What is your diagnosis?

tHe QuestIONs…

Dr Alex WAlkeR, BVsc, Zoetis Intern at Veterinary specialists Aotearoa Dr tOMMy FlueN,

FANZCVs, Registered specialist small Animal Internal Medicine at Veterinary specialists Aotearoa Dr DeVON tHOMpsON,

DipeCVDI, Registered specialist Radiologist at Veterinary specialists Aotearoa

Case history

A 40 kg, 8-month-old, male-entire Rottweiler was presented to its regular veterinary clinic for anorexia and hypodipsia. the hypodipsia was not specifically quantified but water intake was markedly reduced compared to normal. there was no reported history of toxin exposure, diet change, vomiting or diarrhoea.

Clinical findings

on physical examination the dog was dull, weak, and lethargic with an elevated temperature of 40°C. A blood sample was collected and sent to Gribbles Veterinary diagnostic laboratory for haematology and biochemistry (table 1), an additional biochemistry panel was performed the following day. A free catch urine sample was collected and analysed in-house. Haematology was unremarkable, urine specific gravity was optimally concentrated at 1.055, with 3+ protein on dipstick.

table 1. serum biochemistry results for 8-month-old Rottweiler with anorexia and hypodipsia. Red text indicates results greater than the reference interval.

Analyte Units Test 1

Sodium Potassium mmol/L mmol/L

Na K Ratio ratio

Chloride Creatinine urea mmol/L μmol/L mmol/L

Phosphate

mmol/L Cholesterol mmol/L tP Albumin Globulin A/G Ratio Calcium Bilirubin Alk phos ALt g/L g/L g/L RAtIo mmol/L μmol/L Iu/L Iu/L

ASt Iu/L

CK Iu/L

Amylase

Iu/L Bicarbonate mmol/L Anion gap mmol/L

a Sample 2 was collected 24 hours after Sample 1 186 4.1 45.8 138

20 32.1 Test 2a

187 4.2 44.6 139 107 5.6 1.75 5.9 70 42 28 1.52 2.89 4.3 32 66 338 2705 472

Reference interval

141–153 4.0–5.4 27–36 104–123 48–109 2.5–9.0 0.92–1.82 3.3–9.8 54–74 33–44 19–35 0.52–1.7 2.08–2.82 1.0–3.0 0–87 0–88 0–51 0–385 0–1074 18–27 8.0–26.0

Following 2 weeks of intermittent treatment and hospitalisation for a variety of differential diagnoses the dog was subsequently referred. During this time under the care of the referring veterinarian, therapeutics included amoxicillin-clavulanic acid, enrofloxacin, metronidazole, dexamethasone and I/V fluid therapy with lactated Ringer’s solution.

on presentation to the referral clinic, the dog was hyperthermic with a decreased level of consciousness, delayed menace reflex in the left eye and proprioceptive deficits in the left pelvic limb. An inhouse venous blood-gas confirmed persistent hypernatremia (176 mmol/L, reference range 139–150 mmol/L).

Questions

1. What is this dog's problem list? 2. What are your differential diagnoses? 3. What are your next diagnostic steps? 4. What is your treatment plan?

Contact: alex.walker@hotmail.co.nz Answers on page 32