Urinary obstruction means urine cannot leave the kidney (ureteral obstruction) or the bladder (urethral obstruction). In dogs the usual culprit is a stone, and the usual patient is a male dog straining without producing urine. Complete urethral obstruction quickly causes postrenal azotemia and hyperkalemia, so the exam question is nearly always about what to do first.
Key facts
Urinary obstruction at a glance- Species and system: dog; urinary tract (urethra, bladder, ureters, kidneys).
- Main cause: uroliths; in cats the main urethral cause is a matrix-crystalline plug, in dogs it is a stone.
- Classic presentation: male dog straining with little or no urine, a large, firm, painful bladder, then vomiting and depression.
- Life threat: hyperkalemia with bradycardia and arrhythmias, plus postrenal azotemia and metabolic acidosis.
- Golden rule: stabilize before you sedate; calcium gluconate protects the heart but does not lower potassium.
- Zoonotic or reportable: no.
What's inside
12 sections in the full guide- Key facts
- How the NAVLE tests this
- Cause and pathophysiology
- Clinical signs
- Diagnosis
- Differential diagnoses
- Treatment and management
- Prevention, control and public health
- Prognosis
- Quick review
- Test yourself
- References
The full guide also has 5 tables, 3 figures, 3 self-test questions and 11 references, available to NAVLE members.
Read the full study guide
The full guide is part of every NAVLE plan, with diagnosis and treatment tables, figures, a quick review and self-test questions. Start a free trial to try the question bank, or log in if you are already a member.