Toxicology exam 2 (Lectures 11-20)

fumonisins

What mycotoxins are produced by the fungus Fusarium and it produces different lesions in different species?

fumonisins

What toxin produces a characteristic lung lesion in pigs, classic lesion in horse brains, and liver damage in multiple species?

fumonisins

What toxin causes a decrease in myocardial contractility due to the inhibition of L type Ca channel leading to left-sided heart failure and pulmonary edema?

ergot toxicity

What toxicity is caused by claviceps purpurea due to growing conditions and storage as major factors with rye being a classic wheat affected?

ergot toxicity

What toxicity has an influence on the peripheral vasculature due to epinephrine, serotonin, and dopamine increase?

ergot toxicity

What toxicity most commonly causes gangrene of distal extremities due to vasoconstriction and impaired blood flow?

fescue toxicity

What toxicity has the most common variety in tall fescue grass called Kentucky 31 variety, the fungal endophyte has a mutualistic relationship with the plant, produces alkaloids to help protect it from pests, and can cause vascular dysfunction (constriction), altered thermoregulation, and altered hormones regulation?

fescue toxicity

What toxicity causes cattle panting, drooling ,heavy respiration, not eating, not moving, and long periods in water?

Black walnut toxicity

What toxicity comes from wood shavings used for bedding for horses and commonly causes laminitis in horses and is also toxic if ingested?

Warfarin

What is a classic anticoagulant drug that inhibits Vitamin K dependent carboxylase?

2, 7, 9, 10

What are the vitamin K clotting factors?

sweet clover toxicity

What toxicity comes from the molding of sweet clover that promotes the formation of dicoumarol in hay?

warfarin

What is an example of a first generation anticoagulant that require multiple feedings to result in toxicity?

diphacinone

What is an example of an intermediate anticoagulants that require fewer feedings than first generation chemicals and are more toxic to non target species?

brodifacoum

What is a second generation anticoagulants and are highly toxic to non target species after a single feeding?

vitamin K

What is antidotal to anticoagulant rodenticides?

allium spp, allium toxicity

What toxin is released from trauma to plants such as chewing which converts the organosulfoxides to a complex mixture of sulfur-containing organic compounds that causes oxidative hemolysis?

Sulfhemoglobin

What is less soluble than hemoglobin, so it precipitates, aggregates, and binds to the cell membrane and forms Heinz bodies?

zinc toxicity

What toxicity causes oxidative damage to RBCs, does not usually form methemoglobin, can see hemoglobinuria and secondary renal injury and can cause a regenerative hemolytic anemia?

acetaminophen (APAP) toxicity

What toxicity is hepatically metabolized causing sulfation, glucuronidation (cats can't do this), smaller amount is converted to NAPQ1, some converted into para-aminophenol (PAP) that causes oxidative stress?

cats

What species is most sensitive to acetaminophen toxicity due to them lacking glucuronidation capacity?

acetaminophen toxicity

What toxicity causes hepatic injury (dogs), hematologic injury (cats), methemoglobin, cyanosis/dyspnea, icterus, hemolytic anemia, and facial/paw edema (especially in cats)?

N-acetylcyteine

What is the treatment for acetaminophen toxicity?

circulatory toxicity

What type of toxicity in a cat cause stuffy face, puffy paws, pale mucous membranes, low PCV, and methemoglobinemia?

1. acetaminophen

2. allium spp

3. zinc

What are the top differentials for circulatory toxicity in cats?

hepatic lobule

portal lobule

hepatic acinus

What are the three different ways to think about liver structure?

portal vein (from GI tract)

Where is the majority of blood supply coming from to the liver?

Zone 1

Which zone in the liver is more oxygenated?

Zone 1

Which zone in the liver is the most oxygenated, less susceptible to hypoxia, and first to encounter toxins arriving from GIT?

Zone 3

Which zone is least oxygenated, more susceptible to hypoxia, and the area where most metabolic transformation occurs?

Bedlington terriers, west highland terriers, skye terriors

What dog breeds are susceptible to having copper homeostasis issues?

higher levels of phase I enzymes

Why is zonal necrosis most common in zone 3, the centrilobular area?

Pyrrolizidine alkaloids (PA)

What hepatotoxin is caused from the primary consumption of Senecio and Crotalaria spp. and small herbivores such as sheep, goats, rabbits, and guinea pigs and other animals are highly resistant to PA toxicity>

crotalaria spp- showy rattlebox

What hepatotoxin also causes pulmonary damage and is caused by a legume that supports nitrogen fixing bacteria that is considered a soil builder?

