Tox Final Flashcards
1
Q
Most common snake bites are from what group of snakes and in what type of animal?
A
pit vipers (crotalidae) - esp. copperheads dogs
2
Q
Coral snake
A
- shy, non-aggressive, nocturnal
- short, fixed, mem covered fangs w/ venom dripping out
- delayed neurotoxic venom (little rxn at site) –> flaccid paralysis, resp paralysis
3
Q
Coral snake bite treatment
A
- Hospitalize at least 24 hrs b/c tox signs can take 12 + hrs to develop
- supportive care, resp support, compression bandage, broad spec antibiotics
- antivenin treatment discontinued
4
Q
Pit vipers (rattlesnakes and cottonmouth)
A
- retractable fangs + muscle cxn forces venom out
- defensive (dry) or agonal bite (whole load)
- venom meant to pre-digest, not kill
5
Q
toxicity of rattle snake venom
A
rattle snake > water moccasin > copperhead
6
Q
clin signs of diamondback bite
A
marked tissue destruction
coagulopathy
hypotension
7
Q
clin signs of mojave A rattlesnake
A
minimal tissue destruction
no coagulation
severe neurotoxicosis
8
Q
general clin signs of a pit viper bite (can be delayed)
A
regional swelling for ~36 hrs
ecchymosis & petechiation
+/- visible puncture wounds
tachycardia, shallow breathing, nausea, salivation, muscle twitch
9
Q
treat a pit viper bite
A
baseline blood, recheck q6hrs to see level of evenomation
supportive care
Crofab antivenin - affects length of recovery, not survival chance
10
Q
prognosis of pit viper bites
A
SA - good if early treatment
LA - survive initial bite, but often risk of dying w/ secondary tissue damage/infection
11
Q
2 venomous lizards in US
A
Gila Monster
Mexican bearded lizard
12
Q
venomous lizard bites
A
- defensive only, don’t inject venom must be chewed in
- longer bite duration = more evenomation
- pain at bite site, tooth lacerations, regional muscle fasiculations but tissue necrosis rare
13
Q
treat a venomous lizard bite
A
supportive care
broad spec antibiotics
narcotics or fentanyl for pain managment
prognosis good
14
Q
Black widow bites
A
- venom very potent (alpha-latrotoxin)
- causes lactrodectism (muscle tightness/pain first few hours –> weakness/fatigue, insomnia)
- cats very sensitive, get atonic paralysis & severe pain
15
Q
treat a black widow bite
A
Lycovac antivenin
supportive - opiods, dizaepam (muscle rigidity)
16
Q
(brown) recluse spider bite
A
- bullseye lesion, slow to heal (6 mo - 1 yr)
- venom has necrotizing enzymes, sphingomyleinase D
- systemic signs rare
- chemically debride lesion, drugs for pain, pruritis, infection, dapsone to inhibit neut migration
17
Q
Are tarantulas dangerous?
A
US types - no
South America, Africa, Aus types - yes b/c neurotoxin (sometimes kept as illegal pets)
18
Q
Scorpion sting (AZ bark scorpion)
A
- venom has multiple toxins
- sharp instant pain at site, edema, pruritis
- maybe allergic rxn, systemic rxn
- supportive care
- debated if evenomation concerning in dogs/cats or not
19
Q
Tick paralysis
A
- 1 tick to infestation can cause
- MOA of toxin unknown
- ataxia –> paresis, flaccid paralysis –> resp failure, death
- remove tick!! supportive care, topical insecticides
20
Q
Bee stings
A
- bronchiole constriction in cats
- anaphylactic shock, secondary IMHA in dogs
- remove stinger, supportive care, monitor for anaphylaxis
21
Q
Botulism
A
- limber neck (Bird), shaker foal synd (EQ)
- ## Clostridum botulinum, multiple toxin types
22
Q
Botulism MOA
A
toxin is protein, internalized by cell –> block ACh release –> progressive flaccid paralysis
23
Q
3 ways to get botulism toxicity
A
- ingest preformed toxin (common in soil)
- Ingest spores (foals)
- wound contamination (e.g. castration)
24
Q
Treat/prevent botulism
A
remove insiting cause (feed, debride) antitoxin, penicillin
prognosis guarded if have clin signs
prevent - toxoid vacc, good management
25
Tetanus MOA
- Clostridium tetani w/ tetanospamin neurotoxin in soil
- endocytosed into cells, block inhibitory NT release --> uncontrolled muscle contraction --> tetanty, sardonic grin, lock jaw, light sensitivity
