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Toxicology Fall17 > Toxic Principles in Plants > Flashcards

Toxic Principles in Plants Flashcards

1
Q

What toxins do many common household plants that are green all year long have?

A

Insoluble calcium oxalates

Ex: Calla lily, Arum lily (Zantedeschia oethiopica), Chinese evergreen, Umbrella tree, Fishtail palm, Jack-in-the-pulpit..

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2
Q

What is the MOA of insoluble calcium oxalate containing plants?

A

PATIENT MUST CHEW THE PLANT TO RELEASE TOXIC CRYSTALS

crystals will mainly have a local effect of irritation to the oral mucosa, tongue, and throat
*some species of plants produce proteolytic enzymes which cause the release of histamine/kinins byt the body that will increase mechanical damage

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3
Q

What is the MOA of plants with soluble oxalates?

A

Conversion to insoluble Ca oxalate in the bloodstream –> hypocalcemia and precipitation of crystals in soft tissue and kidney damage

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4
Q

What are some examples of plants containing soluble Oxalates?

A 
Halogeton (haloenton spp)
Greasewood (sarcobatus vermiculatus)
***Pigweed (Amaranthus retrofleus)
Beet (beta vulgaris)
Lamb's quarters (Chenopodium album)
Rhubarb (Rheum rhaponiticum)
Sorrel and soursop (oxalis spp)
Purslane (Portulacca oleracea)
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5
Q

What is the MOA of toxicity of plants containing ISOCUPRESSIC ACID?

A

vasoconstriction and decrease uterine blood flow – stimulates the release of fetal cortisol and abortion (in cattle)

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6
Q

What parts of the insoluble Ca.Oxalate containing plants are toxic?

A

All parts of the plant are toxic – but the patient MUST CHEW the plant to release crystals

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7
Q

What are plants that contain Isocupressic acid?

A

**Ponderosa pine (pinus ponderosa)- ingestion of the needles

Monterey cypress (Cupressus macrocarpa)

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8
Q

What plants contain Quinones?

A

St. Johns wart (hypericum perforatum) & St. Johns family (Clusiaceae
Buckwheat (Fagopyrum esculentum) & Buckwheat family (Polyogonaceae)

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9
Q

What is the MOA of toxicity of plants containing Quinones?

A

Primary photosensitization

***The photodynamic substance comes directly from the plant

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10
Q

Is the MOA of St. Johns wart photosensitization primary or secondary?

A

Primary - photodynamic substance comes directly from the plant

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11
Q

Where do photosensitivity reactions occur in animals that have ingested large amounts of Quinone containing plants? What plant species may this be?

A

St. Johns wart and Buckwheat

Photosensitivity reactions occur only in the areas of light-unpigmented skin

clinical signs: puritis, erythema, edema, and necrosis of the skin –> secondary bacterial infections

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12
Q

What are some plants that contain Tannic acid or tannins?

A 
Oak tree (Quercus spp)
Pride of barbados, poinciana, bird of paradise (Caesalpina spps)
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13
Q

What is the MOA of tannic acid containing plants?

A

Causes a precipitation of proteins causing cellular damage all over the body (astringent effect)

Tissue damage: GI lesions and Kidney damage (ruminants)
Mainly GI lesions in monogastric animals

*can cause hemorrhage

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14
Q

What part of the tannic acid containing plants are toxic?

A

All parts - including acorns

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15
Q

What toxin does Lantana (lantana camara) - an always blooming house plant with multi colored flowers contain?

A

Triterpene acids

Also the Vervain family of plants (Verbenaceae)

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16
Q

What is the MOA of Triterpene acid containing plants?

A

**hepaticencephalopathy

Liver damage and hepatogenic photosensitization

Lantana A and B cause damage of the bile canaliculi membranes and cholestasis; decreased elimination of phylloerythrin (which causes photosensitization)

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17
Q

Photosensitization from the ingestion of Lantana is primary or secondary?

