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Pet Rats/Rat listless and in pain


QUESTION: Hello Debbie,
I'm contacting you regarding my rat Nigel. He is a year and 5 months.He recently had his second bout of myco and I put him on baytril for 6 weeks to 'knock it on the head'. This bout didn't seem as bad as the the first and his lungs didn't sound so noisy. He has been off baytril for about 2 weeks.
On Monday he became very listless and lethargic by mid-morning and I was very worried. I had him out the cage and checked him over. He was reluctant to walk and just sat very still (very unlike him!) he was also shallow breathing.  I couldn't explain it he just wasn't his normal self. As I put him back in the cage he fell face first and has a slight head tilt to the left. I took him to the vets at lunch and she thought he was in pain. She suggested he may have scarring in his lungs which may be causing the shallow breathing or it was pain causing him to act this way. She was going to prescribe metacam but I decided to try childrens ibuprofen. She agreed when I told her that it can be used. I only managed to get 3ml down him that day but he was back to his normal self as soon as it kicked in!
On Tuesday he again wasn't very lively but not as bad as the previous day. He wouldn't take any ibuprofen, which had given him slight diarrhoea. I was worried he wasn't eating or drinking. He wouldn't hand feed with any of his usual favourite foods,I tried everything. So I put him back in his cage and he ate some dry pasta and later some of his dinner. He is a fatty so this is unusual (he weighs 845g!)
Today (Wednesday)I took him to the vet as he is still the same but not as bad as Monday. He will move around but not as much and certainly won't climb. He still has a tilt to the left. I figured if he reacted well to the anti-inflammatory on Mon then an injection may get him back on his feet! I use your rat health care booklet as guidance and thought it might also be worth trying Amoxicillin in case of secondary infection.  
Unfortunately my usual rat competent vet/vets weren't there and I had to see one of the partners of the practice. He was very rude,and would only consider injecting metacam. I'm always worried about using it due to reading about fatalities and my cat died while using this! I showed him your book and a discussion on suitable meds started....I suggested dexamethasone. Afterall he has head tilt,right?! We don't have dexaphosphate here! He didn't want to use prednisone as I had used ibuprofen. He basically seemed to think I was telling him how to do his job...he said he'd do what I wanted but he hadn't got all day! ..i know,rude?!  Anyway he said it only lasts 48hrs so I would need to come back again in 2 days time AND I must use with baytril as it lowers immunity.

I have some baytril to use. My question really is am I doing the right thing? And where do I go from here?  I'm very worried, he is more alert since Monday and is now eating some breakfast. He has a lot of Porphyrin around his nose and hands where he is washing. He is prone to Porphyrin but I figure he is more stressed.
We did home trial 2 dogs at the weekend, I had to send them back to foster on Monday as they weren't suitable with my cats. I think this may have stressed him further!

Please bear in mind I'm from England so we don't have all the same drugs available.  I hope you can help.

Many thanks.


ANSWER: Hi Emma,
You need to get him on amoxicillin ASAP. Lethargy is a classic symptom of a secondary bacterial infection, and amoxicillin is the best treatment for that. See more info below. You also want to put him back on the Baytril as a combo of the 2 seems to work best for an inner ear infection.

If you have prednisone, use that instead of the ibuprofen. It is a much more powerful anti-inflammatory.  I think ibuprofen is better than Metacam, though.

For a rat who is sick, no matter the symptoms, amoxicillin is the first treatment I recommend.  Secondary infections, which can include respiratory symptoms, lethargy, poor appetite, and other symptoms, are common in rats, especially young rats and those from pet shops. Older rats can also get secondary infections on top of mycoplasma. In my experience, amoxicillin is the best treatment for secondary infections in rats.  Amoxicillin capsules are good to have on hand for secondary infections, which can get very severe very quickly, killing a rat in a matter of hours or days, and require immediate treatment.  Amoxicillin is also best for skin infections. (However, amoxicillin does not work against mycoplasma. For that I recommend doxycycline, and maybe also Baytril.)

All vets will have amoxicillin, and you can also get amoxicillin over the counter as aquarium fish capsules from some feed stores and specialty aquarium stores. Call the stores in your area and ask before driving there.  Do NOT tell them you are buying it for your rats!  It is legal for them sell it over the counter only for fish.  You will not find it at Petco, PetSmart, etc.  If you can’t find amoxicillin, you can use ampicillin which is basically the same thing, it just isn’t absorbed as well, so just double the dose to 20 mg/lb twice a day.

Some vets won’t prescribe amoxicillin for rats because they learn in vet school that you can't give amoxicillin to hamsters or guinea pigs (it will kill them) so they sometimes generalize this to all rodents.  But amoxicillin is fine for rats and mice, whose digestive systems are very different from quinea pigs and hamsters.  I use it all the time.  (For more about getting your vet to prescribe amoxicillin, see the info at the bottom.)

Rarely you will have an individual who will be allergic or sensitive to amoxicillin, and the most common side effect is diarrhea.  In most cases, this diarrhea is mild enough to be controlled with probiotics (good bacteria for the intestines) but if the diarrhea is severe it will stop when you discontinue the treatment with amoxicillin.

