The Curious Case of the Carrot
May 18, 2010 by J.C. Burcham, DVM
Filed under Exotic Mammals
Meet Toby. He’s a 3-year old guinea pig, and a very loved member of the family. Every day, he wakes up to a clean cage, fresh water and timothy hay, plentiful food, and–his favorite–carrots. Oh boy, does he love carrots! His “mom” gives him about 2-3 baby carrots every day, which he devours.
Toby’s owner knew something wasn’t right when he stopped eating his carrots. Everything else seemed fine–eating, pooping, drinking, acting normally. Trusting her instinct, she brought Toby to Olathe Animal Hospital for an exam. Unable to find anything wrong on physical exam, even after careful examination of the teeth to rule out dental disease, Dr. Burcham recommended whole-body x-rays (radiographs). The problem became crystal clear: a large bladder stone was causing him significant discomfort.
So you may be asking yourself, how did he develop this bladder stone? Could it have been prevented? Reviewing the list of vegetables and their associated oxalic acid content on GuineaLynx.com, we suspect that Toby’s affection for carrots played a significant role. In fact, the top 5 vegetables containing high levels of oxalic acid are:
- Parsley
- Purslane
- Spinach
- Beet leaves
- Carrot
High levels of oxalic acid in the diet are believed to contribute to formation of bladder stones. Other contributing factors may include calcium concentration in the diet, and genetic predisposition. GuineaLynx.com also has an article on bladder stones in guinea pigs, which you may find helpful.
Bladder stones in guinea pigs can only be cured with surgery, as they do not respond to dietary changes. Toby underwent a cystotomy (surgically opening the bladder), and the stone was easily removed. Although it took him about a week post-surgery to return to his normal activity level, he is now fully recovered.


