11: Circulatory and Hematopoietic Systems

Fumonisins are mycotoxins produced primarily by which organism?

A. Claviceps purpurea

B. Fusarium verticillioides

C. Neotyphodium coenophialum

D. Juglans nigra

B. Fusarium verticillioides

Which statement BEST describes fumonisin toxicity?

A. It causes the same lesions in all species

B. It shows species-specific target-organ toxicity

C. It only affects the liver

D. It only affects the cardiovascular system

B. It shows species-specific target-organ toxicity

What is the major target organ of fumonisin toxicity in pigs?

A. Brain

B. Kidney

C. Lung

D. Skin

C. Lung

4. What is the major target organ of fumonisin toxicity in horses?

A. Brain

B. Lung

C. Kidney

D. Esophagus

A. Brain

The classic, best-described manifestation of fumonisin toxicity is:

A. Equine encephalopathy

B. Porcine pulmonary edema

C. Bovine nephrosis

D. Feline hemolysis

B. Porcine pulmonary edema

Fumonisins inhibit which enzyme?

A. Vitamin K epoxide reductase

B. Sphingosine N-acetyltransferase

C. Acetylcholinesterase

D. Cyclooxygenase

B. Sphingosine N-acetyltransferase

Which sequence BEST describes fumonisin-induced porcine pulmonary edema?

A. Increased sphingosine → increased contractility → right-sided failure

B. Increased sphingosine → L-type Ca²⁺ channel inhibition → decreased contractility → left-sided failure → pulmonary edema

C. Hemolysis → anemia → edema

D. Vasodilation → hypotension → pulmonary edema

B. Increased sphingosine → L-type Ca²⁺ channel inhibition → decreased contractility → left-sided failure → pulmonary edema

Which group contains the three toxins discussed as causing peripheral vascular dysfunction?

A. Ergot, fescue, black walnut

B. Zinc, Allium, acetaminophen

C. Warfarin, sweet clover, zinc

D. Fumonisin, arsenic, Allium

A. Ergot, fescue, black walnut

Ergot toxicity is caused by:

A. Fusarium verticillioides

B. Claviceps purpurea

C. Neotyphodium coenophialum

D. Melilotus officinalis

B. Claviceps purpurea

Ergot toxicity in humans is historically known as:

A. Blackleg

B. St. Anthony's Fire

C. Rye fever

D. Red water

B. St. Anthony's Fire

Which grain is classically associated with ergot toxicity?

A. Corn

B. Rye

C. Rice

D. Soybeans

B. Rye

Which is NOT listed as an ergot toxic principle?

A. Ergonovine

B. Ergotamine

C. Lysergic acid amides

D. Dicumarol

D. Dicumarol

Ergot compounds primarily act agonistically at:

A. Biogenic amine receptors

B. GABA receptors

C. Opioid receptors

D. NMDA receptors

A. Biogenic amine receptors

Which receptors may be affected by ergot alkaloids?

A. Alpha-adrenergic, serotonergic, dopaminergic

B. Nicotinic, muscarinic, opioid

C. GABA, NMDA, glycine

D. Beta-adrenergic only

A. Alpha-adrenergic, serotonergic, dopaminergic

Which clinical sign is particularly consistent with severe peripheral vascular effects of ergot toxicity?

A. Polyuria

B. Gangrene of extremities

C. Icterus

D. Ascites

B. Gangrene of extremities

Diagnosis of ergot toxicity may include:

A. Detection of ergot in grain and alkaloids/metabolites in urine

B. Liver biopsy only

C. Serum zinc concentration only

D. Heinz body identification only

A. Detection of ergot in grain and alkaloids/metabolites in urine

Tall fescue toxicity is associated with infection by which endophyte?

A. Claviceps purpurea

B. Neotyphodium coenophialum

C. Fusarium verticillioides

D. Juglans nigra

B. Neotyphodium coenophialum

The fungal endophyte and fescue plant have what type of relationship?

A. Parasitic

B. Mutualistic

C. Predatory

D. Neutral

B. Mutualistic

The alkaloids produced by the fescue endophyte primarily help the plant by:

A. Protecting it from pests

B. Increasing water absorption

C. Increasing nitrogen fixation

D. Increasing seed size

A. Protecting it from pests

Which is a major toxic effect of fescue alkaloids in livestock?

A. Vascular constriction

B. Severe vasodilation

C. Anticoagulation

D. Bone marrow aplasia

A. Vascular constriction

What is the most prevalent ergopeptine in tall fescue?

A. Ergotamine

B. Ergovaline

C. Ergonovine

D. Dicumarol

B. Ergovaline

Ergovaline accounts for approximately what percentage of the ergopeptine content of tall fescue?

