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Pet Rats/Please help!! My little boy has an infection after surgery and also a deep abscess.


QUESTION: Hi Debbie,

I have two fancy boys Frankie and Kevin, they are litter brothers. Born on May 8th 2015.
From about 6 months of age I've taken them for regular vet checks here in the UK. About 5 months ago I felt a lump on Kevin's side, I took him to the vets within two hours, they said it was nothing to worry about because it was pea sized, the vet checked him over 'thoroughly' and said he was looking pretty good. When I got home I bathed the boys and noticed kevin had another lump under his armpit! Larger than the one on his side, I was pretty much livid to ne honest, he had just been checked over by a proffessional who claimed was a specialist on small and exotic animals.
Anyway I called another vet in the morning and took him in later in the afternoon, the vet was very good and patient (I read a lot of rat forums and had many questions) he said the lumps could either be a non malignant tumor as it was under the skin and able to be moved or a cyst. He said if the lumps grew quickly and doubled in size it would be best to operate.
These past few months the lumps were growing, but Kevin was also getting bullied by Frankie who is the dominant, this being their first spring as adults their testosterone was flying at an all time high. Kevin started to loose weight and as soon as I noticed I took him on and booked the op, the vet recommended we also neuter him due to the scrapping.
The surgery went well, thankfully the lumps were pus filled cysts and nothing worse and he got his little furries chopped (I wish I hadn't agreed now, he was in so much pain for the first week) *the vet did not send him home with antibiotics*
I didnt bathe him or frankie for 2 weeks because of the stitches, the scrapping stopped instanly and there has been no aggressive grooming either.

The stitches on his side and armpit healed well however- and this is now my issue- his castration stitches developed an abscess right near his penis, it seems to go down to the muscle wall, he has been visibly in pain (doing the weird back stretches when he walks, or being hunched) ever since the surgery his poos have been thicker, longer and very soft- which is probably because it hurts him to contract his sphincter.
He hates taking meloxicam, I have to burrito him in a towel and force him, which in turn stresses him and causes him pain.
I read abscesses are normal after surgery and to just keep the cage clean (i only have fleece bedding and clumping cat litter) and i clean it everyday and deep clean it every 3 days. So after a few days of this not getting better and him being in pain and loosing weight (hea been off his food 😪) I took him in, the vet said infection, which I already knew, I asked for amoxicillin after some research online it said rats repond well to it, he said its not possible to prescribe human drugs to animals... He said best option is terramycin orally, I had a long winded discussion/argument with my vet because of this, I dont want to force him as his condition isnt great and I dont want to stress him doing the burrito wrap and force any further, eventually he allowed me to have his antibiotics through intramuscular, he had his first shot at the vets on thurs, his next one is sunday evening and the last will be wedneaday.
His abcess isn't looking better, he is off his food, i washed him tonight and did a saline press over the abscess, I have him near me tonight on his carry cage away from his brother.

Please, what can I do to help him heal faster? His only little and he truly is a mummys boy, I can not think of the alternative which the vet mentioned if this infection does not clear. Please any advice is welcome.

Thank you and sorry for my long message, Im just worried sick for my baby 😪

I'm so sorry your boy is having this problem. Making the neuter incision near the penis is just such a bad idea, and is not necessary. Abscesses do tend to be common after neuters, but are usually sterile abscesses, not infections, caused by a reaction to the suture material. But they do not usually cause any discomfort. It just makes it so much worse having it right by the penis. Have you noticed a bad smell around the abscess?  An infection is certainly the most likely reason he is off his food.

I absolutely don't understand why vets in the UK are not allowed to prescribe amoxicillin for rats. Amoxicillin is not just a human drug, it is used in dogs and cats all the time.  If he has an infected abscess, the amoxicillin is the best treatment. You can order it from overseas. See more info below. In the meantime, at least ask the vet for trimethaprim sulfa, which might be able to help, and probably would help more than Terramycin, which is tetracycline.  Even Baytril is likely to work better than tetracycline.

Meloxicam is an NSAID, and so is basically really expensive ibuprofen. Instead you can give him liquid infant ibuprofen at a dose of 15-60 mg/lb twice a day instead. Rats usually like the berry flavor best.

You can order amoxicillin capsules  If your rat is already sick, be sure to ask for overnight delivery! They will even ship OVERSEAS!

You want to mix the amoxicillin in a yummy liquid such as Ensure or slightly diluted Hershey’s strawberry syrup. You can buy a 1 ml syringe for measuring at most pharmacies. A 3 ml or 12 ml syringe is also helpful for measuring out the flavoring. 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 (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.  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 try mixing it in yummy soft food. Or, 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.

You need to know about how much your rat weighs. The normal dose is 10 mg/lb twice a day but you can safely go as high as 50 mg/lb if needed. A 250 mg amoxicillin capsule contains 25  1-lb doses.  

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.  

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

QUESTION: Thank you so much for answering so quickly. I don't think there's a bad smell, I have been applying bacitracin on it twice a day, which I'm pretty sure its useless, he just licks it right out. I had to almost fight with my vet for him to agree on administering terramycin by needle (it was over in a second and Kevin didn't even squeak) I asked about Baytril also and he said it is too broad and will probably not stamp this out. Can I give him amoxycillin with terramycin? He weighs exactly 475 grams (weighed yesterday)

What do you suggest for food? He is off his cheese and yakult which he loves, I dont know what I can offer him that he will take.

Again thank you so much for getting back to me!

Yes, you can give the amoxi along with the Terramycin. 475 grams is just over 1 lb.

Most rats like banana, melon, grapes, cherries, avocado, meat baby foods and cooked meats and fish, sweet flavors of yogurt, scrambled eggs, or soft-cooked egg yolks, cooked cereal, especially when sweetened, drinks like Ensure.

The best supplement for rats who aren’t eating well or who are losing weight is powdered infant formula from the grocery store.  (The liquid form goes bad too fast.)  The brand doesn’t matter because they’re all about the same (Wal-mart's store brand is cheapest).  They contain pretty much all the nutrients a baby needs, and they are 50% fat, so they help put the weight back on them fast. Most rat prefer the soy version to the milk version.

Mix the powder with water, juice or even Ensure.  You can mix it as thick or as thin as you need to.  Thick encourages intake of nutrients and can be fed off your finger, thin encourages intake of fluids.  Most rats love it and will lick it out of a little dish. You can also give it with an eyedropper or syringe. You can also soak or mix ground rat blocks in it.

The infant formula is nearly a complete diet for rats. The only nutrients the formula is short on for rats is the B vitamins.  When giving the formula long-term, add enough liquid vitamin B complex supplement to supply 1 mcg of B12 to each scoop of formula, or you can add ¼ Tablespoon of nutritional yeast (available at health food stores) per scoop of powder.  If your rat doesn’t like it, try adding a tiny drop of vanilla extract or other flavoring.  If that doesn’t work, try adding some whipped cream or ice cream.

If the formula is pretty much all your rat is eating, give about two scoops of the powder a day.  One scoop a day is enough if the rat is eating other foods. Feed your rat at least 3 times a day.  A 1-lb. rat can eat about 10 ml of formula at a time, and needs to take in about 30 ml of fluid each day. A smaller or larger rat will need proportionally more or less formula. The formula should supply all the fluid he needs; additional plain water is not usually necessary.

I highly recommend my Rat Health Care booklet which includes this and a lot more helpful info.  You can find more info about the booklet on my website at on the Books page.

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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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