A

Lantana = Triterpene acids

Secondary photosens. since this is due to the liver damage causing an accumulation of phylloerythrin (photodynamic substance)

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18
Q

T/F: Alkaloids are weak bases that are insoluble in water

A

TRUE

they are soluble only in organic solvents

Ex of alkaloid drugs: atropine and nicotine

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19
Q

What category of toxic plants does the group Colchicine fall under?

A

Alkaloids

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20
Q

What is the MOA of Colchicine alkaloids?

A

Antimitotic by binding tubulin and inhibiting spindle formation during cell division - rapidly dividing cells are the most sensitive

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21
Q

What organ systems are affected by colchicine toxicosis?

A

Pretty much everything - the focus is rapidly dividing cells

  • GI - vomiting, dhr, hemorrhage etc
  • CV: hypotension and arrhythmias
  • Resp
  • renal and hepatic failure
  • Neuro signs/Sz
  • Coagulopathies and Bone marrow supression
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22
Q

What are examples of Colchicine containing plants?

A 
Autumn crocus, Meadow saffron (Colchicum autmnale)
Lily family (Liliaceae) - Glory liliy, climbing lily (Gloriosa superba)
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23
Q

What type of alkaloid poisoning has a similar MOA as Curare, and will cause sudden death in Cattle due to paralysis of respiratory muscles?

A

Diterpene alkaloids

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24
Q

What is the MOA of Diterpene alkaloids?

A

Competitive blockage of the nicotinic receptors at the muscle endplate - similar to curare

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25
Q

What is the antidote to Diterpene alkaloids?

A

Physostigmine (reversible cholinesterase inhibitor) OR neostigmine

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26
Q

What plants are Diterpene alkaloids?

A

*Buttercup family (Ranunculaceae)
Larkspur, Delphinium (Delphinium spp)
Monkshood, Anconite (Anconitum spp) – also has cardiotoxic effect (arrhythmias)

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27
Q

What is the MOA of Ergot alkaloids?

A

Fungus that contaminates many plants: Ergot (Claviceps purpurea)

Causes vasoconstriction and gangrene - chronic loss of hair and deteriorating hooves
Uterine contraction (usually chronic) - abortions

Acute vasoconstriction can cause CNS signs

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28
Q

What three toxins does Locoweed, milkvetches (Astragalus spp and Oxytropis sps) contain?

A
  1. Selenium accumulation
  2. Indonilizidine alkaloids (Swainsonine)
  3. Niropropanol
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29
Q

What plants contain Indolizidine alkaloids?

A

Locoweeds, milkvetches (Astragalus spps and Oxytripis spps) — but not all are toxic and many can be used as forages

Swainsona canescens contains Indolizidine alkaloids aka swainsonine - plant from Australia

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30
Q

What is the MOA of Indolizidine alkaloids?

A

Inhibit lysosomal enzymes essential for glycoprotein formation

Locoweeds - contain a neurotoxin: Alteration of cellular function in the brain and other organ systems: endocrine, repro, heart, immune system

Contain nitropropanol glycoside: causes peripheral neuronal degeneration and respiratory signs

selenium accumulation: hoof and hair abnormalities

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31
Q

What is are the major organ system(s) affected by Lycorine toxicosis?

A

GI - emetic and purgative

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32
Q

What plants contain lycorine?

A

Amaryllis family (Amaryllidaceae)
Narcissus (Narcissus spp)
Kaffir lily, Caffir Lily (Clivia spps)
Spider lily (Hymenocallis caribaea)
Barbados lily, fire lily (Hippeastrum spp)
Zephyr lily, rain lily (Zephyranthes spp)
River lily (Crinum bulbispermum)

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33
Q

What is the MOA of toxicosis due to ingestion of spider lily and barbados lily?

A

emetic and purgative properties

will note: salivation, nausea, vomiting, dhr. hypotension

***large amounts may cause muscle tremors and SZ

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34
Q

What part of Lycorine containing plants is the most toxic?

