10-year-old intact female Yorkshire Terrier

1 month history of distended abdomen, 23 week history of lethargy

  • Echogenic abdominal fluid with multifocal nodules on all serosal surfaces
  • Fluid filled uterus (anechoic) with irregular wall and numerous cysts
  • Well defined mass caudal to the right kidney and at cranial extent of right uterine horn that is the right ovary with no follicles or normal CL (too large for anestrus ovary)
  • Numerous hyperechoic foci in the right kidney that cast an acoustic shadow
  • Carcinomatosis secondary to ovarian mass
  • Mucometra/hydormetra (less likely pyometra due to duration of signs)
  • Abdominocentesis
  • Biopsy/FNA of ovary
  • Thoracic radiographs (already have evidence of disseminated disease so not necessary)
  • Overall this case was well done.  The candidates that failed this question did so because they either failed to identify the mass and tubular structure as ovary and uterus or the primary differential diagnosis was a ruptured pyometra with septic peritonitis.  The tubular structure filled with anechoic fluid has a thick irregular wall with numerous cysts and no distinct layering and was therefore not small intestine.  A diagnosis of septic peritonitis secondary to rupture of a pyometra was also presented but there was no explanation of why the echogenicity of the fluid was so different between the abdominal fluid and the fluid in the uterine horns or why the uterine horns remained so distended.