Case Review
Intussusception in an Older Dog: Where’s the Cancer?
Coby Richter, DVM, DACVS
Patient
A 9-year-old, neutered male, mixed-breed dog was referred to DoveLewis with progressive gastrointestinal signs. Initially seen at the primary care veterinarian two weeks earlier for lethargy, decreased appetite and weight loss, the dog had tested negative for parasites and had not responded to a bland diet. Abdominal radiographs taken prior to referral showed gastric distension, decreased serosal detail and small intestinal distension.
Initial Diagnosis
Upon presentation the dog was mildly dehydrated and febrile, uncomfortable on abdominal palpation, and exhibited diffuse muscle wasting. CBC and chemistry panel prior to surgery revealed a mature neutrophilia, mild anemia and electrolyte abnormalities of hyponatremia and hyperchloridemia. An abdominal FAST scan did not identify any effusion but did find small intestinal distension with shadowing material within the lumen. The patient was stabilized for surgery with IV fluids, fentanyl, maropitant, and broad-spectrum antibiotics.
Surgery
At surgery, serosanguinous abdominal fluid was encountered and collected for culture. The stomach and small intestine were moderately fluid distended oral to a normograde jejunojejunal intussusception (figure 1). The intussusception was non-reducible and intestine beyond the affected segment was mildly thick walled for 15 cm. Mesenteric lymph nodes serving the jejunum were neither discolored nor enlarged. Following gastric decompression with an orogastric tube, resection and anastomosis were performed to remove approximately 55 cm of jejunum. A nasogatric tube was placed to address expected ileus post-operatively. The dog recovered from anesthesia in an uncomplicated manner and was discharged in 36 hours with amoxicillin/clavulanate, codeine and gabapentin. The culture of pre-lavage abdominal fluid failed to grow any organisms and antibiotics were discontinued after 7 days.
The resected bowel was divided lengthwise following surgery exposing an irregular soft tissue mass at the aboral tip of the intussusceptum (figure 2). The entire intussusceptum (20cm) was submitted in formalin for histopathology due to the suspicion of neoplasia. Part of the intussuscipiens was reserved separately in formalin. Initial histopathology reported severe inflammation (ulceration, necrosis, granulation tissue) with no neoplasia found. A request for second examination (“recut”) was made which returned with the same result. The reserved intussuscipiens tissue was submitted which provided a diagnosis of infiltrative lymphoma. Interview with the clients 10 months following diagnosis affirmed that the dog was doing well under the care of a veterinary oncologist.
Figure 1: Normograde jejunojejunal intussusception.
Figure 2: Exposed aboral tip of intussusceptum after dividing intussusception lengthwise
Review
Intestinal intussusception in dogs and cats is frequently associated with three primary co-morbidities; intestinal parasitism, intestinal foreign body and intestinal neoplasm. Other differentials include but are not limited to inflammatory bowel disease, enteritis, electrolyte imbalance and adhesions. In this older patient with no known dietary indiscretion and a negative fecal exam, neoplasia was high on the differential list. The appearance of a small mass at the tip of the intussusceptum was suspicious for the inciting cause, however this area was closely examined by the pathologist without finding cancer. Ideally, submitting all excised tissue for histopathology is recommended. However, in this case the timing (holiday weekend) and volume of tissue involved would have risked sample degradation. Reserving sample tissue in formalin aided in discovering the complete diagnosis.
DoveLewis is thankful to the patience, persistence and thoroughness of our pathology colleagues who help us make a difference in patient lives every day.
