By Dr Sarah Langton
WARNING: This case study contains graphic images from a surgical procedure.
The Case
Reason for presentation:
Zooie, an 8-year-old spayed female labrador, 33 kg, was presented to North Coast Veterinary Emergency and Critical Care for acute onset of lethargy and hyporexia.
Relevant history:
Zooie had been diagnosed with diabetes mellitus four years prior to presentation and had been well controlled with Caninsulin® injections twice daily. She developed bilateral cataracts secondary to her diabetes which had been corrected two years ago by our referral veterinarian in ophthalmology Dr Guy Clare.
Physical examination:
At the time of presentation, we performed a clinical examination of Zooie to identify any abnormalities. Below were the findings:
- Tachycardic with a heart rate of 292 bpm
- Hypodynamic femoral pulses
- Mildly tachypnoeic having a respiratory rate of 36 bpm
- Mild cranial abdominal pain.
Clinical Pathology results:
Zooie also had baseline blood tests performed, which demonstrated the following relevant findings:
- Diabetic ketoacidosis
- Hyperphosphateamia
- Moderate dehydration.
Figure 1 Zooie’s biochemistry panel demonstrating mild hyperphosphatemia, and marked hyperglycaemia, with mild elevations in total bilirubin, cholesterol, amylase, and lipase.
Figure 2 Zooie’s initial complete blood count demonstrating mild monocytosis, and suspected left shift neutrophilia.
Figure 3 Zooie’s blood ketone levels at presentation demonstrating ketonemia
Figure 4 Zooie’s urinalysis results demonstrating proteinuria, glucosuria, ketonuria, and mild haematuria.
Figure 5 Zooie’s blood gas results showing a mixed metabolic acidosis and respiratory alkalosis.
Immediate treatment for stabilisation:
Zooie was commenced on intravenous fluid therapy to help correct her dehydration and to reduce her blood glucose concentrations. She was also started on a short-acting insulin protocol, an Actrapid® CRI, to help reduce her blood glucose levels.
Zooie was officially transferred to the Internal Medicine department for further ongoing management and investigation of the cause of tachycardia and abdominal pain. At the time, she was given methadone IV for pain relief, but she was not adequately analgesed, and she was commenced on morphine, lignocaine, and ketamine CRI.
Diagnostic investigation:
Abdominal ultrasound
Zooie had an abdominal ultrasound as it was less invasive whilst she was still stabilising. Typically, in larger stable patients, we prefer advanced imaging such as a CT (contrast tomography) as it tends to be more sensitive for detecting abnormalities compared to ultrasound.
Relevant findings:
- The right limb of the pancreas is moderately hypoechoic and has a normal shape.
- The left limb of the pancreas is very irregular, with a mass of tissue with nearly anechoic “rim” and with more hypoechoic middle.
- There is moderate effusion with a flocculant appearance.
Figure 6 The ultrasound imaging of Zooie’s left pancreatic limb demonstrating peri-pancreatic fluid (green arrows), and irregular shape and echogenicity of the left limb (yellow arrows).
Medical management
Zooie was treated with supportive care for acute necrotising pancreatitis. However, with marked pancreatic changes and flocculent-free fluid, there was concern she had a pancreatic abscess and/or pancreatic tumour that had ruptured. Zooie was showing minimal improvement with medical management and becoming refractory to the pain relief protocol.
The next treatment option available is exploratory laparotomy and surgical debridement of non-viable tissue. If the pancreatic changes were due to underlying neoplasia, surgery has a better long-term outcome than medical management (i.e. chemotherapy). Surgery and biopsy of the pancreas offer the chance to achieve a definitive diagnosis (rule in or out pancreatic neoplasia). Pancreatic neoplasia, unfortunately, carries a guarded prognosis. A recent paper on exocrine pancreatic carcinoma in dogs found the metastatic disease in 78% of the cases at the time of diagnosis 1. This demonstrates the aggressive nature of the diseases. Contrary to what has been reported in cats and people, pancreatic carcinoma is not often associated with diabetes mellitus in dogs 2.
Advanced imaging (CT of the thorax and abdomen)
We opted for a triple phase CT of the thorax and abdomen to assess the following:
- Vascular supply of the pancreatic tissue
- The regional and distal lymph nodes
- To assess the thorax for signs of metastatic disease.
