VETT 111 Final Exam

What is veterinary toxicology?

Area of science pertaining to the diagnosis and treatment of intoxication in pets, livestock, and wildlife species

What is a toxicant?

A toxic agent / a toxic substance resulting from human activity

What is a toxin?

A poison produced by a biologic source (including venom)

What is acute toxicosis?

Effects appear in first 24 hours

What is chronic toxicosis?

Effects products by prolonged exposure (>3 months)

What is toxicity?

The degree to which a substance can cause harm

What is LD50?

Dose that is lethal to 50% of test subjects

How can intoxication occur?

Inhalation, ingestion, absorption, percutaneous

What factors into the toxicity of a substance?

Species, age, health status, route of exposure, dose, ADME, duration of exposure, frequency of exposure, environment

What are the principles of therapy in toxicosis of animals?

Prevent exposure, supportive/symptomatic treatment, specific antidotes

When is inducing emesis contraindicated in toxicosis cases?

If the toxicant can do even more damage coming back up, if the patient is convulsing, if the patient is sedated, if the patient is already vomiting, etc.

What is a gastrotomy?

What is a rumenectomy?

What are contraindications for activated charcoal in toxicosis cases?

Caustic substances and hydrocarbon as it is ineffective, planned endoscopy or abdominal surgery, GI obstruction, risk of aspiration pneumonia, severe dehydration, hypernatremia, hypovolemic shock, ileus, recent intestinal surgery, protracted vomiting

What are supportive/symptomatic treatments for toxicosis cases?

Anticonvulsants, analgesics, maintain airway/oxygenation, +/- treat for shock, dehydration, electrolyte imbalance, cardiac dysfunction

specific antidotes lecture 10

What species are poinsettias toxic to?

Dogs, cats, horses

Sap is irritating to mouth and stomach

What are the clinical signs of poinsettia intoxication?

Vomiting, ptyalism, diarrhea, skin, or eye irritation

Is treatment usually necessary for poinsettia intoxication?

Not unless clinical signs are severe

What is ptyalism?

Hypersalivation

Poinsettias

What are azaleas also known as?

Rosebay, rhododendron

Azaleas

Which species are azaleas toxic to?

Dogs, cats, horses, goats, etc.

What makes azaleas toxic?

Grayanotoxins disrupt sodium channels

What are the clinical signs of azalea intoxication?

Vomiting, diarrhea, ptyalism, weakness, heart failure, arrhythmias, tremors, seizures, death

What is the prognosis of azalea intoxication?

Fair with treatment

Are lilies toxic to dogs?

Yes, but not as severely as cats

Which part of a lily is toxic?

Any part, including pollen and the water it is in

What does lily intoxication lead to?

Kidney failure that is fatal especially if treatment is delayed

Which lilies can lead to acute kidney injury?

Easter lily, Japanese lily, oriental lily hybrids, casa blanca lily, tiger lily, daylilies

Which lilies can make pets sick but do not result in acute kidney injury?

Peruvian lily, lily of the valley, calla lily/trumpet lily, peace lily, flame lily

What is oleander also known as?

Rose-bay

What is the scientific name of oleander?

Nerium oleander

What species is oleander toxic to?

Dogs, cats, horses

What makes oleander toxic?

Cardiac glycosides lead to electrolyte imbalance in the heart

What are the clinical signs of oleander intoxication?

Ptyalism, abdominal pain, diarrhea, colic, tremors, seizures, depression, death

Hyperkalemia, arrhythmias

Is there an antidote available for oleander intoxication?

Yes but it is expensive and reserved for severe, life-threatening cases

What is the scientific name of foxglove?

Digitalis purpurea

What species is foxglove toxic to?

Dogs, cats, horses

What makes foxglove toxic?

Cardiac glycosides (primarily digitalis and digoxin)

What are the clinical signs of foxglove intoxication?

Ptyalism, abdominal pain, vomiting, diarrhea, colic, tremors, seizures, depression, death

Hyperkalemia, arrhythmias

Is there an antidote available for foxglove intoxication?

Yes but it is expensive and reserved for severe, life-threatening cases

What species is marijuana toxic to?

DOGS!!!!, and cats

What makes marijuana toxic?

Delta-9-THC; and since CBD products are not well regulated, they can contain small amounts of THC that are enough to cause toxicity

What are the clinical signs of marijuana intoxication?

Lethargy, vomiting (more likely in cats), ataxia, bradycardia, sedation, urinary incontinence, excitation, ptyalsim, mydriasis, hypothermia, tremors, hypotension, seizures, coma, death (rare)

Are urine drug tests useful for diagnosing marijuana toxicity?

No; dogs do not reliably produce the metabolite that urine drug tests are testing for, leading to false negatives even in severe cases

Good correlation in cats, but still not perfect

How is marijuana toxicity treated?

Supportive care; IV lipid emulsion therapy if hypotensive or comatose

What is blue-green algae?

Cyanobacteria found in lakes, ponds, and rivers

What does blue-green algae appear as?

Blue-green or red-brown blooms, mats, foam, scum; water smells of rotting plant material

What species is blue-green algae fatal to?

Dogs, humans, etc.

What makes blue-green algae toxic?

Cyanotoxins that lead to liver and neurologic injury after injection

What are the clinical signs of blue-green algae intoxication?

VOmiting, diarrhea, lethargy, pale MM, collapse, ptyalism, tremors, dyspnea, muscle rigidity, paralysis, seizures, respiratory arrest, sudden death

How is blue-green algae intoxication treated?

Supportive care; maybe blood products if coagulopathy due to liver failure

Is there an antidote for blue-green algae intoxication?

