Case report highlights colonoscopy perforation risks in cats

A newly published case report in Veterinary Sciences spotlights a rare but high-stakes complication of feline colonoscopy: intestinal perforation during evaluation of a distal colonic stricture in a 15-year-old neutered male British Shorthair cat. According to the report summary, the cat developed sudden tachycardia, severe hypoxaemia, a dramatic decline in end-tidal CO2, and diffuse subcutaneous emphysema during the procedure, turning a diagnostic workup for chronic GI signs and persistent tenesmus into an anaesthetic and surgical emergency. (pmc.ncbi.nlm.nih.gov)

The case lands in a part of feline medicine where evidence is relatively thin, but the risks are well recognized. Guidance on GI endoscopy in cats has long described bowel perforation as a rare complication, with risk shaped by patient size, tissue fragility, equipment choice, operator experience, biopsy technique, and insufflation. Flexible endoscopy is standard, but even with appropriate equipment and preparation, feline procedures can be technically demanding because of the cat’s smaller anatomy and the difficulty of obtaining adequate visualization and biopsy angles safely. (pmc.ncbi.nlm.nih.gov)

What makes this report especially useful is the anaesthetic framing. Feline anaesthesia guidelines stress that airway protection, oxygenation, ventilation, and vigilant monitoring are central to safe practice, particularly in older cats. In this case, the apparent early warning signs were physiologic rather than grossly visual at first: abrupt hypoxaemia, tachycardia, and a sharp EtCO2 drop, followed by widespread subcutaneous emphysema. Those findings fit the broader pattern seen in perforation-associated air leakage syndromes reported in both veterinary and human literature, where extraluminal air can track into subcutaneous tissues, the mediastinum, and even the pleural space. (pmc.ncbi.nlm.nih.gov)

There’s also important procedural context. Veterinary references note that colonoscopy in cats requires general anaesthesia and intubation, and they caution against overinsufflation, especially when tissue is abnormal or biopsies are being taken. Older guidance specifically notes increased perforation risk with certain techniques and instrumentation choices, while WSAVA educational material emphasizes that bowel perforation, though rare, should be part of pre-procedure consent and planning. (pmc.ncbi.nlm.nih.gov)

Direct outside commentary on this specific case was limited in the public web results, but the surrounding expert literature is consistent: when perforation is suspected, speed matters. A prior feline case involving oesophageal perforation during endoscopy highlighted the importance of prompt surgical intervention, the ability to convert under the same anaesthetic episode, and access to advanced anaesthetic and critical care support. Human case literature around colonoscopic perforation similarly shows that subcutaneous emphysema, pneumomediastinum, pneumoperitoneum, and pneumothorax can evolve quickly, and that early recognition changes outcomes. (pubmed.ncbi.nlm.nih.gov)

Why it matters: For veterinary professionals, this is less about how often perforation happens than about whether teams will recognize it fast enough when it does. A falling EtCO2 trace during colonoscopy might be dismissed initially as an anaesthetic or equipment issue, but in the right context it may be an early marker of catastrophic GI injury. The report also reinforces a systems lesson: colonoscopy candidates with strictures or suspected infiltrative disease may warrant especially deliberate planning around scope selection, insufflation, monitoring, staffing, and surgical backup. That’s particularly relevant for older feline patients, where anaesthetic reserve may already be limited. (pmc.ncbi.nlm.nih.gov)

For general practices, the takeaway may be referral triage and informed consent. For specialty hospitals, it may be protocol refinement: confirming emergency conversion pathways, rehearsing responses to sudden emphysema or unexplained oxygenation and ventilation changes, and making sure pet parents understand that a diagnostic endoscopy can, in rare cases, become an urgent surgical event. That’s an inference from the available guidance and related case literature, but it’s strongly supported by the pattern across sources. (pmc.ncbi.nlm.nih.gov)

What to watch: The next step is whether this report influences continuing education, consent language, and monitoring checklists for feline lower GI endoscopy, especially in cases involving strictures, chronic tenesmus, or suspected fragile colonic tissue. (pmc.ncbi.nlm.nih.gov)