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39 Cards in this Set

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Red Maple
Toxic agent: Unknown
MOA: acute
Clinical signs: Hemolytic anemia (heinz body formation)
Tx: whole blood transfusion, fluid therapy
Animals affected: Horses
Onions and Garlic
Toxic agent: N-propyl disulfide (glycoside)
MOA: Acute, onset of symptoms 1-6 days post ingestion
Clinical Signs: Hemolytic anemia (Heinz body), onion odor in tissue/milk, blood will not clot
Tx: blood transfusion (rapid recovery)
DDX: hemolytic diseases (Babesiosis, Lepto, etc)
Animals affected: cattle and horses; cats>dogs, sheep most resistant
Sweet clover
Toxic agent: Dicoumarol/Dicoumarin (mold causes coumarol/coumarin)
MOA: moldy/damaged clover in hay, chronic exposure. Substitutes for Vitamin K = factors 2, 7, 9, 10 affected
Clinical Signs: massive hemorrhage (internal or external), possibly icterus
Tx: blood transfusion (platelet rich plasma), vitamin K, avoid trauma
DDX: Warfarin, aflotoxin, mycotoxicoses
Animals affected: cattle, sometimes sheep and horses

Note: Trifolium subterran (Subterranean clover) not associated with hemorrhagic syndrome, but rather infertilitiy due to phytoestrogen
Bracken Fern
Blood and neurologic (horses)
Toxic agent: Ptalquiloside (glycoside; aplastic anemia/ hematuria factor), Thiaminase (only horse affected, neurological), carcinogen also present (not the toxic agent)
MOA: Chronic exposure (>4 months), must ingest 100% of body weight
Clinical Signs: hemorrhage, bone marrow disfunction (aplastic aniemia, pancytopenia), capillary fragility
Tx: whole blood transfusion, batyl alcohol
DDX: Radiomimetic agents, x-rays, gamma-rays, alkylating agents, trichloroethylene extracted soybean oil meal, anticoagulant rodenticides, moldy sweet clover
Animals affected: cattle, ruminants
Toxic agent: Cardiac glycosides (similar to digitalis), 20 leaves toxic to horse, 1-2 leaves toxic to child
MOA: Dry plant material (increased palatability), smoke of burning plants, acute exposure
Clinical Signs: vomiting, diarrhea, trembling, cardiac stimulation, vasoconstriction, mydriasis, cold extremities, paralysis, cardiac depression, coma, death; gastroenteritis, widespread petechiation
Animals affected: all, including humans, horses especially susceptible
Toxic agent: taxine (alkaloid), follage, bark, seeds toxic (green and dry)
MOA: Ca++ channel antagonist; acute exposure
Clinical Signs: Depressant: bradycardia -> heart stops in diastole -> death; chicken fat clot in heart
Tx: gastric lavage, atropine, supportive drug therapy, artificial respiration, pacemaker (humans)
Animals affected: all, including humans; primarily horses
Heart and Respiratory
Toxic agent: Gossypol (polyphenolic compound)
MOA: can die after not eating cottonseed for several weeks; survivors are poor doers (pulmonary absecesses/fog fever); do not give free choice to mature ruminants because decreases milk production/food intake, not excreted in milk, but found in organ meat
Clinical Signs: affects hemoglobin content of blood; chronic heart failure -> pulmonary edema -> death; liver, cardiopulmonary
Animals affected: humans, monogastrics, immature ruminants; swine most sensitive, cattle least sensitive
Acute Bovine Pulmonary Edema and Emphysema
Fog Fever
Toxic agent: 3-methyleneindolenine
- L-tryptophan -> 3-methylindole in rumen -> inhaled after eructation -> 3-methyleneindolenine -> swollen alveoli
-may be immune mediated or moldy hay
MOA: summer/autumn, improved pastures; 50% morbidity (30% of those may die within 1-3 days)
Clinical Signs: sudden onset respiratory distress with salivation/frothy nasal discharge/bloat; may become chronic with pulmonary edema and abscesses
Tx: diuretics?, corticosteroids? antihistamine? IV Albumin?
