motrin for my rat

Question
dear Sandra,
     recently my lil buddy Mr. R became sick. we took him to the vet ASAP, he was diagnosed with pneumonia. the vet gave him amoxicillin for it. he started to perk up the last couple days then today he started feeling crappy again. we believe he is in pain because when we pick him up he snaps at us. also he has not been using his hind legs, and his poop doesnt come out all the way like usual. i read one of your other answers on motrin and you said that you would need his weight which is 11oz. i called the vet about this but they not give me any info on it. also if you have any idea about his hind legs would be greatly appreciated so i can have an idea to ask the vet about.
           thank you so much for your time.
                         sincerely,
                            Bryan and Mr.R

Answer
In most cases, pneumonia is caused by mycoplasmosis pulmonis which doesn't respond to amoxil.  The reason being that myco is an organism that lacks a cell wall. Most antibiotics destroy the cell wall in order to kill the infection, but when there is on cell wall, the antibiotic is rendered useless.  Baytril is one of the drugs that destroy the cell of the organism so the only real way to conquer a serious respiratory infection is to use an antibiotic that kills mycoplasmosis. As for his back legs, this could be hind leg paralysis which is seen in older rats. However when heart disease is involved, it is not unusual to see rats suffer from the loss of use of their back legs, often due to poor circulation but could even be from a blockage due to blood clots etc.....   It is not something that should be over looked.  I would prefer the rat be given steroids for this along with his pneumonia. This would alsp help not only with the inflammation of the lung tissue and aid in easier breathing, but would help with inflammation with the hind legs. Many rat owners report a big change in their rats mobility once steroids are used.   Many vets shy away from steroids but these vets haven't done their homework. They still believe that since steroids can indeed compromise the immune system, they forget that this is short term treatment for one thing, and for another, the rats metabolic rate is so fast steroids burn right through not lingering in their body like they do in humans and other animals. Short term steroid treatment in on way will cause the rat to develop sepsis contrary to the fears of some vets. Not all vets feel this way, esp the vet that has studied the rat, the rats body and also knows the ins and outs of treating certain diseases that are commonly seen in pet rats.
If no steroids are given, my next choice is metacam which is a NSAID, but its a bit easier on the rats stomach than motrin is.  Steroids are actually safer for rats than NSAIDS, since NSAIDS are nephrotoxic to all living things.  I would discuss this with your vet ASAP.