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70 Cards in this Set
- Front
- Back
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What animals are primarily affected by the T-2 toxin?
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Chickens
Pigs |
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What animals are primarily affected by deoxynivalenol?
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Dogs & cats
Ruminants Swine |
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What animals are primarily affected by Lolitrem B?
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Cattle
Horses Sheep |
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What animals are primarily affected by tremorgens?
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Small animals
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What are the 3 toxins that are involved in moldy corn poisoning?
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Fumonisin B1, B2 or B3
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Moldy corn poisoning ultimately results in ____________.
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Leukoencephalomalacia
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Compare the susceptibility of horses, swine and cattle to moldy corn poisoning.
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Horses- most susceptible to low dose
Swine- less susceptible Cattle- mildly affected |
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What is the toxic dose of moldy corn poisoning in horses?
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As low as 10 ppm x 30 days--> fatal
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What happens to pigs fed food with 100 ppm of moldy corn poison for 5-10 d?
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Acute pulmonary & hepatic toxicosis
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What happens to pigs fed 50 ppm of moldy corn for 7-10 d?
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Mild hepatic lesions
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What happens when pigs are fed 25 ppm of moldy corn?
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No clinical signs
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What is the source of moldy corn poisoning?
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**Infestation w/ fusarium moniliform and F. proliferatum
-White & yellow corn |
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How can we prevent moldy corn poisoning?
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White & yellow corn screenings
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Where is moldy corn poisoning an issue?
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World wide problem
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What is the seasonal pattern of moldy corn poisoning?
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Seen when drought during growth is followed by cool wet weather during pollination and corn development
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What are 3 reasons that moldy corn poisoning is hard to eradicate?
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1) Water soluble
2) Heat stable 3) Resistant to alkali treatment |
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What is the pathophysiology of moldy corn poisoning in an animal that orally ingested it or used for corn screenings?
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Inhibits enzyme mediated sphinganine to sphingosine---> interferes w/ sphingolipid synthesis---> affects white matter of brain (sphingomyelin synthesis)--> LEUKOENCEPHALOMALACIA
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**What part of the brain is primarily affected by leukoencephalomalacia from moldy corn poisoning?
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Corona radiata
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What are the 6 clinical signs of equine leukoencephalomalacia?
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1) Rapidly progressing depression
2) Blindness 3) Ataxia 4) Aimless wandering 5) Facial paralysis 6) Come & death in 24 hr or up to 1 wk post signs |
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True or false. Facial paralysis occurs on the same side as the lesion.
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False, opposite side of lesion
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What are 6 DDX for moldy corn poisoning in horses?
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1) Trauma
2) Equine protozoal myeloencephalopathy 3) Encephalitis- viral 4) Listerosis 5) Equine herpes 6) Cauda equine neuritis -low on list |
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How is moldy corn poisoning diagnosed?
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-increased liver enzymes
-MRI could visualize lesion in corona radiata -Increased serum sphinganine to sphingosine ratio (sensitive indicator of effect of toxin, most labs can run) |
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What is the treatment for moldy corn poisoning?
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No treatment once clinical signs are evident in horses
-Supportive care of other livestock w/ hepatic lesions and pulmonary edema |
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How do you prevent moldy corn toxicity?
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Analyze corn for fumonisin by HPLC or ELISA if suspect
-Avoid feeding to horses |
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When should you avoid feeding lathyrus species to animals?
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When maturing legumes and seeds are present
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What lathyrus specie causes neurologic effects?
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L. latifolius
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True or false. All species of lathyrus are toxic.
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False, some species non-toxic, other are fatal to sheep & cattle w/ no lesions
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What happens when large quantities of lathyrus seeds are in the diet of animals for weeks to months?
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Can induce both neurolathyrism and osteolathyrism
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What 2 species of lathyrus can produce both neurolathyrism and osteolathyrism?
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L. pusillus
L. hirsutus |
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What specie of lathyrus produces primarily osteolathyrism?
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L. odoratus
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Most species of lathyrus produce primarily _______.
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Neurolathyrism
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What is the scientific name for the false dandelion?
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Hypochaeris radicata
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Where is Hypochaeris radicata located?
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Widely distributed in US, especially west of cascade range
-Wasted areas, overgrazed pastures, lawns |
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What is the seasonality related to Hypochaeris radicata toxicity?
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Only affects some horses and not others in the summer and fall months - bc like dry weather and pastures get overgrazed and then they eat this
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How is Hypochaeris radicata associated with stringhalt?
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Epidemiologically
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What is the toxin associated with Hypochaeris radicata?
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No toxin identified
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What are the clinical signs of Hypochaeris radicata
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-Spastic paresis of legs
-Involuntary spasms of flexor muscles of hock initially -Can spread to spasms of multiple limb muscles and impede walking |
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What species are affected by Hyochaeris radicata toxicity?
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All species including humans but horses are most commonly affected
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**What is the treatment of Hypochaeris radicata (stringhalt) toxicity in horses?
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surgical transection of lateral digital extensor in pelvic limb– just cut a piece out and walk them right afterwards so doesn’t adhere down
-Supportive therapy |
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What is the pathophysiology of stringhalt (hypochaeris radicata) caused osteolathyrism?