Animals affected: cattle (>2 years old, cow-calf), usually not daires
Astragalus emoryanus
Locoweed, Emory Milkvetch, Red-stemmed Peavine
Respiratory and Neurological
Toxic agent: 3- notro propanol/ 3-nitro propionic acid - glycoside
MOA: good forage on tight soils, becomes toxic on sandy soils
Clinical Signs: labored breathing/ husky sound; death 4-20 hours post ingestion. No gross lesions; incoordination of hind quarters, fetlock knuckling, blindness, "cracker heals", axonal degeneration of posterior spinal cord
Animals affected: domestic ruminants
Astragalus/ Oxytropis
Toxic agent: Swainsonine/ Locoine - alkaloid
MOA: chronic exposure (may become habituated/addicted)
Clinical Signs: may disappear and reemerge when excited or stressed (dangerous to horse riders); emaciation, neurological disturbances, respiratory, abortion, teratogenesis, selenium accumulation, reproductive problems, mannose accumulation (inhibition of a-mannosidase); brisket disease/ CHF/ High mountain disease
- horses/cows = excitement
- sheep = depression
Animals affected: horses most susceptible (30% body weight over 2 months = fatal), ruminants need 300% body weight over many months for fatality
Horses> cattle> sheep> goats
Costal Bermuda Grass
Respiratory, neurologic, photosensitization, liver
Toxic agent: unknown
MOA/exposure: Improved pastures (generally not seen if grass is properly baled and fed as hay, nuerological condition can occur from hay)
Clinical Signs: pulmonary edema/ emphysema, tremors/posterior paralysis, icterus, photosensitization
Tx: remove animals from pastures
Animals affected: cattle
Perilla Mint/ Beefsteak Plant
Toxic agent: Perilla ketone (same chemical as in moldy sweet potatoes); egomaketone, isoegomaketone (substituted furans)
MOA/exposure: toxic agent in leaves, stems and roots (150mg/kg is lethal in cattle); all three compounds equally toxic
-plant not usually grazed unless animals hungry, may be found in baled hay
Clinical Signs: pulmonary emphysema/edmea, leaves/seeds in rumen, mint-like odor to GI tract; atypical interstitial pneumonia
Tx: treat symptoms
Animals affected: horses and cattle
Buckeyes, Horsechestnuts
Toxic agent: Aesculin, fraxin - glycosidic saponin
- Ohio buckeye may also have narcotic alkaloid
- Highest concentration of toxin in fruit/seeds, but also found in leaves/bark
MOA/exposure: acute exposure in early spring (increased palatability); invader plant
Clinical Signs: GI irratation, uneasy staggering gait (walking on hot pavement), weakness, trembling, congested mucous membranes, hemolysis, depression -> coma -> death
Tx: symptomatic (stimulants/purgatives?)
Animals affected: cattle, horses, sheep, swine, childern

Unginadia speciosa (Mexican buckeye) - nontoxic
Toxic agent: Brunfelsalmidine, Hopeanine - alkaloids
MOA/exposure: ornamental plant
Clinical Signs: excessive salivation, coughing, gagging, clonic-tonic convulsions (strychnine-like), diarrhea or constipation
Tx: phenobarbitol for convulsions, empty stomach (gastric lavage, charcoal, saline), fluids, intensive care
Animals affected: dogs primarily, but probably all animals
Yellow Star Thistle/ Russian Knapweed
Toxic agent: unknown- lethal dose over several weeks
- Nitrate accumulation
- Designer drug MPTP- produces similar lesions in humans
MOA/exposure: chronic exposure with acute clinical signs, usually June/July or October/November; horses may become addicted
Clinical Signs: sudden onset, variable impairment of eating and drinking- unable to swallow/prehense food, push head into water to drink: CN 5, 7, 12; foreign body pneumonia; may starve to death; "wooden" expression
- Necrosis of globus pallidus, substantia nigra, basal ganglia, putamen = equine nigropalladial encephalomalacia
Animals affected: horses only
Spotted Water Hemlock
Toxic agent: Cicutoxin - highly unsaturated higher alcohol
- Highest concentration in hollow root stock
