Toxicology Final Exam Material Flashcards
T/F: Emetics are recommended in dogs and cats to prevent further absorption of petroleum products
False
Emetics and gastric lavage are generally contraindicated (aspiration pneumonia)
Ingestion of kerosene is most likely to cause:
severe aspiration pneumonia
Signs of aspiration pneumonia such as shivering, incoordination, anorexia, weight loss, fever, coughing, dyspnea, and abnormal lung sounds
Signs of chronic cyanide poisoning in horses are mainly due to:
neuronal degeneration of the spinal cord and brain
What is the toxic principle in this plant?
Tannic acid
Pictured: White Oak tree (Quercus alba)
Mechanism of action: tissue damage including GI lesions and kidney damage; mainly GI lesions and kidney damage in ruminants; mainly GI lesions in monogastric animals
Sternal recumbency while standing on the hind limbs is a clinical sign of what food and water related toxicant?
NPN (Urea)
Signs include restlessness, aggression, muscle tremors, salivation, teeth grinding, colic, bloat, rumen stasis, sternal recumbency while standing on the hind limbs, usually no diarrhea, convulsions and death within 1-2 hours
Sudden onset of signs of hepatic insufficiency such as weight loss, icterus, incoordination, head pressing, aimless wandering, walking in circles and other signs of mania, GI distress, tenesmus, are MAINLY signs due to ingestion of:
- Halogeton (Halogeton spp.)
- Oleander (Nerium oleander)
- Ragwort (Senecio spp.)
- Cottonseed (Gossypium spp.)
- Pigweed (Amaranthus retroflexus)
Ragwort (Senecio spp.)
What three toxic plants are associated with forage-induced photosensitization?
moldy alfalfa, red clover, moldy wheat
Mechanism of action: Secondary photosensitization is due to liver damage. (The photoreactive substance is a metabolite of chlorophyll)
Alsike clover and red clover are in the legume family and cause hepatotoxicity and secondary photosensitization in what species?
horses only
A dog that is showing autonomic signs including vomiting, colic, diarrhea, mydriasis, dyspnea; nervous signs including convulsions; locomotor signs including ataxia; then recovers to show signs of liver failure and metabolic acidosis 2-3 days later is most likely intoxicated with:
Metaldehyde
What is the primary effect of pyrrolizidine alkaloids?
Hepatotoxicity
Which is more toxic: pentavalent arsenic or trivalent arsenic?
Trivalent arsenic
- Inorganic trivalent is more toxic than pentavalent, which is more toxic than organic*
- Trivalent > Pentavalent > Organic*
Poisoning caused by ingestion of large amounts of rhubarb (Rheum rhaponticum) is most likely associated with damage to what organ?
kidney
Toxic principle in rhubarb: soluble oxalates
Mechanism of action: Hypocalcemia and precipitation of insoluble calcium oxalates in soft tissues and kidney damage
What is the toxic principle in this plant?
Insoluble calcium oxalates
Pictured: Chinese evergreen (Aglaonema spp.)
**All parts of the plant are toxic**
What is the main blood carrier for iron?
Transferrin
Which of the following is least likely an effect of marine toad (Bufo marinus) toxins?
- irritation of the mucous membranes
- hepatotoxicity
- cardiototoxicity
- hallucination
hepatotoxicity
The diagnosis of lead toxicosis in dogs is best established on the basis of:
blood levels of lead
What is the toxic principle in this plant?
Calcinogenic glycosides (Vitamin D analog)
Pictured: Day-blooming jessamine (Cestrum diurnum)
Mechanism of action: Hypercalcemia; calcification of the elastic tissues of the arteries, tendons, and ligaments as well as generalized increased density of the bones causing lameness
Chronic selenium in horses mainly causes:
hoof and hair abnormalities
Lameness, hoof abnormalities, emaciation, and loss of hair in cattle most likely suggest toxicosis with:
chronic selenium
What is the toxic principle in this plant?
Lectins (phytotoxins, toxalbumins)
Pictured: Castor bean (Ricinus communis)
What is the toxic principle in this plant?
