> Why is Chocolate Poisonous to Ferrets
> http://www.weaselwords.com/pages/art006.asp
 
Hmmm, so what IS the evidence?  Although many pet sites on the web talk
about theobromide toxicity, the language leads me to think that they are
all quoting one original article.  So I looked for other sources.
 
The medical sources talk about the diuretic and cardiovascular theraputic
effect of theobromide, as a drug, so there is no doubt that there is a
medical effect.  The question is whether chocolate should be considered
poisonous to ferrets.  No original info appeared in my search.
 
Our own Bob Church (known for his impeccable research) says:
"CHOCOLATE: Contains theobromide, which is poisonous in dogs.  There are
lots of reports of ferrets eating large amounts of chocolate without ill
effects.  Most people argue that since it is toxic in dogs, it should be
toxic in ferrets, but one doesn't necessarily prove the other.  The
occasional chocolate chip is probably safe, but if you worry about it,
subsitute carob chips, also occasionally."
http://www.storm.ca/~ferret/bchurch2.shtml
 
(This, BTW, from a post that apparently first appeared on this list in
1998)
 
A chocolate afficionado's site, quirky but well-researched:
"Theobromine, the alkaloid contained in the beans, resembles caffeine in
its stimulant action.  Its effect on muscle, the kidneys and the heart is
more pronounced than caffeine, while its effect on the central nervous
system is less intense."
http://www.mrkland.com/fun/xocoatl/science.htm
 
University of Oxford, UK -- student chemistry site.  Dated 2001.  Nice
reference site.
"The toxicological properties of this material have not yet been
investigated"
http://www.chem.ox.ac.uk/mom/chocolate/theoChemID.html
(many sites did not distinguish between caffeine and theobromide.  The
MSDS for theobromide comes up with the one for caffeine)
 
From a Drugs and Medicine site, on the history of drugs used for
hypertension:
"In 1886, Bronne at the University of Strasburg investigated the diuretic
action of caffeine, which led to his supervisor, von Schroeder, examining
an alkaloid found in cocoa seeds - theobromide - which was found to be a
more effective diuretic(3)"
http://www.freewebs.com/scientific_anti_vivisectionism11/
heartdishypertension.htm
 
From a lecture on the treatment of particular cancers:
"..stay away from foods that contain amines, theobromine, xanthenes, and
caffeine.... These substances, vasoactive amines are called pressor
amines.  They are precursors for catecholamines such as adrenaline,
which trigger carcinoid tumors to secrete vasoactive substances, which
cause symptoms or carcinoid crisis.....Foods that are moderately high
in these substances, such as coffee, chocolate, some nuts and pizza can
be eaten in small amounts"
        http://www.carcinoid.org/MwarnerlectureSept2.htm
 
Respiratory pharmacology (used as a treatment for Asthma):
"Xanthine bronchodilators act to maintain cAMP levels by inhibiting
phosphodiesterase (rather than increasing cAMP levels as with
adrenergics).  In addition to bronchodilation, they are also CNS
stimulants, coronary artery dilators, cardiac stimulates & they promote
diuresis.  Xanthines are a group of vegetable organic compounds, the
most common of which are caffeine, theophylline, & theobromide."
http://www.respresources.com/Pharmacology.htm
 
On the NIH site, an abstract for the effects on rats:
TOXICOL APPL PHARMACOL; 49 (12).  1979.  127-150.  "Therobromine,
a component of chocolate which has caused sweating, trembling, and
headaches when taken in large amounts, was added to the diet of..rats...
prominant effects were anorexia ... , decrease in body weight... growth
retardation,... atrophy of the thymus glands..  testicular atrophy...
Hamsters and mice were more resistant...."
http://toxnet.nlm.nih.gov/cgi-bin/sis/search (search for theobromide)
 
If nothing else, all this highlights the idea that foods and drugs are
not really separate entities, and that something that is normally a
harmless food can, under the right circumstances, act as a drug (good
or bad).
 
--Claire
(Sam, Frankie, Missy, Louis and Lilo)
[Posted in FML issue 4453]