Generalized Megaesophagus Concurrent With Toxocariasis in a Cat

Feline megaesophagus is a rare disorder characterized by esophageal hypomotility and dilation, resulting in regurgitation, weight loss, and occasionally death. This report describes the clinical and paraclinical findings of generalized megaesophagus with a possible contribution of toxocariasis in a kitten. A 2-month-old female cat was referred with chief complaints of lethargy, hyporexia, dyspnea, and vomiting/regurgitation. Physical examination of the kitten revealed bradycardia, bradypnea, hypothermia, dehydration, and lung crackles. The most notable laboratory results were leukopenia with severe toxic changes in neutrophils. Radiographic findings were compatible with the diagnosis of generalized megaesophagus. Despite supportive measures, the kitten died the next day. Necropsy revealed diffuse esophageal dilation and Toxocara spp. roundworms in the stomach and duodenum. Histopathology showed an ascarid larva in the esophagus, necrosis and metaplasia in the pylorus, and absence of villi and Brunner's glands in the duodenum. Based on the morphological identification of the adult gastrointestinal nematodes, the final diagnosis was generalized megaesophagus of unspecified classification concurrent with toxocariasis. However, the exact cause of death could not be established. Although respiratory abnormalities raised suspicion of a pulmonary complication, pneumonia was not confirmed. We hypothesized that toxocariasis may have contributed to esophageal dysfunction in this kitten through potential mechanisms such as vomiting, gastrointestinal obstruction, or neurological involvement; however, these mechanisms could not be directly demonstrated. Therefore, parasitic diseases, including toxocariasis, may be considered among potential differential diagnoses or contributing conditions in young cats presenting with megaesophagus, particularly when concurrent gastrointestinal parasitism or related complications are identified. Further studies are required to clarify the possible relationship between toxocariasis and esophageal dysfunction.