Final Exam Flashcards
Fescue Basics & Toxicity
o Tall fescue
o Common problem in large animals
Toxicity
o Toxic principal – ergovaline
o Peripheral vasoconstriction
o Suppression of prolactin secretion
Fescue Clinical Signs
Summer slump • Hyperthermia • Decrease feed intake • Weight loss • Abortions
Winter – fescue foot • Vasoconstriction -> ischemic necrosis of distal limbs • Loss of appetite • Lameness • Abortions
Repro problems any time of year • Horses > cows > sheep • Prolonged gestation • Dysmature young • Agalactia
Ergot Basics, specific alkaloids, & Mech of Action
o Claviceps fungus found in grass & grains
o Replace seed w/ sclerotia body (hard black)
o Problem in PNW
Mech of Action
o Ergoeptide alkaloids – ergotamine & ergonovine
o Peripheral vasoconstriction
o Affects humans, cattle, swine
Ergot Clinical Signs, Diagnosis, Treatment
Clinical Signs o Feed refusal o Dry gangrene (ischemic necrosis) of distal extremities o Lameness o Neuro symptoms o Small week piglets & claves o Agalactia o Abortion
Diagnosis
o Look for sclerotia
o Analyze feed for ergopeptide alkaloids
Treatment
o symptomatic
Selenium Basics, Diagnosis, Treatment
o Acute or Chronic
o From high selenium forage
o Horses most sensitive
Diagnosis
o Source
o Analysis of blood (antemortem)
o Liver & kidney postmortem
Treatment
o Symptomatic
Selenium Clinical Signs
o Vary between species & duration of exposure
Acute
• Cardiac, lung, liver, kidney, skeletal muscle
• Poliomyelomalacia in swine
Chronic • Bob-tailed dz • Hair-loss on mane & tail • Anorexia • Hoof deformities
Selenium Deficiency
White muscle dz
o cows, goats, sheep, horse
Masseter muscle myopathy
o horses
Paraquat Basics & Toxicity
o Herbicide o Desiccant o Very popular o Color, odor, & emetic added to deter humans o All animals susceptible but dogs often
Toxicity o Acute oral exposures o Less than 20% absorbed o Accumulates in lungs o T1/2 = 24hrs o Most excreted unchanged in urine o Uses MOA & produces free radicals o O2 is substrate
Paraquat Clinical SIgns
Acute
• GI: V, D, abdominal pain
• Pulmonary: inflammation, necrosis, edema, dyspnea
• Death
Chronic
• ~5-7d
• continued pulmonary changes -> fibrosis
• renal issues
Paraquat Gross & Histo Lesions
Gross
• Acute hemorrhage, necrosis, edema of lung & GI
• Chronic fibrosis in lung
Microscopic
• Acute hemorrhage, necrosis, edema of lung & GI
• Chronic interstitial lung fibroplasis & renal necrosis
Paraquat Diagnosis & Treatment
Diagnosis • History • GI, lung, & renal lesions • Urine analysis antemortem • Liver, kidney, lung postmortem
Treatment
• Decontaminate (AS): emesis, *AC, cathartic
• Anti-emetics, analgesics
• GI protectants: sucralfate, H2-antagonists, omeprazole
• IV fluids
• Oxygen??
