Toxicology 2012 Final

Front 1

Toxicology

Back 1

The study or knowledge of toxicants (posions) including their chemical and physical properties, identification, biologic effects and treatment of the disease conditions produced

Front 2

Toxicant (poison)

Back 2

any solid, liquid, gas, or energy, which when introduced into a ciologic system or applied to it, can interfere with the life processes of the organism or its subparts without acting mechanicallu and irrespective of temperature.

Front 3

Toxicity

Back 3

The amount og a toxicant which under specified conditions, will result in detrimental damage in the organism

Front 4

Hazard

Back 4

1. The likelihood or chance that a toxicant will produce a disease state under the conditions of use

2. The likelihood or chance of exposure to a particular toxicant under the conditions of use

Front 5

Toxicologist

Back 5

A health professional interested in and knowledgeable of the properties of toxicants and the treatment of the disease conditions

Front 6

The study of the properties of therapeutically and potentially therapeutically active chemicals

Back 6

Pharmacology

Front 7

The disease state which may result from exposure to a toxicant or poison

Back 7

Toxicosis

Front 8

2 roles of a toxicologist

Back 8

1. Prediction: defines the limits of safety of chemical agents

2. Demonstration of safety or hazard of chemicals prior to their entry on the market

Front 9

3 branches of toxicology

Back 9

1. Environmental
2. Economic
3. Forensic

Front 10

LD50

Back 10

The quantity of a toxicant required to kill 50% of a group of animals

Front 11

LC50

Back 11

the concentration of a toxicant in water or feed that will be lethal to 50% of the animals ingesting the material or living in the material

Front 12

MTD

Back 12

maximum tolerated dose

Front 13

MLD

Back 13

medial lethal dose

Front 14

HNTD

Back 14

highest non-toxic dose

Front 15

LDlo

Back 15

Lowest dose expected to produce death

Front 16

TDlo

Back 16

lowest dose expected to induce signs of toxicity

Front 17

Acute Toxicity

Back 17

The toxicosis expected to occur after a single exposure to a toxicant, monitor for 7 days

Front 18

Sub-chronic toxicity

Back 18

The toxicity expected to occur in an animal after daily exposure for up to 90 days

Front 19

Chronic toxicity

Back 19

The toxicosis expected to occur in an animal after daily exposure for more than 90 days and up to a lifetime of exposure

Front 20

PPM

Back 20

Parts per million = concentration not dose

Front 21

TLV

Back 21

Threshold limit value

Front 22

1 ppm =

Back 22

0.0001%

Front 23

10,000 ppm =

Back 23

1%

Front 24

Margin of safety (therapeutic index)

Back 24

Ratio between the LD50 and ED50

Front 25

NOEL (NOAEL)

Back 25

No Observed (adverse) effect level (mg/kg/day)

* The max dosage level in the most sensitive species which did not produce any adverse effect(s)

Front 26

ADI

Back 26

Acceptable daily intake (mg/kg/day)

* The max quantity of a chemical which people may ingest or take into their body and not expect any afverse effects after a lifetime of use

Front 27

Tolerance

Back 27

That quantity of a chemical or drug which os the max level which can legally appear in food for human consumption or in animal feeds

* Set by the code of federal regulations or the federal register

Front 28

Action Level

Back 28

* Similar to tolerance, it is a guide-line and not legally established

Front 29

"Delaney Clause"

Back 29

An amendment to the Food, Drug, and Cosmetic act which states that a carcinogen may not appear in food for human consumption

Front 30

Calculate ADI

Back 30

NOEL/Safety Factor

Front 31

Calculate Tolerance

Back 31

(ADI X 60kg)/ (Food factor X 1.5 kg of food/day)

Front 32

Elimination of xenobiotics from the body normally follow what?

Back 32

First Order Kinetics

Front 33

What are 4 contraindications for inducing emesis in an animal who as ingested a toxicant?

Back 33

1. Greater than 4 hours beyond ingstion
2. Ingesion of a caustic matrial
3. Ingestion of a tranquilizer
4. Ingestion of a pertroleum based product

Front 34

What therapeutic agents may be used in animals with lead intoxication?

Back 34

1. CaEDTA
2. Dimercaprol
3. 2,3-dimercarol
4. Thiamine

Front 35

Zinc, as part of its MOA, interferes with what?

Back 35

Copper

Front 36

When examining the MOA of selenium, it is important to note that selenium substitutes for which amino acid?

Back 36

sulfur

Front 37

2 phases of Biotransformation

Back 37

Phase I = oxidation

Phase II = conjugation
(Lethal synthesis)

Front 38

only toxic chelating agent

Back 38

BAL

Front 39

In chelation, increasing the Km will do what to the binding of metal?

