Dog illness from eating horse poop

[Angelus9]

Who with horses and dogs can't relate to the occasional canine consumption of road apples?.....but I admit I hadn't thought of this aspect of it before.

http://www.californiaveterinaryspecialists.com/news/Beware-Horse-Poop-Can-Be-Deadly-To-Your-Dog-n20/

Excerpt: "On presentation to the ER, Roxy was disoriented and uncoordinated and her condition was rapidly deteriorating. Recognizing the symptoms and fearing the worst Dr. Jennifer Schultz asked the owner if the horses had been recently dewormed, and the answer was yes. Many horse dewormers contain ivermectin which can be deadly to dogs. Most horse owners know these dewormers can be harmful if given to their dogs directly, but don’t realize that they can be just as deadly if a pet eats the horse droppings after a recent deworming. This toxin can last up to two weeks in the environment in the summer time and longer in the winter time when the colder temperatures delay the toxin’s degradation."

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[awaring1]

Crap! I will have to be extra careful to keep my pups out of the barn on our next deworming cycle.

Thanks for the info!

 

[withoutane]

Yeah ivermectin is pretty nasty stuff. It was given to my dachshund when he was an 8 wk old puppy (pretty standard procedure) and he had a reaction and almost died. My mom was going to go fly down and pick him up from the breeder and they told us to cancel her ticket - that's how sick he was. He's had a really sensitive gastrointestinal system his whole life and I think it's related to the reaction he had. I've also never put him on heartworm preventative (even those without ivermectin) because I'm so afraid he'll have another reaction. I'm probably overreacting but you can never be too safe.

 

[david594]

Yeah ivermectin is pretty nasty stuff. It was given to my dachshund when he was an 8 wk old puppy (pretty standard procedure) and he had a reaction and almost died. My mom was going to go fly down and pick him up from the breeder and they told us to cancel her ticket - that's how sick he was. He's had a really sensitive gastrointestinal system his whole life and I think it's related to the reaction he had. I've also never put him on heartworm preventative (even those without ivermectin) because I'm so afraid he'll have another reaction. I'm probably overreacting but you can never be too safe.

Taking a larger than necessary risk going without HW prevention to avoid a much smaller and predictable risk related to your dog possibly having an ivermectin sensitivity? Yeah, I would definitely call that overreacting.

If you're really concerned about your dog have an ivermectin sensitivity then you might want to consider getting the genetic testing done. The MDR-1 deficiency also affects the metabolism of a bunch of other drugs your dog could potentially receive at some point. Although it's entirely possible your dog is completely normal and the breeder just gave him too much of a horse dewormer.

If you live in parts of canada or other areas where heartworm isn't endemic then I guess my comments don't really apply.

 

[WhtsThFrequency]

I've also never put him on heartworm preventative (even those without ivermectin) because I'm so afraid he'll have another reaction.

I don't know where you live...but considering we get at least one dog a week in necropsy with heartworm disease....I would highly reconsider going without preventative completely. But, that's up to you and your vet.

Since you don't know for sure it was actually the Ivermectin that made him sick, testing would be needed to confirm an actual sensitivity....

But anyways - I hadn't actually heard of "road apples" 🙂laugh🙂 being such a danger - very interesting!

 

[withoutane]

Ah yes, I knew I would get some blowback from my post. Nope, heartworm isn't a big deal where I live. I've never actually even seen a heartworm case. Trust me, I am not dumb or uninformed - I work in a vet office and I'm going to vet school in the fall. If my parents would pay for me to get the genetic test done, then I would. But, unfortunately, I do not control the finances for my pets and my parents don't think we need to know. So, I'm taking a risk (albeit a small one considering that hw isn't prevalent in my area) and my dog isn't on heartworm preventative. He's had the best vet care money can buy otherwise, though, and I test him at least annually for heartworm and intestinal parasites. Haven't had a positive yet! 🙂

 

[cowgirla]

