LA toxicity

Question 1

Toxins affecting the heart and skeletal muscle

Answer 1

• Gossypol
• Ionophores
• Nerium spp. ( oleander)
• Thevetia spp. ( yellow oleander)
• Digitalis spp. ( Foxglove)
• Apocynum spp. ( dogbane)
• Asclepias spp (milkweed)
• Rhododendron
• azalea
• laurel
• Taxus spp (Yew)
• Zigadernus ( death Camas)
• Veratum spp ( false hellebore)
• white snakeroot

Question 2

Toxins affecting the kidneys

Answer 2

• Vitamin D3 (Cholecalciferol)
• Vitamin D2 (ergocalciferol)
• Ethylene glycol / propylene glycol
• Halogeton glomeraturs (halogeton)
• Rhubarb
• Rumex spp ( dock, sorrel, indian tobacco)
• Oxalis
• Quercus spa ( oak)
• Amaranthus spp (pigweed)

Question 3

Pulmonary toxins

Answer 3

• Perilla mint
• Moldy sweet potatoes ( 4-IP )
• Brassica plants
  (rape, kale, turnips)- 3MI

Question 4

Hepatic Toxins

Answer 4

• Pyrrolizidine alkaloids

- Alfatoxin

Question 5

GI Toxins

Answer 5

• Slaframine
• Oak leaves and acorns
• Cantharidin
• Claviceps purpura (ergotism)–> found on rye, oats, wheat, and Kentucky bluegrass

Question 6

Neuro Toxins

Answer 6

• Blue green algae
• Nightshade
• Water hemlock
• Perennial ryegrass
• Lead poisoning
• Sorghum
• Yellow star thistle ( doesn’t effect small ruminants; effects horses)

Question 7

Reproductive Toxins

Answer 7

• False hellbore
• Locoweeds
  (Astragalus, Oxytropis, Swainsona)
• Fescue
  (Neotyphodium coenophialum)
• Lupine (crooked calf disease)
• Ponderosa pine needles

Question 8

Coagulopathy

Answer 8

• Bracken fern
• Cyanide (hgb unable to release O2/ don’t give supplemental oxygen)
• Carbon monoxide (impairs oxygen transport/ give supplemental oxygen) :CHERRY RED MM
• Nitrates (BROWN blood)
• Moldy sweet clover (vitamin k antagonist )
• Anthrax

Question 9

Cardiac Toxins

Answer 9

• milkweed
• gossypol
• oleander
• rhododendron
• foxglove
• white snakeroot
• ** –> all can cause acute death/ arrhythmias
• ionophore (myocardial necrosis and DCM)

Question 10

Zealalenone

Answer 10

(pigs)
- potent estrogenic metabolite produced by fusarium 
- CS: 
Hyperestrogenism
Pseudopregnancy

Question 11

Salt poisoning

Answer 11

CS - neuro ( head pressing, stargazing, blindness, seizures); hemolysis; cerebral edema with fast rehydration

** PERIVASCULAR INFILTRATION OF EOSINOPHILS **

Question 12

Grass tetany/staggers

Answer 12

Cause 1: Phalaris ( canary grasses - phalaris, lolium, cynodon, paspalum)

• stiff-legged gait, hyper excitability, nystagmus, head tremors, fall and flail wildly
• Remove them from the pasture and they should recover

Cause 2:
Hypomagnesium
- Mg= important for nervous system function and enzyme reactions
- occur in lactating animals in early springs on lush pastures that are well fertilized with nitrogen and potassium–> high levels of these inhibit magnesium absorption from the GIT

CS - restless, staggers, over-alert, excitable, fall down with convulsions, die

Question 13

Moldy RED clover

Answer 13

toxin = Slaframine

• hyper salivation
• slobbers

Question 14

Oak leaves and acorns

Answer 14

• hemorrhagic diarrhea
• abdominal pain
• tenesmus
• colic
• death
  ( Cattle - Renal damage) –> not in horses

Question 15

Cantharidin

Answer 15

source: blister beetle

• COLICKING (horse)
• cardiovascular shock
• endotoxic shock
• renal failure
• vesicles in mouth or tongue (watery diarrhea, neuro signs if live long enough )
• renal tubular damage (+/- hematuria), cardiac arrhythmias
• abrupt onset of colic, fever, hyper salivation, frequent urination, hematuria

Question 16

Ergotism (parasitic fungus)

Answer 16

Claviceps purpura
- found on rye, oats, wheat, and Kentucky bluegrass

• alkaloids causes vascular constriction, thrombosis, gangrene, vomiting, colic, diarrhea, constipation
• Find ergot in the grain

