Integumentary, Cardiovasc., ionophore toxicity

Question 1

With weather conditions like __________ plants will have higher toxicant levels

Answer 1

Drought

Question 2

Ingestion (decomination)

Answer 2

Removal
AC
↑ elimination(cathartic- MgSO4)

Question 3

Dermal and ocular exposure

Answer 3

Bathing and flushing

Question 4

Which plants cause photosensitization?

Answer 4

False Queen Anne’s Lace (insoluble Ca oxalates)
Buckwheat (fogopyrin)
Giant Hogweed (ocular toxicity)
Goatweed (hypericin)
St. John’s wort (hypericin and protohypericin)

Question 5

When primary photosensitization occurs what is the common lesion caused by those plants?

Answer 5

Ulcerative and exudative dermatitis
skin involved only

Question 6

Hypericin

Answer 6

Photodynamic red pigment produced in glands of leaves and flowers (highly absorbable)
Not a problem unless in direct sunlight

Question 7

Pathology of hypericin

Answer 7

Enters brain (stimulant effect on behavior)
Peripheral NS- alters heart, vasc. and intestinal function inhibiting catechol enzyme
↑ hepatoxicity of other agents
Inhibits glutamate release

Question 8

T/F: hypericin can be passed to nursing young via milk

Answer 8

TRUE
could cause mother to abort or abnormalities

Question 9

Early CS of photosensitization

Answer 9

Restlessness, scratching, rubbing against objects, intermittent weakness of hindlimb with knuckling over, peeling/ sloughing of skin

Question 10

Progressive CS of photosensitization

Answer 10

Mild diarrhea, swelling around forehead and eyes, inflamed, hyperthermia and necrotic dermatitis

Question 11

Tx of photosensitization

Answer 11

Remove from source and keep shaded 4-7d
Tx wounds, IV fluids and corticos

Question 12

Prognosis of photosensitization

Answer 12

Poor if the liver involved

Question 13

What plants cause secondary photosensitivity

Answer 13

Ranunculus (buttercup)
Symphytum officinale (comfrey)
Heliotrope spp.
Lantana and Ragwort
liver involvement

Question 14

Contact dermatitis

Answer 14

Direct contact with an irritating agents (clothing material, grooming tool, topical/ environmental insecticides, meds, stall bedding)
Enhanced by moisture

Question 15

CS of contact dermatitis

Answer 15

Pruritus (secondary: rx to itching)
Development of papules and vesicles

Question 16

Plants that cause contact dermatitis

Answer 16

Bleeding heart, daffodil, buttercup, sneezeweed, English ivy, fleabane, mum, wild onion and chamomile

Question 17

Lesion location of contact dermatitis

Answer 17

Girth:
Over the back (saddle/ blanket)
Lower limbs (plants, insecticide/ herbicide)
General body (fly sprays, shampoo)

Question 18

Dx contact dermatitis

Answer 18

Hx, CS, patch testing

Question 19

Tx for contact dermatitis

Answer 19

Remove source (soap and rinse)
Reduce inflamm: corticos

Question 20

Cardiac glycosides

Answer 20

Inhibits Na+/ K+ ATPase in arrythmias that can develop into cardiac arrest and death

Question 21

Which plants contain cardiac glycosides

Answer 21

Rhododendren species: azalea, oleander, yew

Question 22

Azalea

Answer 22

Grayanotoxin and sodium channel activators
Causes acute colitis (diarrhea), weakness and cardiac failure

Question 23

Oleander

Answer 23

Fatal
5-10 leaves cause CS and lead to death within hours

Question 24

CS of oleander toxicity

Answer 24

Brady or tachycardia, heart blocks, arrhythmias, cardiac failure, death

Question 25

Postmortem lesions of oleander

Answer 25

Endocardial or epicardial hemorrhages and multifocal myocardial degeneration and necrosis

Question 26

Clin path of oleander

Answer 26

Hyperkalemia, ↑CK, ALT, AST and cardiac troponin

Question 27

Yew

Answer 27

Alkaloid taxanes A & B, volatile oil
Interferes with Ca channels in cardiac myocytes
Death within 30 minutes of ingestion (mouthful)

Question 28

CS of Yew

Answer 28

Tremors, dyspnea, bradycardia, collapse, sudden death (acute heart failure) and colic signs

Question 29

Acute ionophore toxicity

Answer 29

Consumes large amount over short period
Anorexia, colic, ataxia, arrhythmia and tachycardia, paresis, myoglobinuria, a-fib etc
Sudden death

Question 30

Chronic Ionophore toxicity

Answer 30

Small to moderate amounts over a longer period
Unthriftiness, poor performance, exercise intolerance, arrythmias, edema and tachypnea

Question 31

Ionophores

Answer 31

Coccidiostats, lasalocid and monensin
Fatal for equine

Question 32

Pathophysiology of ionophores

Answer 32

Affects Na+-K+ ATP transport
Alters transport of Ca → ↑ intracellular Ca → cell death (affects mitochondria function, induces oxidative stress)
Myocardial necrosis

Question 33

Ionophore toxicity tx

Answer 33

Remove source, ice feet PRN
Fluids, electrolytes, NO CA, anti-inflamms
NSAIDs (vit E and selenium)

Question 34

Recovered patient from ionophore toxicity

Answer 34

Normal tissue replaced with fibrosis
Long term cardiac problems

Question 35

Acer species (red, sugar or silver maple leaves)

Answer 35

Gallic acid that denatures Hb
Fall, spring and summer, wilted leaves

Question 36

CSof acer species toxicity

Answer 36

Appetite loss, Hburia, PU/PD, bronze discolor of gingiva

Question 37

DX acer species toxicity

Answer 37

Onion odor, leaves in lavage
Bronze gums, brownish urine
Smear

Question 38

Tx of acer species toxicity

Answer 38

Aggressive IV fluids
Remove source, eliminate with laxatives

Question 39

Oxidative damage

Answer 39

Allium species: causes oxidative damage to RBCs
CS: anemia (hemolytic, heinz body), Hburia and tachycardia