A

The bulb - underground root

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35
Q

What plants will contain Muscarine and what is the MOA/Clinical signs associated with ingestion?

A

Poisonous mushrooms - Amanita muscaria

MOA: stimulation of muscarinic cholinergic receptors –> CNS stimulation

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36
Q

Piperidine alkaloids can be found in what plants?

A

Poison hemlock, spotted hemlock, California/Nebraska fern (Conium maculatum) - toxin: coniine
Lupines (lupinus spp) - toxin: ammodendrine
Tobacco (Nicotiana tobaccum)
tree tobacco (Nicotiana glauca)
cyote tobacco (Nicotiana attenuata) - tobacco toxin: anabasine

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37
Q

What is the MOA of piperidine alkaloid toxicosis?

A

Nicotinic effects - glanglionic and neuromuscular stimulation followed by ganglionic and neuromuscular blockade

Ataxia, incoordination

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38
Q

T/F: Piperdine alkaloids can cause fetal birth defects when ingested by a gestating female

A

TRUE

these will cross the placental barrier and prevent fetal movement - resulting in birth defects - skeletal malformation and cleft palate

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39
Q

What plants have Pyridine alkaloids (aka nicotine and lobeline)?

A 
Nightshade family (Solanaceae)
Tobacco plant (Nicotiana tabacum)
Tree tobacco (Nicotiana glauca)
Lobelia (Lobelia spp)
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40
Q

What is the MOA of pyridine alkaloids?

A

Act on nicotinic receptors at autonomic ganglia, neuromuscular junctions, and some CNS synapses

Low doses cause depolarization
Large doses cause blockage

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41
Q

What is the onset of signs due to pyridine alkaloids like nightshade plants and lobelia? what is the time frame of onset?

A

Rapid onset of clinical signs

Early: excitation, salivation, lacrimation, vomiting, diarrhea, and tachypnea
Muscle twitching, weakneass, dyspnea
*death is due to respiratory failure

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42
Q

What alkaloid has similar clinical signs/MOA as those seen in pyridine alkaloid toxicosis?

A

Piperidine alkaloids

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43
Q

What is the MOA of pyrrolizidine alkaloids?

A

Hepatotoxicity

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44
Q

What plants are pyrrolizidine alkaloids?

A

Rattlebox or crotolaria (Crotolaria spp)
Senecio, groundsel, and ragwort (Senecio spp)
Heliotrope (Heiliotrpium) - this is an ornamental plant

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45
Q

Potato, eggplant, and tomato all can contain what type of alkaloid?

A

Solanine and solanidine

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46
Q

What plants have solanine and solanidine alkaloids?

A 
nightshade family (Solanaceae)
Black nightshade (Solanaceae niger)
American nightshade (Solanaceae americanum)
Eggplant (solanum melongena)
Tomato (lycopersicon lycopersicon)
Turkey berry (Solanum torvum)
Chalice vine (Solandra guttota)
Chinese lantern (Physalis spp)
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47
Q

What is the MOA of Solanine and solanidine alkaloids?

A

*Irritating - causes severe GI signs

affects the CNS, Resp., and CV as well

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48
Q

Taxine alkaloids have similar MOA and CS as what kind of glycosides?

A

Cardiac glycosides

MOA - Cardiotoxic + GI signs

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49
Q

What plant contains taxine alkaloids?

A

Japanese yew (Taxus sp)

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50
Q

What plants are tropine alkaloids?

A

Jimsonweed, thronapple or angels trumpet (Datura stramonium)
Devils trumpet (Datura metel)
Angel’s trumpet (Brugmansia candida)
Henbane (hyoscyamus spp)

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51
Q

What is the MOA of tropine alkaloids?

A

Anticholinergic effect (atropine, hyoscine, hyoscyamine)

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52
Q

What is the MOA of xanthine alkaloids?

