how can i tell that my guinea pig is getting older

Question
my question is how can you tell that a guinea pig is getting older he is really skinny too when i pet him i can feel his bones i thought guinea pigs were suppose to be fatter he was 6 months old when i got him but i have no idea how old he is now

Answer
Hi Mark.  I recognize the symptom of severe weight loss (defined by the emphasis of his prominent bones) and it usually suggests one of two typical illnesses.  The first being an internal parasitic infestation similar to worms, the second is malocclusion, which is a dental problem.  This involves the overgrowth and misalignment of the molars and incisor teeth and affects the guinea pig's ability to eat much or even at all.  Spurring of teeth can also cause mouth sores and abscesses which in turn can make infection.  I would definitely take your pig to the vet to have his teeth checked and faeces tested for parasites.  In the meantime your pig needs additional dietary help; ask your vet to give you some Oxbow Critical Care or Supreme Science Recovery which are syringe feeds for hand feeding.  I do hope this helps and that your pig gets better very soon.  Keep in touch!