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Inhibition of lysyl oxidase by BAPN (beta-aminoproprionitrile)
-BAPN prevents crosslinking of collagen and elastin in developing bone & cartilage --> fetal abnormalities -Primary experimental disease |
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**What is the pathophysiology of neurolathyrism caused by stringhalt (+ lathyrus)?
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Novel proteins excite glutamate receptors in motor neurons
-BOAA -OAP |
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Neurolathyrism is clinically seen primarily in _____ but also less commonly in _____ & ______
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Horses
Cattle & sheep |
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How do you make a premortem diagnosis of stringhalt?
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No premortem diagnosis -check feed or history o exposure
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What are 6 DDX for stringhalt in horses?
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1) Traumatic damage to nerves supplying pelvic limb
2) Equine protozoal myeloencephalopathy 3) Shivers 4) Upward fixation of patella 5) Fibrotic myopathy 6) Equine motor neuron disease |
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What is the treatment of stringhalt toxicity (not in horses)?
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-No specific treatment
-Remove source of contamination and replace w/ good quality feed -Some animals make full recovery, Chronic exposure usually does not |
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What are the pathological findings of stringhalt toxicity?
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No gross or definitive CNS lesions
-Neuronal degeneration of motor tracts of caudal spinal cord and nerves to hind limbs |
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What condition does yellow star thistle toxicosis result in?
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Equine nigropallidal encephalomalacia
-Deposits in substantia nigra and globus pallidus |
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What is the family of yellow star thistle?
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Compositae
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What is the scientific name of yellow star thistle?
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Centaurea solstitialis
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What are the 2 plants in the compositae family?
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1) Centaurea solstitialis (yellow star thistle)
2) Centaurea- Acroptilon repens (Russian knapweed) |
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**Describe C. solstitialis phenotype.
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Annual weed
1-3'' tall w/ single erect, angular woody stem |
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What color are the florets of yellow star thistle?
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Yellow
-Also have .75'' spines |
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Where is yellow star thistle located?
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Noxious, aggressive weed throughout NW and thrives in arid to semiarid range land and abandoned crop land
-In N. California & S. Or |
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True or false. In spite of the thorns, yellow star thistle is addictive.
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True
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How does C. or acroptilon repens (Russian knapweed) phenotypically vary from yellow star thistle?
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Similar in structure except branches terminate in a base cluster of *purple flowers w/ *NO spines
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Where is Russian knapweed primarily located?
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East of cascades, Rocky mountains
-Noxious & aggressive plant |
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What is the toxic principle of centaurea species?
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No one knows for sure
-Some evidence sesquiterpene lactones or a pyrone compound concentrated in the aerial portions of plant |
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Most centaurea species toxicosis is associated with ingestion of which plants?
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Young plant and flowers, though the dried plant in hay or straw is still considered by some to b toxic
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*****________ may acquire a taste for centaurea species.
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Horses
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****What is the toxic dose of yellow star thistle?
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Toxicosis occurs over a period of 30-90 days, eating a huge amount on a daily basis
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*****What is the mechanism of action of Centaurea sp. toxicity?
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Interruption of dopaminergic nigrostriatal pathway---> loss of coordinating and inhibiting impulses from cerebral cortex---> **UMN impairment of cranial nerves V, VII, IX, XII
-local reflexes and sensations remain intact |
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**What animals are affected by yellow star thistle toxicity?
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Equine ONLY - a condition called nigropallidal encephalomalacia or "chewing disease"
-get addicted -Cattle may graze in early spring, but nutrient value low, as plant matures becomes unpalatable |
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What are the clinical signs of Centaurea species?
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Onset is sudden
-Involuntary lip twitching -Upper lip pulled over teeth (hypertonicity of lips, face and tongue i.e. UMN signs) -Lower lip often droops -Involuntary "jutting" tongue and chewing movements -Yawning -Head tossing -Unable to drink normally or swallow food |
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**What usually causes death from yellow star thistle toxicity?
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Often a result of starvation
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What are the pathological lesions associated with yellow star thistle toxicity?
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Bilteral, symmetrical or nonsymmetrical nonprogressive, focal necrosis and malacia of globus pallidus of cerebrum & substantia nigra of mesencephalon
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What are 6 differential diagnoses for yellow star thistle toxicity?
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1) Foreign body in base of tongue
2) Unilateral fracture of jaw 3) Equine protozoal myeloencephalopathy |
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How do you diagnose yellow star thistle toxicity?
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No premortem test except MRI
-Often made on unique clinical signs and history of exposure -Radiograph to rule out foreign bodies in tongue or throat or unilateral fracture of jaw |
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What is the treatment of toxicosis from Centaurea species? Prognosis?
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Necrotic lesions are not reversible
Prognosis is grave and once clinical signs appear, recovery is not possible |
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How can you prevent and control Centaurea species toxicity?
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Do not allow horses access to areas that are infested w/ these plants
-some biological agents have been used to control yellow star thistle some success -Use sheep to clean up pastures |
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Centaurea species can produce up to 150,000 seeds per year and can lie dormant for how long?
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10 years
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