Integumentary, Cardiovasc., ionophore toxicity Flashcards
With weather conditions like __________ plants will have higher toxicant levels
Drought
Ingestion (decomination)
Removal
AC
↑ elimination(cathartic- MgSO4)
Dermal and ocular exposure
Bathing and flushing
Which plants cause photosensitization?
False Queen Anne’s Lace (insoluble Ca oxalates)
Buckwheat (fogopyrin)
Giant Hogweed (ocular toxicity)
Goatweed (hypericin)
St. John’s wort (hypericin and protohypericin)
When primary photosensitization occurs what is the common lesion caused by those plants?
Ulcerative and exudative dermatitis
skin involved only
Hypericin
Photodynamic red pigment produced in glands of leaves and flowers (highly absorbable)
Not a problem unless in direct sunlight
Pathology of hypericin
Enters brain (stimulant effect on behavior)
Peripheral NS- alters heart, vasc. and intestinal function inhibiting catechol enzyme
↑ hepatoxicity of other agents
Inhibits glutamate release
T/F: hypericin can be passed to nursing young via milk
TRUE
could cause mother to abort or abnormalities
Early CS of photosensitization
Restlessness, scratching, rubbing against objects, intermittent weakness of hindlimb with knuckling over, peeling/ sloughing of skin
Progressive CS of photosensitization
Mild diarrhea, swelling around forehead and eyes, inflamed, hyperthermia and necrotic dermatitis
Tx of photosensitization
Remove from source and keep shaded 4-7d
Tx wounds, IV fluids and corticos
Prognosis of photosensitization
Poor if the liver involved
What plants cause secondary photosensitivity
Ranunculus (buttercup)
Symphytum officinale (comfrey)
Heliotrope spp.
Lantana and Ragwort
liver involvement
Contact dermatitis
Direct contact with an irritating agents (clothing material, grooming tool, topical/ environmental insecticides, meds, stall bedding)
Enhanced by moisture
CS of contact dermatitis
Pruritus (secondary: rx to itching)
Development of papules and vesicles
Plants that cause contact dermatitis
Bleeding heart, daffodil, buttercup, sneezeweed, English ivy, fleabane, mum, wild onion and chamomile
Lesion location of contact dermatitis
Girth:
Over the back (saddle/ blanket)
Lower limbs (plants, insecticide/ herbicide)
General body (fly sprays, shampoo)
Dx contact dermatitis
Hx, CS, patch testing
Tx for contact dermatitis
Remove source (soap and rinse)
Reduce inflamm: corticos
Cardiac glycosides
Inhibits Na+/ K+ ATPase in arrythmias that can develop into cardiac arrest and death
Which plants contain cardiac glycosides
Rhododendren species: azalea, oleander, yew
Azalea
Grayanotoxin and sodium channel activators
Causes acute colitis (diarrhea), weakness and cardiac failure
Oleander
Fatal
5-10 leaves cause CS and lead to death within hours
CS of oleander toxicity
Brady or tachycardia, heart blocks, arrhythmias, cardiac failure, death
Postmortem lesions of oleander
Endocardial or epicardial hemorrhages and multifocal myocardial degeneration and necrosis
Clin path of oleander
Hyperkalemia, ↑CK, ALT, AST and cardiac troponin
Yew
Alkaloid taxanes A & B, volatile oil
Interferes with Ca channels in cardiac myocytes
Death within 30 minutes of ingestion (mouthful)
CS of Yew
Tremors, dyspnea, bradycardia, collapse, sudden death (acute heart failure) and colic signs
Acute ionophore toxicity
Consumes large amount over short period
Anorexia, colic, ataxia, arrhythmia and tachycardia, paresis, myoglobinuria, a-fib etc
Sudden death
Chronic Ionophore toxicity
Small to moderate amounts over a longer period
Unthriftiness, poor performance, exercise intolerance, arrythmias, edema and tachypnea
Ionophores
Coccidiostats, lasalocid and monensin
Fatal for equine
Pathophysiology of ionophores
Affects Na+-K+ ATP transport
Alters transport of Ca → ↑ intracellular Ca → cell death (affects mitochondria function, induces oxidative stress)
Myocardial necrosis
Ionophore toxicity tx
Remove source, ice feet PRN
Fluids, electrolytes, NO CA, anti-inflamms
NSAIDs (vit E and selenium)
Recovered patient from ionophore toxicity
Normal tissue replaced with fibrosis
Long term cardiac problems
Acer species (red, sugar or silver maple leaves)
Gallic acid that denatures Hb
Fall, spring and summer, wilted leaves
CSof acer species toxicity
Appetite loss, Hburia, PU/PD, bronze discolor of gingiva
DX acer species toxicity
Onion odor, leaves in lavage
Bronze gums, brownish urine
Smear
Tx of acer species toxicity
Aggressive IV fluids
Remove source, eliminate with laxatives
Oxidative damage
Allium species: causes oxidative damage to RBCs
CS: anemia (hemolytic, heinz body), Hburia and tachycardia
