Page 1127 - Small Animal Internal Medicine, 6th Edition

CHAPTER 62 Seizures and Other Paroxysmal Events 1099

BOX 62.3
VetBooks.ir Intoxications Resulting in Acute Neurologic Dysfunction Organophosphates and Carbamates

Strychnine
Common use: rat, mole, gopher, and coyote poison Common use: insecticides
Clinical findings: stiff extension of legs and body, erect Clinical findings: excessive salivation, lacrimation,
ears, tetanic spasms induced by auditory stimuli diarrhea, vomiting, and miosis; twitching of facial and
Diagnosis: history of access or ingestion, characteristic tongue muscles, progressing to extreme depression and
signs, chemical analysis of stomach contents tonic-clonic seizures
Treatment: vomiting (if no neurologic signs), gastric Diagnosis: history of exposure, characteristic signs,
lavage, diazepam as needed, pentobarbital to effect; analysis of stomach contents, low serum
establish diuresis acetylcholinesterase activity
Treatment: prevent further exposure; wash if topical
Metaldehyde exposure; gastric lavage and activated charcoal if
Common use: snail, slug, and rat poison ingested; atropine (0.2 mg/kg IV initially and 0.2 mg/
Clinical findings: anxiety, hyperesthesia, tachycardia, kg SC as needed q6-8h); pralidoxime (20 mg/kg IM
hypersalivation, muscle fasciculations, and tremors; not q12h) if within 48 hours of exposure or if was dermal
worsened by auditory stimuli; nystagmus in cats; may exposure
convulse; depression; respiratory failure
Diagnosis: history of access or ingestion, characteristic Lead
signs, acetaldehyde odor on breath, analysis of Common use: ubiquitous in environment in linoleum, rug
stomach contents padding, old lead-based paints (before 1950s), putty
Treatment: gastrointestinal decontamination: induce and caulking material, roofing materials, batteries,
vomiting if mild signs, administer activated charcoal grease, used motor oil, golf balls, fishing sinkers,
with sorbitol as cathartic, diazepam bolus or CRI, pellets, and lead shot
methocarbamol (55-220 mg/kg slow IV, repeat in 12 h Clinical findings: gastrointestinal signs of anorexia,
if needed). Propofol or pentobarbital if needed to abdominal pain, vomiting and diarrhea, and
effect; establish diuresis. megaesophagus; neurologic signs of hysteria,
aggression, nervousness, barking, tremors, seizures,
Tremorgenic Mycotoxins blindness, hypermetria and nystagmus (cats), and
Common use: moldy dairy products, nuts, grains, compost, dementia
garbage Diagnosis: history of exposure, characteristic signs, CBC
Clinical findings: vomiting, tremors, ataxia, seizures changes (basophilic stippling of RBCs, increase in
Diagnosis: history of access or ingestion, characteristic nucleated RBCs); blood lead level (heparinized tube:
signs, analysis of stomach contents >0.5 ppm [50 mg/dL], diagnostic; >0.25 ppm,
Treatment: gastrointestinal decontamination: induce suggestive); radiographs may reveal radiopaque
vomiting if mild signs, administer activated charcoal material in gastrointestinal system
with sorbitol as cathartic, diazepam bolus or CRI, Treatment: emetics, gastric lavage, activated charcoal,
methocarbamol (55-220 mg/kg slow IV, repeat enemas; surgery or endoscopy if lead in stomach;
in 12 h if needed). Propofol or pentobarbital if diazepam or pentobarbital as needed to stop seizures;
needed. specific to chelate lead and hasten excretion: calcium
ethylenediaminetetraacetic acid (Ca EDTA) (25 mg/kg,
Chlorinated Hydrocarbons IV or SC, q6h as 1% solution in dextrose for 2-5 days)
Common use: agricultural products and insecticides; or succimer (10 mg/kg PO q8h for 5 days, then q12h
lipid-soluble products usually absorbed through skin for 14 days; Chemet, Sandofi Pharm, NY)
Clinical findings: apprehension, hypersensitivity,
hypersalivation, exaggerated response to stimuli, muscle Ethylene Glycol
twitching of face and neck progressing to severe Common use: automobile antifreeze, color film processing
fasciculations and tremors; tonic-clonic seizures may solutions
occur Clinical findings: ataxia, severe depression, polyuria-
Diagnosis: history of access, characteristic signs, polydipsia, vomiting; seizures are rare
insecticide smell to haircoat, analysis of stomach Diagnosis: history of exposure, characteristic signs, severe
contents metabolic acidosis, calcium oxalate crystalluria;
Treatment: wash with warm soapy water to prevent further eventually, decreased urine production and acute renal
exposure; if ingested (rare), gastric lavage and instill failure. Diagnosis and treatment of this disorder are
activated charcoal; pentobarbital to effect discussed in detail in Chapter 44.

CBC, Complete blood count; CRI, constant rate infusion; IM, intramuscular; IV, intravenous; ppm, parts per million; RBC, red blood cell; SC,
subcutaneous.