You can order amoxicillin and doxycycline capsules from If your rat is already sick, be sure to ask for overnight delivery!

You can also get amoxicillin mail order from Jedd’s Pigeon Supplies at 800-659-5928.  Ask for Greg, and be sure to order CAPSULES.  Also, you can get it from Doctors Fosters & Smith, 800-826-7206.  Order the capsules for aquarium fish, item #CD-18876.  (Please note that they sometimes change the item number, so just search for amoxicillin in the fish department.)  

You need to know about how much your rat weighs.  The dose is 10 mg/lb twice a day but you can safely go as high as 50 mg/lb.  In most cases (check the package) each amoxicillin capsule contains 250 mg, which is 25  1-lb doses.  

If you have access to small syringes for measuring (a 1 ml syringe or insulin syringes with the top broken off) you can mix the amoxicillin in a liquid.  Amoxicillin does not dissolve but forms a suspension.  The powder will sink to the bottom, so before taking out a dose, you need to stir the mixture with the syringe extremely well, being sure to scrape up all the powder off the bottom so it is in suspension.

Mix one capsule of 250 mg amoxicillin in 7.5 ml of flavoring such as Ensure or slightly diluted Hershey’s strawberry syrup. (If you have 500 mg capsules, use twice the amount of flavoring: 15 ml.) A small pill bottle is about the right size to mix it in.  Keep in the refrigerator.  Amoxicillin doesn’t taste too bad to most rats and most rats will eagerly lick this right from the tip of the syringe.  The normal dose is 0.3 ml/lb twice a day.  (Note: 1 cc = 1 ml = 100 units on an insulin syringe, so 0.3 ml = 30 units.)  You can go as high as 5 times that normal dose if necessary, and it’s a good idea to give a double dose the first time.

If your rat won’t take the amoxicillin mixture voluntarily, you can make the dose 0.1 ml which is too small for them to spit out when you put it in the back of their mouth.  Mix one capsule with 2.5 ml of flavoring. Then the dose is only 0.1 ml/lb twice a day.

If you don’t have small syringes, you can mix it in food.  Dump a capsule out on a plate.  If it is granular, grind it to a powder.  Divide the powder in half, and half again, etc.  Until you have 24 piles. Since it’s hard to divide it more than this, you can give the 1-lb dose to rats who weigh less than a pound.   It’s better to give too much than not enough.  Scrape a pile into a little bit of food such as baby food, mashed avocado, etc.  

Give the dose twice a day.  If it's going to work the symptoms should improve within 2-3 days.  If it does work you need to continue the treatment for at least 2-3 weeks.  If it doesn’t work then you need to try a different treatment.  If the symptoms are all gone within 3 days you should continue the treatment for 3 weeks.  If it takes longer for all the symptoms to go away, give it for 4-8 weeks and maybe longer.  The longer it takes for all the symptoms to go away, the longer you should continue the treatment.  If the symptoms stop improving, or if the amoxicillin doesn't help at all, you will need to try doxycycline instead.

You can buy 100 ml of 10% oral generic Baytril (enrofloxacin but they call it Enroxil) from Jedd's Pigeon Supply for $40 plus shipping.  The dose for a 1-lb rat is 0.1 ml, which means that 100 ml is 1000 rat doses!  Very economical.   You need to give it twice a day.  Do not refrigerate the Baytril!
I’ve had the best luck giving it in in 4-6 ml of a product such as strawberry Ensure or Boost in a baby food jar lid, or in 1/8 teaspoon of the soy baby formula powder, making a paste.  It helps if you put the baby food jar lid on a small magnet to help keep your rat from tipping it over.  

Jedd’s Pigeon Supplies is 800-659-5928. If you order by phone ask for Greg. When ordering, just ask for the 10% Enroxil.  Do not say “for my rats” because it is available without a prescription for pigeons only.  Greg is cool about it though.  You can also order it on their website at If ordering online, order item #5002.  It won’t say it’s Baytril, as they keep it quiet.

You can also get doxycycline capsules from Jedd's.  Ask for Greg.  Be sure to ask for CAPSULES otherwise they will send loose powder.  It will cost about $35 for 100 capsules of 100 mg each plus shipping.  Don’t say “It is for my rats.”  You can only buy them over the counter for birds. However, Greg is very cool about it.

To mix doxycycline capsules:

In a small pill bottle, put 12 cc (12 ml) of liquid such as Hershey’s strawberry syrup.  Open and dump in the contents of one 100 mg doxycycline capsule.  Stir well.  The amount for the typical dose of 2.5 mg/lb is 0.3 ml/lb (0.3 cc or 30 units on an insulin syringe) twice a day.  For 5 mg/lb give twice that.  To use an insulin syringe for oral dosing, break off the whole needle assembly.  Be sure to refrigerate the mixture.

If you don’t have the proper syringes for dosing, dump the capsule out on small plate and divide the powder into 40 equal piles.  (Divide in half, then in half again, etc.)  Each pile is a dose and can be scraped into soft food.