A. 10%

B. 40%

C. 60%

D. 90%

D. 90%

Cattle in summer are panting, drooling, breathing heavily, not shedding, and spending long periods in water. What is the most likely diagnosis?

A. Ergot toxicity

B. Fescue toxicity

C. Zinc toxicity

D. Warfarin toxicity

B. Fescue toxicity

Which lesion is specifically associated with fescue toxicity?

A. Heinz bodies

B. Fescue foot

C. Centrilobular necrosis

D. Pulmonary edema

B. Fescue foot

Black walnut toxicity is particularly important in:

A. Cats

B. Dogs

C. Horses

D. Pigs

C. Horses

Black walnut shavings in horse bedding are strongly associated with:

A. Laminitis

B. Methemoglobinemia

C. Pulmonary edema

D. Pancytopenia

A. Laminitis

The main toxic component of black walnut is:

A. Juglone

B. Ergovaline

C. Dicumarol

D. NAPQI

A. Juglone

The toxin from black walnut bedding is thought to be absorbed through the:

A. GI tract only

B. Coronary band and skin

C. Lungs

D. Liver

B. Coronary band and skin

What is the most important initial treatment for black walnut toxicity?

A. Vitamin K1

B. N-acetylcysteine

C. Remove the horse from the source

D. Blood transfusion

C. Remove the horse from the source

Hematopoietic toxicity can result from:

A. Bone marrow suppression

B. Peripheral destruction of blood cells

C. Reactive oxygen species formation

D. All of the above

D. All of the above

Which reactive oxygen species are mentioned in the lecture?

A. Superoxide anion, hydrogen peroxide, hydroxyl radical

B. Carbon dioxide, bicarbonate, oxygen

C. Calcium, sodium, potassium

D. Nitric oxide only

A. Superoxide anion, hydrogen peroxide, hydroxyl radical

Reactive oxygen species can ultimately contribute to:

A. Hemolysis

B. Thrombocytosis

C. Polycythemia

D. Hypercalcemia

A. Hemolysis

Chloramphenicol, sulfonamides, diclofenac, and mycotoxins may cause:

A. Bone marrow aplasia

B. Methemoglobinemia

C. Thrombocytosis

D. Polycythemia

A. Bone marrow aplasia

Trimethoprim-sulfadiazine, cephalosporins, and phenobarbital may cause:

A. Pancytopenia

B. Polycythemia

C. Thrombocytosis

D. Leukocytosis

A. Pancytopenia

The possible mechanism of this drug-associated pancytopenia is:

A. Immune-mediated destruction of stem cells

B. Vitamin K inhibition

C. Calcium-channel blockade

D. Increased RBC production

A. Immune-mediated destruction of stem cells

Arsenic may cause:

A. Hemolytic anemia and dyserythropoiesis

B. Thrombocytosis

C. Polycythemia

D. Neutrophilia only

A. Hemolytic anemia and dyserythropoiesis

Nitrites, nitrobenzenes, phenacetin, and methylene blue are associated with:

A. Toxic methemoglobinemia

B. Bone marrow aplasia

C. Vitamin K deficiency

D. Polycythemia

A. Toxic methemoglobinemia

Toxic methemoglobinemia occurs through:

A. Oxidation of RBC hemoglobin

B. Platelet destruction

C. Vitamin K inhibition

D. Stem cell damage

A. Oxidation of RBC hemoglobin

Heparin, gentamicin, aspirin, acetazolamide, cephalexin, and gold salts may cause:

A. Thrombocytopenia

B. Thrombocytosis

C. Polycythemia

D. Neutropenia only

A. Thrombocytopenia

The thrombocytopenia associated with these drugs may occur through:

A. Immune-mediated platelet destruction

B. Increased platelet production

C. Vitamin K activation

D. Hemoglobin oxidation

A. Immune-mediated platelet destruction

Warfarin is classically considered a(n):

A. Anticoagulant

B. Oxidizing agent

C. Mycotoxin

D. Heavy metal

A. Anticoagulant

Warfarin causes bleeding through inhibition of:

A. Vitamin K-dependent coagulation factor carboxylation

B. Platelet production

C. Fibrin breakdown

D. Calcium absorption

A. Vitamin K-dependent coagulation factor carboxylation

Which coagulation factors are vitamin K-dependent?

A. II, VII, IX, X

B. I, III, V, VIII

C. VIII, XI, XII, XIII

D. I, II, III, IV

A. II, VII, IX, X

Sweet clover toxicity is associated with:

A. Fresh sweet clover

B. Spoiled sweet clover hay or silage

C. Fresh rye

D. Moldy corn

B. Spoiled sweet clover hay or silage

Molding of sweet clover promotes formation of:

A. Dicumarol

B. Juglone

C. NAPQI

D. Ergovaline

A. Dicumarol

First-generation anticoagulants generally require:

A. Multiple feedings

B. A single feeding

C. IV exposure

D. Inhalation

A. Multiple feedings

Which is considered an intermediate anticoagulant?