A 
Blocking adenosine (A) receptors  -- releases Nor EPI = excitatory rxn
Inhibiting phosphodiesterase - increase intracellular Ca and release catecholamines
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53
Q

What are examples of xanthine alkaloids?

A

(Caffeine, theophylline, theobromine)

Plants:
Cocoa - Theobroma cocao
Coffee - Coffea arabica

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54
Q

What is the most commong xanthine alkaloid toxicosis we see in vet med?

A

Chocolate toxicosis in dogs

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55
Q

What clinical signs are associated with xanthine alkaloid toxicosis?

A 
Salivation, vomiting, dhr, colic
CNS stimulation and sz
Muscle tremors
Tachycardia and hypotension
Urination
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56
Q

What is the MOA of Anthraquinone glycosides?

A

Purgatives

Coffee weed also have an unknown toxin that causes skeletal and cardiac muscle degeneration and the urine may be coffee colored due to myoglobinuria –> kidney damage

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57
Q

What do horses with coffee weed poisoning most often die from?

A

Anthraquinone glycoside: Coffee weed (senna occidentalis)

Horses usually die from liver failure and NOT muscle degeneration like other spps

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58
Q

What plants are anthraquinone glycosides?

A

Cascara sagrada from the tree Rhamnus purshiana DC
Buckthorn (Rhamnus sp)
Coffee weed, senna (Senna occidentalis)

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59
Q

What glycosides will have a smililar MOA to Cholecalciferol rodenticide?

A

Calcinogenic glycosides (vitamin D analog)

MOA: hypercalcemia - calcification of the elastic tissues of the arteries, tendons, and ligaments, as well as increased density of the bones –> causing lameness

60
Q

What plants are vitamin D analogs?

A

Calcinogenic glycosides

Day-blooming Jessamine (Cestrum diurnum)
Turkey berry (Solanum torvum) - also Solanine/solanidine alkaloid (GI irritation)
61
Q

Cocklebur (Xanthium strumarium) is what type of glycoside?

What is the MOA of toxicosis?

A

Carboxyatractyloside (sulfated glycoside)

Heptotoxicity = primary target
Excessive salivation from mechanical injury
May be renal damage and hypoglycemia

62
Q

What is the MOA of cardiac glycosides?

A

Cardiotoxic by inhibiting the Na/K ATPase pump

and GI irritation

63
Q

What plants are cardiac glycosides?

A 
Foxglove (Digitalis purpurea)
Oleander (Nerium oleander)
Yellow oldeander, Lucky nut, Be-still tree (Thevetia peruviana)
Periwinkle (Catharanthus roseus)
Desert Rose (Adenium obesum)
Frangipani (plumeria sp)
Bridal bouquet (plumeria sp)
Squill (Ureginea maritima)
Lily-of-the-valley (Convallaria majalis)
Christmas Kallanchoe (Kallanchoe sp)
64
Q

What plant is a coumarin glycoside and what is the MOA?

A

Sweet clover (Melilotus officinalis)

Form dicoumarol in spoiled plants

Hemorrhage due to antagonism of Vitamin K by inhibiting Vitamin K epoxide reductase resulting in a deficiency of coag factors II, VII, IX, X

65
Q

When are cyanogenic plants toxic?

A

When they are damaged - frosted or stunted

Release HCN on hydrolysis in damaged plants

66
Q

What are come cyanogenic plants?

A 
Wild cherries (Prunus spp)
Johnsongrass, sudan grass, and sorghum 
Elder berry (Sambucus canadensis)
67
Q

What is the MOA of chronic poisoning with wild cherries?

A

Cyanogenic glycosides - Chronic poisoning = neuronal degeneration

68
Q

What is the MOA of acute poisoning with Johnsongrass or sorghum?

A

Cyanogenic glycosides

Inhibition of cytochrome oxidase and inhibition of cellular respirtation
*vasoconstriction
*inhibition of glycolysis –> lactic acidosis
Inhibition of TCA
Irritation of the MM

69
Q

Where are you most likely to find plants with Cycasin?