Senecio- Tansy ragwort

What hepatotoxin causes liver necrosis and death in cattle due to the toxin being metabolized in the liver, some being activated to more reactive, toxic compounds and others being detoxified?

pyrrolizidine alkaloids

What hepatotoxin are potent electrophiles that react with nucleophilic substrates including DNA, proteins, and amino acids primarily affecting zone 3 of the liver?

pyrrolizidine alkaloids

What hepatotoxin causes acute liver failure including anorexia, depression, icterus and edema with chronic animals presenting with photosensitivity and icterus, there is no specific treatment, and prevention is the best defense?

mycotoxins

In most cases of contact with this hepatotoxin we will decontaminate, monitor for clinical syndromes, and treat clinical signs?

mushroom identification

What should you not do with mycotoxins due to this being very dangerous and invite liability?

death cap or destroying angel (amanita phalloides)

What is the most dangerous mushroom?

inhibiting nuclear RNA polymerase

What is the mechanism of toxicity for mushroom toxicity- amanita phalloides?

cells with high metabolic rate such as hepatocytes, renal tubular cells, and GI epithelium

Which cells are most vulnerable to mushroom toxicity due to the decrease in messenger RNA results in decreased protein synthesis?

one "death angel" is sufficient to kill an average sized dog

What is the toxic dose of mushrooms?

amanitoxins are well absorbed and have a short half-life

What is true about mushroom toxicity?

psilocybe spp.

What other mushroom toxicity contains physcoactive compounds (hallucinogens)?

gastrointestinal distress

What clinical signs do most mushrooms cause?

sago palm (cycads)

What is the single most dangerous plant or dogs?

sago palm (cycads)

What hepatotoxin causes hepatic necrosis, contains Beta-methylamino L-alanine (BMAA) that causes muscle weakness, paralysis, and seizures, and an unidentified third toxin causes axonal degeneration?

ingestion of 1-2 seeds

What is the lethal dose in a dog of sago palms (cycads)?

aspergillus and penicillium

What are the two main groups of aflatoxins?

turkeys

what species is most susceptible to aflatoxins?

aflatoxins

What hepatotoxin causes the liver to become enlarged and shows marked fatty accumulations and massive centrilobular necrosis and hemorrhage?

peanut products

What products are notoriously susceptible to aflatoxin contamination?

cocklebur

What hepatotoxin has highly toxic seeds and are present in fields and baled hay commonly affecting pigs, ruminants, and horses causing signs of weakness, vomiting, twisted neck, and weak pulse?

cocklebur

What hepatotoxin has a characteristic lesion that is severe, diffuse, centrilobular hepatocellular necrosis?

trifolium spp

What hepatotoxin primarily affects horses leading to chronic liver failure and associated with Alsike and red clovers?

copper

What hepatotoxin affects sheep, cattle, goats, and dogs and occurs when it accumulates in the liver, causes hepatocellular damage, a stressful incident occurs, it is released into the blood and damages RBCs, and then goes to the kidneys and causes renal damage?

xylitol

What toxin is documented in dogs and ferrets, can cause hypoglycemia to develop within 30-60 minutes of ingestion, liver injury may not occur until >24-48 hours post ingestion, and can cause depression, vomiting, icterus, and coagulopathy?

owner should apply Karo syrup to gums to transport patient immediately to veterinary facility for evaluation

What should you tell the owner to do if a dog ingests xylitol?

insoluble oxalate toxicity

What toxin has calcium oxalate crystals produce physical damage to skin and mucous membranes where contact occurs and systemically can produce hypocalcemia and crystallize in renal tubules resulting in kidney damage?

raphides

In order to cause oxalate toxicity, the stems and leaves are chewed causing sharp crystals called what to be forcibly ejected from idioblast cells in the plant?

insoluble oxalate toxicity

What toxicity causes immediate clinical signs including pain in the mouth, head shaking, intense salivation, and unusual vocalization?

pokeweed: phytolacda americana

What toxin affects sheep, cattle ,goats, horses, pigs , and poultry, have the toxic principles saponins and oxalates, causes irritation of the mucosal surface, and can cause oral irritation, excessive salivation, vomiting, colic, bloody diarrhea, depression, prostration, and death with mild to severe gastroenteritis with ulceration of the gastric mucosa?

castor bean: Ricinus communis

What toxin has the toxic principle ricin with the highest concentrations found in the seeds, it depurates the 28S ribosomes in RNA, protein synthesis ceases and the cell dies, 4 seeds can be lethal in human, and the primary effects are on the GI tract, practicularly the GI mucosa?

buttercup: ranunculus spp

What toxin has the toxic principle ranuculin converted to protoanemonin when chewed, is a potent vesicant that irritates mucous membranes of the GI system, the vesicants can cause blister formation, and with severe intoxication, effects to the kidney have also been reported?

castor bean: Ricinus communis

What plant is considered the most toxic in the world with toxicity varying among animal species?

autumn crocus: crocus autumnale

What toxin has the toxic principle Colchicine which interferes with mitotic spindle formation in normally dividing cells, a few seeds are considered potentially lethal, and multiple organ systems are affected with myelosuppression seen in animals that survive?

Slaframine toxicity

What is the toxin that has the mycotoxin toxic principle (slaframine and swainsonine) found in a common fungal pathogen of red clover that cause black patch disease in plants, and causes salivation (slobbers) in most animals (mostly horses)?