- EQ, rum more susceptible than dogs, cats
26
treat/prevent tetanus
- penicillin, antitoxin tx, clean/debride wound
- quiet dark space, maybe tranquilize
- prognosis guarded w/ clin signgs
- prevention key - good husbandry/mgmt, tetanus vacc
27
Cyanobacteria (blue-green algae)
- risk factors: warm weather, increased nutrients (runoff) in water, algal blooms in late summer/early fall
- increased wind concentrating cyanobacteria
- often just see acute death
28
Microcystin or nodularin cyanobacteria toxicosis
hepatotoxic lethargic, vomiting, pale mucous mems, death in 24+ hrs
29
Anatoxin-a cyanobacteria toxicosis
muscle tremors, rigidity, resp distress/paralysis, convulsions, death in 30 min
30
Anatoxin-a(s) cyanobacteria toxicosis
SLUDGE, tremors, dyspnea, convulsions, death in 1 hr (resp arrest)
31
Treat cyanobacteria ingeston
Prevention is key - don't eat
prognosis poor if have clinical signs, supportive care & decontaminate
atropine if anatoxin-a(s) - to blocK ACH while AChE blocked
32
Blister Beetles (aka Cantharidiasis)
- beetles crushed in alfalfa, horse eats, cantharidin toxin (vesicant) rapidly absorbed in GI and conc in urine
- acute colic, discomfort, bloody urine
- enhance elimination, control pain, fix dehydration/electrolytes
- prognosis poor, better if diagnosed early. Prevention!
33
Toad toxicity (FL, TX, AZ, CO, HI)
- dogs
- parotid glands on toad release toxin, absorbed in buccal mucosa
- toxin is cardiac glycoside --> inhibit Na/K/ATPase pumps --> decreased AP's
34
clin signs & treatment of toad toxicity
- hypersalivation, vomiting --> convulsions, neuro --> coma, death w/in 15 mins sometimes
- decontaminate - rinse mouth, supportive care
- prognosis good if early decontaminate, don't lick toads
35
Aflatoxins (from Aspergillus)
- found in corn, usually exposure by feed contamination
- metabolized into a reactive metabolite - carcinogenic, teratogenic, immunosuppressive
- chronic exposure = liver dz
- acute dose = emesis, diarrhea, convulsions, epistaxis, death
- prevention key, activated charcoal + oxytetracycline for hepatic damage - recovery prolonged/incomplete
36
Citrinin & Ochratoxin (aspergillus, penicllium spp)
- grains, beans, black pepper, coffee, etc.
- pigs and rats
- Porcine mycotoxin nephropathy
- enterohepatic recycling = longer half life, accums in kidneys
- chronic = kidney dz
- acute = gastroenteritis, emesis, tenesmus, etc
37
Why are ruminants relatively immune to ochratoxin toxicosis?
rumen microbes cleave the toxin into an non-toxic form
38
Ergot (Claviceps spp)
- grasses, cereal grains
- 5-HT(serotonin) agonist, Dopamine antagonist, NE agonist
- cause vasoconstriction
39
4 forms of Ergot toxicosis in livestock
1. Cutaneous & gangrenous lesions (tail, extremities)
2. Hyperthermia, production loss
3. Repro failure (weak foals, stillborns)
4. convulsive/neuro form (acute ingestion of large dose)
fescu foot
40
Trichothecenes (Fusarium spp)
- contaminated feeds during flowering, seed development (high rain, humidity) + delayed harvest
- most animals recover rapidly except pigs (highly sensitive, can't metabolize vomitoxin --> vomiting)
41
Zearalenone (Fusarium spp)
- corn, stable in environ
- pigs, mebe sheep
- enz's that produce acid are induced at low temps --> clin signs freq in colder areas
- enterohepatic recycling = increased half life
- acts as weak estrogen: swelling/redness of female parts, ovarian atrophy, weight gain
- remove contamination, PG F2- alpha can correct anestrus
42
Fumonisin
- ELEM (eq encephalomalacia) or PPE (porcine pulmonary edema)
- cattle resistant
- guidelines for max allowed in feed
- no treatment
43
ELEM clin signs
MOA not understood - cardio dysfunc
| Neurotoxic and hepatic syndrome
44
PPE clin signs
MOA - inhibit myocardial Ca channels --> decreased contractility
3-6 days post exposure
L sided heart failure, pulmonary edema --> dyspnea/tachypnea, cyanosis, sudden death
45
Tremorgenic Mycotoxins - "Staggers"
reduce GABA, glutamate --> prolonged depolarization --> neuro probs, ataxia etc.
