A 12-year-old, 13-lb (6-kg) neutered male domestic shorthair cat was admitted for boarding for 5 days. He was being treated with glargine insulin (1 U SC every 12 hours) for diabetes mellitus and fluoxetine (10 mg PO every 24 hours) for behavioral issues. The cat had a decreased appetite for canned food and chicken but a good appetite for dry food. He was vocal and friendly during daily physical examination, and no abnormalities were noted. He was discharged without incident.
Emergency Presentation
The evening following discharge, the cat was presented emergently for lethargy, vomiting, and decreased appetite. Glargine insulin and fluoxetine had been administered the evening of discharge.
Physical Examination
The patient was quiet, alert, and responsive. Weight was 12.4 lb (5.6 kg). Temperature was 100.5°F (38°C). Pulse was 200 bpm, and respiration rate was 50 breaths per minute. The cat was 6% dehydrated, and the mucous membranes were pink and slightly tacky. He was tense and painful, particularly cranially, on abdominal palpation.
Diagnostics
Blood
Packed-cell volume: 42% (range, 28%-47%)
Total protein: 8.4 g/dL (range, 5.7-8.6)
pH: 7.15 (range, 7.35-7.45)
Sodium: 148.2 mEq/L (range, 145-158)
Potassium: 2.94 mEq/L (range, 3.4-5.6)
Chloride: 116 mEq/L (range, 104-128)
Glucose: 291 mg/dL (range, 64-170)
Lactate: 0.8 mmol/L (range, <2.5)
BUN: 28 mg/dL (range, 14-36)
Creatinine: 1.6 mg/dL (range, 0.6-2.4)
Urine
Urine specific gravity: >1.050 (range, 1.015-1.060)
pH: 6.5 (range, 5.5-7)
Ketone: 160 (normal, negative)
Glucose: 500 (normal, negative)
Treatment
The patient was hospitalized for management of diabetic ketoacidosis (DKA) and treatment of presumptive pancreatitis.
Plasmalyte, a multiple electrolyte isotonic IV solution, (6 mL/kg/hour) + potassium chloride (20 mEq/L) + potassium phosphate (20 mEq/L)
Insulin loading: blood glucose monitoring every 1 hour; regular insulin (1 U IM every 1 hour) until value is <250
Cisapride: 2.5 mg PO every 12 hours
Ranitidine: 3.5 mg/kg PO every 12 hours
Ampicillin/sulbactam: 30 mg/kg IV every 8 hours
Maropitant: 1 mg/kg PO every 24 hours
Buprenorphine: 0.02 mg/kg transmucousally every 12 hours
Progress
Electrolytes
Day 2
Chloride: 109 mEq/L (range, 104-128)
Phosphorus: 1.8 mg/dL (range, 2.4-8.2)
Potassium: 2.4 mEq/L (range, 3.4-5.6)
Sodium: 157 mg/dL (range, 145-158)
→ Increased potassium phosphate to 40 mEq/L
Day 3
pH: 7.383 (range, 7.35-7.45)
Phosphorus: 7.2 mg/dL (range, 2.4-8.2)
Potassium: 7 mEq/L (range, 3.4-5.6)
Sodium: 161 mg/dL (range, 145-158)
→ Iatrogenic hyperkalemia; decreased potassium chloride in IV fluids
Day 4
Chloride: 109 mEq/L (range, 104-128)
Potassium: 3.6 mEq/L (range, 3.4-5.6)
Sodium: 158 mg/dL (range, 145-158)
→ Supplemented potassium chloride in IV fluids
Serum Chemistry Profile/CBC
Day 3
Alanine aminotransferase: 202 IU/L (range, 10-100)
Packed-cell volume: 41% (range, 28%-47%)
Total protein: 7.8 g/dL (range, 5.7-8.6)
Total bilirubin: 0.8 mg/dL (range, 0.1-0.4)
Blood Glucose (range, 65-155)
Day 3
410, then 316
Day 4
420
Day 5
414
Day 6
339
Urine Glucose/Ketone
Day 4
2000/small (normal, negative/negative)
→ Insulin switched to glargine (2 U SC every 12 hours) onday 5
Outcome
On day 6, the patient was eating well. On day 7, he was transferred out of emergency services, recovered well, and was discharged.
The Generalist’s Opinion
Barak Benaryeh, DVM, DABVP
DKA is a disease state that every clinician will encounter. This cat’s DKA was likely brought on by the boarding episode, which may have triggered pancreatitis. The clinician’s did a very good job of quickly identifying the problem and instituting appropriate treatment. This case serves as a reminder and cautionary tale about boarding patients: it does not take much for patients with diabetes to destabilize. It is also a good review for treating both pancreatitis and DKA.