Ah yes, I knew I would get some blowback from my post. Nope, heartworm isn't a big deal where I live. I've never actually even seen a heartworm case. Trust me, I am not dumb or uninformed - I work in a vet office and I'm going to vet school in the fall. If my parents would pay for me to get the genetic test done, then I would. But, unfortunately, I do not control the finances for my pets and my parents don't think we need to know. So, I'm taking a risk (albeit a small one considering that hw isn't prevalent in my area) and my dog isn't on heartworm preventative. He's had the best vet care money can buy otherwise, though, and I test him at least annually for heartworm and intestinal parasites. Haven't had a positive yet! 🙂

Oregon does have HW, and it is getting more prevalent
http://www.heartwormsociety.org/veterinary-resources/slide.html

I lived in a "cold" state for a while (one thats less colorful than OR on te map!) and we still saw about 2-3 cases a year. Most of them were dogs not on preventative who lived in the same house/neighborhood as a HW+ dog coming up from the south.

I think the chances of him having a bad reaction to the HW treatment is way more likely than to a non-ivermectin preventative, but thats JMO. Hope your luck continues to hold out, that was never a risk I could bring myself to take even with dogs in the "MDR1 family" of breeds.


Re: the road apples. I imagine this is true of many drugs we give our horses. So why do organic farmers always want to buy our manure?

 

[lunajett]

Who with horses and dogs can't relate to the occasional canine consumption of road apples?.....but I admit I hadn't thought of this aspect of it before.

http://www.californiaveterinaryspecialists.com/news/Beware-Horse-Poop-Can-Be-Deadly-To-Your-Dog-n20/

Excerpt: "On presentation to the ER, Roxy was disoriented and uncoordinated and her condition was rapidly deteriorating. Recognizing the symptoms and fearing the worst Dr. Jennifer Schultz asked the owner if the horses had been recently dewormed, and the answer was yes. Many horse dewormers contain ivermectin which can be deadly to dogs. Most horse owners know these dewormers can be harmful if given to their dogs directly, but don’t realize that they can be just as deadly if a pet eats the horse droppings after a recent deworming. This toxin can last up to two weeks in the environment in the summer time and longer in the winter time when the colder temperatures delay the toxin’s degradation."

Huh, very interesting. I just had to bring my guy to the KSU ER yesterday for sudden onset blindness. Working him up, one of the questions the opthamalogist asked was "has he been exposed to Ivermectin?" Apparently it could cause some of the optho signs we were seeing, but there's no way he's been exposed to Ivermectin.

And, small world, I used to work at CVS with Dr. Schultz.

 

[bunnity]

Why not use Revolution or Advantage Multi for HWP - neither of them contain ivermectin. If the dog does get HW the treatment is way more toxic than any preventative.

Re: the rest of the thread... of course a horse amount of ivermectin could be toxic to a dog. A horse amount of plenty of other things could be toxic to a dog too (water...?).

 

[racccjlm]

I don't have my dog on any heart worm preventative - which I absolutely hate. We've pretty much exhausted the list - she gets sick for literally months with whatever type of preventative we try. Very frustrating - but the vet finally just said that if we kept going, it was going to kill her. So, she's screened regularly - though I don't know what would happen if she actually did get heart worm. Treatment is nasty!

 

[thumbz]

I'm not usually in the vet forums but wow this thread had insane timing. A week or two ago our border collie/blue heeler cross with the recessive gene for ivermectin got into the horse poop after they had been dewormed.

About 6 hours later she started seizing upstairs on the couch so we rushed her to the emergency vet. That night she went completely blind, was unable to walk or perform most functions. The vet knew right away what happened thank goodness. From there the vet got Intralipid from the local hopsital and started the dog on an aggressive treatment. The next day she showed no improvement. Got another treatment of intralipid and started to improve. Last Sunday (a week ago), 5 days after that first night, she got to come home because she was able to feed herself and the catheter could come out. And now she is almost back to her normal self. She is still having some vision problems but apparently it can take up to a month for her to make a full recovery.