vasoconstriction in cerebrum can --> cerebral anoxia
clin signs in ~7 days but resolve in few days once exposure removed
46
Slaframine - "Slobber syndrome" or "clover poisoning)
- Rhizoctonia leguminicola fungus synthesized indolizidine alkaloid from lysine = black patch on clover
- active form (ketoimine metabolite) is parasympathomimetic agent --> stim's salivation in ~15 mins
- atropine can stop activity, but not reverse effects
- remove contaminant
47
Fescue grass + N. coenophialum (fungal endophyte)
Produces ergot alkaloids
| Fescue foot, summer syndrome, fat necrosis or lipomatosis
48
Penitrem A & Roqefortine
blue moldy cheese
| crosses BBB --> CNS issues in Dogs (tremors --> death)
49
How does radiation affect the body
- damages genetic structure, then cells die during division (mitotic death)
- can kill organ or animal itself
50
ARS (acute radiation syndromes)
```
Occur w/ whole body radiation
Cerebrovascular syndrome
GI syndrome
Hematopoietic syndrome
Pulmonary syndrome
Cutaneous radiation injury syndrome
```
51
Cerebrovascular syndrome
acute, >50 Gy dose
radiation neurotoxin --> disrupt BBB, circ --> perivascular edema and hemorrhage
nausea/vomiting, disoriented, discoordinated, resp distress, seizure --> death in 72 hrs
52
GI syndrome
7+ Gy dose
| nausea, vomiting, diarrhea --> septicemia, shock --> death in 3-10 days
53
Hematopoietic syndrome
3-8 Gy dose
severity depends on individual, level of exposure
bone marrow stem cell destruction --> pancytopenia
clin signs occur after pancytopenia
chills, fever, bruising, etc. - impaired immune sys, impaired coag --> death before anemia develops, 1-2 mo post exposure
<5 Gy exposure, supportive care; 8-10 Gy = small window for bone marrow transplant
54
pulmonary syndrome (rare)
>8 Gy
| animals that survived hematopoietic syndrome still could die in ~30 days b/c of inflammatory pneumonitis
55
Cutaneous radiation injury syndrome
ARS's usually have some level of skin damage
inflammation, erythema, dequamation, etc.
may have latent phase
Can be independently lethal or complicate recovery from hematopoietic
56
Prodromal radiation syndrome
radiation sickness that can preceed any ARS, may predict outcome
latent
easily fatigued, anorexia, vomiting
patient recovers or dies
57
low dose irradation vs. high dose whole body irradiation
low dose: late effects like genetic change, cancer
| high dose: acute effects, likely death
58
What is the main concern about radiation exposure?
smaller doses over a longer period of time --> cancer
| biological effects depend on absorbed dose (stochastic - random)
59
RBE (radiation biological effectiveness)
helps determine how efficient a type of radiation is at producing biological effect
approximated using WR (Radiation weighting factor)
60
Radiation Protection Equivalent Dose
```
combines physics (absorbed dose) with RBE (biology) to estimate injury
ED (equivalent dose) = absorbed dose x WR
Equivalen dose x Wt = effective dose
```
61
the annual radiation occupational limit for a radiation worker
```
5 Rem (= 50 mSv)
aka the stochastic random risk of getting cancer
Lifetime dose shouldn't exceed yrs age x 1 REM
```
62
Who watches over radiation safety?
