Organic synthetic herbicides Dr. Shokry Flashcards
What class of organic synthetic herbicides do Paraquat & Diquat belong to?
Dipyridyls
What is the most common Phenoxy acid compound toxicity seen?
2,4-D
What is the general tx for organic synthetic herbacide toxicosis
Decontamination
& symptomatic
What property of phenoxy derivatives of fatty acids (2,4-D compounds) is unique & causes what problem
They are plant hormones.
Alter metabolism of plants → incr. accumulation of nitrates & cyanide!
Improve plant palatability of normally unpalatable poisonous plants.
Which spp most susceptible to 2,4-D toxicosis
Most sensitive?
Cattle & Dogs
Dogs
2,4-D is lipid soluble T or F?
How does this affect metabolism?
How does this affect tx?
True
metabolized mainly by hydrolysis but,
- excreted mainly unchanged in urine by secretion*
- Alkalinization of urine enhances renal excretion*
Main CS with 2,4-D toxicosis
GI ulcers (esp. buccal mucosa)
Non specific/GI signs
rumen stasis w/ingested food in ruminants
Lab diagnosis of 2,4-D toxicosis
elevated Alkphos (AP), lactate dehydrogenase (LDH) & creatine phosphokinase (CPK) levels
indicates damage
Main lesions for 2,4-D toxicosis
GI & NM (neuromuscular)
What type of herbicides ar paraquat & diquat
dipyridyl
paraquat is RUP (restricted use pesticide)
diquat is GUP (general use pesticide)
What is an important property of dipyridyl herbacides that can help w/ tx?
Paraquat binds strongly to soil!
(Fullers earth can be used in tx)
How toxic is paraquat?
Which spp especially susceptible?
What enhances toxicity of paraquat?
Highly toxic!
Dogs (malicious poisonings!)
Selenium/Vit E deficiency, depletion of tissu glutathione & O2 therapy
What are the toxicokinetics/MoA of paraquat
respiratory signs d/t lung damage
high conc in lungs (10x)
produces singlet oxygen (free radical producer)
CS of paraquat toxicosis
Acute
Early signs: GI irritation but,
may not see signs until 3 days after exposure!
Delayed signs (2-7 days): respiratory damage done!
Subacute or chronic:
7d - 3wks resp signs d/t progressive pulm. fibrosis
CS/lesions of paraquat toxicity
hepatization of lungs (hemmorage makes lungs look like liver!)
lingual ulcers