MOA/exposure: acute exposure during early spring
Clinical Signs: 15-30 minutes post-ingestion - salivation, tremors, convulsions, opisthotonus, teeth grinding, mydriasis, hyperpyrexia, paralysis and respiratory failure (cause of death)
Tx: unknown
Animals affected: all warm blooded animals, including humans
Claviceps purpurea
Calviceps cinerea
Calviceps paspali
Ergot- a fungus
Toxic agent: lysergic caid derivatives - Ergotamine, Ergotoxine; polypeptide derivatives of this indole alkaloid
- C. purpurea - rye grass and cultavated rye
-C. cinerea - Tobosa grass
-C. paspali - Bahia and Dallis grass
Clinical Signs: convulsions, incoordination, abortions (during nervous stage), gangrene after several days/weeks, lameness, necrosis of margins of ear, loss of tail switch, line of demarcation on limbs; thrombus formation
-Nervous syndrome = C. purpurea, C. cinera
-Gangrene = all (paspalum staggers with C. paspali)
Tx: none, change diet, mow Dallis grass (knocks off seed heads, rest of plant is safe to graze)
DDX: milk fever, ketosis
Animals affected: primarily cattle
Poison Hemlock
Toxic agent: Piperidine alkaloid - Coniine, etc
MOA/exposure: acute exposure with clinical signs appearing less than one hour after ingestion
Clinical Signs: nervousness, trembling, ataxia, mydriasis, bradycardia (weak), hypothermia, coma, abortion and teratogenesis (swine, cows); widespread congestion with no gross lesions
Tx: TLC, symptomatic
Animals affected: all, including humans
Sago Palms
Neurologic and liver
Toxic agent: Cyasin- carcinogenic glycoside
-Seed most toxic - also found in roots
- Methylazoxymethanol - toxic cycasin metabolite related to nitrosamine
MOA/exposure: GI bacteria cleave cycasin -> methylazoxymethanol -> neoplasm
Clinical Signs: hepatosis, jaundice, anemia, depression, diarrhea, gastroenteritis, ascites, hemorrhage, nausea, coma, paralysis, death
-Cattle - neurotoxic effects
-Dogs- neurotoxic effects, especially trembling/ convulsing, hepatic failure
-If the animals bacterial flora can convert cycasin effectively, neoplasm production is 100%
Tx: supportive care, control hemorrhage and anemia
Animals affected: all animals, including humans
Toxic agent: Delphinine and other diterpine alkaloids
-Also found in Aconitum spp (Monkshood)
-5gm/kg= lethal in cattle, 2-5 mg total = lethal in humans
MOA/exposure: acute exposure in spring, may be found dead with plant in their mouths (spurred flower)
Clinical Signs: sudden death, nervousness, staggering, hypersalivation, twitching, rapid bloating, irregular tachycardia, respiratory paralysis; death within 24 hours or survival
Tx: place animal in sternal recumbency with head elevated to prevent bloating; antiarrthymics (procainamide?)
Animals affected: primarily cattle; horses, humans, sheep are resistant
Toxic agent: Helenalin - sesquiterpene lactone
-H. amarum: bitter sneezeweed/bitterweed = nontoxic (imparts bitter taste to milk)
-H. microcephalum: small-headed sneezeweed = very toxic
-H. hoopseii: orange sneezeweed = less toxic ("Spewing sickness")
MOA/Exposure: invader plant that can compete with grass; H. hoopseii only grows at high elevations
Clinical Signs: weakness, ataxia, diarrhea, dyspnea, nasal discharge (regurgitation through nose); horses may have skin lesions (contact dermatitis)
Animals Affected: primarily sheep; cattle, goats, horses
Bitterweed, Bitter rubberweed, Pingue
Toxic agent: Hymenoxon - sesquiterpene lactone
MOA/Exposure: stunted plants probably most toxic, first greens in December; sheep may become addicted
Clinical Signs: anorexia, depression, rumen stasis, effects on CN 9, 11, 12 (cannot control pharynx), pulmonary congestion, hemorrhages on viscera
TX: none
Prophylaxis: diets with ethoxyquine may be preventative; diets containing natural protein (no urea) may be prophylactic
Animals Affected: sheep, sometimes goats, cattle?
