Gradual weight loss with no other symptoms

[CerLynn]

So Koko has been concerning us a bit lately... over the past couple months, he's been gradually losing weight (with significant drops some weeks) - weights are taken around the same time in the evening each time:

2/15/13 - 694
2/23/13 - 675
3/1/13 - 683
3/8/13 - 678
3/15/13 - 675
3/23/13 - 677
3/29/13 - 656
4/5/13 - 653
4/12/13 - 650
4/19/13 - 644

The strange thing is that absolutely nothing else has changed. No observable change in appetite, feed (Oxbow pellets and timothy hay), water intake, poo, or energy level. He's as energetic and happy as ever at playtime, and his stomach feels fine (no obvious discomfort with poking and prodding around).

Any thoughts what this could be? With nothing else to go on, at what point should we consider taking him in for a vet checkup? Thanks in advance.

 

[AZChins]

It could just be a seasonal fluctuation. But, watch him very closely. This could be an indication of a problem, it's probably just a little too early to tell.

How old is he?

 

[CerLynn]

He'll be coming up on 5 years this summer. He's always been pretty consistent with his weight, usually right around 700-710. We did have to take him to the vet last summer when he suddenly stopped eating (no obvious sign of teeth issues), but they really couldn't find anything. Teeth looked good in the x-rays, though there was a potential "mass" in his abdomen, but they couldn't say for sure if it was just an organ or some artifact. After a week or two of Metacam, Critical Care, and Lifeline, he came right back up and stayed stable, so we didn't feel there was a need to follow up at that time. This little guy never lets us relax!

 

[ticklechin]

Silent giardia can cause weight loss with no symptoms, if this was my chin it would be on my radar screen due to losing 5% of its body weight, when it hit 10% I would start being aggressive about a diagnosis.

 

[CerLynn]

Thanks Dawn, I had wondered if it could be parasitic. We do use a 3-stage Pur filter as a preventative, but I'm sure it's still a possibility. We'll definitely continue to keep a close eye on both our boys (Kenai's shown no sign of any issue, but they do share playtime space), and will get Koko checked out if this doesn't improve very soon.