This was also a good opportunity during general anaesthesia to place a central line in the jugular vein. This provides an easier way to deliver ongoing treatments and close monitoring of the electrolytes, phosphate, blood pH, glucose, and ketone levels. It’s considered less invasive compared to having multiple needle sticks for monitoring every couple of hours.
CT findings:
The main findings of the CT include:
- Acute pancreatitis, mostly of the left lobe and body. The body had an organising area which is suggestive of necrotising pancreatitis and an early abscess.
- There was also steatitis and a lot of peritoneal fluid.
- Absence of metastatic disease.
Exploratory laparotomy
Zooie was transferred to our surgery department and had a ventral midline celiotomy. The left limb and body of the pancreas appeared severely inflamed and had multiple structures adhered to it, including the spleen, left kidney, transverse colon, duodenum, and omentum. It appeared to have multiple pockets of necrotic tissue and purulent material. The splenic artery was within this abnormal tissue and unable to be debrided. Subsequently, the left limb and body of the pancreas were resected, and the spleen had to be sacrificed. Fortunately, the fibrous adhesion to the kidney, colon and intestine were able to be gently debrided.
By only doing a partial pancreatectomy and sparing the right limb of the pancreas, Zooie still has functional pancreatic tissue for digestive processes. If the whole pancreas were removed, then Zooie would have a disease called exocrine pancreatic insufficiency (EPI) and require digestive enzyme supplementation every time she eats for the rest of her life.
Figure 7 The resected left limb of Zooie’s abnormal and thickened pancreas (yellow arrowheads). The peri-pancreatic fat is inflamed and adhered (blue stars) to the nearby spleen (green arrowheads).
Why we didn’t place a feeding tube:
It is worth noting that Zooie remained hyporexic in the hospital. So ideally, for straight-forward pancreatitis management, she would have a feeding tube placed to encourage enteral nutrition, which is associated with an improved outcome.
Due to Zooie’s size, a gastrotomy tube would be ideal; however, with the indication of already having peritonitis, placing a feeding tube within the abdomen could be a high risk for a nidus for infection, and subsequent breakdown of the stoma site where the tube is placed. This would result in an open wound through the abdominal wall and the stomach.
Alternatively, there was an option for an O-tube. Again, it is not a risk-free procedure. We found the risk assessment when considering Zooie had a lot of neck fold, subcutaneous tissue, and diabetes, which is associated with poor wound healing and increased risk of infection.
In this particular case, it was decided that we would manage the abdomen, and then Zooie should begin to eat as she would be more comfortable. If Zooie doesn’t eat, then we can always place a feeding tube later.
Pancreatic histopathology and culture and sensitivity results:
The histopathology of the resected pancreas indicated severe subacute necrotising and suppurative pancreatitis with peripancreatic fat necrosis and saponification.
The peritoneal fluid and pancreatic tissue culture were negative.
Outcome:
Fortunately, after the necrotic pancreatic tissue was removed, Zooie became very easy to manage in the hospital. She began eating within 24 hours, we were able to transition her from her Actrapid® CRI to her normal Caninsulin®, based on her blood glucose and ketone levels. We were able to de-escalate her pain relief, as her abdominal pain resolved within 48 hours post-op.
We discharged Zooie from the hospital with a Freestyle Libre sensor placed. This is a monitor that owners can measure the interstitial glucose by scanning the sensor, typically every 8 hours. We have access to the data online to assess insulin response over 14 days. During the initial period at home, we did not aim for tight control of her diabetes as she was recovering from major abdominal surgery.
Figure 8: Zooie’s first night home after discharge from the hospital. Zooie’s enjoying much-needed rest next to her sister. Notice the small Freestyle Libre® monitor on her back.
Zooie is currently very stable, having completely healed from her surgery, and we are managing her diabetes now.
Figure 9 Zooie is all smiles today! She is happy and recovered after surviving her extraordinary ordeal several months ago.
Thank you to the Fawke family for allowing us to share Zooie’s story and providing photo updates.
For more information on pancreatitis in dogs, contact SASH at ncvs.net.au or call (07) 5453 7555.
References:
1. Pinard CJ, Hocker SE, Weishaar KM. Clinical outcome in 23 dogs with exocrine pancreatic carcinoma. Vet Comp Oncol. 2021;19(1):109–14.
2. Ettinger S, Feldman E, Cotte E. Textbook of Veterinary Internal Medicine. 8th Edition. Elsevier; 2017.