Dogs And Tryptophan - Silly Rumour Or Not?

[UltimatePup]

Hi

I've been reading something that strikes me as utterly daft, so I thought I'd check with you guys for your knowledge... There's a rumour about that Tryptophan is not good for dogs, hence to avoid feeding them turkey. Seeing as Tryptophan has been in pretty much every form of meat protein since the dawn of time it seems very unlikely that any carnivore or omnivore would be harmed by it in any way. Also, it's used in isolated form (L-Tryptophan) in many calming agents used for animals, including dogs.

The only scientific reference I have come across was a study that fed large amounts of D,L-Tryptophan to dogs over many weeks, which produced dangerous changes in their bladders. Seeing as D-Tryptophan is not natural(?) and large amounts of any isolate are not natural, that seems like a far cry from normal amounts of Tryptophan bound within protein foods or small amounts of L-Tryptophan in supplements...no?!

I'm hoping the rumour originated from the same people that advise feeding dogs toast and Wheatbix, but do just want to check in case there's a real foundation for it.

Ta

[Staranais]

There's nothing on VIN about any kind of tryptophan toxicity, and I've never heard of it.

Wouldn't turkey contain mainly L-stereoisomer tryptophan anyway, like any other meat?

I too have heard of tryptophan being used for anxiety disorders, though, it theoretically makes extra serotonin in the CNS.

[sheena]

Sounds like the report was written by some vegetarians I for one, don't believe everything I read. Dogs have been eating meat for a very long time & they havn't become extinct yet.

[Chezy]

my dogs are gunna get their turkey leg each 2morrow , like every year

[ruffpup]

I remember it (supplements) was banned back in the 90s, and just now did a search and checked out the Wikipedia site, it mentions both that way-back ban, and also a belief that turkey is high in it, not so, Wiki reckons.

Lengthy but interesting info (depending on how much one can believe anything on the net lol)

eta clarification

Edited December 24, 2010 by ruffpup

[Erny]

I remember it (supplements) was banned back in the 90s, and just now did a search and checked out the Wikipedia site, it mentions both that way-back ban, and also a belief that turkey is high in it, not so, Wiki reckons.

Lengthy but interesting info (depending on how much one can believe anything on the net lol)

eta clarification

The "ban" was in the USA, wasn't it? And that had something to do with there being a bad batch of whatever it was they were producing as the L-Tryptophan supplement back then?? Can't remember, but remember something about it. But I don't think it was about Tryptophan being bad (generally speaking) for dogs. I don't know much about it other than Tryptophan being what transverses the blood brain barrier and converts to Serotonin which itself has the calming influence over dogs.

[AmandaJ]

I remember it (supplements) was banned back in the 90s, and just now did a search and checked out the Wikipedia site, it mentions both that way-back ban, and also a belief that turkey is high in it, not so, Wiki reckons.

Lengthy but interesting info (depending on how much one can believe anything on the net lol)

eta clarification

Tryptophan supplements were banned as the manufacture process was linked to changes that made it carsinogenic. It is back on the market mow. I have used natural whole foods high in tryptophan to try and elleviate an anxiety disorder in a dog - without success - you need to much of the whole food to get the levels up sufficiently. I haven't been able to find any info on what it was in the original manufacture process that was believed to cause the problem so I won't take the risk and use the new supplements.

Edited to say - L-Tryptophan

Edited December 24, 2010 by AmandaJ

[ruffpup]

Apparently the ban started in the US but other countries followed suit. My then dr advised me to get some back then, which I didn't straight away then it was suddenly not available, taken off the market (Australia-wide I was told). And yes, it's back now, I think has been for quite a while.

Wikipedia doesn't mention dogs that I saw, just reading the screen quickly, but there's a chart on tryptophan content and turkey is about halfway down the food list, equal to chicken and just above beef. There wouldn't be much left if we avoided all on the list.

I haven't seen anything yet about adverse effects on dogs, there's a lot on giving it to dogs though.

edited - typos

Edited December 25, 2010 by ruffpup

[UltimatePup]

I haven't been able to find any info on what it was in the original manufacture process that was believed to cause the problem so I won't take the risk and use the new supplements.

It was one Japanese company who started genetically engineeering the bacteria they used to produce Tryptophan. Being GM, the bacteria, of course, changed in ways other than intended, which resulted in an unknown toxic byproduct which caused illness in very tiny concentrations. The company settled for a huge sum of money. Tryptophan is now produced (I believe) from plant materials, so should be perfectly fine (unless some bright spark decides to GM those too...)

Also, it never went off the market per se. e.g. It was still manufactured by approved companies for use in baby formula for all those years, otherwise we'd have had screaming little nutters for babies. Some countries just restricted its import as a sensible precaution but, because slow bureaucratic minds work v e r y s l o w l y, it was a great many years after this isolated incident that they finally lifted the ban.

Edited December 25, 2010 by UltimatePup

[ruffpup]

thanks for those extra details, UP. At this time of year I forget details too quickly to type them up and I'm wary of putting links or big pages of detailed info into a thread. The ban I remember was for supplements - I presume vitamin tablet style - and probably in a higher dose than for things like additives.

fwiw, my pooches get turkey a lot and love it, close favourite after chicken in their varied diet. They're still healthy.

Cheers

[AmandaJ]

Just some light reading for those interested:

http://avmajournals.avma.org/doi/abs/10.24...ma.2000.217.504

http://www.ncbi.nlm.nih.gov/pubmed/8575968