Young adult female Koala (Phascolarctos cinereus)

Pre-contrast soft tissue reconstruction of the abdomen

Post-contrast soft tissue reconstruction of the abdomen

  • The mid-to-distal ureters are enlarged and irregularly shaped with lobular borders.
  • Diffusely thickened urinary bladder wall with diffuse contrast enhancement.
  • Hyperattenuating soft tissue (~84 HU), non-contrast enhancing material within the urinary bladder lumen surrounded by hypoattenuating soft tissue (~24 HU).
  • Enhancement of the endometrium and myometrium of the uteri with hypoattenuating material within the lumens. Also enhancement of the wall of each vaginae (how many do they have?) with luminal hypoattenuating soft tissue material.
  • Poor serosal detail within the peritoneum. Fat deposition within the retroperitoneum.

1. Bilateral mid-to-distal ureteritis.

2. Diffuse cystitis with luminal contents that may represent blood, abscess, or poorly mineralized calculus.

3. Uteromegaly with vaginitis; consider pyometra, mucometra, or hydrometra.

4. Poor serosal detail can be a combination of visceral crowding and species related fat deposition. Peritonitis or small volume peritoneal effusion is not entirely excluded.

Lower urinary tract infection with urinary bladder luminal blood diagnosed via endoscopy. There is an ascending bacterial infection with bilateral ureteritis. After initial culture/diagnostics and endoscopy, antibiotic therapy was initiated.

Serial computed tomography studies initially demonstrated progressive ureteritis and persistent cystitis at 2 week.

At 4 week recheck, the ureters, urinary bladder, and uteri/vaginae were normal.


Koalas are very susceptible to gastrointestinal ileus with antibiotic therapy. Judicious use of antibiotics were guided by the CT imaging.