(need to breath but O2 is substrate for parquat)
Polytetrafluoroethylene (PTFE) Basics, Toxicity, Treatment
o Nonstick surfaces, lightbulbs, heat lamps, irons, ironing board covers, baking sheets, ovens, heaters
o Birds most susceptible
o Polymer fume fever
Toxicity
o Above 500F PTFE releases fumes & particulates
o Acute respiratory distress
Treatment
o Remove from environment
o O2
Slaframine Basics, Diagnosis, Treatment
o Fungus on red clover, alfalfa, legumes
o Slaframine is gland M3 agonist
o Excessive salivation
Diagnosis
o Test for Slaframine in Feed source
o Salivation
Treatment
o Remove access to feed
Zearalenone Basics
o Produced by Fusarium o Metabolized to zearalenol which binds to estradiol 18B receptor o Found on grains o Weak estrogen o Swine > cows o Test for Zearalenone in food
Strychnine Basics & Mech of Action
o Common in PNW
o Rodenticide
o Died grain or liquid
o All animals susceptible
Mech of Action
o Rapid absorption & wide tissue distribution ->
o reversible antagonism of inhibitory NT glycine at postsynaptic sites in spinal cord + medulla ->
o reflex stimulation, extensor muscles predominate ->
o muscle rigidity similar to tentanus
Strychnine Clin Signs, Diagnosis, Treatment
Clinical Signs o Acute onset o Extensor rigidity o Tonic seizures induce by stimuli o Death is common
Diagnosis
o History
o clinical signs
o Chemical analysis of stomach contents
Treatment o Control tonic seizures & rigidity w/ pentobarbital o Decontaminate (mostly if asymptomatic) o O2 o Fluids o Lower temp o Put in quiet place o Monitor acidosis o Watch for 24hrs
Metaldehyde Basics
o Slug & snail bait (molluscicide)
o Often combined w/ acetylcholinesterase inhibitors
o DUMBSLED = Ds, urination, miosis, bradycardia, salivation, lacrimation, emesis & dyspnea
o All species susceptible; most commonly dogs
o Usually not as fatal as strychnine
Metaldehyde Clin Signs
- Early ‘apprehension’ phase
- muscle tremors (face, body
- sensitive to external stimuli
- dose high enough -> tonic/clonic seizures -> death (respiratory failure)
- Hyperthermia
Metaldehyde Diagnosis & Treatment
Diagnoisis
o Muscle tremors
o History
o Chem analysis of stomach contents
Treatment
o Decontaminate; emetic, AC, etc
o Control tremors / seizures – length of sedation (hrs to days)
o Supportive care: IV fluids / acid-base / oxygen / control T
o Prognosis better (24-48 hrs) depends on dose and success of decontamination
Penitrem A & roquefortine Basics
o Penicillium mold species o Tremergenic mycotoxins o Moldy foods, decaying organic material, walnuts - cheese – bread, egg shells, coffee grounds, carrot peels, corn o All species susceptible o hard to estimate dose
Penitrem A & roquefortine Clin Signs
o Onset rapid
- Initial ‘apprehensive’ phase
- intention tremors, ataxia
- tonic/clonic seizures
- sensitivity to external stimuli
- nystagmus
- 50% will vomit
- cerebellar component
Death if dose is high enough or no treatment provided
Penitrem A & roquefortine Diagnosis & Treatment
Diagnosis
o History
o Chemical analysis of Stomach contents, Serum, bile, urine
Treatment
o Decontaminate; emetic, cholestyramine, cathartic, lavage
o Control tremors / seizures w/ methocarbamol or diazepam
o Supportive: IV fluids / acid-base / T / oxygen / ataxic patient
o Prognosis – variable (depends on dose and success at decontamination) – 24 to 48 hrs
Bromethalin Basics
o Rodenticide o Dogs most common o Cats 10X more sensitive o Long T ½ = 6 days o Important to do math
Bromethalin Mech of Action
o Uncoupler of oxidative phosphorylation in mitochondria of CNS ->
o drop in ATP ->
o build up of extracellular fluid ->
o fluid filled vacuoles between myelin sheaths, edema ->
o pressure impairs nerve conduction and increase in intracranial pressure ->
o paralytic syndrome / convulsant syndrome
Bromethalin Clinical Pathology, Diagnosis, Treatment
Clinical Pathology
o More likely to see lesions after 24hrs
o Edema postmortem
o Vacuolation w/in myelin sheaths
Diagnosis
o History
o Abrupt onset of lethargy, paralysis, convulsing
o Maybe chem analysis of stomach contents acutely
o Chem analysis of fat postmortem
Treatment o Decontaminate o AC every 6-8hrs for 24hrs o Maybe cholestyramine o Control temors & seizures o support
Bromethalin Clinical Signs
o Lag phase up to 2-5 days
Paralytic form • Any toxic dose • hind limb paresis / paralysis • abdominal distension, ileus • more common in cats
Convulsant form
• Dose greater than LD 50
• V, muscle tremors, tonic/clonic seizures
• Hypersensitivity to external stimuli
