Poisonous Plants - Exam 2 Part 1 Flashcards
Red Rooted Pig Weed (Amaranthus retroflexus) toxin?
nitrates (NO3)
Kochia Weed (scoparia) toxin?
nitrates (NO3)
Lambs Quarter (Chenopodium spp.) toxin?
nitrates (NO3)
Sudan Grass (Sorgum vulgare) toxin?
nitrates (NO3)
Sunflower (Helianthus annus) toxin?
nitrates (NO3)
Russian thistle (Salsola kali) toxin?
nitrates (NO3)
nitrates (NO3) toxicity MOA:
MOA: Plant Nitrate (NO3) in rumen → Nitrite (NO2) which reacts with Hb → Methemoglobin
What are clinical signs for nitrate poisoning?
drowsiness, weakness, tremors, staggering gait, tachypnea, tachycardia, brown mucosa (muddy mm) (20% methemoglobin), hypoxic death (80% methemoglobin)
What are dangerous levels of nitrate in feed?
forage >1% NO3 dry matter toxic
>0.2% NO3 abortion risk
What is the treatment for nitrate poisoning?
Methylene Blue (reduces methemoglobin so Hb can bind O2 and restore body w/ O2)
what enhances nitrate toxicity that you should not supplement your animals with
monensin
Sorghum Hybrids - Johnson Grass (Sorghum halepense) toxin?
cyanide (prussic acid)
Choke Cherry (Prunus virginiana) toxin?
cyanide (prussic acid)
Service berry (Amelanchier alnifolia) toxin?
cyanide (prussic acid)
Elderberry (Sambuccus canadensis) toxin?
cyanide (prussic acid)
Mountain mahogony (Cercocarpus montanus) toxin?
cyanide (prussic acid)
Arrow Grass (Triglochin maritima) toxin?
cyanide (prussic acid)
Poison Suckleya (Suckleya suckleyana) toxin?
cyanide (prussic acid)
Blue Flax (Linum lewisii) toxin?
cyanide (prussic acid)
Bermuda Grass Hybrid (Tifton 85) toxin?
cyanide (prussic acid)
Sudan Grass (Sorgum sudanensis) toxin?
species:
MOA:
symptoms:
cyanide (prussic acid)
ruminants & horses
chronic exposure to cyanogenic glycosides
urinary incontinence, hindleg weakness, goiter
cyanide (prussic acid) poisoning MOA:
MOA: Cyanogenic glycosides hydrolyzed → HCN via glucosidases/hydroxynitrile lyase, HCN binds Fe3+ → inhibits cytochrome c oxidase → prevents utilization of O2 → O2 saturation of Hb & cellular anoxia
What plant components contribute to Cyanide poisoning?
Highest toxicity in young rapidly growing plants in cool moist conditions
plant stress (drought, frost, wilting, chewing), water, alkaline pH 6-7 favors conversion
What gastric conditions contribute to Cyanide poisoning?
alkaline pH (acid reduces conversion)
ruminants > simple stomachs
What are clinical signs of cyanide poisoning?
Sudden death 1-2 hours, cherry red venous blood immediately after death, dilated pupils, ataxia, muscle tremors/convulsions, tachycardia, acute resp difficulty
lesions such as pink mm, prolonged clotting, generalized congestion, hemorrhage in the heart/lungs
What is the treatment for cyanide poisoning in livestock?
Sodium Thiosulfate
IV Sodium Nitrite or inhaled Amyl Nitrite
What is the treatment for cyanide poisoning in dogs?
Hydroxocobalamin (vitamin B12a) IV
Larkspur MOA
Methyllycaconitine (dominant MSAL-type) blocks nAChR at the NMJ
Larkspur clinical signs
sudden death 3-4 hours, muscular weakness, staggering gait, tachycardia, sternal then lateral recumbency, death from neuromuscular paralysis and/or bloat
Larkspur treatment:
treatment:
- minimize stress, place head/chest uphill, stomach tube or trochar for bloat
- Neostigmine (AChE inhibitor)
larkspur grazing management
less sensitive animals in high risk areas
mineral salt supplements
Water Hemlock (Cicuta maculata) toxin?
toxin: Cicutoxin
water hemlock MOA
noncompetitive inhibitor of GABA
water hemlock clinical signs
convulsions, seizures, respiratory failure, sudden death 2-3 hours, violent chewing/tongue biting, bloat, mydriasis
water hemlock treatment
unlikely –
pentobarbital experimented in sheep
benzodiazepines or barbiturates in humans
Death Camas (Zigadenus venenosus) toxin & MOA:
toxin: cevanine steroidal alkaloid -
Zygadenine
MOA: alkaloids with hypotensive properties depolarize Na+ channels causing them to remain open resulting in hypotension and cardiovascular collapse → dilate arterioles, constrict veins, irregular heart rate
death camas clinical signs
salivation, nausea, vomiting, urination/defecation, muscular weakness/staggering, convulsions, coma, death
Yew toxin & clinical signs
Taxin A, B & Taxane
sudden death, muscle trembling, difficulty breathing, bradycardia, arrhythmias, vomit, diarrhea, convulsions
milkweed MOA
Na/K ATPase inhibitor resulting in initial increase in cardiac contractility but increase vagal stimulation to slow heart rate
foxglove MOA
Na/K ATPase inhibitor resulting in initial increase in cardiac contractility but increase vagal stimulation to slow heart rate
milkweed clinical signs
Sudden death, cardiac arrhythmias, abdominal pain, diarrhea, rapid breathing, cold extremities, rapid/week irregular pulse
5 major treatment options for cardiac glycosides
- emesis
- activated charcoal + cathartic
- monitor serum K+
- IV fluids
- anti-arrhythmic drugs (KCl, procainamide, lidocaine, atropine, K2EDTA)
Lectins MOA
plant glycoproteins that bind to cell surface carbohydrates to facilitate entry into the cells and inhibit ribosomal protein synthesis
Lectin toxicity clinical signs
1-2 day lag period
initially pyrexia, depression, anorexia, colic
progresses to vomit, weakness, hemorrhagic diarrhea
3 plants associated with lectin toxicity
castor beans
rosemary pea
black locust
Castor Beans (Ricinus communis) toxin:
Lectins - Ricin, Ricinine, Ricinoleic Acid
Rosary Pea (Abrus precatorius) toxin?
Lectins - Abrin
Black Locust (Robinia pseudoacacia) toxin?
Lectins - Robinin
Treatment for Lectin toxicity
removal of beans from GI via emesis or laxatives
activated charcoal
fluids, electrolytes
vitamin C
Lily of the Valley (Convallaria majalis)
toxin:
toxin: Cardiac Glycoside - Convallerin & Convallamarin
Avocado (Persea Americana) toxin
toxin: Cardiac Glycoside- Persin
Oleander (Nerium oleander)
toxin:
toxin: Cardiac Glycoside - Oleandrin & Neriin
Yellow Oleander (Thevetia peruviana)
toxin:
toxin: Cardiac Glycoside - Thevitin, concentrated in fruit
Azalea/Rhododendron (Rhododendron spp.) toxin:
cardiotoxin - toxin: Grayanotoxins
- can accumulate in honey from bees
MOA for grayanotoxins found in rhododendrons and azaleas?
inhibit voltage gated Na+ channels