 

[Ben and Me]

Why not use Revolution or Advantage Multi for HWP - neither of them contain ivermectin. If the dog does get HW the treatment is way more toxic than any preventative.

Or Sentinel...

 

[eventualeventer]

Thumbz, glad your pup is doing OK!

As for the rest of the thread, I'm guessing that there's a reason ivermectin is the most heard-of side effect (other than ralphing in bed later) of road apple consumption. If you'll bear with me for a thought experiment....

I haven't had pharm, but, thinking about it logically, in order for the original drug to be an issue for feces eaters, the drug or a toxic metabolite would need to be present in the horse feces in sufficient concentration (horses on high forage diets can produce 40++ lbs of manure per day) for the dog to reach the toxic dose before getting full or horking it up behind the barn. This is more likely to be a problem if the dog is more sensitive to the drug than the horse, as in dogs with MDR-1 mutations eating ivermectin-containing manure muffins.

For this to happen, the drug would have to have at least one of several characteristics. I suppose if a drug has a low enough oral absorption and is not degraded in the GI tract, that would produce toxic poo. It could be eliminated (heh) by biliary excretion, but it would have to be excreted either unchanged or, alternatively, as a toxic metabolite. Many drugs are degraded into inactive metabolites before excretion and/or eliminated in the urine, which is much less delectable to canines. There are other pharmacological properties which would slow down the rate of excretion of a given dose of drug, such as drugs that are taken into fat stores and slowly released, causing it to be present in smaller quantities in any given pile o' poo.

Finally, the horse has to get the drug in the first place. Since ivermectin is a very commonly used dewormer, a large number of horses in any given year will get at least one dose of ivermectin, possibly more. I'm speculating without numbers, but I would wager that even phenylbutazone, which every lesson barn seems to have on their shelf, is not administered with anything approaching the frequency of ivermectin. I understand that moxidectin can be a problem as well because of the frequency of use (albeit still not as commonly used in some areas as ivermectin) and the narrower therapeutic window.

In sum, there are a lot of factors involved in whether a horse drug will be enough of a problem for manure chowhounds to become a topic on an Internet message board. And thus concludes my stream-of-consciousness on toxic horse waste. Feel free to tell me I'm crazy and/or wrong.

 

[withoutane]

I really appreciate your concern but trust me - I've given this a lot of thought! My vet/boss felt like, since my clinic hasn't even had a heartworm case in years, that the risk of my dog reacting to heartworm preventative is too great. A lot of the non-ivermectin-containing brands have compounds that are very similar to ivermectin and I just can't take the chance. Now, Oregon did see a jump in heartworm cases after Hurricane Katrina but my area didn't feel the hit. Just lucky I guess. 😉

Again, thanks for your concern but I've made my choice and I feel like it is the best plan for my dog's special needs.

However, one thing I am very worried about is leptospirosis. All of a sudden it is spreading through our patients like wildfire! We've had 5 positive cases in the last few weeks. What's even weirder is that some patients were infected with multiple different strains! I definitely have both my dogs vaccinated for lepto!

 

[rubygirl]

im surprised that there have been NO cases of heart worm in your area withoutane, in NH he have seen a huge upsurge in the number of cases of HW seen primarily due to all the southern dogs coming up, we see at least one a month probably in the clinic i am currently at.
As a side note, it does seem fairly ridiculous that ivermectin FROM THE HORSE POO would be the problem, as someone mentioned earlier, it is digested and excreted primarily as metabolites, but if your horses are anything like my knw they are experts at spitting out a good sized chunk on the ground, as well as wearing it like lipstick for the rest of the day, and proceeding to rub it on everything. while my dogs have never gotten sick, the chunk that comes out could probably be plenty to be toxic to a small dog, i wonder if it is less poo eating and more hoover cleanup of the dropped dewormer that is causing the problem

 

[eventualeventer]

Actually, the avermectins (ivermectin, moxidectin) ARE eliminated unchanged in the feces, which is part of why they are a problem for sensitive dogs. I'm sorry I wasn't clear in my long ramble about why other drugs are less of an issue.

