Unit 2 - Toxic Plants in Large Animals I Flashcards
What species are affected by Yellow Star thistle/Russian knapweed toxicosis?
Horses only
T/F: Fresh or dried Yellow Star Thistle is toxic.
True
What is the indicated toxic principle of Yellow Star Thistle?
Sequiterpine lactones
What do sesquiterpine lactones do?
Depletes glutathione which results in oxidative damage, mitochondrial dysfunction and neuronal death
What clinical signs are associated with Yellow Star thistle toxicosis?
Involuntary chewing moments, food falling from mouth
Depression
Inability to eat
How is Yellow Star thistle toxicosis diagnosed?
Clinical signs
History of exposure
What is necessary for horses to get Yellow Star thistle toxicosis?
They need to have an extended period of consumption - high intake over 30+ days
What lesion does Yellow Star thistle cause?
Nigropallidal encephalomalacia
How is Yellow Star thistle toxicosis treated?
There is no treatment - euthanasia is recommended
When do perennials grow?
In spring/summer
T/F: Locoweed or milkvetch is typically eaten when other forages are not present.
False - it is palatable and nutritious and may be eaten even when other forages are present
What is the toxic principle of locoweeds?
Indolizidine alkaloid -Swainsonine
Where is swainsonine located in locoweeds?
In all parts of the plant - it is highest in leaves, flowers, and seedpods
Swainsonine is ______ absorbed, crosses the _____, is secreted in _____, and excreted _______ in ________.
Rapidly placenta milk unchanged urine
What is the MOA of swainsonine?
- Inhibits alpha-D-mannosidase and Golgi mannosidase II
- Accumulation of oligosaccharides in lysosomes of cells in the brain and other tissues
- Generalized lysosomal storage disease ensues
What species are affected by locoweed toxicosis?
Cattle, horses, sheep, goats, and elk
When do clinical signs due to Locoweed toxicosis occur?
After several weeks of consumption
How do sheep with Locoweed toxicosis typically appear?
Blind with stargazing behavior
What clinical signs are associated with Locoweed toxicosis in horses?
Neurologic signs - depression, procioceptive deficits, circling, ataxia, and falling over backwards
What clinical signs are associated with Locoweed toxicosis in cattle and sheep?
Reproductive problems - abortions, fetal resorption, skeletal malformations, testicular atrophy, and decreased spermatogenesis
What lesions are associated with Locoweed toxicosis?
Vacuolation of neurons, renal tubular epithelia, and macrophages
What species are affected by Jimson weed?
All species - pigs and horses are worse
What do Jimson weed plants look like?
2-5 feed high with simple irregular toothed leaves
Tubular flowers with 2-4
T/F: Jimson weed is normally palatable
True