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
1080 Sodium monofluoroacetate Basics & Mech of Action
o Banned in US
o All animals susceptible
o Secondary poisonings occur
Mech of Action
o Affects krebs cycle & ATP production
1080 Sodium monofluoroacetate Clinical Signs Dogs, Cats, Livestock
o Lag phase 30 min to 2 hrs
Dogs
• GI & CNS
• Cycles of vocalizing, running, deficating, seizures intensify
• Respiratory & cardiac arrest
Cats
• GI & CNS depression or excitation
Livestock
• Cardiac
1080 Sodium monofluoroacetate Diagnosis & Treatment
Diagnosis
o History
o Clinical signs
o Chem analysis of urine & kidney
Treatment
o Doesn’t really work
o Maybe pentobarbital + Na bicarbonate
Methionine Basics, Clinical Signs, Treatment
o given to dogs for lawn care
o transient hind limb paralysis / abnormal posture
o metabolite is homocysteine
Clinical Signs
o vomiting, ataxia / acidosis, lethargy, diarrhea, weakness, PD, hypermetria, disorientation, tremors, anorexia, vocalization
Treatment
o Fluids & confinement
o bicarbonate
o emetics if asymptomatic within 2-4 hours
Methylxanthines; what are they?
Theobromine
o Cacao beans
o Chocolate foods
Caffeine
o Coffee, tea etc
o Coffee beans (chocolate covered?)
o No-Doz
Theophylline
o Bronchodilator
o Tea
Methylxanthines Toxicity
o All animals susceptible, dogs common o Variation in chronic dose for different individuals o Long T1/2 o Enterohepatic recirculation o Chocolate delays gastric emptying o Pancreatitis can be concern due to fat o DO THE MATH
Methylxanthines Clinical Signs & Diagnosis
Clinical Signs o CNS excitation, excessive urination, CV effects, GI o Increased HR & BP o Muscular excitability o V, D, urination, bloat o Hyperactivity, tremors o Tachycardia, hypertension o Tonic/clonic seizures o Cardiac arrhythmias
Diagnosis
o Exposure
o Clinical signs in order of GI -> PU/PD -> tremors -> CV
Methylxanthines Treatment
Asymptomatic
• Emesis up to 6hrs post ingestion
• AC 3x in 24hrs
• Cathartic
Symptomatic • Control tremors w/ benzos • Monitor ECG, BP, HR, CNS, Na levels • IV fluids • Anti emetics • Send home after 8-12 hrs
Glow Jewelry
o Dibutyl phthalate
o Biggest risk to cats
o Acute salivation & catnip like behavior change
o Rinse mouth, eyes, etc
o give Zinc sulfide or strontium aluminate
Basics of Lead
o Found in paint, batteries, sinkers/shot
o All animal susceptible
o Often in cattle & acute
o Often chronic in raptors & waterfowl
o Young animals have increased absorbtion in GI
o Excreted in bile
Mech of Action of Lead
o Bind to protein on RBCs
o Premature release of immature RBCs in dogs & cats
o Increased vascular permeability -> edema of CNS/PNS & demylination of peripheral nerves
o GI irritation
o Renal changes
o Liver necrosis
Clin Signs of Lead in Dogs, Cats, Cows, Horses, Birds
Cats/Dogs
• GI first then maybe CNS
• Vs, Ds, anorexia, abdominal pain
• Hysteria hyperexcitability
Cows • CNS & PNS maybe GI • Blindness, wandering, twitching • Acute death in calves • Hyperthermia
Horses
• Never seen!