Cycasin
Pictured: Sago palm (Cycas revuluta)
Mechanism of action - cycad palms have three toxins:
- Cycasin is a glycoside that causes GI irritation and liver damage and it is also teratogenic, mutagenic and carcinogenic
- β‐methylamino‐L‐alanine (BMAA) is a neurotoxic amino acid
- Unknown toxin that may cause axonal degeneration in the CNS
[sahy-kuh-sin]
What is the toxic principle in this plant?
Piperidine alkaloids (and pyridine alkaloids)
Pictured: Tobacco (Nicotiana tabacum)
Mechanism of action: start with ganglionic and neuromuscular stimulation followed by ganglionic and neuromuscular blockade. Neuromuscular blockade prevents fetal movement resulting in birth defects
What domestic species is most sensitive to ethylene glycol toxicity?
Cats
T/F: This is a dog
True
Nice job! Finals week hasn’t gotten you yet :)
Deferoxamine is the chelating agent of choice for:
iron
What is the toxic principle in this plant?
Carboxyatractyloside (sulfated glycoside)
Pictured: Cocklebur (Xanthium strumarium)
Mechanism of action: Hepatotoxicity, excessive salivation, maybe renal damage and hypoglycemia
The presence of an odor of rotten garlic in a fresh carcass is suggestive of acute __________ toxicosis
selenium
What is the toxic principle in this plant?
Colchicine
Pictured: Glory lily (Gloriosa superba)
Mechanism of action: Antimitotic by binding to tubulin and inhibiting spindle formation during cell division
(Pronounced kol-chuh-seen)
T/F: Cats are the most susceptible species to toad intoxication
False
Ingestion of plants that have been sprayed with the recommended levels of 2,4-D herbicides may cause poisoning in livestock mainly as a result of:
accumulation of toxic levels of nitrate or cyanide by the plant
The toxic principles of which of the following poisonous plants act mainly by blocking nicotinic receptors at the neuromuscular junction?
- Castor bean (Ricinus communis)
- Lily-of-the -valley (Convallaria majalis)
- Larkspur (Delphinium spp.)
- Milkweed (Asclepias spp.)
Larkspur (Delphinium spp.)
Toxic Principle: Diterpene alkaloids
Mechanism of action: Competitive blockade of the nicotinic receptors at the muscle endplate similar to curare
- Castor bean (toxic principle: lectins) inhibit protein synthesis resulting in cell death
- Lily-of-the-valley and Milkweed (toxic principle for both: cardiac glycosides) are cardiotoxic by inhibiting Na/K ATPase
What plant part accumulates the highest amount of nitrate?
Stalks
The stalks (closest to the ground) contain the highest concentrations. Leaves contain less than stalks or stems
T/F: Seizures associated with strychnine toxicosis and water deprivation/sodium ion toxicosis are elicited by external stimuli
False
- Seizures associated with strychnine toxicosis are elicited by external stimuli.*
- Seizures associated with water deprivation/sodium ion toxicosis are not elicited by external stimuli!!*
What is the mechanism of action of glucosinolate (thiocyanate glycosides)?
Antithyroid
Which of the following is least likely a clinical sign of marine toad (Bufo marinus) intoxication?
- slow onset clinical signs (2-3 days)
- foaming of the mouth
- seizures
- tachycardia or bradycardia
slow onset clinical signs (2-3 days)
What anionic detergent is considered to be the most toxic?
Automatic Dishwashing Detergents
Even though they are anionic detergents (moderately toxic), they often contain alkali (NaPhos, NaCarb, etc.), which increases the risk of toxicity
What is the toxic principle in this plant?
Xanthine alkaloids
Pictured: Cocoa (Theobroma cocao)
Mechanism of action: block adenosine (A) receptors, inhibition of phosphodiesterase
T/F: Sodium nitrite IV is useful for treating hydrogen sulfide toxicity
True
Sodium nitrite IV forms methemoglobin that binds the hydrated sulfide radical to reduce toxic effects and reactivate cytochrome oxidase
Ragwort or senecio (Senecio spp.) is a common plant in western Oregon and Washington that causes losses in livestock mainly because it has this toxic principle:
pyrrolizidine alkaloids
What is the toxic principle in this plant?
Insoluble Ca2+ oxalate
Pictures: Dumbcane (Dieffenbachia spp.)
Mechanism of action: hypocalcemia and preceipitation of insoluble oxalates in soft tissue and kidney damage; produces proteolytic enzymes which cause _release of histamine_ and kinins by the body increasing the mechanical damage
What is the toxic principle in this plant?
