Radiation-Associated Immune-Mediated Hemolytic Anemia, Megaesophagus, and Intestinal Fibrosis in a Maine Coon Kitten Following Airport X-Ray Exposure: A Case-Based Mechanistic Review

Non-medical radiation exposure of companion animals is rarely discussed in the veterinary literature, despite increasing use of high-energy X‑ray systems in aviation security. This paper presents the case of a three‑month‑old Maine Coon kitten (Mimi) who experienced unquantified, close-range exposure to an airport baggage X‑ray scanner at Toronto Pearson International Airport. In the subsequent weeks, she developed a constellation of serious conditions: immune‑mediated hemolytic anemia (IMHA), megaesophagus with esophagitis, and a chronic jejunal fibrotic ring consistent with intussusception identified at necropsy, followed by fatal metabolic collapse from mismanaged refeeding syndrome.We reconstruct Mimi’s clinical course from contemporaneous records and owner documentation, then examine each major pathology in light of established radiobiology. Ionizing radiation is known to damage bone marrow and erythrocytes, disrupt immune tolerance, injure gastrointestinal mucosa and vasculature, and cause neuromuscular dysfunction. Juvenile animals are particularly radiosensitive due to high rates of cell division and limited tissue reserve. The timing of Mimi’s IMHA (three to four weeks post‑exposure), early megaesophagus (identified during her first hospitalization), and chronic intestinal fibrosis (documented at necropsy) is consistent with delayed effects of moderate whole‑body irradiation. No alternative unifying etiology was identified.This case-based mechanistic review argues that Mimi’s radiation exposure is the most plausible common trigger for her IMHA, megaesophagus, and chronic intestinal fibrosis, and that it primed her for catastrophic metabolic decompensation when refeeding syndrome was inadequately recognized and treated. We conclude by highlighting the regulatory gap surrounding non‑medical X‑ray exposure in pets, the need for greater transparency about scanner dosimetry, and the importance of including radiation in the differential diagnosis when veterinarians are faced with unexplained multisystem disease in juvenile animals.