• Lethargy & laryngeal paralysis
Birds • Chronic GI & PNS symtoms • Lethargy anorexia • Ds, crop stasis • Wing paralysis
Lead; clin path & lesions
Clin Path o nRBCs + regeneration o chronic anemia in birds o maybe renal tubular nephropathy o maybe elevated liver enzymes
Lesions o Cerebral edema o Pale-cooked muscle o Polioencephalomalacia o Liver & kidney necrosis
Lead Diagnosis, Treatment, Prognosis
Diagnosis o Exposure o Radiographs o Lead analysis of whole blood o Liver & kidney postmortem
Treatment o Decontaminate; emetics or surgery o Chelation w/ succimer o CaEDTA (in cows) o Maybe penecillamine o Thiamine hydrochloride o Control seizures
Prognosis
o SA do well
o LA & birds do not
Non-protein Nitrogen Basics & Toxicity
o Urea most common
o Fertilizer
o Anhydrous ammonia fertilizer can cause pulmonary
Toxicity
o All species susceptible
o Ruminants most common
o Excessive ammonia levels in vivo
Non-protein Nitrogen Mech of Action
o Urea + water -> NH3 + CO2 (urease)
o Rumen flora take ammonia and carbs -> amino acids + protein
o Microflora overwhelmed -> rumen buffers to NH4 ->
o Increased NH4 -> pH rises (> *8-10); overwhelm buffering capacity & increase NH3 concentrations
o NH3 gets absorbed -> overwhelms buffer and urea cycle -> hyperammonemia (toxicosis)
o Rumen alkalosis / metabolic acidosis -> hyperkalemia-induced cardiac failure
Non-protein Nitrogen Clinical Signs, Diagnosis, Treatment
Clinical Signs
o Onset <4hrs
o Usually after new feed introduced
o Salivation, Abdominal pain – grinding
teeth
o Muscle tremors, Ataxia, weakness, dyspnea
o Convulsions, bloat, death
o Rapid clinical progression
Diagnosis o Many animals affected o Rumen pH >8-10 o Collect eyeball immediately after death & freeze to confirm high ammonia o Analyze supplement
Treatment o Often not possible o Treat w/ in 20 mins of signs o Cold water & Vinegar to convert NH3 to NH4 o Correct acidosis w/ fluids & bicarb
Organophosphates & Carbamates Basics & Mech of Action
o Acetylycholinesterase inhibitors
o Insecticides
o Affects all animals
Mech of Action o Bind Acetylcholinesterase -> o Phosphorylate or carbamylate -> o inactivate o build up of acetylcholine leading to overstimulation -> o muscarinic, nicotinic, & CNS
Organophosphates & Carbamates Clinical Signs & Treatment
Clinical Signs o Not all symptoms all the time o DUMBSLED o Nicotinic = tremors o CNS excitation & seizures o Death due to respiratory failure o Pancreatitis in dogs/cats o Colic & Ds in horses
Treatment o Decontaminate o Atropine for muscarinic signs o Oximes bind unbound pesticide o O2
Organophosphates & Carbamates Diagnosis
Che inhibition screening tool
• No inhibition for carbamates because too fast = false (-)
• Inhibition due to anemia or others = false (+)
Chemical residue of GI, skin, etc
Organophosphates & Carbamates: Delayed neuropathy syndrome Vs Intermediate Syndrome
Delayed neuropathy syndrome
o Inhibition of neuro toxic esterase
o Signs 1-2 weeks after exposure
o Polyneuritis = ascending paralysis
Intermediate Syndrome
o Lipophilic compounds
o Long term accumulation at receptor induces tolerance / down regulation of cholinergic receptors
o Anorexia, neuromuscular weakness, ventro-flexion of the neck
Dead Birds
DRC-13 or Starlicide
o nephrosis that kills at roosting site
Avitrol
o neurotoxin
Natural pyrethrins, pyrethrum & Synthetic pyrethroids Basics & Toxicity
o Insecticides, flea tick repellent
o Dogs very sensitive to bifenthrin
o Cats very sensitive to permethrin
o Products w/ 65% or greater
Toxicity
o Low mammalian toxicity
o Should not use on cats or dogs in a cat home
o Spot on treatment can cause epidermal paresthesia -> inflammatory contact dermatitis (especially pyrethroids)
Natural pyrethrins, pyrethrum & Synthetic pyrethroids Clinical Signs & Diagnosis
Clinical Signs o CNS excitation o Salivation o Tremors, twitching o Temporary blindness o Convulsions
Diagnosis
o history
o Chemical residue analysis
Natural pyrethrins, pyrethrum & Synthetic pyrethroids Treatment
o Decontaminate by sedating, bathing w/ mild soap, AC-cathartic-gastric lavage w/ stomach tube
o Control tremors/seizures w/ methocarbamol
o Control body tmep
o IV lipid rescue therapy for permethrin
o Apply Vit E to application site
