Kidney and Urinary System Notes

Kidneys and Urinary System Overview

• The kidneys are part of the urinary system, crucial in filtering blood and excreting waste.
• Structure of the urinary tract includes:
  • Kidneys: Two organs located near the spine, with the right kidney more cranial than the left in cats and dogs.
  • Ureters: Tubes that carry urine from the kidneys to the bladder.
  • Bladder: Where urine is stored before excretion.
  • Urethra: Conducts urine out of the body; longer in males and opens into the penis, while in females it opens into the vagina.

Common Urinary System Issues

• Urinary Tract Blockage: Especially in male cats due to narrow urethra curvature, leading to plugs or stones that cause painful blockages.
• Symptoms of Urinary Tract Disease:
  • Stranguria: Straining to urinate.
  • Hematuria: Presence of blood in urine, commonly seen in cases with obstructions.
• Emergency Situations: Blockage can lead to kidney damage due to toxin build-up, requiring immediate veterinary attention.

Kidney Functions

• Main functions include:
  • Filtration: Filter waste products like urea nitrogen and creatinine from the blood.
  • Regulation: Control of electrolyte balance (e.g., sodium, potassium) and fluid balance.
  • Hormonal Function:
  • Erythropoietin: Stimulates red blood cell production in bone marrow.
  • Renin: Helps regulate blood pressure; monitored closely in kidney failure patients.

Diagnosing Kidney Issues

• Common diagnostic tools include:
  • Urinalysis: Examining urine for specific gravity, protein levels, and sediment, looking for abnormal components like crystals or blood.
  • Blood Tests: Measuring blood urea nitrogen (BUN) and creatinine to assess kidney function. Elevated levels indicate potential kidney dysfunction.
  • Imaging: Ultrasounds or radiographs to visualize kidney structures, looking for obstructions or abnormalities.

Acute and Chronic Kidney Problems

• Acute Kidney Injury (AKI): Results from toxins (e.g., antifreeze, leptospirosis) and can lead to rapid kidney failure.
• Chronic Kidney Disease (CKD): Progressive loss of kidney function, often seen in older cats and some dog breeds, manifested with weight loss, increased drinking (polydipsia), and frequent urination (polyuria).
• Diagnostic Staging: International Renal Interest Society (IRIS) uses a staging system to assess kidney function severity based on diagnostic tests.
• Emergency Treatment for AKI: Includes IV fluids and potential use of alcohol to bind toxins, although prognosis can vary.

Urinary Tract Infections (UTIs) and Cystitis

• Cystitis: Inflammation of the bladder often due to bacterial infection.
  • Symptoms: Frequent straining to urinate, pain, and blood in urine.
  • Diagnosis via urinalysis and culture; typically treated with antibiotics.
• Feline Lower Urinary Tract Disease (FLUTD): A complex condition with multiple potential causes including idiopathic cystitis and urolithiasis (formation of stones).

Urolithiasis (Urinary Stones)

• Common types:
  • Struvite Crystals: Often form due to urinary pH changes, treated by dietary adjustments (e.g., Hill's SD).
  • Calcium Oxalate Crystals: Dangerous as they can cause blockage, particularly in male cats.
  • Management includes dietary changes and possibly surgical intervention for removal of stones.

Home Care and Management

• Electrolyte balance is vital; many cases can be managed at home with client education on administering subcutaneous fluids for hydration.
• Awareness of behavioral changes in pets is key to early detection of urinary issues; alterations may suggest underlying kidney problems or urinary infections.

Summary

• Early detection of urinary tract and kidney issues improves prognosis, making regular veterinary check-ups essential for pet owners. Common diseases include urolithiasis, FLUTD, chronic kidney disease, and cystitis, each requiring specific management strategies.