Lecture 6

Question 1

What are examples of anticoagulants and anticoagulant rodenticides

Answer 1

Warfarin- first generation compound; short half life

Brodifacoum- seond generation compound; long half life

Question 2

Anticoagulant MOA

Answer 2

Inhibits vitamin K epoxide reductase and prevents formation of vit k dependent clotting factors

Question 3

Clinical signs of anticoagulants

Answer 3

Delayed onset
Depression, anorexia, anemia, dyspnesa, nose bleeds, bleeding gums, bloody feces
Hemorrhage

Question 4

Diagnosis of anticoagulants

Answer 4

History
Evidence of coagulopathy
Response to vit k therapy
Increased PT, APTT, or PTT with normal platelet counts

Question 5

Treatment of anticoagulants

Answer 5

Emesis, adsorbent, cathartics
Vit K administration for long time (2 weeks to 1 month)
Possible blood transfusion if needed

Question 6

Where are nitrates found

Answer 6

Fertilizers, plants, contamination of water

Question 7

Who is susceptible to nitrate toxicosis

Answer 7

Pigs>cattle>sheep>horses

Question 8

What does nitrate converted to nitrite cause

Answer 8

Vasodilation and oxidized ferrous iron in hemoglobin resulting in methemoglobinemia
Results in oxygen starvation of tissue

Question 9

Clinical signs of nitrate

Answer 9

levels of MetHb:
<10%= asymptomatic
15%= cyanosis, brown blood and membranes
50%= ataxia, seizures, coma
>70%= death

Question 10

How to diagnose nitrate toxicosis

Answer 10

Measure levels in food and water

Save plasma, serum, or eye for analysis in necropsy

Question 11

Treatment of nitrate

Answer 11

IV methylene blue- most effective in ruminants; causes urine to become dark green
Use abscorbic acid in cats and horses
Educate farmers
Feed corn to increase nitrite reduction by rumen flora

Question 12

Cardiac glycosides MOA

Answer 12

Come from plants- oleander, lilly of the valley, foxglove

Inhibit Na/K ATPase pump through competition with potassium for binding sites

Question 13

Clinical signs of glycosides

Answer 13

Trembling, staggering, dypsnea
High Ca and Na and K
Tachy, arrhythmias, weak pulse

Clinical signs can depend on which plant and what part of plant is consumed

Question 14

Treatment of glycosides

Answer 14

GI decontamination
Treat arrhtyhmias with propranolol
Treat hyperkalemia
Antidote is digoxin immune Fab fragments (digibind)

Question 15

Where is cyanide found

Answer 15

Wilted leaves and seeds of wild black cherry, white clover, or fresh sorghum
Fertilizers, pesticides, rodenticides, fumigants, combustion

Question 16

When is cyanide not toxic

Answer 16

When it is dry

Toxic when it is hydrogen cyanide gas

Question 17

Cyanide MOA

Answer 17

Inhibition of cytochrome oxidase and oxidative phosphorylation

Question 18

Clinical signs of cyanide

Answer 18

Very rapid
Cherry red blood that is slow to clot
Sudden death, dyspnea, weakness, tremors

Question 19

Treatment of cyanide

Answer 19

1. Induce methemoglobin formation with sodium nitrite to bind cyanide. Afterwards can treat MetHb
2. Give sodium thiosulfate to increase formation of thiocyanate, which is non toxic

*basically just find another buddy for the cyanide besides the mitochondria

Question 20

What are methylxanthines and where are they found

Answer 20

Caffeine, theobromine, theophylline

Found in chocolate, coffee, and medications

Question 21

Methylxanthine MOA

Answer 21

Competitive antagonist of adenosine receptors
Cause CNS stimulation, vasoconstriction, and tachycardia
Prevents Ca reuptake leading to increased skeletal and cardiac muscle contractility
Inhibits phosphodiesterase which increased cAMP and GMP concentrations

Question 22

Methylxanthine clinical signs

Answer 22

Vomiting, diarrhea, diuresis
Hyperactivity, panting, bounce
Tachycardia, hypertension
Ataxia
Tremors and seizures
Coma
Death from arrhythmia or resp failure

Question 23

Diagnosis of methylxanthine

Answer 23

Can detect theobromine in system for 3-4 days after ingestion

Question 24

Methylxanthine treatment

Answer 24

Gi decontamination- emesis and charcoal
Monitor EKG- treat with lidocaine in dogs
Treat seizures
Maintain respiration
Fluids

Question 25

Where is gossypol found

Answer 25

Cottonseed- natural deterrent for insects to not eat the seed Issue for large animals not small animals

Question 26

Gossypol MOA

Answer 26

Accumulates in the plasma with time Chelates iron and causes anemia Inhibits dehydrogenase leading to low energy and stress

Question 27

Clinical signs of gossypol

Answer 27

Weight loss, weakness, dyspnea, anemia, edema secondary to heart failure, myocardial necrosis, CHF Dairy cows and lambs may die suddenly

Question 28

Diagnosis of gossypol

Answer 28

History of ingestion Cardiac necrosis, edema, vacuolization Chemical analysis of gossypol

Question 29

Treatment for gossypol

Answer 29

Feeding high protein diet, add vitamin A, iron, and lysine | Remove gossypol source

Question 30

Where does cantharidin come from

Answer 30

Blister beetles or spanish flys in alfalfa hay

Question 31

Who does cantharidin usually affect

Answer 31

Horses

Question 32

MOA of cantharidin

Answer 32

Inhibits protein phosphatases | Irritates mucous membranes

Question 33

Clinical signs of cantharidin

Answer 33

Colic, frequent urination, diaphragm contraction with heart beat, shock Ulceration of oral, GI, and bladder epithelia (will see them dipping muzzles in water) Causes cardiac toxicity

Question 34

Cantharidin diagnosis

Answer 34

``` Alafala hay consumption Search for beetles in hay or stomach Hypocalcemia, increased BUN Ulceration of mm Cardiac necrosis Sudden death with no struggle ```

Question 35

Treatment of cantharidin

Answer 35

GI decontamination and protection, antibiotics