Zinc Phosphide Flashcards
What products is Zinc Phosphide used in?
Restricted Use Products
What are the sources of Zinc Phosphide?
Accidental ingestion of baits
Ingestion of poisoned rodents
Cages birds can get poisoned by ingestion of food contaminated by the feet of rodents
Malicious poisoning
What are the properties of Zinc Phosphide?
Gray-black powder with acetylene odor (dead fish)
Stable when dry but decomposes in air within 2 weeks
Liberates phosphine gas (PH3) under acidic conditions
Insoluble in water
Irritant
What is a property of phosphine gas?
Toxic and flammable
What is the acute toxicity of zinc phosphide due to?
Phosphine gas
What enhances the toxicity of zinc phosphide?
Gastric Acid
What are the toxicokinetics of zinc phosphide?
Gastric acid causes hydrolysis of zinc phosphide to phsophine gas
What decreases the toxicity of zinc phosphide?
Vomiting or alkaline stomach pH
How can phosphine gas be absorbed?
Inhalation
GI Tract
Skin
What is dangerous of about Phosphine gas excretion?
Can be excreted by the lungs - Dangerous for personnel!
What is the mechanism of Action of zinc phosphide?
Direct irritation of GI mucosa from Zinc Phosphide
inhibits oxidative phosphorylation and cellular energy production
What tissues are effected the most by zinc phosphide?
tissues with high oxygen demand (heart, kidney, liver, lung)
What are the clinical signs of Zinc phosphide?
Anorexia
Vomiting with blood
Abdominal pain and bloat in cattle
Increased rate and depth of respiration, wheezing, and dyspnea
Compulsive hypermotility (“mad dog running”)
yelping convulsions
What usually is the cause of death due to zinc phosphide?
Tissue Anoxia
What are the lesions seen with zinc phosphide?
Acetylene, garlic, fishy odor of vomitus/GI contents
Gastroenteritis (may be hemorrhagic)
Congestion of liver/kidney/lungs
What are the laboratory findings for zinc phosphide toxicosis?
Metabolic acidosis
dehydration
hypocalcemia
elevated serum zinc
What is the treatment for Zinc Phosphide toxicosis?
Good ventilation
decontamination: Emetics and gastric lavage with sodium bicarbonate
Antacids to raise the gastric pH
Symptomatic treatment
What is the symptomatic treatment of Zinc Phosphide toxicosis?
IV Fluids Oxygen Calcium gluconate for hypocalcemia Treat seizures or muscle tremors Treat GI mucosal damage
What is the prognosis for zinc phosphide toxicosis?
If no signs by 8-12 hours post ingestion or 12-24 hrs after vomiting
Animals with severe signs have a guarded to poor prognosis
