Comparison of three techniques for the diagnosis of urinary tract infections in dogs with urolithiasis.
OBJECTIVE
To identify an appropriate sampling technique(s) to accurately detect the bacteria causing urinary tract infections in dogs with urolithiasis.


METHODS
Twenty-one dogs with urolithiasis were included in the study. Three types of samples were taken from each dog. Urine was collected by cystocentesis, and a urinary bladder mucosal biopsy and urolith were retrieved during cystotomy. The samples were then cultured on blood agar and MacConkey's agar to identify the bacteria associated with urinary tract infections.


RESULTS
Bacterial urinary tract infection was found in 16 cases (76.19 per cent). The most prevalent bacteria found to cause urinary tract infection were Escherichia coli (n=7), followed by coagulase-positive Staphylococcus species (n=4), Klebsiella pneumoniae (n=2), Pseudomonas aeruginosa (n=2) and Proteus mirabilis (n=1). In the case of a positive urine culture, the same bacteria were also cultured from the urinary bladder mucosal biopsy alone or from both the urinary bladder mucosal biopsy and urolith. However, in the case of a negative urine culture, bacteria were found to be present in the urinary bladder mucosal biopsy or urolith cultures in 23.81 per cent of dogs. The uroliths that gave positive culture results were either infection-induced uroliths composed of struvite and calcium carbonate phosphate, ammonium acid urate only or metabolic uroliths composed of calcium oxalate and calcium phosphate, or calcium phosphate only. All the uroliths that gave negative culture results were metabolic uroliths composed of calcium oxalate and/or calcium phosphate, and uric acid and calcium phosphate.


CONCLUSIONS
When the culture from the urine obtained by cystocentesis is negative, cultures of urinary bladder mucosal biopsy and urolith are recommended in dogs with urolithiasis in order to accurately assess the microbiological status of the urinary tract.
Gatoria
I S
IS
Department of Veterinary Surgery and Radiology, and Department of Veterinary Microbiology, Guru Angad Dev and Veterinary and Animal Sciences University, Ludhiana 141004, Punjab, India.
Saini
N S
NS
Rai
T S
TS
Dwivedi
P N
PN
D000818:Animals; D001706:Biopsy / Q000662:veterinary; D003937:Diagnosis, Differential; D004283:Dog Diseases / Q000175:diagnosis* / Q000382:microbiology; D004285:Dogs; D004926:Escherichia coli / Q000302:isolation & purification; D007711:Klebsiella pneumoniae / Q000302:isolation & purification; D011513:Proteus mirabilis / Q000302:isolation & purification; D011550:Pseudomonas aeruginosa / Q000302:isolation & purification; D013210:Staphylococcus / Q000302:isolation & purification; D016482:Urinalysis / Q000662:veterinary; D001743:Urinary Bladder / Q000737:chemistry / Q000382:microbiology / Q000473:pathology; D001744:Urinary Bladder Calculi / Q000737:chemistry*; D014552:Urinary Tract Infections / Q000175:diagnosis / Q000382:microbiology / Q000662:veterinary*; D052878:Urolithiasis / Q000175:diagnosis / Q000382:microbiology / Q000662:veterinary*