A. Brodifacoum

B. Diphacinone

C. Warfarin

D. Bromadiolone

B. Diphacinone

Which is a second-generation anticoagulant?

A. Warfarin

B. Pindone

C. Brodifacoum

D. Coumafuryl

C. Brodifacoum

Why are second-generation anticoagulants especially dangerous?

A. They may be highly toxic after a single feeding

B. They require years of exposure

C. They only affect rodents

D. They cannot affect wildlife

A. They may be highly toxic after a single feeding

What is the antidote for anticoagulant rodenticide toxicity?

A. Vitamin K1

B. Vitamin K3

C. N-acetylcysteine

D. Atropine

A. Vitamin K1

Which is included in Allium spp.?

A. Onions

B. Garlic

C. Chives

D. All of the above

D. All of the above

Allium species contain:

A. Organosulfoxides

B. Coumarins

C. Fumonisins

D. Indanediones

A. Organosulfoxides

Chewing Allium plants converts organosulfoxides into:

A. Sulfur-containing organic compounds

B. Vitamin K antagonists

C. Calcium antagonists

D. Heavy metals

A. Sulfur-containing organic compounds

The primary toxicologic mechanism of Allium toxicity is:

A. Oxidative hemolysis

B. Anticoagulation

C. Bone marrow aplasia

D. Vasodilation

A. Oxidative hemolysis

Why are cats particularly susceptible to oxidative RBC damage?

A. Their hemoglobin is 2-3 times more susceptible to oxidative damage

B. They have excessive catalase

C. They have excessive glucuronidation

D. They cannot make RBCs

A. Their hemoglobin is 2-3 times more susceptible to oxidative damage

Sulfhemoglobin precipitation in Allium toxicity leads to formation of:

A. Heinz bodies

B. Dohle bodies

C. Howell-Jolly bodies

D. Spherocytes

A. Heinz bodies

Oxidation-induced membrane cross-linking can result in formation of:

A. Eccentrocytes

B. Target cells

C. Schistocytes

D. Acanthocytes

A. Eccentrocytes

58. U.S. pennies produced in 1983 and later contain a core that is approximately:

A. 25% zinc

B. 50% zinc

C. 75% zinc

D. 97.5% zinc

D. 97.5% zinc

Zinc toxicity primarily causes:

A. Oxidative damage to RBCs

B. Anticoagulation

C. Bone marrow aplasia

D. Vasoconstriction

A. Oxidative damage to RBCs

Which anemia is associated with zinc toxicity?

A. Nonregenerative anemia

B. Regenerative hemolytic anemia

C. Iron-deficiency anemia

D. Aplastic anemia

B. Regenerative hemolytic anemia

Zinc toxicity does NOT usually cause significant:

A. Hemoglobinuria

B. Methemoglobin formation

C. Hemolysis

D. Secondary renal injury

B. Methemoglobin formation

Acetaminophen is primarily metabolized in the:

A. Kidney

B. Liver

C. Lung

D. Spleen

B. Liver

Which metabolite is the primary toxic metabolite of acetaminophen?

A. PAP

B. NAPQI

C. GSH

D. Sulfhemoglobin

NAPQI

NAPQI is normally detoxified by conjugation with:

A. Vitamin K

B. Glutathione

C. Albumin

D. Bilirubin

B. Glutathione

Why are cats especially sensitive to acetaminophen toxicity?

A. They have poor glucuronidation capacity

B. They have excessive glucuronidation

C. They have excess glutathione

D. They metabolize NAPQI too slowly because of kidney failure

A. They have poor glucuronidation capacity

What is the major concern with acetaminophen toxicity in dogs?

A. Hematologic injury

B. Hepatic injury

C. Renal injury

D. Peripheral gangrene

B. Hepatic injury

What is the major concern with acetaminophen toxicity in cats?

A. Hepatic injury

B. Hematologic injury

C. Bone marrow suppression

D. Thrombocytopenia

B. Hematologic injury

Brown or chocolate-colored blood is characteristic of:

A. Methemoglobinemia

B. Hyperbilirubinemia

C. Hemoglobinuria

D. Thrombocytopenia

A. Methemoglobinemia

What is the primary treatment highlighted for acetaminophen toxicity?

A. Vitamin K1

B. N-acetylcysteine

C. Atropine

D. Pralidoxime

N-acetylcysteine

A cat presents with facial edema, paw edema, pale mucous membranes, low PCV, and brown/chocolate-colored blood. What should be your TOP differential?

A. Zinc toxicity

B. Acetaminophen toxicity

C. Warfarin toxicity

D. Fescue toxicity

B. Acetaminophen toxicity