title: Urethral Sphincter Mechanism Incompetence in 163 Neutered Female Dogs: Diagnosis, Treatment, and Relationship of Weight and Age at Neuter to Development of Disease.
abstract: BACKGROUND
  Urethral sphincter mechanism incompetence (USMI) is the most common cause of urinary incontinence in neutered bitches and is most common in dogs weighing >20 kg.
  
  
  OBJECTIVE
  To describe a population of neutered bitches with USMI and investigate their initial presentation, the relationship between weight and age at neuter, and treatment.
  
  
  METHODS
  One hundred and sixty-three female dogs with USMI (UI) diagnosed between January 2009 and December 2012, and 193 continent neutered control (C) bitches.
  
  
  METHODS
  Retrospective data were collected from neutered female dogs with USMI and healthy, continent neutered females presented between January 2009 and December 2012.
  
  
  RESULTS
  Urinary incontinent dogs weighed more than C dogs (P = .003), and there was no difference in age at neuter. The relationship between weight at diagnosis and age at neuter was found to impact the hazard of USMI. A decrease in the hazard of USMI was found in dogs weighing >25 kg for every month delay of neuter in the first year. The hazard did not change for dogs <15 kg. Median time from neuter to development of incontinence was 3.73 years. Phenylpropanolamine was prescribed in 75.5%, diethylstilbestrol in 21.5%, and both in 3.1% of dogs.
  
  
  CONCLUSIONS
  Neutering bitches expected to be >25 kg adult weight later in their first year may decrease the hazard of developing USMI, whereas age at neutering of bitches <25 kg may not impact continence. Heavier dogs have increased risk of USMI, and onset occurs within a few years of neuter.
authors.affiliation: Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Ames, IA.
authors.forename: J K
authors.initials: JK
authors.lastname: Byron
authors.affiliation: Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Ames, IA.
authors.forename: K H
authors.initials: KH
authors.lastname: Taylor
authors.affiliation: Department of Biomedical Informatics, College of Medicine, Center for Biostatistics, The Ohio State University, Columbus, OH.
authors.forename: G S
authors.initials: GS
authors.lastname: Phillips
authors.affiliation: Merck Animal Health, Madison, NJ.
authors.forename: M S
authors.initials: MS
authors.lastname: Stahl
mesh_terms: D000367:Age Factors; D000818:Animals; D001835:Body Weight; D004054:Diethylstilbestrol / Q000627:therapeutic use; D004283:Dog Diseases / Q000175:diagnosis / Q000188:drug therapy*; D004285:Dogs; D005260:Female; D010052:Ovariectomy / Q000009:adverse effects / Q000662:veterinary; D010665:Phenylpropanolamine / Q000627:therapeutic use; D012189:Retrospective Studies; D014522:Urethral Diseases / Q000175:diagnosis / Q000628:therapy / Q000662:veterinary*; D014549:Urinary Incontinence / Q000175:diagnosis / Q000188:drug therapy / Q000662:veterinary*
chemical_list: D010665:Phenylpropanolamine; D004054:Diethylstilbestrol
keywords: Incontinence; Ovariohysterectomy