NAVLE Urinary

Feline Acute Kidney Injury (AKI) Study Guide

March 28, 2026 25 min read 18 views
Acute kidney injury (AKI) is defined as an abrupt reduction in kidney function resulting in alterations in glomerular filtration, urine production, and tubular function.

Overview and Clinical Importance

Acute kidney injury (AKI) is defined as an abrupt reduction in kidney function resulting in alterations in glomerular filtration, urine production, and tubular function. AKI represents a continuum from mild nephron injury to severe, life-threatening kidney failure. The term AKI has largely replaced "acute renal failure" in veterinary medicine, allowing for greater stratification of severity and earlier treatment intervention.

Feline AKI is a commonly encountered emergency in small animal practice. Cats present unique challenges due to their small ureteral diameter (approximately 0.4 mm), making them highly susceptible to obstructive uropathy, and their sensitivity to certain nephrotoxins such as lilies and ethylene glycol.

Stage Description and Clinical Features
1. Initiation Duration: Hours to days. Original insult occurs (ischemia, toxins, infection, obstruction). GFR begins to fall but clinical signs often absent. Therapeutic window exists for early intervention.
2. Extension Duration: 1-2 days. Ongoing hypoxia and inflammatory response. Tubular cells undergo necrosis and apoptosis. GFR continues to decline. Early laboratory changes may become apparent.
3. Maintenance Duration: Days to weeks. Characterized by azotemia and uremia. Oliguria (less than 0.5 mL/kg/h) or anuria may occur. Tubular repair begins. Maximum supportive care required.
4. Recovery Azotemia improves. Renal tubules undergo repair and regeneration. Marked polyuria may occur (post-obstructive diuresis). Recovery may be complete or result in residual CKD.

Pathophysiology of AKI

AKI results from direct damage to renal tubular cells and ischemia, leading to inability to maintain fluid, electrolyte, and acid-base balance. The pathophysiology can be described in four distinct stages:

You've been studying hard

Create a free account to keep reading

Free accounts get 5 articles/day + daily practice question

Join 14,000+ vet students already studying with NavleExam.

No credit card needed — free account takes 30 seconds.

Create Free Account — Keep Reading Already have an account? Log in
or skip signup — just get daily questions

No spam. One question per day. Unsubscribe anytime.

NAVLE Exam Prep Platform

Everything you need to pass the NAVLE

✓
10,000+ Practice Questions
Exam-style with full explanations
✓
Past Exam Papers
Real previous exam questions
✓
Flashcard Mode
Species & topic quick review
✓
High-Yield Study Guides
What's actually on the exam
Start Free Trial → See Plans & Pricing No credit card required to start

Related Articles

NAVLE

Feline Kidney Lymphoma Study Guide

 NAVLE

Feline Idiopathic Cystitis Study Guide

 NAVLE

Equine Urolithiasis Study Guide