Zinc Phosphide Flashcards
Are zine phosphide rodenticides general or restricted use products?
Most are restricted use pesticides
Available as grain bait, past, tracking powder
T/F: Aluminum and magnesium phosphide have similar toxic effects as zinc phosphide
TRUE
How are pets exposed to zinc phosphide baits?
Accidental ingestion
Relay toxicosis has been observed
malicious poisoning
What are the properties of zinc phosphide poison?
Grey-black powder
Garlic or dead fish odor
***when exposed to acid - liberates phosphine gas (PH3) - gas is toxic, flammable, and an irritant
relatively insoluble in water
Acute zinc phosphide toxicosis is due to _______
Phosphine gas
When a patient ingests zinc phosphide - the acidic environment of the stomach/GI will liberate the toxic gas
pH below 7, and even more so pH below 4
T/F: Ingestion of zinc phosphide is more dangerous on an empty stomach
FALSE
when a patient has not eaten in hours the stomach will be more alkaline, so less gas will be liberated
What causes chronic zinc phosphide toxicosis?
both the zinc phosphide and phospine gas
Toxic effects of zinc phosphide can be seen in dogs at doses of _______ mg/kg
20 - 40 mg/kg
Hydrolysis and liberation of phosphine gas occurs at a pH of ____ or lower
4
- *hydrolysis and liberation of gas**
- vomiting or alkaline stomach pH will decrease toxicity
Where is zinc phosphide and phosphine gas absorbed?
GIT
Phosphine gas can also be absorbed through inhalation
Where is zinc phosphide and phosphine gas excreted?
Gas is excreted through the lungs
small amount zinc phos will be metabolized, inactivated, and excreted in the urine
What tissues are most greatly effected by zinc phosphide toxicosis?
Tissue with high O2 demand: brain, heart, kidney, liver, lung
What is the suspected MOA of phosphine gas?
Inhibition of oxidative phosphorylation –> decreased cellular energy production and cell death
increase in oxgen radicals resulting in peroxidation and cell damage
damage to RBCs, and blood vessels
What clinical signs are observed in a patient with zinc phosphide toxicosis?
Rapid onset (min - hrs) Anorexia, vomiting, abdominal pain, bloat-cows, increased resp rate and effort
Dogs may show CNS excitation
death within 3-48 hours due to tissue anoxia
What lesions are associated with zine phosphide toxicosis?
Smell of the bait in vomitus
Gastroenteritis - may be hemorrhagic
Congestion of liver, kidney, and lungs