A

In warm weather - Palm spps

Cycad family - Cycadaceae: Sago palm (cycas cirinalis), Japanese cycad (Cycas revoluta)

Zamiacea: Cardboard plam (Zamia furfuraceae), Coontie (Zamia pumila)

70
Q

What is the MOA of toxicosis of Sago palms?

A

3 toxins:

  1. Cycasin: GI irritation and liver damage - teratogenic and carcinogenic
  2. Beta Methylamino-L-alanine (BMAA): neurotoxic amino acid
  3. Unknown toxin that may cause axonal degeneration in the CNS
71
Q

What clinical signs are associated with an animal that has ingestiong Cycad palms?

A

dependent on amount and duration of exposure

GI and liver dz syndrome: DOGS: vomiting (may have blood), anorexia, dhr, depression, sometimes sz
OR
Ataxia and CNS syndrome: CATTTLE “Zamia staggers” - ataxia, weakness, wt. loss

Sheep: mainly GI signs and wt loss

72
Q

T/F: The effects of glucosinolate (thiocyanate glycosides) are acute

A

FALSE

Only chronic effects

73
Q

What plants are glucosinolate/thiocyanate glycosides?

A

Rape seed, kale, broccoli, cabbage, brussel sprouts, turnip, cauliflower (Brassica spp)
Soybean (Glycine sp)
Flax (Linum sp)

74
Q

What is the MOA of thiocyanate glycosides?

A

Antithyroid

75
Q

What plants contain nitropropanol glycosides?

A

Milkvetch (Astragalus spp) - legume family (Fabaceae)
Violets (Viola sp)
Lotus (Lotus sp)
Indigo (Indigofera spp)

76
Q

What are the three toxins that can be found in Milkvetch (Astragalus spp)?

A
  1. Selenium
  2. Indolizine alkaloid
  3. Nitropropanol
77
Q

What are three toxins that can be found in Pigweed (Amaranthus sp)?

A
  1. Soluble Oxalate
  2. Nitrates
  3. Unknown toxin that causes renal damage/failure in large animals
78
Q

What is the MOA of nitropropanol glycosides?

A

Inhibits enzymes in the Krebs cycle and cellular oxidative phosphorylation

*CS: respiratory and neuro signs in cattle and sheep (“cracker heels” and “roaring” dz)

79
Q

What is the MOA of phytoestrogens?

A

Bind to estrogen receptors causing infertility in both sexes, decreased libido and feminization in males

80
Q

What plants are phytoestrogens?

A 
White clover (Trifolium repens) - Europe/New Zealand
Subterranean clover (Tifolium subterraneum) - Australia
Alfalfa (Medicago sativa) - USA
81
Q

What is the MOA of plants with Protoanemonin?

A

Severe GI signs*** mm/skin irritation/dermatitis

Protoanemonin is a volatile oil released by hydrolysis of the glycoside

82
Q

What plants have protoanemonin?

A

Buttercup family (Ranunculaceae): Anemone, Ranunculus, Clematis, Helleborus

(other species in the buttercup family have Diterpene alkaloids)

83
Q

What is the toxin in bracken fern or brake fern (Pteridium aquilinum)?

A

Ptaquiloside

84
Q

What is the MOA of Bracken fern toxicosis?

A
  1. Death of precursor cells in the BM - aplastic anemia: Cattle and sheep
  2. Neoplasms in the urinary tract of cattle - enzootic bovine hematuria
  3. Tumors of the Upper GIT and Retinal detachment: sheep
  4. Vitamin B1 deficiency due to thiaminase : NON- ruminants only
85
Q

What plants are steroidal saponins?

A 
Agave family (Agavacese)
lechuguilla agave
agvae americana
Nolina spp - agave family
Panicum spp - agave family
Dracaena spp aka dragon tree
86
Q

What is the MOA of steriodal saponins?