NSAIDs

What has pharmacological effects of an analgesic, antipyretic, anti-inflammatory?

acetaminophen

What drug does not have anti-inflammatory effects but is considered an NSAID?

COX-1

What form of cyclooxyrgenase exists in the tissue?

COX-2

At the site of inflammation, cytokines stimulate the induction of what form of cyclooxyrgenase?

NSAID toxicity

What toxicity inhibits cyclooxyrgenase, the inhibition of PG synthase in the gastric mucosa lead to GIT damage and the inhibition of PG in afferent arterioles of the kidneys cause vasoconstriction and reduced GFR and lead to nephrotoxicity?

GI hemorrhage, erosions, ulcerations/perforation, and acute renal failure if severe

What are the common adverse effects with NSAID use?

arsenic

A farmer calls you about cattle that suddenly died with pre-mortem signs being hemorrhagic gastroenteritis, watery diarrhea, cramping ,and bloating, the farmer notes that he recently burned a large amount of wood, what toxicity is this?

burned wood-arsenic becomes concentrated in the ashes

What is the worst origin of arsenic?

arsenic

What toxin is inhibitory to cellular respiration, causes failure of ATP production, severe GI signs (hemorrhagic diarrhea), weakness, ataxia, and sudden death?

nephron

What is the functional unit of the kidney?

Prerenal

What type of acute renal failure causes include hypovolemia, renal vasoconstriction, and poor cardiac output?

postrenal

What type of acute renal failure factors include obstruction of the ureters, bladder, or urethra?

renal

What type of acute renal failure factor result in ARF leading to decreased GFR including tubular injury, glomerular injury, interstitial disease, and renal vascular compromise?

ischemia/repurfusion and nephrotoxicosis

What counts for over 90% of acute renal failure cases?

1. direct injury to renal tubular epithelium leading to epithelial cell necrosis, sloughing and obstruction of tubules by cellular debris

2. detachment of lethally injured cells causing lumen obstruction

3. renal vasoconstriction, resulting in hypoxia and ischemic necrosis

4. damage to the glomerular filtration barrier

5. impairment of renal healing and repair

What are the five different mechanisms in which neurotoxins damage the kidneys?

acute renal injury or failure

These clinical signs indicate what: polydipsia, nausea or vomiting, lethargy, anorexia, weakness, dehydration, and polyuria/oliguria/anuria?

mycotoxin: ochratoxin

What kind of nephrotoxin is produced by various fungi including aspergillus and penicillium, reported to cause toxicity in a variety of animal species, cattle are thought to be resistant due to degradation of this toxin within the rumen, and pigs are considered the most sensitive species?

aminoglycoside antibiotics

What nephrotoxin exerts their nephrotoxic effects through induction of apoptosis and necrosis in cells or many (most) regions of the nephron, can also produce ototoxicity, and has a relatively narrow therapeutic index?

aminoglycoside antibiotics

What category of drugs do these belong to: neomycin, gentamicin, streptomycin, kanamycin?

NSAIDs

The primary impact of COX-induced inhibition of PG synthesis in the kidney is the reduction of renal blood flow, resulting in ischemia is what drug group?

Cholecalciferol

What toxin has become common due to the phase-out use of anticoagulant rodenticides?

dystrophic calcification

What is the underlying mechanism of cholecalciferol?

cholecalciferol

What toxin increases the uptake of calcium-> hypercalcemia -> inappropriate mineralization in the tissues?

cholecalciferol

What toxin treatment involves hormonal therapies to block Ca release from the bone and block Ca uptake at the GI (ex: pamidronate)?

redroot pigweed- amaranthus spp

What toxin is grown throughout the US, renal injury has been reported in pigs, cattle, and sheep which typically presents with peri-renal edema and widespread degeneration of proximal and distal tubules, and the toxic principle is not known?

pyrrolizidine alkaloids

Which group of toxin can be from the plants Crotolaria, heliptrophium, and senecio and predominantly affects horses, cattle, and pigs, cause tubular degeneration and necrosis, and hepatic lesions?

oxalic acid- soluble oxalates

Which toxin is found mostly affecting pigs and ruminants, and causes tubular degeneration and necrosis, and intra-tubular calcium oxalate crystals?

acer rubrum- red maple

Which toxin is mostly seen in horse and causes acute tubular degeneration and necrosis with hemoglobin casts in tubules?

bracken fern

Which toxin has thiaminase that causes a hypovitaminosis B1 in horses and has ptaquiloside that causes epistasis, melon, hemorrhage, and enzootic hematuria mostly in cattle?

lilium spp and hemerocallis spp (lillies)

Which toxin affects cats, any part of the plant can produce toxicity, where even exposure to the pollen or drinking water from the vase that contains these plants is potentially toxic?

Lily species lilium and hemerocallis

Which toxin has an uncertain toxic dose, the mechanism is unknown but severe damage to the renal tubular epithelium and sloughing of tubular cells occurs?

vitis spp- grapes, rasins, and currants

Which toxin causes acute renal failure in dogs, and anecdotally cats and ferrets and the toxic principle appears to be tartaric acid?