Final Flashcards
What is equine leukoencephalomalacia?
It is a condition caused by fumonisins, a mycotoxin produced from moldy corn
What is the main adverse affect of fumonisins?
They are hepatotoxic
What are the clinical signs of equine leukoencephalomalacia?
- Blindness
- Head pressing
- Aimless walking
- Stupor
- Glossopharyngeal paralysis
- Delirium
- Recumbency
- Seizures
- Death
Fumonisins cause ______ morbidity and _______ mortality in ________.
Low
High
Horses
What are the lesions that equine leukoencephalomalacia cause?
Subcortical white matter necrosis- can be bilateral or unilateral
What toxins can cause blindness in animals?
- Lead-Cattle
- Ivermectin
- Pyrethrins-Dogs/cats
- Metaldehyde-
- Fumonisin
- Salt
What substrate will grow fumonisin?
Corn
Why is fumonisin a public health concern? Aflatoxin?
It can cause esophageal cancer in humans
Alflatoxin is carcinogenic
How would you confirm a case of equine lueikoenceaphcalomalacia from fumonisin?
Screen corn by analyzing representative samples
What nicotinic products are the most hazardous and why?
Liquid cartridges and refills for e-cigarettes as they have concentrated levels of up to 2,000mg
What are the clinical signs of a nicotine toxicity?
- Vomiting
- Hyperactivity
- Tremors
- Seizures
- Respiratory paralysis leading to death
How long is the nicotine half life?
Short
How do you diagnose a nicotine toxicity?
Nicotine residues
What is the treatment for nicotine toxicity?
It is patient dependent, but should decontaminate with lavage/AC, control the CNS excitation and give oxygen support.
Which receptors does nicotine bind to?
Nicotinic acetylcholine receptors in the parasymphathetic and sympathetic nervous system
Which genetic issue is involved with ivermectin?
MDR1 (ABCB1) mutation in some dogs
Which species should you never use ivermectin in?
Turtle
What is the MOA of the MDR1 (ABCB1) mutation?
P-glycoprotein isn’t produced, so drugs can’t get pumped out of the blood brain barrier and end up staying in the CNS. In addition, the drug accumulates in the bile and kidney instead of being secreted.
If a dog has a MDR-1 mutation, what do you need to be aware of?
They can have multiple drug resistance, not just to ivermectin.
The half life of ivermectin varies in length due to three factors, what are these?
- Sensitive/non-sensitive patient
2. Hezterozygote or homozygote
What is the mechanism of action of ivermectin?
It targets the GABA and glutamate-gated chloride channels releasing inhibitory neurotransmitters.
What are the clinical signs of an ivermectin toxicity?
- Depression
- Lethargy/weakness/recumbency
- Tremors (high dose)
- Seizures (high dose)
- Reversible blindness
- Coma leading to death
How long can the clinical signs last with ivermectin toxicity?
Hours, days to weeks as it is hard to predict
A client tells you that she gives her horses oral ivermectin twice a year and now her dog is showing signs of depression, lethargy, recumbency and blindness. What may be going on?
Ivermectin toxicity
How would you chemically confirm an ivermectin toxicity?
You can only confirm exposure, but can use fat, liver, bile, feces and serum samples
What is the treatment for an ivermectin toxicity?
- Decontaminate with AC
- Aggressive supportive care
- Physostigmine (dogs/cats)
- IV lipid therapy
What is the prognosis of an ivermectin toxicity?
Most recover over 24 hours to 31 days and the severity of signs is not a good predictor of prognosis unless there are uncontrollable seizures.
What can you use physostigmine for?
Treatment for larkspur plant toxicity and ivermectin toxicity
Will IV lipid therapy help an animal with the MDR1 mutation that was given too much ivermectin?
It may not
An animal can experience salt toxicity if one of the following three circumstances are met…what are they?
- TOO much SALT intake
- TOO much SALT intake with WATER DEPRIVATION
- WATER DEPRIVATION
If ingested, which products can cause hypernatremia in animals?
- Whey
- Electrolyte supplement
- Play dough
- Ice melts
- Mixing errors
- If used as an emetic
- Crafts
- Ingesting sea water
- Paint balls
- Single or repeated AC doses
If a dog drinks too much water right after being hypernatremic, what can this cause?
Salt toxicity
What is the mechanism of salt toxicity?
