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Feline (DSH) · Radiograph — Abdomen
Presenting complaint
The patient is vocalizing and has not defecated for several days. Bloodwork and urinalysis were normal. Had two enemas at the referral DVM before presenting to ER.
Imaging findings
- Markedly dilated large colon filled with fecoliths.
- The colon measures about 1.7 times the length of L5. Over 1.5 suggests megacolon, so this colon is markedly enlarged.
Diagnosis
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Obstipation due to megacolon
Highly suspected
- Species
- Feline
- Breed
- DSH
- Age
- 3 years
- Sex
- Female spayed
- Weight
- 5.8 kg
- Level
- Vet student and tech
Key take-home points
- On a lateral projeciton, measure the widest part of the colon and compare it to the length of the L5 vertebra
- Less than about 1.3 times L5: normal
- About 1.3 to 1.5 times L5: full of stool, likely constipation
- More than 1.5 times L5: suggests megacolon
- One big measurement isn't enough. If the colon stays wide after it has been emptied, megacolon is much more likely.
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Contributed by
- Luke Winter
BVM&S · WAVES Vet
3 cases - Oren Ofer
DVM, DVSc, DACVR
25 cases
Educational use only — not clinical advice.
Cite this case
Winter L. Obstipation due to megacolon. Radabase case 6b3dd387. Retrieved 2026-09-23 from https://www.radabase.vet/case/6b3dd387-0e54-4c47-b9a0-c4c317173823