I see what you mean about unswallowed bits of paste, but you might want to reevaluate your technique if they are spitting a good chunk out on the ground - besides the risk to the dogs, the horses are likely getting underdosed, risking inadequate treatment of their parasite burden as well as encouraging resistance, which is becoming a problem in many areas.

One of the most common mistakes is not getting it far back enough on the tongue - you should be burying the paste syringe in their mouth as far as you can without putting your hand in their mouth, pointing it straight back. Being right-handed, I like to stand on the horse's right facing forward and use my left hand and arm to restrain their head. I put my left arm under their head and grab the bridge of their nose with my left hand so that if they are trying to drop their head, I can support it on my left shoulder, and if they try to lift their head out of reach, I have a hand on their nose. This leaves my right hand free to maneuver the syringe in at the corner of the mouth, then rotate it so it's pointing back towards the throat and push it the rest of the way in before pushing the plunger. If this doesn't work or they are trying to run me over/strike/etc., I put a lip chain on, back them into the corner so they're not on top of me and have fewer places to escape to, and stand facing the horse but a bit to the side and pop the syringe in that way. If it's a large volume, I give 15-20 cc, give them a break, pat them, etc., then give another 15-20 cc. For occasional things like wormers, you can also use an empty worming syringe to "dose" them with applesauce to get both of you used to it before you have to do the real thing.

 

[rubygirl]

Actually, the avermectins (ivermectin, moxidectin) ARE eliminated unchanged in the feces, which is part of why they are a problem for sensitive dogs. I'm sorry I wasn't clear in my long ramble about why other drugs are less of an issue.

I see what you mean about unswallowed bits of paste, but you might want to reevaluate your technique if they are spitting a good chunk out on the ground - besides the risk to the dogs, the horses are likely getting underdosed, risking inadequate treatment of their parasite burden as well as encouraging resistance, which is becoming a problem in many areas.

One of the most common mistakes is not getting it far back enough on the tongue - you should be burying the paste syringe in their mouth as far as you can without putting your hand in their mouth, pointing it straight back. Being right-handed, I like to stand on the horse's right facing forward and use my left hand and arm to restrain their head. I put my left arm under their head and grab the bridge of their nose with my left hand so that if they are trying to drop their head, I can support it on my left shoulder, and if they try to lift their head out of reach, I have a hand on their nose. This leaves my right hand free to maneuver the syringe in at the corner of the mouth, then rotate it so it's pointing back towards the throat and push it the rest of the way in before pushing the plunger. If this doesn't work or they are trying to run me over/strike/etc., I put a lip chain on, back them into the corner so they're not on top of me and have fewer places to escape to, and stand facing the horse but a bit to the side and pop the syringe in that way. If it's a large volume, I give 15-20 cc, give them a break, pat them, etc., then give another 15-20 cc. For occasional things like wormers, you can also use an empty worming syringe to "dose" them with applesauce to get both of you used to it before you have to do the real thing.

i didnt mean to imply they spit it all out, they do sometimes spit out a small chunk no matter how its given, its not the technique they are just quite crafty with there tongue. the amount spit out is negligible when it comes to dosing my 1000 pound horse but when some comes out, proportionally it would be a lot for a dog. i have been worming my horses for many years and we have never had an issue with worms, we have run periodic fecals on them too.

 

[RadRadTerp]

Moxidectin is actually a Milbemycin type Macrocyclic lactone (macrolide), and not an Avermectin. If I remember my Parasit studies well, that would make moxidectin more lipophilic than ivermectin.

Found this (Veterinary Pharmacology and Therapeutics By Jim E. Riviere, Mark G. Papich) in google books:
http://books.google.com/books?id=ie...ge&q=moxidectin milbemycin avermectin&f=false