Lecture 5 Flashcards
What are examples of phenoxyacetic herbicides
2,4-D (scotts weed and feed)
2,4,5-T
Silvex
How toxic are phenoxyacetic acid herbicides
Very low toxicity
MOA of phenoxyacetic acid herbicides
Unknown
What are GI effects of phenoxyacetic acid herbicides
Usually GI are the only signs seen in dogs
Vomiting, diarrhea (bloody), oral and GI ulcerations
What are muscle effects of phenoxyacetic acid herbicides
Hesitation to move, rigid skeletal muscle, ataxia, weakness, seizures, myotonia with high doses, rumen atony
What are other signs of phenoxyacetic acid herbicides
Renal tubular degeneration
Hepatic necrosis
How to diagnose phenoxyacetic acid herbicides
Oral and GI ulcers Enteritis and rumen stasis Congestion of kidney/liver Hyperemia of lymph nodes Chemical analysis of serum and urine
Treatment of phenoxyacetic acid herbicides
Emesis, lavage, bath
Activated charcoal
Ion trapping IF kidneys are normal
What produces ergot alkaloids
Claviceps purpurea in small grains
Ergot alkaloids MOA
Dopamine and serotonin agonists which produce hallucinations, decreased prolactin secretion, smooth muscle contraction from alpha 1 antagonist
Clinical signs of erogtism in cattle
Reduced feed intake and weight gain, heat intolerance, retain winter coat “summer slump”
Gangrene of extremities
Fat necrosis
Poor repro performance
Clinical signs of ergotism in other animals
Horses- abortions, weak foals, prolonged gestation
Pigs- infertility, early parturition, decreased milk production
How to diagnose ergotism
See sclerotia in feed
How to treat ergotism
Remove source
Metoclopromide and domperidone to increase prolactin and normalize gestation in mare
What are ionophores
Compounds that form lipid soluble complexes with cations
Used as antibiotics
Ex: monensin, salinomycin
Ionophores MOA
Increase intracellular Na and Ca leading to mitochondrial swelling and cell death
What usually causes ionophore toxicosis? Who is most susceptible
Feed mixing errors
Horses are most sensitive, poultry are least sensitive
Clinical signs of ionophore toxicosis for horses and cattle
12-72 hours after ingestion
Anorexia, colic, profuse sweating on flanks, uncoordinated and weak
Cattle are similar to horses but with diarrhea and resp difficulty
Clinical signs of ionphore toxicosis of other animals
Unlikely
Poultry- down with legs and wings stretched out
Dogs- posterior paresis and paralysis
Cats- polyneuropathy
Diagnosis of ionophores
Increased muscle enzymes, myoglobinuria, AST, CK, ALP, BUN, bilirubin
Decreased K and Ca
Chemical analysis of feed
What should you differentiate ionophore toxicosis from
Other causes of colic, vitamin E or selenium deficiency, white snakeroot, blister beetle, gossypol, botulism
Treatment for ionphore
No specific treatment
Supportive therapy and feed change
Who does tetanus mostly affect
Cattle when spores get in puncture wounds
Tetanus MOA
Blocks release of GABA and glycine
Clincial signs of tetanus
Stiffness and reluctance to move Twitching and tremors of muscles Lockjaw Unsteady gait with stiff tail Bloat Collapse, spasm, death
Treatment of tetanus
Antitoxin but only useful at very early stages
Supportive therapy
Poor prognosis
What toxins cause ventilatory muscle paralysis
Botulism, tetanus, snake venom
OPs
Strychnine
What toxins cause resp center depression
Barbituates, opiates, opioids EG Hypnotics, sedatives Tricyclic antidepressants Crude oil
What is paraquat
Herbicide that induces oxidative damage
Clinical signs of paraquat
Vomiting, burning skin, acute pulmonary edema, renal failure, coughing, pulmonary fibrosis
Treatment of paraquat
Emesis, charcoal, gastric lavage, fluids,
NO oxygen unless absolutely necessary