You will find more info about treating respiratory infections on my website at on the Rat Info page.  I also highly recommend you order my Rat Health Care booklet.  It is only $7 plus $2 shipping (CA residents add 58 cents tax.)  The address is Rat Fan Club, 857 Lindo Lane, Chico CA 95973.

Concerning amoxicillin and veterininarians:  Many vets don’t want to use amoxicillin on rats.  This is probably because in vet school they learn that amoxicillin can’t be used in guinea pigs, rabbits or hamsters (because it kills the good bacteria in their intestines), and they probably generalize this to rats and mice.  However, rats and mice usually tolerate amoxicillin quite well.  In my experience only a very small percentage of them will get diarrhea from it, and this is not life-threatening; it will usually clear up with a probiotic, or the amoxicillin can be stopped.

Here are some references for using amoxicillin in rats for your vet to check if they are reluctant to prescribe amoxicillin:

Exotic Animal Formulary, Third Edition, James W. Carpenter, MS, DVM editor, Elsevier Saunders Publishing
Page 377, Antimicrobial and antifungal agents used in rodents.
Ampicillin for mice and rats: dosage 20-50 mg/kg PO, SC, IM q12h
(Note: ampicillin and amoxicillin have essentially the same adverse reactions and effectiveness, so they can be used interchangeably)

ViN (Veterinary Information Network, Inc.) Website

Thomas Donnelly, BVSc on 02/05/2006  “Amoxicillin is safe to give rats.”

Johanna Briscoe, VMD, on 07/08/2004  “I have used Clavamox liquid in a rat and it worked beautifully on an abscess that I thought may have been from a bite….  Clavamox dose same as in other mammals—13.75 mg/kg PO BID.”
(Note: Clavamox is the brand name for a mixture of amoxicillin and clavulanic acid.)

Elizabeth Mitchell on 06/01/2007  “I have used Clavamox a few times in rats without problems, although I am always very careful to warn owners to watch for diarrhea.  I  generally have gone with a dose more similar to dogs and cats (20-30 mg/kg BID) but if you search on PubMed you will find all sorts of much higher doses.”

---------- FOLLOW-UP ----------

QUESTION: This is as I suspected!  The vet said amoxy wouldn't do anything! I disagreed and I knew from asking previously that they have to order it in.

He had a dexy injection this morning when would I need to start using prednisone?  What dose? Is it just injection or is it available in tablet/liquid form? How long would I use it for?

I have oral amoxy it is 125mg in 5mg. Nigel weighs 845g, I figure that makes his dose roughly 1ml twice daily?! Is that okay? What dose shall I give for baytril? He was taking 0.4ml daily.        
Should I space the baytril and amoxy apart or can they be given one after another?  

I've just checked on him again,he as slept pretty much all afternoon as the last 2days I have kept checking him and he's been uncomfortable.  He appears more relaxed and is climbing again.

Thank you for replying so quickly.

ANSWER: Sounds like the dex might be helping him already!

The normal dose of amoxi for rats is 10 mg/lb twice a day. Nigel is a big boy!  He isn't quite 2 lbs, but we are going to dose him as if he is.  (Antibiotics treat the bacteria, not the patient, and it is best to overdose slightly rather than risking underdosing.)  125 mg/5 ml = 25 mg/ml. So, yes, Nigel's dose is about 1 ml. Good job!  

The normal dose for Baytril is 10 mg/lb twice a day also. You need to tell me what the concentration of your Baytril is before I can tell if his dose is correct.

They can be given at the same time.

The dex injection is good for 24 hours, so start the prednisone tomorrow morning. For pred I get tablets and mix them into a liquid myself. The dose I recommend is 1 mg/lb twice a day, so you'd want to give him just under 2 mg.  You could mix a 20 mg tablet in 4 ml of flavoring (I use a store brand of strawberry Ensure) so it would be 5 mg/ml, and then his dose would be 0.35 ml.

---------- FOLLOW-UP ----------

QUESTION: The baytril bottle says   .5x baytril oral solutions 2.5%

Does that mean it's only a 2.5% concentration?  Help! I've been giving 0.4ml daily.

Sounds like it is a 2.5% solution. I don't know what the .5x means. The dose?  Anyway, a 2.5% solution is 25 mg/ml, so the proper dose for Nigel would be 0.8 ml twice a day. The dose you have been giving him is for a 1-lb rat. Go ahead and give him a double dose now (1.6 ml) if you can get it down him to give him a boost start. It's a good idea to give a double dose of an antibiotic to start.

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Debbie Ducommun


I can answer any questions about pet rats, but you will probably be able find answers to simple questions more quickly on my website at If you have a life-threatening emergency you can try calling me at 530-899-0605. I am not usually on the computer on the weekend.


I have been "The Rat Lady" since 1985 and am recognized as one of the world's experts on pet rats. I have 3 published books and already answer lots of questions about rats daily.

President of Rat Assistance & Teaching Society

I am a monthly columnist for Pet Business magazine, and my writing has appeared in other magazines. I have 3 published books.

BA in Animal Behavior

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