You are here:

Ask the Veterinarian/Urinary Infection



I have a female, 11 year old English Mastiff, 175 lbs.  She is in general good health but has a urinary infection. I use a house calls vet since she does not like to get in the car, so he comes to us.  He ran urine test, including culture and drug sensitivity.  She has Klebsiella, she has accidents in the house and drinks lots of water, eats fine and OK otherwise.  The drugs showing promising are mostly IV, Gentamycin, Tobramycin etc and the only oral was Bactrim, which my vet does not like because he says it can cause permanent dry eye.  Not sure if he is too experienced with giant breeds, but he had to call another vet to find out dosage, he keep on saying it looks like too much medication according to his book.  Let me ask you, what do you use and how much is right for my dog.  Is the Bactrim really bad and cause permanent dry eye.  He said she needed 3 tablets of Bactrim DS per day.  Help!!  While I wait for him to learn to calculate dosage my dog can get worse. I need to tell him what to do. Thank you.


ANSWER: Bactrim is a good drug and it can cause dry eyes, but it is very rare.  Klebsiella urinary tract infection is very RARE and I would question that.  Was the urine collected free catch or by a needle placed into the bladder (cystocentesis)?   If it was by cysto, I would more likely believe the results, but if it is from a free catch, I would not.

[an error occurred while processing this directive]---------- FOLLOW-UP ----------

QUESTION: It was free catch, I did it at home and brought it in.  It appears she is also in heat at this time.  At her age I would not let a vet collect it through the other method, too stressful and not a procedure that would be very easy in a home visit,which complicates matters.  He said the infection showed as over  100,000, and not questionable, he termed it "real".  The lab doing the culture has lots of experience, so I doubt they made a mistake.  Initially he had her on Cipro until the final results came in, 750 mg twice daily, but it did nothing.   I have since put her on 2 Bactrim daily on my own, since he not sure of how much.  Just wondering what is the correct dose?  Doing nothing is not an option.   Very difficult in my area to get a house calls vet, so I he is my only option, I have tried.

Cipro is a very poor choice as most dogs do not absorb it from their intestines.  If the culture said sensitive to Bactrim, then 3 of the DS tablets a day should help.  I would advise to re-culture after 7 days of treatment so that dog does not have to be on Bactrim any longer than is needed.

Ask the Veterinarian

All Answers

Answers by Expert:

Ask Experts


Dr. Louis N. Gotthelf


Dermatology and ear diseases of dogs and cats


I am the author of "Small Animal Ear Diseases; An Illustrated Guide" published by W.B. Saunders. I have over 25 years of clinical experience with a special interest in dermatologic conditions and ear diseases.

American Academy of Veterinary Dermatology

Veterinary Forum
Veterinary Medicine
Waltham Focus

©2017 All rights reserved.

[an error occurred while processing this directive]