A

Liver damage and the inability to eliminate phylloerythrin –> Secondary photosensitization aka hepatogenic photosensitization

87
Q

What toxicosis comes from ingesting too much cottonseed?

A

Gossypol

Cottonseed (Gossypium spp)

88
Q

What is the MOA of gossypol?

A

only free gossypol is toxic Binds to proteins, aa, iron
Cardiotoxic and secondary hepatic damage
Reduces male fertility
Causes protein malnutrition, inhibits enzymes, interferes with hemoglobin synthesis

89
Q

What will change the toxic free gossypol to the less toxic protein pound gossypol?

A

HEAT

Iron salts will also decrease toxicity by increasing gossypol inactivity and excretion

90
Q

Is gossypol toxicicosis an acute or chronic dz?

91
Q

What animals are most sensitive to gossypol toxicosis?

A

Monogastric animals&raquo_space;> Ruminants

92
Q

What organ systems are involved in chronic molybdenum poisoning?

A

GI, Neuro, musculoskeletal - lameness

causes signs of copper deficiency: *dhr/wasting, depigmentation, demyelination, osteoporosis
Only chronic toxicosis

93
Q

What plants can copper be found in?

A

Clovers

Chronic poisoning in sheep - hemolytic crisis

94
Q

What plants often accumulate selenium?

A 
Aster
Woody aster (Xylorrhiza spp)
Princess's plume (Stanlyea spp)
Milkvetch (Astragalus spp)
Goldenwood (Onopsis spp)
Paintbrush (Castilleja)
Saltbrush (Atriplex spp)
Alfalfa (Medicago sativa)
Tall grasses (sorghum spp)
95
Q

What is the MOA of Selenium toxicosis - acute and chronic?

A

Acute - GI irritation and respiratory signs

Chronic - hoof and hair abnormalities

96
Q

The sunflower (Helianthus annuus) can have what toxin, that in the chronic toxicosis will cause decreased progesterone and abortion during pregnancy?

97
Q

T/F: Nitrates can cause abortion in acute toxicosis

A

TRUE

Also in chronic - but it is by different mechanisms

acute - fetal methemoglobinemia and death
Chronic - decreased progesterone

98
Q

What is the MOA of nitrate toxicosis?

A

Nitate is converted into toxic nitrite –> GI irritation and methemoglobinemia

99
Q

Lectins may also be refferred to as what two names?

A

phytotoxins and toxalbumins

100
Q

Besides thyiocyanate glycosides, what is the toxin found in the Mustard family (Brassicaceae)?

A

Dimethyl disulfide

101
Q

What is the major injury caused by Dimethyl disulfide?

A

Hemolysis

Heinz body anemia

102
Q

Where does Dimethyl disulfide get activated in the body?

A

Hydrolysis by the rumen or intestinal microflora

toxic to both monogastrics and ruminants

103
Q

What is the MOA of Diterpene esters?

A

Direct irritation of the skin and MM

Activate protein kinase C resulting in cell damage and enzyme dysfunction

104
Q

What animals show the most severe signs of Diterpene ester toxicosis?

A

large animals and horses

signs are usually mild in small animals

105
Q

What are some examples of plants with Diterpene esters?

A 
Spurge family (Eurphorbiaceae): Candelabra cactus, Poinsettia, Pencil tree, Crown of thorns
*Croton (Codiaeum variegatum)
Chenille plant, cat tail (Acalypha hispida)
Christmas Candel

**these plants often have a milky sap

106
Q

Grayanotoxins have a MOA that causes what clinical signs?

A

Mainly GI signs, but all systems can be involved

MOA: Bind to Na channels in excitatory cells (nerve, skeletal muscle, heart, CNS): Increase permeability of Na ions and depolarization
Also a GI irritant

CS: salivation, vomiting, colic, dhr, depression, recumbency, tachycardia, sz

107
Q

What is the usual cause of death due to grayanotoxin toxicosis?

