I would not put her on Tylan because she has porphyrin in her eyes or nose. That doesn't mean she needs to be put on Tylan. It could be anything from being exposed to dusty bedding, stress of the pregnancy, etc.

I have heard of pregnancy complications due to Tylan in rats.

Here is more information on porphyrin.
http://www.ratbehavior.org/porphyrin.htm