Page 143 - Raw Diet References Book 2019

7.2.2 Toxic agent

The principle toxic components of chocolate and life is much shorter (4.5 hours) (Farbman 2001, Hooser
cocoa products are the methylxanthine alkaloids, & Beasley 1986).
of which theobromine is the major toxin (Campbell
2001). As long ago as 1917, cacao bean shell The LD50 of theobromine has been reported to be
intoxication in horses was attributed to theobromine between 250mg and 500mg per kg body weight (BW);
by French researchers. Theobromine is particularly lethal cases have been seen when dogs ingested
toxic to dogs, because its elimination is very slow amounts of chocolate that reflect an estimated
compared with the rate in other species such as theobromine intake of 90-115mg/kg BW (Glauberg
man (Hooser 1984, Glauberg 1983). The half life of 1983, Hooser & Beasley 1986, Carson TL 2001).
theobromine in dogs is about 17.5 hours (Farbman
2001, Hooser & Beasley 1986). Theobromine The level of theobromine content of chocolate varies,
undergoes enterohepatic recirculation resulting in an with dark chocolate containing the highest level (Table
accumulative effect (Campbell 2001, Farbman 2001). 1). Unsweetened baking chocolate should definitely
As a consequence, repeated intakes of smaller (non- be kept out of reach of dogs, since it contains up to
toxic) quantities may still cause intoxication. The slow 20mg of theobromine per gram. Dogs also voluntarily
elimination of theobromine is also responsible for eat cocoa powder, in which the average theobromine
decreased survival rate in affected dogs and death level varies from 10 to 30mg/g (Sutton ‘81). About four
may still occur at a stage when clinical signs are grams of cocoa powder per kg BW may be sufficient to
already attenuating (Strachan & Bennett 1994). kill a dog (Faliu 1991). Increasingly cocoa shell mulches
are used to prevent weeds and for landscaping in
Caffeine is another methylxanthine present in gardens. They are often attractive to dogs because of
cocoa products, and may contribute to the toxicity. the chocolate smell and therefore may be a potential
However, the levels of caffeine in cocoa products are cause of theobromine poisoning (Hansen et al. 2003).
much lower than those of theobromine and the half

Table VII-15. Theobromine content of different types of chocolate and
cocoa products (mg/g)

White chocolate 0.009 - 0.035 Cocoa powder 4.5 - 30

Milk chocolate 1.5 - 2.0 Cocoa beans 10 - 53

Sweet to semisweet dark chocolate 3.6 - 8.4 Cocoa shell mulches 2 - 30

Bitter chocolate, chocolate liquor,
baking chocolate 12 - 19.6 Coffee beans -

Farbman DB 2001, Gwaltney-Brant S. 2001, Hansen et al. 2003, Shively et al. 1984, Carson 2001.

7.2.3 Clinical signs

In dogs methylxanthines cause stimulation of the beating), respiratory stress and hyperactivity (Campbell
central nervous system with tachycardia (fast heart 2001, Farbman 2001). The clinical signs include

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