Na is passively diffused into the CSF and neurons which leads to inhibition of glycolysis. Without the energy, active transport of Na won’t occur out of the CSF and neurons. Water then follow the Na into the CSF. The second the patient rehydrates, more water will follow the Na and cause cerebral edema and hemorrhage.
What are the clinical signs of salt toxicity?
CNS signs like wandering, circling, head pressing, blind, dog sitting, tremors, seizures, excessive thirst, vomiting, and death.
What pathological lesion will you see in pigs suffering from salt toxicity?
Eosinophilic meningoencephalitis
What are the clinical lesions associated with salt toxicity?
- Cerebral edema
2. Cerebral malacia
What tips off when taking a history would lead to a salt toxicity problem?
- Lack of water
- New feed
- Access to high salt sources
How could you confirm a salt toxicity?
Need to know the fluid/hydration status in order to interpret Na numbers that you see in the serum, CSF, and cerebrum..also look for lesions.
How do you treat a salt toxicity?
- SLOW rehydration
- Remove the source
- DO NOT GIVE ACTIVATED CHARCOAL
What are the 6 most common problems with mushroom ingestion?
- Gastroentertitis
- Muscarinic signs
- CNS excitation
- CNS depression
- Liver disease
- Renal disease
Which clinical sign is present with any mushroom ingestion?
Gastroenteritits
When dealing with a mushroom toxicity, what should you focus on?
- Preventing liver and renal disease
- Monitoring for CNS excitation/depression
- Treating muscarinic and gastroenteritis clinical signs
How would you treat an animal that ate muscarine mushrooms?
- Decontaminate via emesis and AC/sorbitol
- Administer atropine and maropitant to stop the vomiting
- Chem panal to establish baseline
- GI and Liver protectants
- Follow up chem penal at 48 hours and renal recheck in 10 days
How could you confirm the type of mushroom you are dealing with?
Email images and location to a mycologist so they can identify it
What kind of grass contains an endophytes that can contain ergovaline?
Tall fescue
What is the MOA of ergovaline?
Peripheral vasoconstriction and suppressing of prolactin secretion in large animals
What are the three syndromes that can be caused by fescue poisoning? What species and what time of year is this most likely to occur?
- Summer slump-cattle-summer
- Fescue foot-cattle-winter
- Reproductive problems-horse/ruminants-anytime of year
Why does fescue poisoning cause summer slump?
Vasoconstriction from the ergovaline leads to hyperthermia which leads to decreased feed intake, loss of body weight/condition, and abortions
Why does fescue poisoning cause fescue foot?
Vasocontriction from the ergovaline leads to ischemia necrosis and dry gangrene of the distal extremities and ears/tail, also causes abortions
Why does fescue poisoning lead to reproductive problems in horses and ruminants?
The suppressions of prolactin prolongs gestation leading to dysmature foals, agalactia and abortions.
How can you diagnose fescue poisoning?
Testing the hay or urine for ergovaline
What is domperidone used for?
its a dopamine antagonist that is used to treat summer slump and reproductive issues stemming from fescue poisoning.
What is the toxic principle of ergot?
Ergopeptide alkaloids:
- Ergotamine
- Ergonovine
You see a sclerotia body in grain, what is it?
Ergot, a mycotoxin
What can ergotamine and ergonovine do to the body of large animals? Which large animals?
Peripheral vasoconstriction
Cattle and swine
What form of ergot is the most dangerous? and why
Pelleted grain as the ergot gets crushed during processing, so it makes it hard to see.
What are the common clinical signs of ergot poisoning?
- Feed refusal
- Dry gangrene with lameness
- Agalactia leading to small/weak piglets
- Abortions
How can you confirm a diagnosis of ergot poisoning?
Analyze for ergopeptide alkaloids in the feed and look for sclerotia bodies
What characteristics determine the type of disease selenium poisoning causes?
- Form of selenium
- Duration and route of exposure
- Species affected
What are the acute clinical signs of selenium poisoning?
- Cardiac-myocardial necrosis
- Lung-pulmonary edem a
- Poliomyelomalacia (swine)
Which species is most sensitive to selenium poisoning?
Horses
What are the most common sources of selenium poisoning?
- Forages, especially obligate accumulators
- Supplements and mixing errors just as injectables and hay
- Water contamination
What can cause bobtailed disease?
