My rat has sores

Question
Hi Debbie,

I have two stunning little rats.
Misty(female) and Ratty(male) (how original, i know).

Misty has recently (11 days ago) given birth to 13 beautiful little pups.
So of course, when we noticed she was starting to nest, we had to separate her and the pups from Ratty.
so its been just under 3 weeks that Ratty has been in his own separate cage.

The pups are doing great and seem to be well along the right path!
However, there are 2 out of the 13 pups that are a tremendous amount skinnier than the others and aren't as alert.

Ratty has also been sleeping a lot more than usual and eats on the bare minimal! He has also recently developed these little sore/ scabs right on the corners of his mouth!

So my questions for you are:

1: What could be the cause of the 2 babies being a lot skinnier than the rest/ and what can i do to help? ( i have tried feeding them goats milk through a syringe but they refused to drink)

2:What could be the cause of the sores on Ratty's mouth? and how should i go about treating it?

Thanks a mil,
Morganne x

Answer
Hi Morganne,
It's not unusual for there to be a runt or two, but this sounds like maybe there is something wrong with the pups and they might not survive. The best thing to try is to temporarily separate some of the other babies into another container to give the runts a better chance at the nipples. Leave about 4-5 babies with the runts to stimulate the mom to suckle them. The mom may not pay attention to just one or two babies.

As long as the rest of the other babies are kept warm, there is no harm in them being away from the mom for up to 4 hours. You can put them in a little box with nesting material on a heating pad on low or near a light bulb. Keep a thermometer next to the babies so you know exactly what temperature they are experiencing. Use a small weather thermometer, not a medical thermometer, as the latter can't record drops in temperature. Keep the temperature around 100-102 degrees F. Rotating the groups of babies with the mom every 2-4 hours will give the runts the best chance. (BTW, this info is on my website at www.ratfanclub.org along with a lot more.)

As for Ratty's sores, this is not something I remember seeing before. The corners of his mouth is the only place he has sores?  He doesn't maybe have a few on his chin, neck, cheeks or shoulders?  Maybe he is just stressed being alone? Is his cage near the mom and babies cage? If not, move them next to each other.
Deb