OSHA - checks for failures of compliance
ICRP/NCRP (US version) - makes reports that determine policy
EPA, nuclear regulatory council, DOE, OSH, states implement policy
63
what must the principal user or vet radiation safety office do
provide instruction to personnel on safety
provide documentation
responsibilities extend to vets who aren't primary user b/c operating x-ray equipment = small but definite radiation risk
64
What happens to pregnant employees?
give voluntary written notice to principal user
| additional monitoring, keep exposure below 0.05 rem/mo
65
ALARA (as low as reasonably achievable)
common sense + education
provide rules and documents, dosimeters, follow the rules
Time, distance, shielding
66
Mercury toxicity
- metallic mercury is a liquid - vapors are the problem
- water converts methy murcury --> di-methly mercury which is lipid soluble
- targets nervous, renal, cardio, GI, hematopoietic
67
diagnose mercury toxicity
History most important
Acute - hg levels in blood, urine, liver, kidney
Chronic - test hair
Can only treat acute - egg white, charcoal, then succimer
68
Mercury PM
Gastric ulcers
tubular necrosis
cerebellar hypoplasia w/ MeHgs
69
Arsenic toxicity
- don't burn treated wood
- As binds to lipoic acid affects TCA cycle, energy metabolism
- targets actively dividing cells (high oxidative E use), intestinal epithelium, epidermis, kidney, liver
- clin signs: abdominal pain, ataxia, watery diarrhea, dehydration
70
Diagnose As toxicity
Urine or liver As levels above diagnostic levels
| Hair if chronic exposure
71
Treat As toxicity
Detox - Dimercaprol (pulls arsenic off lipoic acid), Succimer
72
Arsenic PM
GI tract erythema, petechia & accumulation of fluid
| epithelial necrosis
73
Lead (Pb) toxicity
- most common heavy metal toxicity
- in muscle not toxic (walled off), ingested = toxic b/c in acidic environment
- target tissues: CNS (primarily), hemolymphatic system, GI
74
Sources of Pb
batteries - most common in cattle
lead based paints
shot, weights, smelter exposure, etc.
75
Pb toxicity MOA
- absorbed in GI by active transport using Ca absorption mech (where Ca is, lead will be)
- Binds to RBC's, accums in soft tissue, bone (chronic)
76
Diagnose Pb toxicity
whole blood sample
77
Pb toxicity clin signs
Very common to not see anything clinically
Blindness, headpressing in run
roaring in EQ, anemia in cats
aggression, anorexia
78
Diagnose Pb toxicity
Hx of clin signs
Immature RBC's w/ basophilic stippling
whole blood Pb levels above diagnostic levels (or kidney, urine)
Radiographs - Pb objects in GI
79
What 3 Metal/Feed toxicities are hard to differentiate between?
Lead poisoning
PEM
Water deprivation
80
Treat lead poisoning
Ca-EDTA, Succimer
| Remove lead from GI if seen
81
Pb toxicity on PM
Rumen - laminar cortical necrosis, lead pieces
Rental tubular epithelium degeneration, necrosis
Intranuclear inclusion bodies
Waterfowl - muscle wasting, Pb shot in gizzard
82
Molybdenum (Mo) Toxicity & Copper deficiency causes
Primary Cu deficiency - low Cu in diet
Secondary Cu deficiency - High Mo in diet --> low Cu
High Sulfur intake - potentiates Mo, often from water
83
Molybdenum (Mo) Toxicity & Copper deficiency
Low Cu = low Cu enzymes
First see low Cu in liver where it's absorbed, serum Cu will remain normal
After serum levels decrease, see low Cu enz & clinical signs affecting all tissues
84
Molybdenum (Mo) Toxicity & Copper deficiency clinical signs
Chronic diarrhea (when Mo high)
Bleached dull hair, spontaneous fractures, decreased production & immune response
ADR (ain't doing right)
Swayback in lambs, kits
85
Swayback
lambs, kits only NOT rum
| sheep fetus doesn't accumulate Cu in liver during gestation but cattle fetus does
86
What can decrease copper utilization
Dietary Mo and sulfur
| Excess zinc, iron
87
Diagnose Molybdenum (Mo) Toxicity & Copper deficiency
Serum Cu low, serum Mo high
liver Cu levels low
Determine dietary Cu and Mo (Should be <4 Cu : 1 Mo)
