and give them the happiest life you can.”

My guinea pigs have had an issue with calcium, what should I feed them now? 

If your guineas are displaying signs of having too much calcium in their diets, limit the high calcium foods to just once or twice a week. 

Owners of guinea pigs with bladder issues or similar health concerns, in particular, may also want to consider "low calcium diets" where they keep an eye on the Calcium:Phosphorus ratio. As explained earlier, it is important to also consider phosphorus when keeping an eye on calcium since those two work together. 

All in all, the ratio Calcium:Phosphorus should be around 1.5:1. You do not need to get the ratio perfect - as long as it is somewhere within the range of 1.3:1 to 1.6:1, and you are feeding a good variety in moderation. 

To calculate the ratio in your piggies' vegetables and fruits, you can use this free Calcium:Phosphorus ratio calculator by Guinea Lynx. Always aim for a ratio between 1.3:1 to 1.6:1.

Also take into account the calcium and phosphorus content in your guinea pig’s nuggets. By consulting the nutritional analysis section on the packaging, you can also figure out their ratio (usually they are given as a percentage). Some nuggets are made with Lucerne, which is Alfalfa hay, and rich in calcium. Whilst piggies find it very tasty, it should be fed in moderation to adults. Instead, look for foods made with Timothy hay, which is lower in calcium.

When it comes to hay, feed Timothy hay as it is lower in calcium than Alfalfa hay or clover hay.  It’s important to be aware that baby guinea pigs need more calcium than older piggies as their bones are still developing. For that reason, feed calcium-rich Alfalfa hay to little ones to ensure they’re getting enough. The same applies to pregnant and nursing mums. However, once your piggy is fully grown, switch to Timothy hay which is lower in calcium but high in fibre.

Please find below four examples of calcium-balanced meals for two guinea pigs with a ratio betwee1.3:1 to 1.6:1. 

4 examples of calcium-balanced meals  for 2 guinea pigs

Reminder of some golden rules for feeding your guinea pig:

  • Your guinea pig should have an eighth of a cup (16g) of pellets per day.
  • The rest of their food should be made up of fresh food and hay.
  • Feed your piggy 1/2 to 1 cup of fresh leafy greens or other vitamin C rich vegetables daily (approximately 50g per guinea pig).
  • Guinea pigs require 10 to 30 mg/kg of vitamin C daily to prevent scurvy
  • Only give fruit as an occasional treat, once or twice a week.
  • Your piggy should have constant access to fresh water.
  • Be careful to only feed your guinea pig calcium-rich veggies such as kale or spinach two to three times a week only 
  • As spinach leaves often come in mixed salad bags, save a few of the leaves for your guinea pig but only serve them once or twice a week as a treat.


Calcium is an important part of your guinea pig's diet for healthy bones and teeth. If calcium rich foods are fed too frequently, guinea pigs have an increased risk of developing urinary tract stones. However, as long as you feed your guinea pigs a balance diet, by following the tips outlined above, don't sweat it unless you notice an issue! Should your guinea pig show signs of a high calcium diet, such as gritty or sludgy white urine, it is advised to consult a cavy savvy vet to further assess your guinea pigs calcium and phosphorus levels.

 golden rules for feeding your guinea pig piggy eating parsley

Further resources 

For more guidance on a healthy diet for your piggy, check out Kavee’s free downloadable care sheets and daily feeding guides.

Also check those two great resources below for more information on calcium in guinea pigs:


Males vs females - which guinea pig should you choose?

How to keep guinea pigs in 2021

The ultimate guide to using fleece liners for guinea pigs

How to bathe a guinea pig - the ultimate step-by-step guide

The truth about how big your guinea pig cage size

All you need to know about guinea pigs fights

The genesis of Kavee: A guinea pig love story

4 reasons to add a stand to your C&C cage

Do guinea pigs smell?

Recommended guinea pig vets in the UK: Cavy savvy vet maps

6 ways in which C and C cages got better

Why are guinea pig owners swapping from wood shavings to fleece

How many guinea pigs are there in the world?

How to clean a C&C cage?

The real and shocking cost of owning guinea pigs

20 best ways to bond with your guinea pigs

The ultimate guide to foraging for your guinea pigs & rabbits

Reducing your guinea pigs’ carbon footprint

Step-by-step guide to cleaning your guinea pigs ears

Do guinea pigs fart? All about bloating

The definitive guide to floor time for guinea pigs


Guinea pig careGuinea pig health

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