Pyrrolizidine alkaloids
Pictured: Rattlebox (Crotolaria spp.)
Mechanism of action: hepatotoxic
Which of the plants pictured is a soluble oxalate-containing plant?
Sorrel (Oxalis spp.)
What are the general signs you’d expect to see associated with chronic fluoride poisoning in cattle?
lameness, exostoses, and excessive dental wear
You may also observe anorexia, emaciation, rough haircoat, reduced milk production and reproduction
What is the toxic principle in this plant?
Triterpene acids
Pictured: Lantana (Lantana camara)
Mechanism of action: liver damage and hepatogenic photosensitization
T/F: Selenium deficiency causes blind staggers in cattle
False
Selenium _toxicosis_ causes blind staggers in cattle
T/F: Ethylene glycol is known to cause heinz body anemia in cats
False!
Propylene glycol is known to cause heinz body anemia in cats
….dummy
T/F: Phytonadione is the treatment of choice for anticoagulant rodenticide toxicity
True
Phytonadione is Vitamin K1 (oral route is recommended)
Identify this selenium indicator plant that is grown widely in the west:
Prince’s Plume
Stanleya pinnata
A dog that was treated in the ER for tremors and hyperthermia related to metaldehyde ingestion was doing fine on discharge but now, a few days later, is showing inappetence and vomiting.
What organ/body system is most important to assess at this time?
Liver
A reddish-brown gas that produces bronchial constriction and pulmonary edema is:
nitrogen dioxide (NO2)
What species are most susceptible to soluble oxalate poisoning?
Sheep & Cattle
- Sheep and cattle are the most susceptible (although the rumen microflora can detoxify oxalates to carbonates and bicarbonates)*
- Sheep may be poisoned by 0.55% of body weight. Starved sheep or water deprived can be killed by only 0.1% of body weight.*
What is the toxic principle in this plant?
Isocupressic acid
Pictured: Ponderosa Pine (Pinus ponderosa)
Mechanism of action: Maybe vasoconstriction and decrease uterine blood flow that stimulates release of fetal cortisol and abortion
Clinical signs: abortion in cattle
If a patient ingests an antifreeze product that contains a rust inhibitor, what biochemistry value may rise in the first few hours post-ingestion but not be related to renal injury?
phosphorous
T/F: As low as 0.1g/kg Xylitol can cause hyperglycemia
False
- As low as 0.1g/kg Xylitol can cause hypoglycemia*
- Xylitol is a potent promoter of insulin release in dogs, resulting in hypoglycemia. Large doses can cause liver failure, GI hemorrhage, and DIC*
- Hypoglycemia can occur within 30-60 minutes or may take several hours depending on the amount ingested*
T/F: Petroleum products with low boiling points, low viscosity, and low surface tension usually have more pneumotoxic potential
True
Generally products with high boiling points (low volatility) such as asphalt, mineral oil or waxes are relatively non-toxic because of poor absorption
What is the toxic principle in this plant?
Anthraquinones
Pictured: Coffee Senna (Senna occidentalis)
Mechanism of action: Purgative, and coffee weed also has an unknown principle that causes skeletal and cardiac muscle degeneration and the urine may be coffee colored due to myoglobinuria which may cause kidney damage
Horses usually die from liver failure and not muscle degeneration
[an″thrah-kwin´ōn]
Which of the following poisonous plants is most likely to produce a photodynamic substance that causes photosensitivity?
- Horsetail (Equisetum hymenale)
- Cottonseed (Gossypium spp.)
- Johnsongrass (Sorghum spp.)
- St. John’s wort (Hypericum perforatum)
- Milkweed (Asclepias spp.)
St. John’s wort (Hypericum perforatum)
The mechanism of action for St. John’s wort is primary photosensitization. The photodynamic substance comes directly from the plant.
- Horsetail (toxic principle: thiaminase) produces signs of thiamine deficiency
- Cottonseed (toxic principle: gossypol) causes heart and liver damage
- Johnsongrass (toxic principle: cyanogenic glycosides) inhibits the citric acid cycle, cytochrome oxidase, cellular respiration, and glycolysis
- Milkweed (toxic principle: cardiac glycosides) causes cardiotoxicity and irritation of nervous tissue