Validation of a model to develop a symptom index for benign prostatic hyperplasia in dogs

Benign prostatic hyperplasia (BPH) is a spontaneous and age-related condition in humans and intact male dogs. A symptom index for BPH in men was created by the American Urological Association. In this study, it has been developed and statistically validated as a model to assign an objective score to canine BPH severity based on clinical signs observed and/or subjectively reported to the veterinarian by dog owners. The medical records of the Animal Reproduction Unit of University of Bologna (Italy) were used to select dogs with a clinical diagnosis of BPH. A data set was built up, and the animals were included in the statistical analysis as dependent variables. A score of 1-3 was assigned to the disease severity of each case based on signs annotated, graded using a scale ranging from 1 to 4. Signs of BHP were entered as predictors while disease severity as dependent variable to generate the predictive model. The model was finally used to re-classify each case of the data set, and the percentage of corrected predictions calculated. Overall, 373 subjects were entered in the model. Between them, 243, 107 and 23 animals have been represented based on medical records with a BPH severity score of 1, 2 and 3, respectively. The model correctly predicted the response variable in 97.3% of the cases. In this study, a BPH symptom index was created for the first time in dogs, which may be useful to standardize BPH severity with an objective score and to evaluate the necessity, the kind and the effectiveness of treatment.