Back 39

* The more tightly bound the metal

* Metal with higher Km will displace metal with lower Km

Front 40

Heavy metal MOA

Back 40

binds with sulfhydril (SH) groups on active sites on enzymes

Front 41

Drugs are approved for animal use by what organization?

Back 41

FDA

Front 42

Pesticides are approved for use by who?

Back 42

EPA

Front 43

Factual witnesses

Back 43

Factual witnesses do not render an opinion, but only testify to the facts in the case

Front 44

Expert Witnesses

Back 44

Expert Witnesses may prepare a report or opinion for the lawyer, may also be a factual witness

Front 45

best choice for animal that has ingested a strong acid

Back 45

Magnesium oxide

Front 46

Arsenic effects depend on what?

Back 46

on BV integrity—leads to microscopic evidence of vasculitis

Front 47

TX for arsenic

Back 47

* BAL (dimercaprol)
* Sodium thiosulfate

Front 48

Acutely, heavy metals cause what?

Back 48

GI signs

Front 49

Acute Lead toxicity

Back 49

GI, CNS

Front 50

Chronic Lead toxicity

Back 50

interferes with Hb metabolism

Front 51

Cu toxicity is caused by what?

Back 51

* Caused by accumulation in liver

* Stress causes mobilization of Cu stores thus causing severe hepatocellular necrosis; hemolysis

Front 52

Cu toxicity is a problem in what species?

Back 52

Sheep

Front 53

MOLYBDENUM toxicity is a problem in what species?

Back 53

cattle

Front 54

Cu/Mo ratio that is ideal?

Back 54

6:1

Front 55

Cu/Mo ratio toxic ratios?

Back 55

10:1 = Cu tox
2:1 = Mo tox

Front 56

What metal interferes with copper?

Back 56

Zinc

Front 57

Tx of Cu toxicity

Back 57

* Remove from source
* Blood transfusion
* Penicillamine
* Ammonium Mb

Front 58

Tx of Mo toxicity

Back 58

Copper glycinate

Front 59

FLUORIDE is required nutrient but in excess can cause what things?

Back 59

* Acute: GI, CNS problems

* Chronic: Bones and teeth affected, Subperiosteal exostosis

Front 60

FLUORIDE toxicity is common in what species?

Back 60

Equine and humans primarily

Front 61

Tx for FLUORIDE toxicity

Back 61

Aluminum salts

Front 62

Iron toxicity primarily seen in what species?

Back 62

Humans (children)

Front 63

Effects of Iron toxicity

Back 63

* Cardiovascular collapse
* Hepatic necrosis
* Chronic = hemosiderosis

Front 64

tx of Iron toxicity

Back 64

Deferoxamine

Front 65

Effects of cadmium toxicity

Back 65

* Nephrotoxic
* GI irritant

Front 66

cadmium toxicity

Back 66

* NO chelating agents

* Chelating agents increase tissue damage (especially BAL)

* Compounds with Cd, increases renal damage

Front 67

Beer drinker’s cardiomyopathy is caused by what?

Back 67

Cobalt

Front 68

CHROMIUM effects

Back 68

* Chronic ulcers in nasal septum

* Carcinogenic, irritating

Front 69

BARIUM stimulates which muscles?

Back 69

All of them!!

Front 70

Tx of barium toxicity

Back 70

Sodium/magnesium sulfate (forms the insoluble form of barium)

Front 71

MAGNESIUM toxicity effects?

Back 71

CNS depressant

Front 72

MAGNESIUM Deficiency is known as what?

Back 72

grass tetany

Front 73

Tx for MAGNESIUM toxicity

Back 73

Calcium

Front 74

What is iodide used to treat?

Back 74

treat respiratory infections/ foot rot

Front 75

Iodide toxicity may mimic what?

Back 75

vit A deficiency or hyperthyroid

Front 76

Tx of iodide toxicity

Back 76

Remove from source

Front 77

What causes slate grey discolorations?

Back 77

Silver

Front 78

Selenium substitutes in amino acids containing what?

Back 78

Sulfur

Front 79

Selenium effects?

Back 79

* Acute: cardiovascular collapse, GI problems

* Chronic : Hair loss, Liver disease, affects keratinized structures

Front 80

Selenium effects in pigs?

Back 80

CNS- Posterior paralysis

Front 81

SELENIUM Tx

Back 81

remove from source

Front 82

Sulfur effects?

Back 82

* Polioencephalomalacia in cattle

* Converts sulfates to sulfide gas in rumen

* Interferes with cytochrome oxidase

Front 83

Sulfur tx

Back 83

NONE

Front 84

Sulfur problems are commonly associated with what?