Chronic selenium poisoning
What plant contains high amounts of selenium?
Locoweed
How is selenium poisoning analytically diagnosed antemortem and postmortem?
Antemortem: 1. Blood 2. Hair/hoof if chronic Postmortem: 1. Liver
And testing water
What is the treatment for selenium poisoning?
Supportive care of symptomatic patients
White muscle disease is caused by _________ and affects mainly __________. The main clinical sign seen is _________.
Selenium deficiency
Horses
Masseter muscle myopathy
What is paraquat?
Herbicide use to die plants out, especially popular with potatoes
Which species is most likely to be poisoned by paraquat?
Dog and sometimes large animals in recently treated areas
What is the MOA of paraquat?
It produces free radicals with the substrate being oxygen leading to cell death
What are the routes of exposure of paraquat?
- Oral leading to acute toxicity
2. Respiratory..accumulates in lung in 24 hours
How is paraquat excreted?
%70 unchanged in the urine
What the clinical signs of an acute paraquat toxicity?
- GIT: vomit and abdominal pain
2. Pulmonary: dyspnea and tachypnea
How do dogs normally die when poisoned with paraquat if its an acute manifestation?
From the pulmonary effects that cause dyspnea and tachypnea
What are the clinical signs of a chronic paraquat toxicity?
- Pulmonary: dyspnea from irreversible fibrosis
2. Renal: vomit and abdominal pain
How do dogs normally die when poisoned with paraquat if its a chronic manifestation?
Renal failure
If you did a necropsy on a dog that died from acute parquet poisoning, what would you see? Chronic?
- Hemorrhage of GIT and lungs
- Necrosis of GIT and lungs
- Heavy lungs
- Inflammation of the GIT
With chronic would also see fibrosis in lungs
You send samples into a pathologist for histology on a dog what died from chronic paraquat poisoning. What does the report say? What about an acute poisoning>
Chronic: Renal, adrenal and cardiac necrosis with interstitial lung fibroplasia
Acute: Hemmorrhage, edema and necrosis of the lung and GIT
What samples are best to test postmortem if you suspect paraquat poisoning?
Antemortem?
- Liver
- Kidney
- Lung
Urine, but only in acute disease
Why do animals start vomiting after they ingest paraquat?
It is an emetic
If a dog is asymptomatic after drinking paraquat, what should you do? Why is this scenario unlikely?
Decontaminate with activated charcoal and antiemetics
Paraquat is an emetic, so most animals will by symptomatic already.
How do you treat a symptomatic
paraquat toxicity patient?
- Antiemetic
- Activated charcoal
- Analgesics
- GI protectants
- IV fluids
- Oxygen supplementation
Why would you give IV fluids to a paraquat toxicity dog?
- Enhance excretion in the urine
- Decrease contact time in renal tubules
- Maintain hydration
Where can you find PTFR
Non stick cooking surfaces, lightbulbs, headlamps, irons, ironing board covers, and heaters
Which species is most sensitive to PTFR’s and what does it do to them?
Birds
Acute respiratory distress
At what temperature range can you be confident that PTFR fumes and particulates are not being expelled into the air?
less than 500 degrees F or 260 degrees C
How do you diagnose a PTFR toxicity when the pathological lesions are nonspecific and there are no tests for it?
Good history taking for sources
What plants can cause fog fever in cattle?
- 3-methyl-indole in grass
- Mustard
- Moldy sweet potatoes with ipomeanol
- Perilla mint
A horse is slobbering profusely , but you see nothing else wrong, what could be causing this?
Slaframine mycotoxin
Which plants can slaframine mycotoxin grow on?
- Red clover
- Alfalfa
- Legumes
What does DUMBSLED stand for?
Diarrhea Urination Myosis Bradycardia Salivation Lacrimation Emesis Dyspnea
How can you diagnose and treat a slaframine toxicity?
Test the feed with representative samples, remember hot spots
Remove access to feed
Don’t treat with atropine
What is the mycotoxin called that is estrogenic, grows on grains and some grasses and hay and affects cattle and swine causing vulvovaginitis and mammary gland enlargement?
Zearalenone
What are the three main causes of seizures?
- Metabolic
- Structural
- Idiopathic epilepsy
What is the most common type of generalized seizure?
Tonic/clonic
What are the three types of seizures?
- Generalized
- Partial/focus
- Behavioral/psychological