Treatment of chocolate toxicosis in a Mynah bird (a case report)

Abstract

Introduction:

Etiology: Chocolate is derived from the roasted seeds of Theobroma cacao . The toxic principles in chocolate are the methylxanthines theobromine (3,7-dimethylxanthines) and caffeine (1,3, 7-trimethylxanthine). Although the concentration of theobromine in chocolate is 3-10 times that of caffeine,both contribute to the cinicalsyndrome seen in chocolate toxcsis.
Pathogenesis: Theobromine and caffeine are readily absirbed from from the GI thact and are widely distributed throughout the body. They are methabolizes in the liver and undergo enterohepatic recycling. Methylzanthines are excreted in the urine as both methabolites and unchanged parent compounds. The halflives of theobromine and caffeine in dogs are 17.5 hours and 4.5 hours respectively.
Theobromine and caffeine competitively inhibit cellular adenosine receptors, resulting in CNC stimulation, diuresis and tachycardia. Methylxanthines also increase intracellular calcium levels by increasing cellular calcium entry and inhibiting intracellular sequestration of calcium by the sarcoplasmic reticulum of straited muscle. The next effect is increased strenght and conractility of skeletal and cardiac muscle. Methylxantines may also compete for benzodiazepine receptors within the CNS and inhibit phosphodiesterase, resulting in incresed cyclic AMP levels. Methylxantines may also increase circulating levels of epinephrine and norepinephrine.

Clinical signs in birds: Abnormal behavior, aggression, changing habits, anorexia, arrhythmia, diarrhea, dullness, excitement, hyperesthesia, seizures or syncope, sudden death, vomiting or regurgitation
Previous reports: the reports of chocolate toxicity in captive birds are sketchy and anecdotal and much less frequent than in dogs. It has been suggested that birds are less likely to eat toxic amounts of chocolate but that they may be more sensitive to its effects as all previously reported clinical cases have resulted in death of the bird. Clinical signs reported before death have included depression or hyperactivity, cardiac arrhythmias, regurgitation, convulsions and diarrhea. There is a single non-peer reviewed case report of chocolate toxicity in an african grey parrot that ate a chocolate doughnut and died showing liver, lung and renal congestion as its main pathological findings.

Case history: A 4 year old Mynah bird was admitted to the clinic with a history of periodic convulsions and tremors during the past four mounts.
Clinical signs: In clinical examination the bird was active and in good body condition. It had moderate to severe tremors and frequent convulsions (2-3 times a day) since last 4 months. After asking some questions about the feeding habits of the bird, we found that since 4 mounts ago their child fed the bird with some chocolate.
Treatment: Due to the signs and the simultaneity of the onset of the clinical signs and chocolate consumption, we treated the bird for theobromine poisoning. The owner was informed about the toxicity of cocoa and caffeine containing foods and a diphenhydramine HCL elixir was prescribed to control the tremors at a dose of 2.2 mg/l of drinking water.
Result: The convulsions discontinued the day after the treatment started and the tremors decreased. The Mynah completely recovered after 4 days and the drug discontinued 7 days after admitting to the clinic.
Keywords: toxicosis, chocolate, theobromine poisioning, cocoa, Mynah

References:
Lightfoot TL, Yeager JM. Pet Bird Toxicity and Related Environmental Concerns. Veterinary Clinics of North America: Exotic Animal Practice 2008;11:229-259

Cole G, Murray M., suspected chocolate toxicosis in an african grey parrot (psittacus erithacus). In: proceeding of the annual conference of the Association of avian veterinarians: monterey; 2005, P. 339-400

Merck veterinary manual 15th edition, pages 2362-2364

Full text

Treatment of chocolate toxicosis in a Mynah bird (a case report)
Mokaram G. Sara
DVM and PhDof veterinary surgery from the university of Tehran
Corresponding Author’s email: mokaram@ut.ac.ir
Introduction:
Etiology:Chocolate is derived from the roasted seeds of Theobroma cacao . The toxic principles in chocolate are the
methylxanthines theobromine (3,7-dimethylxanthines) and caffeine (1,3, 7-trimethylxanthine).Although the concentration of
theobromine in chocolate is 3-10 times that of caffeine,both contribute to the cinicalsyndrome seen in chocolate toxcsis.
Pathogenesis:Theobromine and caffeine are readily absirbed from from the GI thact and are widely distributed throughout the
body.They are methabolizes in the liver and undergo enterohepatic recycling.Methylzanthines are excreted in the urine as both
methabolites and unchanged parent compounds. The halflives of theobromine and caffeine in dogs are 17.5 hours and 4.5 hours
respectively.
Theobromine and caffeine competitively inhibit cellular adenosine receptors, resulting in CNC stimulation, diuresis and
tachycardia.Methylxanthines also increase intracellular calcium levels by increasing cellular calcium entry and inhibiting
intracellular sequestration of calcium by the sarcoplasmic reticulum of straited muscle. The next effect is increased strenght and
conractility of skeletal and cardiac muscle.Methylxantines may also compete for benzodiazepine receptors within the CNS and
inhibit phosphodiesterase,resulting in incresed cyclic AMP levels.Methylxantines may also increase circulating levels of
epinephrine and norepinephrine.
Clinical signs in birds:Abnormal behavior, aggression, changing habits, anorexia, arrhythmia, diarrhea, dullness,
excitement, hyperesthesia, seizures or syncope, sudden death, vomiting or regurgitation
Previous reports:the reports of chocolate toxicity in captive birds are sketchy and anecdotal and much less frequent than in dogs. It
has been suggested that birds are less likely to eat toxic amounts of chocolate but that they may be more sensitive to its effects as all
previously reported clinical cases have resulted in death of the bird.Clinical signs reported before death have included depression
or hyperactivity, cardiac arrhythmias, regurgitation, convulsions and diarrhea.There is asingle non-peer reviewed case report of
chocolate toxicity in an african grey parrot that ate achocolate doughnut and died showing liver, lung and renal congestion as its
main pathological findings.
Case history: A 4 year old Mynah bird was admitted to the clinic with ahistory of periodic convulsions and tremors during the past
four mounts.
Clinical signs: In clinical examination the bird was active and in good body condition. It had moderate to severe tremors and
frequent convulsions (2-3 times aday) since last 4months.After asking some questions about the feeding habits of the bird, we
found that since 4mounts ago their child fed the bird with some chocolate.
Treatment:Due to the signs and the simultaneity of the onset of the clinical signs and chocolate consumption, we treated the bird
for theobromine poisoning.The owner was informed about the toxicity of cocoa and caffeine containing foods and a
diphenhydramine HCL elixir was prescribed to control the tremors at adose of 2.2 mg/l of drinking water.
Result: The convulsions discontinued the day after the treatment started and the tremors decreased. The Mynah completely
recovered after 4days and the drug discontinued 7days after admitting to the clinic.
Keywords:toxicosis,chocolate, theobromine poisioning,cocoa, Mynah
References:
Lightfoot TL, Yeager JM. Pet Bird Toxicity and Related Environmental Concerns.Veterinary Clinics of North America:Exotic
Animal Practice 2008;11:229-259
Cole G, Murray M., suspected chocolate toxicosis in an african grey parrot (psittacus erithacus). In: proceeding of the annual
conference of the Association of avian veterinarians:monterey;2005, P. 339-400
Merck veterinary manual 15th edition, pages 2362-2364