Expert: Jessica - 10/3/2009

Question
My daughter has two kittens and one of them had an infection and got medicine and is better but now is getting some red mouth sores. Is this maybe a reaction to the medicine, or something else, seems fine otherwise, thanks Deanna

Answer
Hi Deanna.  Mouth sores can be caused by a number of problems ranging from viral infections to kidney and liver failure.  Of course, in the case of kittens, viral infections are the most common cause.  Kittens very often contract a virus called calici, which can cause upper respiratory symptoms like sneezing and runny eyes (with clear discharge), but also causes classic sores in the mouth.  The tongue, roof of the mouth and gums may all become ulcerated.  The throat and lungs can also develop sores, and because of this, pneumonia can be a serious complication of this disease.  Also, because of mouth pain, some kittens stop eating and drinking.  This is the most dangerous aspect of calici virus.  Kittens who refuse to eat need to be force fed until the virus passes.  Symptoms usually pass in 7-10 days but may last for weeks in young ones or animals with compromised immune systems.  Because all of these sores are very open to infection, an antibiotic that treats oral infections is strongly recommended.  These include clindamycin and a new, one-time injectable antibiotic called Convenia, among others.

Kittens can also have mouth sores due to a condition called lymphocytic plasmacytic stomatitis.  The condition isn't well understood but appears to be an over-reaction of the immune system, perhaps to plaque in the mouth.  While there are cases of juvenile onset, stomatitis tends to be fairly uncommon in kittens, and is mostly found in cats who are at least a few years old.  

A reaction to the antbiotic she was given is certainly a possibility, but I have never seen this type of reaction occur myself.

At any rate, I would highly recommend getting her back to the vet, I hate to say.  It could be this is a continuation of the infection she was already suffering, and the vet may just say to monitor her.  However, if she now has a different infection, treatment with another antibiotic may be needed.

Also, keep an eye on the second baby, since viral infections tend to be very contagious.

Hope the little one is much better soon!

Jessica