An old Guinea Pig

Question
I have a 7 year old male guinea pig named Ping.  I know he had allergies and he doesn't like heat, but now he sneezes a lot and coughs.  Today when I opened the cage, I found a lup of I don't know what, could it bee a hairball?  If so, what can I do to prevent another one or help him not suffer so much with them?

Also, I take him outside on warm dry days for a walk.  When he's out for about a half an hour now, he get's a temporary head tilt.  Is that just from old age?

I had found Ping one morning with a white eye.  He is blind in that eye, but it's not infected and it doesn't seem to bother him.  There usually isn't anything sharp in the cage, although we do put sticks in occasionaly for them to chew on.  Could he have scratched his eyes on a stick or is this old age too?

I have a female guinea pig that was found in a box at the Humane Society.  After she had 2 litters there, one litter from her own pup, I took her becuse they didn't know how to take care of her.  At first when I picked her up, one could feel every bone in her body.  3 mounths after I recieved her, she is fat.  She is at least 3 times heavier than my male pig.  Her age in unknown and so is most of her past health.  How fat should a guinea pig get?

Also, she goes through a mini bale of hay a mounth.  She eats hay constantly and not much else.  I give them vita water, and yogert treats from the pet store, but I don't know if eating mostly just hay is good or not.  I do very the diffrent types of hay between: Orchard Grass, Bermuda Grass, Timothy Hay, and Alfalfa grass.  Is there one hay that is best for them.

Answer
Hi Melanie

I doubt ping has produced a hairball as piggies cant vomit.

The head tilt may be due to old age but may also be an ear infection which you can get checked by the vet.

I tend to think the white eye may be blindness caused by old age but again he might have scratched it as the eye goes white when injured.

A female piggy should weigh between 700-1300 grams. A variety of hay is fine and a good idea. Ideally she should have a balanced diet between hay, dry food, fruit and veggies.

andy