Evaluation of the morphologic characteristics and prevalence of canine urocystoliths from a regional urolith center.
OBJECTIVE
To determine whether morphology of single-mineral urocystoliths and age, sex, or breed data could be applied to facilitate radiographic and clinical urocystolith mineral type prediction, respectively, in dogs.


METHODS
Database of 2,041 dogs with pure mineral composition urocystoliths.


METHODS
All uroliths were characterized according to geologic descriptive terminology and by breed, sex, and age of dog at time of sample submission. Summary statistics were used to compare features with specific mineral types. Observed trends were analyzed for statistical relevance between observed and expected frequencies for age, sex, color, size, shape, and surface, using the null hypothesis that differences by urocystolith mineral type did not exist. On the basis of expected breed occurrence derived by equations, the null hypothesis that urocystolith occurrence paralleled canine breed popularity was tested.


RESULTS
Urocystoliths > 10 mm in any dimension were > 92% likely to be magnesium ammonium phosphate hexahydrate (MAP). Smooth, blunt-edged or faceted, and pyramidal urocystoliths were usually MAP. Jackstone shapes were almost always silica. Botryoidal (grape-like clusters) urocystoliths were likely to be oxalates. Breeds with high relative likelihood of urocystoliths included: English Bulldog, Pekingese, Pug, Welsh Corgi, and West Highland White Terrier. Breeds with low relative likelihood of urocystolith production included: German Shepherd Dog, Shar-Pei, and German Shorthaired Pointer. About 94% of urocystoliths produced in females or spayed females were MAP, whereas males and neutered males produced a greater assortment.


CONCLUSIONS
For pure mineral composition urocystoliths, trends in mineral type among breeds and between sexes can be exploited clinically in the diagnosis and management of urolith-related disease. Size and shape, used in conjunction with age, breed, and sex, can facilitate pure urocystolith mineral type prediction.
Weichselbaum
R C
RC
Department of Small Animal Clinical Sciences, College of Veterinary Medicine, University of Minnesota, Veterinary Teaching Hospital, St Paul 55108, USA.
Feeney
D A
DA
Jessen
C R
CR
Osborne
C A
CA
Koehler
L
L
Ulrich
L
L
D000367:Age Factors; D000818:Animals; D016208:Databases, Factual; D004283:Dog Diseases / Q000453:epidemiology*; D004285:Dogs; D005260:Female; D008297:Male; D016017:Odds Ratio; D009919:Orchiectomy; D010052:Ovariectomy; D015995:Prevalence; D012727:Sex Characteristics; D013045:Species Specificity; D014545:Urinary Calculi / Q000737:chemistry / Q000453:epidemiology / Q000662:veterinary*