o Prognosis good w/in 24-72 hrs bad in cats
Chlorinate Hydrocarbons Basics & Toxicity
o Insecticides
o Limited use in US
o Environmental contamination
Toxicity
o Affects most mammals
o Lipid soluble, stable -> persists in environment & body
o Diffuse nervous stimulant
Chlorinate Hydrocarbons Clin Signs, Diagnosis, Treatment
Clinical Signs
o Onset 30-60 mins
o Early premonition period
o muscle tremors of head, neck, entire body
o tonic/clonic seizures (continuous, intermittent)
o Excessive response to external stimuli
Diagnosis
o History
o Tremors/seizures
o Chemical analysis of fat, serum, milk, liver, brain, GI contents
Treatment o Control tremors, seizures o Decontaminate o Maintain hydration, acid-base status, temperature, etc. o Prognosis variable
Cyanobacteria Basics & Clinical Signs
o Blooms all year round
o Stagnant, low O2, high nutrients, high light, warm clam water
Clincal Signs o Acute onset o Muscle tremors o DUMBSLED o Seizures / paralysis o Death due to respiratory paralysis
Cyanobacteria Toxins
Anatoxin-a
• mimics acetylcholine (nicotinic)
• 20X more potent than ACh
Anatoxin-a(s)
• inhibits acetylcholinesterase (nicotinic and muscarinic)
• more potent than anatoxin-a
Cyanobacteria Diagnosis & Treatment
Diagnosis o History o Acetylcholinesterase inhibition in blood o Algae ID o Test water & GI for toxin
Treatment
o Support
o Adequate respiration
o Cholestyramine
Perennial Ryegrass Staggers Basics & Toxicity
o Common in NW
o endophyte grows on lower leaf sheath & seed of Lolium
o Symbiotic
o Late summer & fall grazing or anytime if over grazed
Toxicity
• Lolitrems
• Purkinje cell problem
• High morbidity / low mortality
Perennial Ryegrass Staggers Clinical Signs, Diagnosis, Control
Clinical Signs • Fine muscle tremors • rhythmic palsy of head, neck and limbs • exaggerated when forced to move or eyes covered • look almost normal when at rest
Diagnosis
• History
• Analyses of food for lolitrem
Control
• Remove source
• Avoid overgrazing
Equine Leukoencephelomalacia Basics & Clinical Signs
o Moldy corn o Fumonisins o Problem in E & MW o Hepatotoxic to all species o Can cause esophageal cancer in humans
Clinical Signs • Onset 1-4 wks • Low morbidity / high mortality • Blindness, head pressing, aimless walking, stupor, • glossopharyngeal paralysis • delirium, recumbency, seizures, death
Equine Leukoencephelomalacia Lesions & Diagnosis
Clin Lesions
• Necrosis of subcortical white matter
• Hepatic necrosis, fibrosis, biliary hyperplasia
Diagnosis
• Corn screening
• Analyze food for fumonisin
• No treatment
Nicotine Basics, Signs, Diagnosis, Treatment
o Cigarettes, chewing tobacoo, e-cig cartriges
o Short T1/2
o Nicotinic acetylcholine receptor agonist
Clinical Signs
• Initial Vs
• Hyperactivity, tremors, seizures
• Death due to respiratory paralysis
Diagnosis
• Nicotine residue
Treatment
• Decontamination
• Control CNS excitation
• O2
Ivermectin Basics, Toxicity
o Antiparasitic
o Relatively safe
o Cats & dogs w/ MDR1 mutations
o Bad for turtles/tortoises
Toxicity
• Long T1/2
• Inhibits GABA & glutamate-gated chloride channels
Ivermectin Signs, Diagnosis, Treatment
Clinical Signs • Ataxia, depression, lethargy, weakness • Reversible blindness • Tremors, seizures • Coma & death (uncommon) • Can persist for days-weeks
Diagnosis
• Chemical analysis of feces, fat, liver, bile (only shows exposure)
Treatment • Decontaminate • Multiple AC • Cholestyramine • NO benzos • Support • IV lipid therapy
Salt; Basics & Mech of Action
o Electrolyte supps, play dough, ice melts, etc
o Not enough water or too much water after hypernatremia
Mech of Action • Fluid shifts from intracellular to intravascular -> • Cells shrink & die -> • Neuro signs -> • Passive diffusion of Na into CSF & neurons -> • Inhibition of glycolysis -> • More neuro signs -> • Rehydrate -> • Na trapped in CNS -> • Cerebral edema & hemorrhage
Salt; Signs, Diagnosis, Treatment
Clinical Signs
• V, D, anorexia
• Wandering, circling, head press, blind, tremors, seizures
• Cerebral edema & malacia
• eosinophilic perivascular cuffing lesions in pigs
Diagnosis
• Increased Na levels in serum & CSF
Treatment • Remove source • NO AC • SLOW rehydration • OR remove fluids if edema is an issue