A

Aspiration pneumonia

108
Q

What plants have grayaotoxins?

A

Heath family - Ericaceae
Rhododendra, Azalea
Mountain laurel, sheep laurel, sheepkill (Kalmia spp)
Japanese pieris, mountain pieris (Pieris spp)
Dog hobble, dog laurel, black laurel (Leucothoe spp)
Maleberry, fetterbush, staggerbush (Lyonia spp)

109
Q

In order for an animal to get toxicosis from a lectin, what must happen?

A

*in most cases, toxin is in a bean and it must be chewed

If the bean is swallowed whole - no issue

110
Q

What are some examples of phytotoxic plants?

A

Aka Lectins aka toxalbumins

Castor bean (Ricinus communis)
Precatory bean (Abrus precatorius)
Black locust (Robinia pseudocacia)
Beans (soybeans, pinto, kidney, navy) - toxic when eaten raw
111
Q

What is the MOA of toxalbumins?

A

Aka lectins aka phytotoxins

*Ricin and abrin are glycoproteins that inhibit cellular protein synthesis resulting in cell death (GI mucosa, vascular endothelium, liver, cardiac etc)

112
Q

What are the main clinical signs noted in an animal with lectin toxicosis?

A

severe hemorrhagic GI signs

Can also get lung damage when inhaled

113
Q

The Chinaberry (Melia azedarach) is a plant with Meliatoxins, which have 3 main toxins involved in their pathogenicity. What are they?

A
  1. Tetranortriterpens (Cytotoxic limonoid concentrated in fruit)
  2. Alkaloid
  3. Resin
114
Q

What is the MOA of Chinaberry and the mahogany family of plants ?

A

Meliatoxins

Enterotoxic and neurotoxic

GI signs with or without blood
CNS, PNS signs similar to nicotine
Death from respiratory failure

115
Q

What toxin do onion, garlic, shallots, chives, and leek (Allium sp) have that will cause a hemolytic anemia/heinz body anemia when ingested in toxic doses?

A

Propyl disulfide

Amaryllis family

116
Q

What is the MOA of Propyl disulfide and clinical signs associated with toxicosis?

A

Produce oxygen free radicals which cause damage of RBC membranes and hemolysis - denaturing of hemoglobin will also cause heinz bodies

*may note an onion odor

CS: anorexia, ataxia, tachycardia, tachypnea, dyspnea, icterus, and abortion

117
Q

What plants can tetradymol be found in?

A 
Horsebrush (tetradymia spp)
Sunflower family (Asteraceae)
118
Q

What animals are most susceptible to tetradymol found in the horsebrush plant and sunflowers?

A

Sheep

CS- sudden onset of anorexia, depression, incoordination, dyspnea, icterus, head pressing, skin swelling erythema, necrosis, and sloughing

119
Q

What the MOA of tetradymol toxicosis?

A

Liver damage and secondary hepatic photosensitization (due to decreased elimination of Phylloerythrin)

120
Q

What does Thiaminase do?

A

It destroys thiamine in the diet and produces signs of thiamine (vitamin B1) deficiency in monogastric animals

121
Q

How should you treat a horse that has thiaminase toxicosis?

A

Vitamin B1 injection IV

122
Q

What plants have thiaminase?

A

Horsetail (Equisetum hyemale)

Bracken fern, brake fern (Pteridium aquilinum)

123
Q

T/F: Thiaminase activity will cause a thamine (B1) deficiency in ruminants

A

FALSE

only in NON ruminants

124
Q

What is the major sign associated with triterpenoid saponin toxicosis?

A

Severe GI signs - due to direct irritation of the GI mucosa

salivation, anorexia, vomiting, dhr, colic, hypothermia

125
Q

What plants have triterpenoid saponins?

A

Alfalfa (Medicago sativa) — Se, Nitrates as well
Holly family (Aquifoliaceae) - English/christmas holly (Ilex aquifolium), American holly (Ilex opaca)
Ginseng family (Araliaceae)
English/Common Ivy (Hedera helix)
Pokeweed family (Phytolaccacea)

126
Q

What is the physical state of resins at room temperature?