Determine dietary S & Mo (should be <100 S : 1 Mo)
PM - no diagnostic signs
88
Treat Molybdenum (Mo) Toxicity & Copper deficiency
Increase dietary Cu: Mo ratio w/ special salt/trace mineral mix
CuO boluses given PO
careful w/ sheep - susceptible to Cu toxicity
89
Cu toxicity
Mostly a sheep, goat problem
- Don't feed EQ, Pig, Poultry feeds to sheep or cattle (higher in Cu)
- Don't let sheep graze in pasutres w/ pig or poultry manue
- Accidental oversupplementation --> accum in liver, then affects blood, renal causing damage
90
Clin signs of Cu toxicity
~2 weeks before signs, already liver is necrosing but liver values may not be particularly high until hemolytic crisis already occuring
serum Cu may/not be changed depending on chronicity
Hemoglobinuria, Icterus, anoxia, death
91
Treat Cu toxicity
Focus on reducing risk in rest of herd
| Feed a Cu deficient diet, add thiomolybdate
92
PM signs of Cu toxicity
Gunmetal blue kidney
| liver is swollen, friable w/ fibrosis in portal areas, bile duplication
93
Zinc toxicity (Zn)
- dogs, sometimes birds
- pennies minted after 1982, galvanized surfaces, industrial
- MOA some kind of enz inhibition --> RBC membrane damage, oxidative damage
Target tissue: GI, RBC's
94
Zn toxicity clin signs
Dog, cat - vomiting, diarrhea, icterus, Hemogobinuria & emia, anemia
Birds - depress, anorexic, wt loss, fluffed feathers, seizure
95
Diagnose Zn toxicity
Radiographs
Royal blue tops for serum Zn (no hemolysis)
Regenerative hemolytic anemia w/ basophilic stippling, heinz bodies, nucleated RBC's
PM - non-specific gross pathology - hepatic hemosiderosis & hepatocellular necrosis
96
Treat Zn toxicity
remove foreign object from GI
supportive care, blood transfusion
Ca-EDTA for birds
97
Sulfur toxicity
- Large animals
- High SO4 in water, or plants in high S soils, molasses-based diets, corn gluten
- Sulfur reduced by rumen bacteria --> sulfide --> sulfide absorbed in blood or lungs --> inhibits cytochrome sys --> decreased energy production
- target: CNS
98
Clin signs of sulfur toxicity
blindness, head pressing, recumbency, anorexia
99
Diagnose sulfur toxicity
Determine water and feed So4 levels (total dietary level)
| Hard to differentiate between Pb and water deprivation
100
Treat sulfur toxicity
supportive care
decrease S intake, feed roughage
Thiamine if treating for PEM
101
PM findings from sulfur toxicity
Rotten egg smell from rumen, rumen contents black
| PEM in brain (polioencephalomalacia) - necrosis, softening, swelling
102
Water deprivation/salt toxicity
- brine water, or high dietary salt + limited water intake, restricted water intake (4-7 days to develop)
- Increased serum Na --> increased brain, CSF Na --> increased glycolysis & energy --> excess Na trapped in brain, CNS
- clin signs: blindness, wandering, head pressing, depression, weak
103
Diagnose Water deprivation/salt toxicity
History, dehydration status
serum, CSF Na values
Hard to differentiate between PEM & Pb toxicity
PM - cerebral edema, test aqueous or vitreous humor for Na levels
104
Treat Water deprivation/salt toxicity
rehydrate slowly over 48 - 72 hours otherwise cause more probs
IV hypertonic saline to reduce cerebral edema
105
Urea/Non protein nitrogen toxicity
- additive in feedlots
- increased blood, brain NH3 --> decreased ATP, citric acid, etc. increased lactate
- muscle tremors, weakness, colic
106
Diagnose Urea/Non protein nitrogen toxicity
Hx, Rumen pH >8.0
Dietary urea analysis
Rumen fluid, vitreous fluid, serum NH3
PM - no lesions, rumen pH >8.0
107
Treat Urea/Non protein nitrogen toxicity
Infuse rumen w/ 5% acetic acid (vinegar) or cold water
| Preventions - limit NPN to <3%, don't feed NPN w/ full roughage diet
108
Ionophores
- promote growth in cattle
- alters rumen fermentation --> increased propionate, acidosis
- concentrates in liver - can cause toxicity/damage at high conc's
- anorexia, sweating, colic, hypotension, death
109
Use succimer to treat what?
arsenic
mercury
lead toxicities