No

What does ingestion of Amanita spp. cause?

Acute liver failure; GI signs 6-12 hours after exposure, liver failure, death in 1-2 days if severe

What does ingestion of psilocybin, hydrazine, and isoxazole mushrooms cause?

Neurologic signs; onset in minutes to hours (<6hrs): weakness, ataxia, tremors, seizures, alternating lethargy and agitation, GI signs

What does ingestion of muscarinic mushrooms, etc. cause?

GI signs; onset in minutes to hours (<6hrs): vomiting, diarrhea, hypovolemia, bradycardia, SLUDGE signs

What does ingestion of Cortinarius spp. cause?

Potentially nephrotoxicity, but no reports in dogs or cats; signs delayed 12 hours to days: PU/PD, vomiting, dehydration

What are SLUDGE signs?

Salivation, lacrimation, urination, dyspnea, GI upset, emesis

How is mushroom intoxication treated?

Stabilize, decontaminate, provide supportive care

If possible, once stable, contact expert for identification of the mushroom

What are methylxanthines?

Theobromine and caffeine

What makes methylxanthines toxic?

They increase intracellular calcium, increase epinephrine/norepinephrine, etc.

What species are methylxanthines toxic to?

Dogs, cats

What other differentials can methylxanthine intoxication appear as?

Amphetamine intoxication, pseudoephedrine intoxication, cocaine intoxication, antihistamine intoxication, antidepressant intoxication

When do clinical signs appear following methylxanthine exposure?

6-12 hours after

What clinical signs does a 20mg/kg dose of methylxanthine intoxication cause?

Vomiting, diarrhea, polydipsia, restlessness

What clinical signs does a 40-50mg/kg dose of methylxanthine intoxication cause?

Tachycardia, bradycardia, hypertension, hypotension, tachypnea, muscle tremors, hyperthermia, arrhythmias, cyanosis, muscle tremors, may develop pancreatitis

What clinical signs does a 60+mg/kg dose of methylxanthine intoxication cause?

Seizures

How much milk chocolate can be fatal to a dog?

1 once per pound of body weight potentially fatal

How is methylxanthine intoxication diagnosed?

EKG, bloodwork

How is methylxanthine intoxication treated?

Stabilize, treat symptoms, decontimate (emesis/gastric lavage), urinary catheter to make sure methylxanthines not reabsorbed by bladder mucosa

Should activated charcoal be used in the treatment of methylxanthine intoxication?

No; only in high dose exposures where emesis has not been successful

What is xylitol?

Sweetner in sugar-free foods, deodorants, sunscreen, etc.

What species is xylitol toxic to?

Dogs

What does a >75 mg/kg xylitol intoxication cause?

Insulin release leading to hypoglycemia (30 mins to 18 hours) leading to vomiting, weakness, ataxia, depression, hypokalemia, seizures, coma, death

What does a >500 mg/kg xylitol intoxication cause?

Liver injury (unknown mechanism) hours to days after exposure, leading to vomiting, depression, icterus, coagulopathy, hyperbilirubinemia, thrombocytopenia, hyperphosphatemia, death

How is xylitol intoxication diagnosed?

History, exam/blood work

How is xylitol intoxication treated?

Decontamination (emesis if asymptomatic), hospitalization, IV fluids + dextrose, serial bloodwork (BG q1-2 hours, liver values q24hrs), hepatoprotectants (SAM-e, silymarin, N-acetylcysteine)

What percentage of canine xylitol intoxication cases with liver injury died/were euthanized?

62%

What other differentials can xylitol intoxication appear as?

Insulinoma, heat stroke, mushroom intoxication, blue-green algae intoxication, sago palm toxicity

What is blackpatch?

Rhizoctonia leguminicola infection of red clover and other legumes in hot/humid weather. When severe, leaves/stems die, making them look blackened/scorched

What does slaframine cause?

Hypersalivation ("slobbers")

What species is blackpatch toxic to?

Horses, ruminants, camelids

What are the biggest risks of blackpatch intoxication?

Dehydration and electrolyte abnormalities

Is treatment for blackpatch intoxication necessary?

Maybe not if signs are mild, just remove from source

What is the scientific name for yew?

Taxus spp.

What is yew?

Ornamental shrubs containing toxic alkaloids

What species is yew toxic to?

Sheep, cattle, horses, goats, pets, people, etc.

What are the clinical signs of yew intoxication?

Vomiting, diarrhea, bradycardia, dyspnea, nervousness, tremors, ataxia, seizures, sudden death (only because people do not tend to check on livestock very often)

How is yew intoxication diagnosed?

Observance of leaves in the stomach/rumen

How is yew intoxication treated?

Remove animal from source, atropine if needed

Yew

What makes bracken fern toxic?

Contains several toxic compounds and carcinogenic in many species (low doses, long exposure)

What species is bracken fern toxic to?

Cattle, horses, sheep

What does bracken fern intoxication cause?

Coagulopathy and urinary tract neoplasia -> hematuria -> anemia, weakness, weight loss, dyspnea, pale MM, hemorrhage

What does bracken fern intoxication lead to in sheep?

Bright blindness (tapetal hyperreflecitivity and blindness)

What does bracken fern intoxication lead to in horses and other monogastrics?

Bracken staggers if high doses for long duration (anorexia, weight loss, ataxia, crouched stance while arching the back and neck, standing with feet placed wide apart, trembling, arrhythmias, seizures, death)

What are ionophores?

Feed additives that increase gains in food producing species (monensin, lasalocid, salinomycin)

What species are ionophores toxic to?

Horses, dogs, rabbits