Back 84

excess sulfates in feed/water

Front 85

Zinc toxicity is primarity a problem in what animas?

Back 85

Young puppies and horses

Front 86

Zinc effects?

Back 86

* Poor growth- interferes with Cu utilization
* Renal problems
* Foals get enlarged joints, lameness, cartilage defects

Front 87

Zinc Tx

Back 87

reduce dietary zinc concentrations & supplement Cu

Front 88

ORGANOPHOSPHATES and CARBAMATES inhibit what?

Back 88

Cholinesterase inhibitors

* Organophosphates: irreversible
* Carbamates: Reversible

Front 89

tx of ORGANOPHOSPHATES and CARBAMATES

Back 89

* Atropine at 10x preanesthetic dose
* Glycol ok, but more expensive
* 2-PAM (CI in carbamate poisoning)

Front 90

Most used insecticide?

Back 90

Pyrethrin

Front 91

Pyrethrin is most toxic to what species?

Back 91

CATS

Front 92

Clinical signs of pyrethrin toxicity?

Back 92

trembling, salivation

Front 93

Tx of pyrethrin toxicity?

Back 93

Diazepam

Front 94

Strychnine (rodenticide) MOA?

Back 94

blocks glycine receptors on Renshaw cells in spinal cord

* Spinal convulsant

Front 95

tx of Strychnine (rodenticide)?

Back 95

pentobarbital (not pheno)

Front 96

Do animals with strychnine tox vomit?

Back 96

Animals with Strychnine poisoning do not vomit—have full stomachs upon examination

Front 97

Anticoagulant rodenticides block what?

* DICOUMAROL, WARFARIN, BRODIFACOUM, DIPHACINONE

Back 97

* Block 2, 7, 9, 10 clotting factors
* Block Vitamin K epoxide reductase

Front 98

#1 cat and dog toxicity

Back 98

Anticoagulant rodenticides

Front 99

SODIUM FLUOROACETE-1080 (rodenticide) blocks what?

Back 99

aconitase

Front 100

Do animals with sodium fluoroacete tox vomit?

Back 100

YES- Vomit on empty stomach

Front 101

perfect homicidal agent

Back 101

Thallium sulfate

Front 102

Thallium sulfate MOA

Back 102

Follows K+ in body and replaces it

Front 103

Thallium sulfate affects what organs? animals?

Back 103

Affects all organs, all animals

Front 104

Tx of Thallium sulfate

Back 104

Prussian blue—given orally, chelates thallium as it is excreted into the gut

Front 105

MOA of Phosphorous toxicity

Back 105

* Turns into phosphine gas in the acid pH of the stomach

* affects cellular metabolism

Front 106

Cholecalciferol MOA

Back 106

* Vitamin D analogue

* Causes hypercalcemia—ADR animal/nonspecific symptoms

Front 107

Tx of Cholecalciferol

Back 107

No good tx—calcitonin, corticosteroids, fluids

Front 108

Cholecalciferol effects

Back 108

* Acute = stops heart in systole

* Chronic = calcium deposits in tissue

Front 109

Bromethalin MOA

Back 109

* Affects energy formation by uncoupling oxidative phosphorylation

* Inteferes with H+ gradient

Front 110

Bromethalin is a problem in what animals?

Back 110

Avitrol of greatest concern—especially in horses/cattle

Front 111

DEET toxicity looks like what type of toxicity?

Back 111

pyrethrin

Front 112

Amitraz MOA

Back 112

* works similar to xylazine as an α-2 agonist

* Prolongs hyperglycemia

Front 113

What is metaldehyde?

Back 113

molluscicide

Front 114

metaldehyde a problem in what animals?

Back 114

Horses more toxicity than dogs

Front 115

metaldehyde effects?

Back 115

* Liver damage/disease-recover then liver failure

* Convulsions, look drunk (CNS depression), nystagmus in cats

Front 116

Tx of metaldehyde tox

Back 116

Pentobarbital

Front 117

METHYL BROMIDE (Fungicide) effects?

Back 117

CNS depression – animal looks drunk

Front 118

PHTHALIMIDES (Fungicide) effects?

Back 118

Dyspnea, anorexia, depression, ascites

Front 119

CARBAMATE DERIVATIVES Do not inhibit what?

Back 119

Do not inhibit AchE - benzene ring prevents binding to AchE

Front 120

Dipyridyl compounds cause production of what?

Back 120

superoxide radicals

Front 121

Dipyridyl compounds effetcs?

Back 121

Fibrogenic lung response +/- kidney disease

Front 122

safest herbicide?

Back 122

Glyphosphate

Front 123

Thiocarbamates—don’t inhibit cholinesterases-why?

Back 123

b/c their structure doesn’t allow it