Cardiovascular and Hematopoietic

Question 1

learning objective - appreciate the range of cardiotoxins for large and small

Answer 1

Anticoagulants

Nitrates

Question 2

Anticoagulants were widely used for _________.
______ has a short half life, 15 hours and a low potency.
______ has a long half life, 20 days and high potency, can kill in a single feeding, LD50 only 0.25mg/kg.

Answer 2

rodent control
warfarin
brodifacoum

Question 3

mechanism of action of Anti-coags

Answer 3

inhibit Vitamin K epoxide reductase which is responsible for Vitamin K dependent clotting factors.

Question 4

Clinical signs of Warfarin/brodifacoum?

Answer 4

hemorrhage (chest and abdomen) and hematoma

depression, anorexia, anemia, dyspnea, nosebleeds, bleeding gums, bloody feces.

Question 5

Diagnosis of anticoags?

Answer 5

1. history of exposure
2. evidency of coagopathy
3. response to vitamin K therapy

Question 6

Nitrates are found in many fertilizers and plants. When converted to nitrites they cause vasodilation and ______ formation, ultimately _______.
Which animals are most susceptible?

Answer 6

methemoglobin, oxygen starvation of tissues.

pigs>cattle>sheep>horses

Question 7

At asymptomatic amounts of methemoglobin you may see changes in ____. When _____ methemoglobin, ataxia, seizures, coma occur.

Answer 7

membrane color, cyanosis, brown blood

50% methemoglobin

Question 8

Treatment nitrate toxicosis

Answer 8

methylene blue IV (best in ruminants)

Can feed cattle corn to inc. nitrite reduction in rumen.

Question 9

What are common plants that contain glycosides?

mechanism of action?

Answer 9

foxglove, oleander.

inhibit Na/K ATPase

Question 10

clinical signs of glycoside toxicity

Answer 10

trembling, staggering, inc. Ca and intracellar Na. Racing heart rate, arrhythmia, weak pulse. Hyperkalemia.

Question 11

Treatment for glycoside toxicity

Answer 11

GI contamination if recent.

Tx arrhythmia with propanolol.

Question 12

cyanide can be found in wilted leaves and seeds of ______ as well as ______.
It also isn’t toxic when dry.

Answer 12

wild black cherry, white clover, sorghum.

fertilizers, pesticides, fumigants, combustion

Question 13

mechanism of cyanide toxicity

Answer 13

inhibits cytochrome oxidase and oxidative phosphorylation (mitochondria shut down)

Question 14

clinical signs cyanide toxicity

Answer 14

cherry red (superoxygenated) blood  that is slow to clot. 
sudden death, dyspnea, weakness tremors

Question 15

treatment for cyanide toxicosis

Answer 15

Find another recipient for the cyanide

1. induce methemoglobin formation with sodium nitrite to bind cyanide
2. Na thiosulfate

Question 16

Methylxanthines include _______, theobromine, theophylline, and are found in ____, ______ and medications.

Answer 16

caffeine

coffee, chocolate

Question 17

What are the most toxic forms of chocolate?

Answer 17

Unsweet baking and Dark

Question 18

Methylxanthines mechanism of action

Answer 18

competitive antagonist adenosine receptors, vasoconstriction and tachycardia.
prevents Ca reuptake, skeletal and cardiac contractility.

Question 19

Treatment methyxanthines

Answer 19

treat arrthmias with lidocaine in dogs, or metoprolol.

treat seizures with diazepam or barbituates.

Question 20

gossypol mechanism of action?

diagnosis?

Answer 20

chelates iron, anemia, reduces protein availability.

hx, cardiac necrosis, edema, vacuoloization

Question 21

treatment gossypol toxicosis

Answer 21

high protein diet, add Vit A, iron, lysine

Question 22

ulceration of mucous membranes, cardiac necrosis, sudden death w/o struggle. May find beetles in stomach

Answer 22

catharidin toxicity