Cats & Boarding
Pet owners of diabetic cats often choose a boarding facility connected to a veterinary hospital for proper management of any complications. All boarding facilities should have a monitoring system in place for recording appetite, urination, defecation, and general behavior. If glucose levels are not being monitored, there is no way to know if appropriate insulin levels are being administered. Blood glucose should be measured just prior to insulin administration during the first 1 to 2 days of boarding, as this will provide an idea of whether the dose should be adjusted without requiring an entire curve. These readings are not definitive; however, if readings are exceedingly high or low, stress may be having a significant effect, and more careful monitoring is needed.
Owners should be informed that monitoring is to ensure appropriate administration of insulin and there will be a charge for the service. It is not uncommon for insulin requirements to change in a boarding situation. Glucose levels should be monitored to ensure appropriate doses are being administered. This cat was receiving fluoxetine for pre-existing behavioral issues; any potential anxiety or stressor can change insulin needs.
Diabetic Ketoacidosis: Treatment
The clinicians used an intramuscular insulin protocol. Some studies have compared the IM route to an IV CRI.1,2 Both routes are considered appropriate methods, but clinician preference and comfort level vary. In critical cases, there is likely a benefit to using an insulin CRI, but there are no studies to my knowledge that address this issue specifically. This cat was relatively stable, and using the IM protocol was effective.
Insulin therapy appears to have been administered immediately. For management of DKA, delaying insulin therapy—by 4 to 6 hours—until after fluid therapy has been instituted is generally safer. Insulin administration can trigger movement of glucose and water from the intravascular to the intracellular space and can potentially lead to further complications (eg, shock) if instituted too quickly.2
Feline Pancreatitis
In this case, pancreatitis was a presumptive additional diagnosis on the basis of pain in the cranial abdomen. Cats with DKA commonly have concurrent or predisposing illnesses.3 Pancreatic enzyme values were not included here; however, whether the values were normal or elevated does not rule in or out the possibility of pancreatitis. Abdominal ultrasonography (although also not completely reliable) would have been a helpful test in determining a diagnosis. Diagnosing feline pancreatitis is difficult. Instituting treatment based on suspicion, as was done in this case, is often the only option.
The Specialist’s Opinion
Gretchen Statz, DVM, DACVECC
Medical boarding is commonly offered by veterinary clinics to accommodate patients not healthy enough for a regular boarding facility. Medical boarding patients are generally considered stable and are not always assessed as often or as thoroughly as other hospitalized patients. Boarding patients are sometimes kept in the back of the clinic and are not observed as closely as patients in an ICU setting. This case demonstrates the importance of clinician assessment of medical boarders on at least a daily basis. Records of appetite, urinary and defecation habits, and ideally body weight (especially for longer stays) should be kept. All notes from the daily and nursing assessments should be in the medical record. In this case, daily assessments were made and changes in appetite were noted; however, the clinical signs were not seen until the cat returned home.
Diabetes mellitus can quickly become a frustrating and potentially life-threatening disease. Seemingly stable diabetic patients can have unexpected changes in glucose regulation and insulin needs without much warning, which can lead to a hypoglycemic crisis or DKA. These potential complications make close assessment of diabetic patients especially important during boarding. These patients should also be kept on their normal feeding and insulin schedules as much as possible. Changes in food intake and insulin schedules can easily disrupt diabetic regulation. This cat had a change in diet from canned to dry food, which (along with the stress of boarding) may have precipitated the decline.
Workup for Diabetic Ketoacidosis
In patients with DKA, looking for a reason for the change in diabetic regulation is ideal. Urine culture and abdominal ultrasonography can be helpful to observe for evidence of pancreatitis or UTI, both of which are common in diabetic cats. This patient was assumed to have pancreatitis based on abdominal pain and other clinical signs and was treated with antibiotics. Whether further diagnostics were offered is not mentioned.
Bloodwork & Fluid Therapy
Some classic bloodwork changes associated with DKA, including hypokalemia and hypophosphatemia, were present. Potassium and phosphorus often drop when insulin is initiated; monitoring electrolytes closely with relatively aggressive treatment is thus important. Potassium dropped initially in this case but was treated accordingly and eventually corrected. Sodium increased with treatment, likely indicating free water loss and dehydration. Initially, the patient may not have been treated aggressively enough with IV fluids. Patients with DKA often require high fluid rates to correct dehydration and keep up with ongoing losses.
Options for Insulin Therapy
Patients with DKA are most often treated with short-acting insulin, which can be administered via intermittent IM injections or CRI. Blood glucose levels in this case remained relatively high, never dropping <250 mg/dL. A CRI of insulin may have been more effective at achieving normoglycemia and keeping levels stable. Insulin CRIs require 24-hour care by experienced veterinary professionals.