Recurrent Megacolon and Fecaloma in a Cat

Abstract

Background: The Megacolon is characterized by dilation and hypomotility of the large intestine which results in fecal retention, being common a chronic cause of constipation in cats, and usually idiopathic. The affected shows progressive and recurrent signs of constipation throughout months to years. The initial treatment is clinical with laxatives, enemas, prokinetic medications and dietary adjustments. However, in cases of unsuccessful results of medical therapy, surgical intervention is necessary. The objective of this report is to describe the management of a male Persian cat with chronic constipation, obstipation and recurrent megacolon treated by clinical and surgical means.

Case: A 1.2-year-old male Persian cat, weighing 4.35 kg , presented over 8 years, several episodes of constipation and megacolon confirmed by clinical, laboratory, simples and/or contrast radiographic and ultrasound exam. Despite the initial success of the clinical treatment, it recurred after 4 months and clinical exam and new radiographs indicated recurrence and the patient was treated with mineral oil and suppositories. After 12 months, the patient presented fecal retention, rectal protrusion and tenesmus, when clinical and alimentary adjustments were performed. After new crisis, the cat was hospitalized and underwent to several clinical procedures with no success, being referred to colotomy, and 30 days after, subtotal colectomy. During 2.5 years, the patient received clinical attention in another veterinary center. After this, a serious constipation recurred and colotomy was performed. Two years later, the patient suffered with frequent constipation and was submitted to total colectomy, after failure of clinical treatments. Despite surgery, the cat developed acute renal failure and died after the procedure.

Discussion: The megacolon, characterized by increase in the diameter of the large intestine and hypomotility, is not a specific disease, but a condition with many causes such as neurological, endocrine, behavioral or congenital. Between others, the idiopathic is the most common, as observed in this patient. In this case, the diagnosis was achieved through history, laboratory and imaging exams, including radiographs which showed the colon distended and replete of feces, a typical find of patients with megacolon. The contrast radiography ruled out anatomical malformations, but did not provide a conclusive diagnosis regarding the etiology. The clinical treatment included a combination of pasty diet, mineral oil, suppositories, enemas and medications, in addition to fluid therapy, as complementary treatment. Although there was temporary improvement with lactulose and psyllium, which facilitate the intestinal transit, the alimentary management was not efficient at long term. It is recognized that over time the patients develop generalized colonic smooth muscle dysfunction, as identified in this patient by ultrasound, which indicates colonic inertia and need for surgical intervention. The subtotal colectomy was performed after several attempts at medical and surgical approaches over more than two years. Studies indicate that preserving ileocolic junction can minimize the recurrence of constipation, opposite to excision which can increase diarrhea in the long term. Usually, the post-surgery survival is long, with good quality of life, as long as an adequate diet maintenance, which was a challenge in this patient, since it refused the high-fiber diet. The medical treatment of constipation should be applied but may be unfeasible or ineffective, as observed several times in this case. This case illustrates the severity of idiopathic megacolon in cats and reinforces the need to consider early surgical intervention when the condition is not responsive to diet and medical therapy, to improving the patient quality of life and avoid complications which can cause increased morbidity and contribute to patient mortality.

Keywords: constipation, colotomy, subtotal colectomy, total colectomy.