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Chocolate Toxicosis 159

• Modified live and inactivated cell culture inactivated vaccines. Lethargy, fever, anorexia, SUGGESTED READING
vaccines are available; do not prevent infec- and limb soreness may occur 1-3 weeks after Sykes, JE. Chlamydial Infections. In Sykes JE, editor:
vaccination.
VetBooks.ir • Vaccines are not considered core but are Technician Tips AUTHOR: Renee T. Carter, DVM, DACVO Diseases and Disorders
tion but reduce the severity of clinical signs
Canine and feline infectious diseases, St. Louis,
2014, Elsevier, pp 326-333.
recommended in situations in which a
large number of cats will be housed together
(catteries). Close contact is required for cat-to-cat transmis- EDITOR: Joseph Taboada, DVM, DACVIM
sion. Cats with suspected infection should be
• Vaccines should be used with caution singly housed to limit transmission. Decon-
in immunocompromised cats; use only taminate contact surfaces/cages between uses.

Chocolate Toxicosis Client Education
Sheet

BASIC INFORMATION • Dehydration Advanced or Confirmatory Testing
• Cardiac arrhythmias (sinus tachycardia, pre- Methylxanthine levels in serum, plasma,
Definition mature ventricular contractions, ventricular stomach contents, and urine are not helpful
Chocolate toxicosis refers to the acute onset tachycardia) for treatment and are seldom measured.
of stimulatory signs that occur in a dose- • Hyperthermia
dependent manner after ingesting chocolate • Tremors, seizure TREATMENT
containing naturally occurring alkaloids referred
to as methylxanthines. Theobromine and caf- Etiology and Pathophysiology Treatment Overview
feine are the methylxanthines of concern in • Proposed mechanism of action Decontamination can be considered in
chocolate. ○ Competitive inhibition of cellular adenos- asymptomatic patients up to 8 hours after
ine receptors: cerebral cortical stimulation, exposure and is extremely effective in reducing
Synonym seizures, diuresis, increased myocardial the risk of clinical signs. After signs are present,
Methylxanthine toxicosis contraction, and smooth muscle relaxation treatment involves adequate fluid administra-
○ Caffeine: stimulates synthesis and release of tion for cardiovascular support and to prevent
Epidemiology catecholamines, especially norepinephrine dehydration, the use of sedatives to control
SPECIES, AGE, SEX central nervous system (CNS) stimulation,
Dogs far more often affected than cats DIAGNOSIS antiarrhythmics for cardiac dysrhythmias, and
supportive care for GI upset.
GEOGRAPHY AND SEASONALITY Diagnostic Overview
Major holidays (Easter, Christmas, Valentine’s A tentative diagnosis is made based on history Acute General Treatment
Day, Halloween) result in increased opportunity (or other evidence of exposure to chocolate such • Decontamination of patient (p. 1087):
for intoxication due to increased presence of as chocolate in vomitus), compatible clinical ○ Emesis (p. 1087): up to 8 hours after
chocolate in homes. signs, or both. There are no clinically relevant exposure in asymptomatic dogs.
confirmatory tests. ○ Activated charcoal 1-2 g/kg PO once, with
Clinical Presentation sorbitol or other cathartic: chocolate will
DISEASE FORMS/SUBTYPES Differential Diagnosis increase the risk of hypernatremia from
Signs are typically dose dependent • Toxic: caffeine, theophylline, aminophylline, activated charcoal. Monitor for hyperna-
• <20 mg/kg of methylxanthines: gastro- guarana, 5-hydroxytryptophan, pseudo- tremia and associated signs (tremor, ataxia,
intestinal (GI) upset, polydipsia, and ephedrine, phenylephrine, amphetamines, seizures). Benefit must outweigh the risk
pancreatitis albuterol, cocaine, phenylpropanolamine, of hypernatremia; give only if over a lethal
• 20-40 mg/kg of methylxanthines: above plus antihistamines, metaldehyde, serotonergic dose of chocolate.
hyperactivity medications (antidepressants) ○ Urinary catheter: caffeine may be reab-
• 40-50 mg/kg of methylxanthines: above plus • Nontoxic: vomiting, arrhythmia (p. 1284), sorbed through the bladder wall. High
cardiotoxicity hypersalivation (p. 1274) doses may warrant placement of a urinary
• >60 mg/kg of methylxanthines: above plus catheter to help decrease this reabsorption
tremors and seizures Initial Database and increase caffeine elimination.
• Packed cell volume (PCV)/total solids (TS): • CNS stimulation
HISTORY, CHIEF COMPLAINT ± evidence of hemoconcentration due to ○ Acepromazine 0.025-0.05 mg/kg IV,
Owners will typically report an exposure to dehydration titrate up as needed, for hyperactivity
chocolate. Pets will often be polydipsic and • Serum chemistry profile ○ Methocarbamol 55-100 mg/kg slow IV
may vomit before presentation, with chocolate ○ Blood glucose: ± hyperglycemia to effect for tremors
evident in the vomitus. Signs can progress to ○ Electrolytes: risk of hypernatremia, ○ Diazepam 0.5-2 mg/kg IV or midazolam
hyperactivity, tachycardia, tremors, and seizures. especially if activated charcoal is given 0.1-0.5 mg/kg IV for hyperactivity,
• Electrocardiogram (ECG [p. 1096]): sinus tremors, and seizures
PHYSICAL EXAM FINDINGS tachycardia, rarely ventricular dysrhythmias ○ Barbiturates, gas anesthesia for seizures
• Tachycardia • Blood pressure (p. 1065): hypertension possible refractory to benzodiazepines
• Tense, often distended abdomen • Abdominal imaging: if persistent GI signs or • Cardiac arrhythmias
• Hypersalivation abdominal pain, to rule out other differential ○ Beta-blockers for significant sinus tachy-
• Hyperactivity diagnoses cardia in calm patients
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