Diarrhea in Guinea Pigs

There are many causes of diarrhea in guinea pigs and identifying why your guinea pig is unwell is crucial in their recovery. Diarrhea may be caused by diseases or infections in the gastrointestinal tract, by lack of a healthy diet or by a secondary illness that is yet to be discovered. Do not ignore signs of diarrhea in your guinea pig.


There are many different signs of diarrhea in guinea pigs, and while it is often something that passes quickly sometimes it can be the result of a secondary illness. If your guinea pig is producing a very dark to black, foul smelling liquid instead of stools, seek immediate emergency vet treatment as this is a sign of serious internal illness or injury. 

  • CHANGE IN STOOL SHAPE: Guinea pig stools should be fairly uniform in shape and colour during a bowel movement. If your guinea pig has diarrhea their stools will be misshaped, lighter in colour, watery and soft.
  • CHANGE IN STOOL COLOUR: Guinea pig stool colour alters depending on their diet, however mostly varies between dark browns. A stool lighter in colour can be signs of diarrhea or even bloat, if your guinea pig has light, watery stools that are painful to pass then it’s crucial you seek vet treatment.
  • FOUL SMELL: Generally, guinea pig stools do not have a strong odor to them but abnormal stools, such as diarrhea, will. If your guinea pig regularly has foul or strong smelling stools, it may be a sign that there is an internal health problem.
  • LETHARGY & DEHYDRATION: Diarrhea can cause dehydration, which in turn leads to lethargy in guinea pigs. If you find your guinea pig is sleeping more than usual, or is very slow and tired they could be dehydrated. When a guinea pig is severely dehydrated, their eyes may sink into their heads and appear smaller. If your guinea pig is showing signs of severe dehydration, seek immediate vet help.
  • SQUEAKING WHEN PASSING STOOLS: Just like in humans, diarrhea can be painful. Your guinea pig may cry or make noises when trying to pass a stool. You may also find your guinea pig hunches over or curls their spine when trying to pass urine or stools. These signs should not be ignored.
  • RAISED FUR: Guinea pigs are very good at hiding pain so they may not cry if something hurts them. Instead, the fur around the affected area may stand up on it’s ends and appear raised or spiky. If you see your guinea pig has raised fur around it’s sides or backs while they attempt to go to the toilet, they are most likely in pain and need medical treatment.
  • SWELLING OF ABDOMEN AREA: Place your guinea pig on a flat surface and look down at them. If one side of their body (left) looks bigger, they could be suffering from a gas build up which can lead to bloat. This can be extremely painful for guinea pigs and should be tended to as soon as possible.


  • COPROPHAGY: Guinea pigs have a special type of stool that they will eat to help keep their digestive tracks healthy. These stools are usually a deeper green shade in colour, are softer to touch and can have a strong scent to them but still hold their regular shape. When sick with diarrhea or similar issues, a guinea pig may also eat the droppings of a healthy guinea pig to help their digestive health. This is normal behavior and is very important to keep healthy.


  • CHANGE IN DET: Guinea pigs have sensitive digestive systems and a sudden change in diet can lead to diarrhea. Slowly introduce new foods that your guinea pig hasn’t tried. If switching what type of pellet you feed your guinea pig, slowly mix the new pellets into their old ones over the course of a week. Fresh grass in large amounts after not digesting grass for large periods of time may also cause diarrhea.
  • EXCESS FRUITS & VEGETABLES: Excess amounts of fresh fruits and vegetables in a guinea pigs diet can lead to diarrhea. If you suspect you have been feeding your guinea pig too many vegetables, remove them and ensure your guinea pig has 24/7 access to hay for the much needed fiber. Fresh vegetables may be fed again once the diarrhea has passed. Find more information on a balanced guinea pig diet here.
  • LACK OF ROUGHAGE:  Hay is a key part in maintaining the health and well being of your guinea pig. A lack of roughage and fiber in a guinea pigs diet can alter the normal movement of their intestines.
  • BACTERIAL INFECTIONS: E. coli and Salmonella both may cause diarrhea in guinea pigs. Bacterial infections can spread through contaminated hay, bedding, food or other pets.
  • USE OF ANTIBIOTICS: Many antibiotics can cause fatal gastroenteritis guinea pig. If you find your guinea pig has developed diarrhea after the use of medication, immediately discontinue the use of it and notify your vet.  Be sure your vet is experienced in treating guinea pigs to prevent misdiagnosis.
  • DENTAL PROBLEMS: Overgrown teeth, gum infections or sore molars can all affect how your guinea pig chews. Incorrectly digested food can lead to diarrhea and other health issues. Hay is a major component in keeping guinea pigs teeth healthy as it provides the much needed roughage to keep their teeth short, as well as fiber for a healthy digestive system.


While some cases of diarrhea are only short, it is important that the diaognosis is accurate to prevent any serious illnesses that may occur. The only way to get a true diagnosis for your guinea pig is to take them to a vet who is experienced in treating guinea pigs.


It’s important to provide your vet with as much information on your pet as possible. Giving an accurate description of your guinea pigs diet, environment and contact with other animals can help ensure that your vet gives your pet the correct diagnosis. When taking your guinea pig to the vet for diarrhea, it’s always a good idea to bring a sample of both their urine and fecal matter so your vet can see if there is any unwanted bacteria in your guinea pigs body.


  • DIET MODIFICATION: Long term diet modification may be necessary if the cause of diarrhea is due to an inadequate amount of fiber.
  • FLUID THERAPY: Your guinea pig may need fluid therapy if they become severely dehydrated.
  • ANTIBIOTICS: If the diarrhea is a result of a bacterial infection, your guinea pig may be prescribed antibiotics. There are many popular antibiotics (such as penicillin) that are not safe for guinea pigs and should under no circumstances be used. Ensure your vet is experienced in treating guinea pigs.
  • DE-WORMING: Some parasites can cause diarrhea in guinea pigs and must be de-wormed to eliminate the parasite.
  • FORCE FEEDING: In some cases your guinea pig may have to be force fed. This means syringe feeding them crushed pellets or Critical Care at various hours of the day to ensure your guinea pigs health. It’s vital that guinea pigs continue eating while sick and recovering to maintain a functioning digestive system.


  • DIET MODIFICATION: The best way to ensure your guinea pig is getting the fiber it needs is to give them 24/7 access to hay (preferably Timothy hay). If you are using an alfalfa based pellet, consider switching to a timothy hay based pellet instead. This not only increases their fiber consumption, but lowers their risk of bladder stones which excess calcium can cause.
  • SUPPLEMENTS: Healthy supplements that are made for guinea pigs can aid in digestive care. Oxbow Animal Health has a small, but great variety of small animal supplements including Digestive Support and Papaya Support which are both excellent for when recovering after an illness.
  • ANTIBIOTICS: If your guinea pig is placed on antibiotics, it’s important to ask your vet for a probiotic. Antibiotics can alter your guinea pigs gut flora, which can create irregular bowel movements and diarrhea. If you are unable to get a probiotic, you can mix the droppings of a health guinea pig with a small amount of water and syringe feed that to your guinea pig. Alternatively, many guinea pigs will simply eat the fresh dropping of another guinea pig without a fuss. A small amount of powder from a acidophilus capsule can also be sprinkled over their food to help restore gut flora.

Diarrhea should be treated as an emergency and your guinea pig should see a vet as soon as possible. Of course all guinea pigs are different and the looks of their stools will vary, but if you do suspect your guinea pig is producing abnormal stools or is otherwise ill, please seek treatment from a vet who is experienced with treating guinea pigs.

You may also like...