porphyrin around my rats eye

Question
Hi,
My pet rat broke his leg this past summer (his thigh, it broke below the hip
and above the knee.) I took him to the vet (of course!) and he was given
painkillers and left in a small cage alone to heal for almost 2 months. He still
has a bit of a limp now as the leg healed a little funny because we didn't want
to re-break it to set it perfectly. Other than the limp, he seems the exact
same as before, very energetic, social, eats well, etc.
The only thing is, ever since the break, I've noticed he has red gunk around
one of his eyes, which from doing a little research I assume is porphyrin.
I was just wondering if it's normal that he is still producing this after his leg
has healed. Do you think this means there's something wrong?
Thanks so much,
Monica

Answer
Porphyrin is produced by a large gland located behind the rats eyes called the harderian gland.  Some rats never have it, even when sick, and others have it all the time no matter what. If he has had it for all of this time, I would not really worry about it. When to worry is when they produce alot of it out of the blue followed by lack of appetite, lethargy, congestion etc...etc...  Sometimes certain litters/beddings can trigger it too.  I had a rat that had alot of it all the time during the entire four years he was alive. The last few months before his death I started using yesterdays news rather than aspen and also started using it in a litter box rather than scattered all over the bottom of his cage and this actually helped clear up the porphyrin which taught me that his discharge was triggered by being exposed to aspen in large amounts.