Question 17

Blue green algae

Answer 17

Source:
( Anabaena, microcystis, Aphanizomenon)

• Toxin absorbed through MM, causes post-synaptic depolarizing block
• Dead animals next to a pond (birds and cattle)
• CS: miosis, ptyalism, bradycardia, diarrhea, ataxia, convulsions, death, can die within minutes
• • 2 kinds:
    
    • nicotinic agonists - mimics the mechanism of acetylcholine
    • Acetylcholinesterase inhibitor

Question 18

Nightshade

Answer 18

(atropine)

• CNS signs - dilated pupils, progressive paralysis, depression

Question 19

Water hemlock

leaves- very toxic

Answer 19

• grand mal seizures
• salivation
• tachypnea
• birth defects similar to LUPINE
• death
• rapid onset and progression
• toxin = resinoids
• small fatal dose

Question 20

Perennial ryegrass

Answer 20

ataxia and tremors as result of activating GABA receptors when infected with an endophytic fungus

Question 21

Sorghum

Answer 21

• myelomalacia = softening of the spinal cord

- Lesion = myelomalacia of lower spinal cord - pelvic limb incoordination, urine dribbling - DEATH

Question 22

Yellow star thistle

Cenaurea solstitialis

Answer 22

** Lesion = Nicropallidal encephalomalacia - loss of globus pallid us and substantia nigra **

• loss of prehension ( dystonia of lip muscles and tongue )
• tremoring, dysphagia,
• • GRAVE prognosis
• euthanasia - will die of dehydration or starvation

Question 23

False hellbore

veratrum californicum

Answer 23

Teratogen called cyclopamine – cyclopia, anophthalmos, cleft palate, metacarpal
hypoplasia

• Day 14 (gestation) - craniofacial deformities

• Day 30 (gestation) -
limb and bone shortening in MC/MT joints

Question 24

Locoweeds

Astragalus, Oxytropis, Swainsona

Answer 24

• abortions, weak lambs, bent legs

▪ Inhibit alpha-mannosidases – widespread neurovisceral cytoplasmic vacuolation –
and abortion and neuro system abnormalities (i.e. ataxia)

▪ Grow in WEST with other forages are scarce – see in dry condition in Rocky
Mountains

Question 25

Fescue

Answer 25

toxin = Neotyphodium coenophialum (ergopeptine alkaloids – dopamine agonists) ▪ Prolactin suppression – inhibit lactation, thickened placenta, dystocia, agalactia, prolonged gestation, weak or stillborn foals = REPRO FAILURE IN MARES - Reproductive inefficiency, does not cause congenital defects ▪ Clinical signs = lameness, sloughing of rear hooves, decreased weight gain, fat necrosis

Question 26

Lupine

Answer 26

"crooked calf disease" - arthrogryposis - malpositioning in the uterus - cleft palate (adults) : - inappetence, dyspnea, convulsions, death from respiratory paralysis

Question 27

Ponderosa pine needles

Answer 27

- edema of vulva and udder, bloody mucoid vaginal discharge seen just prior to abortion - abortions in LAST trimester - retained placenta common after aborting --> calves that survive = weak and cows don't produce enough colostrum or milk

Question 28

Coffee Senna

Answer 28

- ** decreased muscle tone , weakness, slow gait that progresses to sternal recumbency within a few days ** - remain BAR, eat, drink - Myoglobinuria - coffee-colored urine

Question 29

Pyrrolizidine Alkaloids

Answer 29

- hepatic fibrosis, megalocytosis, biliary hyperplasia - fibrosis = irreversible and once clinical, patient is SOL --> poor prognosis * senecio (tansy ragwort) * Amsinckia ( fiddle neck ) * Heliotropium * Crotolaria (rattle box)

Question 30

Chronic fluorosis

Answer 30

CS: - enamel hypoplasia , decrease in food intake, stunted growth in calves - can cause osteomalacia, osteoporosis, and exostoses in long bones Causes/ sources: - pasture near industrial sites, water from deep wells, phosphorus supplements with fluorine ** Oxytet administration in young animals and pregnant dams ---> can lead to enamel hypoplasia as well

Question 31

``` Acer rubrum ( red maple) ( wilted, dry leaves contain toxin ) ```

Answer 31

- acute Intravascular hemolytic anemia - hemoglobinemia, methemoglobinemia, Heinz bodies, and eccentrocytes CS - weak, depression, tachypnea, tachycardia, icterus, cyanosis, brown blood and brown urine ** fatal --> if horse survives hemolysis, renal failure with develop due to pigmenturia Tx - supportive care

Question 32

Who is more sensitive to Cyanide poisoning ( ruminants or monogastrics)

Answer 32

ruminants ( cattle > horses )