Human time and guinea pig equivalent age:

3 months = 2.5 years old	2 years = 20 years old	5 years = 50 years old	8 years = 80 years old
6 months = 5 years old	3 years = 30 years old	6 years = 60 years old	9 years = 90 years old
1 year = 10 years old	4 years = 40 years old	7 years = 80 years old	10 years = 100 years old

 

A six-monthly health check for your pet guinea pig is equivalent to you visiting the doctor once every five years.