akane":9klrplea said:
Just because they don't have obvious symptoms doesn't make it safe. My dog had no symptoms her blood had been thinned by something until I took her in for spaying and she nearly bled out. 2 surgeries and a week of IV fluids and vit k to keep her alive from what appeared to be a perfectly fine dog. Cedar shavings and the arguments over pine shavings are another good example. It took awhile for people to realize respiratory ailments and eventually through laboratory testing otherwise unseen liver damage came from the harmful oils in soft woods. People are just now recognizing that garlic and onion can cause hemolytic anemia if fed long term at too high of amount. How many dogs died of poisoning by grapes and raisins before someone figured that out? You can't always connect 2 things together or know what's under the surface before an event happens. You might not know why that random doe died while trying to kindle or only lived 8 years instead of 15 years and blame it on genetics or bad luck when it was actually something you fed without seeing any symptoms ahead of time.
Perhaps I did not explain myself clearly- if no
reliable source (preferably one that lists references) lists something as unsafe (i.e. they consider it safe), I'm going to assume it safe over the advice of a list that contradicts a lot of known safe/unsafe foods. If my rabbits manage to ingest something generally considered to be unsafe, obviously I'd remove the source of it but once it's down the hatch.. well, no getting it back so we might as well try to learn something from it.
Hemolytic anemia caused by sodium thiosulphate occurs fairly consistantly and is proven to be caused by cumulative feeding. Grapes, on the other hand.. do not appear toxic to all dogs, amounts ingested before renal damage becomes apparent (if it occurs at all) vary widely. The causative agent has never been discovered but it seems likely to be something that is toxic only for certain individuals for lack the genes (or having mutated genes) to utilise that food source. Ivermectin is a great example of that- If you tested that drug only on collies, it'd be a wash- almost always fatal in larger amounts and terribly risky. But not every dog is a collie- in fact, collies and collie-derivative dogs (dogs who carry the mutated MDR1 gene) are the only dogs for which ivermectin is high risk. It carries
some risks for all breeds but that's to be expected and risks are weighed against potential benefits.
Your examples prove my point nicely for me- some things are just plain old toxic to all and sundry (things like Atropa belladonna) whereas other things vary by species (comfrey) or individual (grapes).
It's tempting to say "well, let's avoid all risk and not feed any fodder that's
at all questionable" but that'd be like humans abandoning peanut butter as a food source because some people are allergic to it. And dairy products. And shellfish. And gluten. And all other nuts. And so on and so forth. Not terribly sensible, especially not when we can test for initial tolerance (starting with information to suggest the food source is safe) and then feed as part of balanced daily forage, monitoring for changes* that might suggest problems or intolerances. A sensible, evidence-based approach goes a long way in feeding a natural diet.
*Amount of water consumed per day, colour of urine or any changes there, stools, eyes, muscle tone, hydration and so on.