Are cherry pits really poisonous to dogs?

August 4, 2008 12:46 PM

My yard contains lots of cherries dropped from my tree, and thousands of cherry pits from dropped cherries of yore. My puppy finds them irresistible. Googling indicates that the pits contain cyanide and are potentially harmful to dogs . . . but are they really?

Once I realized last night that he was actually swallowing the cherries and not just playing with them, I became concerned about the possibility of a physical obstruction, and in researching that learned about the cyanide thing. This morning I got up and raked up as much of the tree litter as possible, and have been picking cherries all morning--but it's an impossible task to get them all. There are thousands! And even though I thought I got all the dropped cherries and pits up, every time I turn around my puppy has one or two in his mouth (which he very nicely lets me remove in exchange for peanut butter, good boy!). He's closer to the ground than I am and is obviously a more skilled cherry pit hunter.

I called the vet hospital (one of the top vet hospitals in the country) last night and they said it was too late to make him throw up, so just keep an eye on him and he'd probably be fine. They didn't actually seem that worried about it. And so far he is fine. I'm sure he's been eating them since I brought him home six days ago.

I think he is just sort of rolling them around in his mouth and lightly chewing them. I went around with a baggie and squished all the poop I could find, and so far have found five whole pits but no crushed pits.

It is now apparent that the cherry pit problem is insurmountable short of chopping down the tree. Every year will bring more cherries, and I will never be able to eradicate all cherries and cherry pits from my yard. The tree is a major landscape feature and cutting it down would be a SERIOUS blow to my already not-lovely abode. However, poisoning my puppy is not an option.

So here are my questions:

1) What is the real risk here? Does anybody know how many he'd need to eat before it's a problem? Are whole ones dangerous or just ones that are chewed up?
2) Is there a way to keep the tree but keep it from making cherries? Some kind of tree hormone or something?

Thanks!

posted by HotToddy to pets & animals (13 comments total)

I'm not a vet.. but I did grow up on an orchard. Had a Schnauzer that would eat cherries by the pound. Forget 5.. all he had in his droppings was pits! We worried at first, but he seemed happy and never had a health issue. He eventually evolved to apricots on low hanging branches.. they're a choking hazard to boot.
posted by Vantech at 12:57 PM on August 4, 2008

I don't have an answer for you, but I can commisserate. Our two got into a pound of coffee beans someone left at the back door. We spent the night first calling animal poison control ([phone]--they charge you a fee, too), making our dogs vomit, and picking coffee beans out of the mulch by flashlight.
An animal behaviorist might be able to advise you about teaching your dog an aversion to cherries, but that doesn't sound fun.
Maybe some cherry-picking mefite can come along and tell you how to put a diaper on your cherry tree...
posted by Mngo at 1:10 PM on August 4, 2008

It's a little hard to find precise amounts. The best I found was this toxicological profile of cyanide (check the middle of page 32).

Black cherry pits contain about 78micrograms per seed. The LD50 for dogs is 5-6mg/kg (see here and here). Assuming your dog weighs 10kg, then that's 641 seeds worth. Note also that that's for seeds, not pits. The dog would have to extract the cyanide from the seed itself, which is inside the hard pit.

Different cherry varieties may contain more or less cyanide, though. Do you know what kind you have?
posted by jedicus at 1:16 PM on August 4, 2008 [3 favorites has favorites]

It's a Starkrimson black cherry tree.
posted by HotToddy at 1:18 PM on August 4, 2008

Awesome answer, jedicus! My dog is only 5 lbs., but will be 15-18 at maturity. I think the most he would ever crack open, and even this seems doubtful, is two. I took a hammer to a couple of them and they are very hard to crack. However, not knowing the first thing about toxicology (I had to look up what LD50 is) (median lethal dose, for anyone who doesn't know either), I wonder how much less than the LD50 it would take to cause illness or organ damage.
posted by HotToddy at 1:35 PM on August 4, 2008

To give you a sense of scale, the LDlo (the lowest observed lethal dose) for dogs was 1700 micrograms/kg, or 1.7mg/kg. That's about a third of the LD50, or about 50 seeds worth for your 2.27kg dog.

Humans can detoxify cyanide at a rate of about 17 micrograms/kg/minute. Assuming it's the same for dogs, that's about 55.5mg/day. In other words, your dog would have to consume lots of pits very quickly in order to overwhelm its ability to detoxify the cyanide. Again, assuming that dogs detoxify cyanide similarly to humans. I have no idea if that's true or not, and you should ask your vet. That should put you on the right track for determining if drastic measures should be taken re your cherry tree.
posted by jedicus at 1:55 PM on August 4, 2008

MeFi to the rescue once again! Thank you so much, this is exactly the information I was looking for. Amazing.
posted by HotToddy at 2:13 PM on August 4, 2008

"Is there a way to keep the tree but keep it from making cherries? Some kind of tree hormone or something?"

Proper pruning will reduce the number of cherries (in exchange you'll get larger, healthier fruit). Cherries are a lot easier to pick off the tree than off the ground. If you are not interested in the fruit yourself a post to the local free cycle when the cherries are ready will probably garner enough free labour to remove the cherries from your property.
posted by Mitheral at 2:29 PM on August 4, 2008

My friend with a cherry tree, who also happens to hate cherries, posted about it on a local food listserv and within a day foodies with buckets had stripped the tree of them.
posted by melissam at 6:25 PM on August 4, 2008

I realize I'm not answering the questions asked, but since you seem to have found those answers, I'll offer another thing to try.

My husband uses a product called Critter Ridder around his garden in an ongoing attempt to keep our dogs from nosing around there. I hesitate to actually recommend this product specifically (His comment on its effectiveness: "Eh"), but you may find it (or its ilk) is worth a shot to keep your pup from ingesting too many pits at once.

I wonder also if you might try something like putting cayenne or other equally noxious taste on some pits, and leave them around for puppy to try. Maybe one or two bad snorts will be enough to teach him to leave them [mostly] alone?
posted by SuperSquirrel at 7:09 PM on August 4, 2008

For the existing pits you could probably get a good portion of them with a shop vac. Cut your grass as low as you can and use a wideish hard floor tool.
posted by Mitheral at 8:07 PM on August 4, 2008

Re: the shop vac - If it's a wet/dry vac, be sure to use the appropriate setting. You will probably be vacuuming up rotting cherries as well as pits, and rotten fruit stinks. You could ruin your vac. I know this because I once used our shop vac on the wrong setting, on something wet and stinky, and several years later, there is still a residual stink every time the shop vac is used.
posted by SuperSquirrel at 8:14 PM on August 4, 2008

ASPCA would know the seriousness of it. I think anything could be poisionous if the animal eats too much and/or is sensitive.
posted by dasheekeejones at 10:59 AM on August 5, 2008