A

Solid, semisolid, or brittle

these are easily melted, insoluble in water, soluble in organic solvents, lack a nitrogen group

127
Q

What plants have resins or resinoids?

A

Milkweeds (Ascelepias spp)
Marijuana (Cannibis sativa)
Chinaberry (Melia azedarach) - Mahogany family (Meliaceae)

128
Q

What is the MOA of resins?

A

Irritation of the nervous or muscle tissue

129
Q

What dz does aslike and red clover cause in horses?

A

Hepatotoxicity and secondary photosensitization

Large amounts - hepatic encephalopathy

130
Q

In what species is avocado (Persea americana) toxic?

A

Caged birds, rabbits, goats, sheep, cattle, horses

131
Q

What is the MOA of toxicosis of avocado in caged birds?

A

Cardiotoxic

Goats, horses, rabbits: Cardiotoxic, non infections mastitis, and agalactica

132
Q

What does black walnut (Juglans nigra) toxicosis cause in horses?

A

Laminitis

Horses will eat the shavings of heartwood (used as bedding)

133
Q

Moldy Alfalfa, red clover, and moldy wheat will all cause _____ in large animals?

A

Photosensitization

In cattle - secondary due to cholestatic liver disease

134
Q

In what species of animal are grapes and raisins toxic?

A

DOGS ONLY

Grapevine (Vitis spp)

135
Q

What is the MOA of grape toxicosis in dogs?

A

Unknown - causes acute renal failure

CS- vomiting followed by signs of acute renal failure

136
Q

Easter Lily (Lilim longiflorum) and Day lily (Hemerocallis spp) are toxic to what animals? What do they cause?

A

Renal failure in cats - super toxic

Toxin is unknown

GI irritation in both dogs and cats

137
Q

What are the MOA of pigweed (Amaranthus spp)?

A

Acute nitrate poisoning - methemoglobinemia
Chronic nitrate - abortion
Soluble oxalates - hypocalcemia and kidney damage
**unknown toxin that causes renal tubular nephrosis in ruminants, pigs, and horses

138
Q

What does red maple poisoning cause in horses? What is important about the leaves?

A

Leaves must be wilted /dried out

unknown toxin causes hemolytic anemia, hemoglobinema, and heinz body formation

*hemoglobin may precipitate in the renal tubules causing renal failure

139
Q

What are the main clinical signs associated with Senna (Coffee - Senna occidentalis and Sicklepod - Senna obtusifolia) toxicosis?

A

Muscle and myocardial myopathy (unknown toxin)

diarrhea (Anthraquinone glycoside is a cathartic)

140
Q

What part of the coffee senna and Sicklepod plant are most toxic?

141
Q

What plants cause ENE (Equine Nigropallidal Encephalomalacia) aka chewing dz in horses?

A 
Yellow starthistle (Centaurea solstitialis)
Russian knapweed (Acroptilon repens)
142
Q

What is the MOA of toxins causing ENE?

A

Equine Nicropallidal Encephalomalacia

Toxins interact with dopamine transporter resulting in death of dopaminergic neurons in the brain especially substantia nigra and globus pallidus

Toxins are unknown: may be - sesquiterpene lactones, aspartic acid, and glutamic acid

143
Q

What animals will have toxicosis if exposed to macadamia nuts?

144
Q

What is the MOA of macadamia nut toxicity? What clinical signs will be noted?

A

Unknown and toxin is unknown

3-6 g/kg = clinical signs within 12 hours:
Weakness in hind limbs, depression, ataxia, tremors, hyperthermia, lameness, vomiting, colic, diarrhea, pale MM

145
Q

What is the prognosis of macadamia nut toxicosis in dogs?

A

Very good

dogs have a full recovery within 2 days

Toxicology Fall17 (38 decks)

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