Morning Glory
Toxic agent: Lysergic acid amide - indole alkaloid (LSD)
MOA/Exposure: escaped ornamental, noxious weed in crops
Clinical Signs: Hallucinations, respiratory depression (have to swallow 200-300 seeds); no gross lesions
Animals Affected: primarily humans
Rayless goldenrod
White snakeroot
Neurologic, photosensitization, liver
Toxic agent: Tremetol (alcohol form); Trematone (ketone)
-Excreted in milk- affects those who drink it = "milk sickness"
MOA/Exposure: usually in spring; Iscoma one of the first to green
Clinical Signs: Fetlock knuckling; progresses to posterior paralysis, convulsions and death; ketone breath; elevated liver enzymes, heart problems in horses; icterus, photosensitization
TX: remove from source, place in shade with feed and water, minimize handling
Animals Affected: all warm blooded animals
-Iscoma: cattle and horses
-Eupatorium: Angora goats (hepatic effects)
Toxic agent: unknown
MOA/Exposure: chronic exposure, heavily grazed pastures with disturbed, arid soils
Clinical Signs: kunckling of fetlocks-> posterior paralysis; convulsions precede death; sheep have similar signs but walk on carpus; congestion/hemorrhage of viscera, no CNS lesions
TX: place animals in shade with feed and water, minimize handling
Animals Affected: cattle, sheep, goats
Toxic agent: Karwinol A - polycyclic compound (cumulative poison)
-Fruit is 100x more toxic than leaves
MOA/Exposure: acute or chronic exposure, goats> sheep> cattle (sensitivity)
Clinical Signs: newly introduced animals, unthrifty, depression, trembling and incorrdination ("limber leg"); death may be first sign; demylenation of posterior spinal cord
TX: none, mildly affected animals may recover
DDX: Triaryl phosphate, tri-ortho-cresyl-phosphate, Acacia berlandieri (Guajillo) intoxication
Animals Affected: all domestic mammals including humans
Toxic agent: unknown; contains three sympathomimetic amines
-Usually on ok forage as long as diet supplemented with long-term consumption
MOA/Exposure: chronic exposure, sole diet for 6-9 months
Clinical Signs: "Guajillo Wobbles" (Limber leg), progresses to paralysis; most animals die from starvation/dehydration due to inability to move; no gross lesions
TX: move animals, supplement ration; most animals completely recover
DDX: Coyotillo, Truaryl phosphate, Caltrops
Animals Affected: sheep, goats - after a prolonged drought
Triaryl Phosphate
Tri-O-Cresyl Phosphate
Toxic agent: organophosphate
MOA/Exposure: used in lubricants, oil fields and feed mills; chronic exposure; anit-esterase (does not inhibit AChE); biotransformation-> neurotoxic esterase (more toxic than parent compound); toxic to myelin
Clinical Signs: rough hair coat, weakness (muscular atrophy), bloat, dyspnea (loud), posterior paralysis, classical delayed neuropathy (demyelination)
TX: no recovery
DDX: Coyotillo, Guajillo, Haloxon (anti-helmenthic), Sorghum cystitis in horses
Animals Affected: all, young chicks most susceptible
Indian Tobacco, Cardinal Flower
Toxic agent: N-methyl piperidine (alkaloid)
MOA/Exposure: problem for weekend ranchers between Houston and Corpus Christi; usually springtime only; hard to digest so may see clinical signs long after exposure
Clinical Signs: very very sleepy cow; diarrhea, anorexia, mydriasis, hypersalivation, nasal discharge, ulcers between upper lip and dental pad; may present as downer cow
TX: CNS stimulants not effective; hand feed and water, protect animal
DDX: vesicular diseases, milk fever, nutritional disease
Animals Affected: cattle, goats, sheep, not yet reported in wild ruminants
Toxic agent: Vasicine, harmaline, harmine, harmalol - alkaloids
MOA/Exposure: in the desert, near roadsides, overgrazed pastures; requires soil sterilization to get rid of it
Clinical Signs: fetlock kuncking, acute death, chronic poor doer - nonspecific neurological condition
TX: eliminate access to plants, supply feed and water
Animals Affected: cattle, sheep, guinea pigs, horses, humans (hallucinogenic)
Toxic agent: Thiaminase (equine); Aconitic acid (bovine), Palustrine alkaloid (bovine)
MOA/Exposure: chronic exposure
Clinical Signs:
-Horses: biochemical lesions similar to braken fern; decreased Thiamine, increased pyruvate
-Cattle: lose condition and decrease milk production
