Diabetes type 1 and 2 are both common in guinea pigs. Diabetes type 1 usually occurs in younger guinea pigs, about 1 year old or younger, while diabetes type 2 usually occurs in adult guinea pigs. (Reference 1) Being able to recognize diabetes symptoms in your guinea pig will enable you to know when your guinea pig needs to be seen by a veterinarian.
Check to see if your guinea pig is drinking more than usual. Like with humans, guinea pigs will have an increase in thirst and drink excessively. You can check this easily by changing your guinea pig's water on a consistent basis, such as every day at the same time or every other day.
Take note on if your guinea pig is urinating more frequently. Although this is usually due to excessive thirst, it can also be due to a urinary tract infection. Frequent urinary tract infections are often a symptom of diabetes.
See if your guinea pig is losing weight. This can be difficult to tell because guinea pigs have fluffy bodies and often look pudgier than they actually are. However, you may notice that he or she feels lighter when you are handling them.
Check your guinea pigs bottom frequently. Having a chronic wet bottom is common in guinea pigs with diabetes and should be monitored.
Look at your guinea pig's eyes for cataracts. Although they may be hard to see with the human eye, guinea pigs with diabetes will often form cataracts rapidly in a short amount of time.
Take your guinea pig to a veterinarian. This is the only way to know for sure whether your guinea pig has diabetes and to see what treatment options are available.