Sodium ion Toxicosis

Question 1

What animals are the most susceptible to salt poisoning?

Answer 1

• Swine (most!)
• Cattle
• Dog

Question 2

What is the MOA for saltwater poisoning?

Answer 2

• Na⁺ moves into the brain tissue with dehydration ⇢ decreased energy metabolism (Na-K APTase) ⇢ impairs the sodium pump
• Water follows into the brain ⇢ cerebral edema and increased ICP

Question 3

What does cerebral edema grossly look like?

Answer 3

• Congestion
• Flat gyri
• Narrow sulci

Question 4

What are the clinical signs of salt poisoning in swine?

Answer 4

• Rapid onset, often after reintroduction to water - within hours
• Thirst
• Constipation
• blindness
• circling
• head pressing
• dog-sitting with head jerking progressing to intermittent convulsive seizures

Question 5

How is salt poisoning diagnosed?

Answer 5

• History - check water delivery, availability
  
  • Typically after dehydration followed by return to free access water
• Brain histopathology:
  
  • Cattle: neuronal necrosis
  • Cortical laminar necrosis
  • Swine: eosinophilic meningoencephalitis with perivascular cuffing
    
    • less prominent/absent in cattle
• Measure sodium (serum & CSF/brain)

Question 6

What is the normal and toxic levels of sodium in the brain?

Answer 6

• Normal - 650-1200 ppm
• Toxicosis 1800+ ppm (often over 2000)

Question 7

What puts cattle at risk for salt poisoning?

Answer 7

• Sudden access to salt
  
  • especially with restricted water intake
• Salt added to feed to limit feed intake
  
  • with limited water available
  • % salt in the diet when limiting feed intake can vary from 6-50% salt
• Oil well drilling brine
  
  • waste water associated with fracking
• Bucket calves - limited water
  
  • transition to weaning
  • unfamiliar with water sources

Question 8

What is the clinical picture of cattle with salt poisoning?

Answer 8

• Within a few hours after rehydration
• Tremors, ataxia, lateral, seizures
• Lateral recumbence, paddling, muscle tremors
• Fractious
• Death in 12-24 hrs
• With prolonged signs- recovery associated with ataxia & knuckling of fetlocks

Question 9

What are sources for salt toxicosis for dogs?

Answer 9

• Consumes high salt foods or materials
  
  • Salt cured country ham
  • Sea water
  • Salt-flour “play dough”
  • Misformulated pet foods

Question 10

How is salt poisoning diagnosed in dogs?

Answer 10

• Normal brain sodiu < 1940
• Serum sodium >160 mEq/L
• Eosinophilic brain response unlikely
• Brain edema possible

Question 11

What is the treatment for salt poisoning?

Answer 11

• Rehydrate slowly
  
  • D5W IV
  • slow return to water - replace free water deficit:
    
    • FWD = 0.6 x bw(kg) x (1 - normal Na⁺/current Na⁺)
  • Mannitol (25%) @ 1-2 g/kg for cerebral edema
  • hypertonic saline
  • Furosemide (loop diuretic) 2.2 - 4.4 mg/kg PO, IV, or IM bid