TX: Thiamine
Animals Affected: horses, cattle
Solanum dimidiatum
Potato Weed, Thread salve
Toxic agent: unknown
-Indolizidine alkaloid (?)-> inhibits lysosomal hydrolase -> lysosomal storage disease
MOA/Exposure: cows may eat berries after a frost
Clinical Signs: "crazy cow syndrome" - recurrent seizures, head/limb extension, opisthotonos, nystagmus, falling; don't usually die barring trauma; microscopic lesions only - degeneration of Purkinje cells in cerebellum with inclusion bodies and torpedo shaped axons
Animals Affected: cattle
Mountain Laurel, Mescalbean, Silky Sophora
Toxic agent: Cytisine - quinolizidine alkaloid
-Highest concentration in seeds, but also in leaves/stems
MOA/Exposure: Animals only get sick if they crush the seeds during mastication
Clinical Signs: exercise induces signs - stiffening of limbs with muscle tremors and falling over, animal becomes somnolent and/or comatose; cattle die, sheep recover; no gross lesions
TX: none, keep animal quiet
Animals Affected: cattle, sheep, goats, humans, zebras
Neurologic and Renal
Toxic agent: Glycosides, beta-cyano-L-alanine (cyanide)
MOA/Exposure: outbreaks usually in April to July; mature cattle (>3 years old), mortality 50%, chronic exposure (6 weeks of grazing contaminated pasture)
Clinical Signs:
-V. sativa in poultry: convulsions, blindness, chirping, death
-V. sativa in cattle: ADR, death
-V. vilosa in cattle: 3 syndromes
1. nervous derangement, bellowing, sexual excitement, locomotor difficulty, convulsions, death
2. SQ swellings of head, neck, body, herpes like eruptions in oral mucous membranes, respiratory signs, alopecia, anorexia, weakness, and death after 12-15 days of illness
3. Most Important! dermatitis, roughened coat with popular swellings, exudate, skin ulceration, pruritus, thickened skin, ocular lesions, ADR body signs
-V. leavenworthii in cattle: granulomatous reaction, dermatitis
DDX: cutaneous arthropod infestation, allergic uticarias, cutaneous mycoses, photosensitization, chlorinated naphthalene poisoning, pox virus, rabies
Animals Affected:
Toxic agent: Zagacine - steroidal alkaloid
-0.5-6% body weight toxic, all plant parts toxic
MOA/Exposure: early spring in grasslands and woodlands
Clinical Signs: excess salivation, frothy nasal/oral discharge, vomiting may follow ataxia, weakness, trembling, dyspnea, hyperesthesia, prostration, cardiac depression, coma precedes death; no gross lesions, congested kidney, lungs
TX: TLC, treat for hypotension; atropine and CNS stimulants have been recommended (?), steroidal alkaloids cause hypotension and teratogenesis
Animals Affected: sheep, cattle, horses, chicken; swine susceptible but vomit before intoxicated
Heart and Neurologic
Toxic agent: Cardenolides/ Bufadienolides (cardiac glycosides)
MOA/Exposure: animals graze plants during drought/over-grazing largest problem with hay/ green-chop; similar to ouabain
Clinical signs: decreased CO (decreased heart rate), trembling, staggering, falling, fever, bloat, respiratory depression and death
TX: symptomatic (GI irritation, glycoside intoxication, CNS signs)
Animals effected: grazing animals
Desert Balieya
Toxic agent: unknown (sequiterpene lactone?)
-All parts of plant are toxic, flower usually ingested
MOA/Exposure: actue exposure
Clinical signs: rapid, pounding heart, audible without stethoscope, widespread hemorrhage of viscera, pneumonia, ascites
TX: none
Animals effected: sheep
Jimson weed, Thornapple, Moon trumpet, Angel trumpet
Heart and Neurologic
Toxic agent: tropane alkaloids (Belladonna alkaloids; atropine and scopolamine)
MOA/Exposure: found in fertile disturbed sites (barnyards, pens, creek bottoms)
Clinical signs: tachycardia, incoordination, paralysis, restlessness, muscular twitching, death from respiratory paralysis (no gross lesions)
TX: Physostigmine (naturally occurring carbamate, uncharged cholinergic
Animals effected: all, humans most frequently
-"red as a beet, dry as a bone, mad as an old wet hen"- hyperthermia
Toxic agent: Bufadienolides (cardiac glycosides)
MOA/Exposure: indoor ornamental (primarily an issue with dogs)
Clinical signs: cardiac and neurological signs
TX: symptomatic (GI irritation, cardiac glycoside toxicity)
Animals effected: primarily a problem in dogs