Lecture 11: Toxicity: circulatory and hematopoietic systems

fumonisins

mycotoxins produced by the fungus Fusarium verticillioides

fumonisins is a good example of

a toxin type that produces different lesions in different species

what deoes fumonisins cause it multiple species

liver damage

what species specific affects does fumonisins have

lungs in pigs

brain in horses

kidney in rats, rabbits and sheep

esophagus in rats and pigs

manifestation of fumonisin

toxins causing periphreal vascular dysfunction

ergot

fescue

black walnut

ergot toxicity agent

claviceps purpurea

where is ergot typically seen

rye

ergot symptoms

seizures, hallucinations, abortions, paralysis, GI distrurbance, gangrene of extremities and death

ergot

what is the fescue toxicity relationship

the fungal endophyte has a mutualistic relationship with the plant and produces alkaloids that help protect it from pest

clinical causes of fescue toxicity

vascular dysfunction (constriction)

altered thermoregulation

altered hormone regulation

most prevalent ergopeptine

ergovaline

a cow presents in the summer time panting, drooling, heavy respiration, not eating, not moving, not shedding, long periods in water

fescue toxicity

what is a common way black walnuts are ingested

wood shavings that are used for bedding of horses

what does black walnut poisoning do to horses

laminitis and ingestion is toxic

what does hematopoietic toxicity result in

off target inhibition leading to decreased bone marrow response or a result of peripheral effects leading to destruction of blood cells

what is the classic anticoagulant drug

warfarin

sweet clover toxicity

molding of sweet clover promotes the likelihood of formation of dicumarol in the hay

first generation anticoagulants feeding needs

require multiple feedings to result in toxicity

intermediate anticoagulant feeding needs

requirer fewer feedings

the second generation anticoagulants are highly toxic to

non target species

what is antidotal to anticoagulant rodenticides

vitamin K1

what species is onion

allium spp

allium toxicologic mechanism

oxidative hemolysis, which occurs when the concentration of oxidants in the

erythrocyte exceeds the capacity of the antioxidant metabolic pathways.

what species are more susceptible to allium toxicity

cats and dogs

what causes the formation of heinz bodies with allium toxicity

sulfhemoglobin being less soluble than hemoglobin, so it precipitates, aggregates and binds to the cell membrane

zinc toxicity

-Oxidative damage to RBCs

-Does not usually form metHb

-Can see hemoglobinuria and secondary

renal injury

-Regenerative hemolytic anemia

acetaminophen metabolism is what in nature

hepatic

what animal is very sensitive to acetaminophen

cats

acetaminophen toxicity results in

excess of NAPQI

increase levels of PAP

glutathione is depleted

clinical effects of acetaminophen toxicity

hepatic injury

hematologic injury

clinical signs of acetaminophen toxicity

chocolate blood

cyanosis/dypsnea

icterus

hemolytic anema

facial/paw edema

acetaminophen toxicity treatment

acetylcysteine

a cat comes into the clinical with a puffy face, puffy paws, pale mucous membrane. blood shows low PCV, methemoglobinemia

what is your top differentials

1. acetaminophen

2. allium spp

3. distances but zinc