Help = Horse Paste Dosage
Hello – has anyone done the math and have an exact dosage of Durvet 1.87 horse past for a 250 lb horse?
Thank you for your help – Deb
I’m not a doctor, pharmacist, & also quite poor at math, but a veterinary doc on another site stated 1.87% paste should be 18.7 mg per cc/ml; which interestingly is close what is recommended for your 250 lb little pony.
231–250 lb 105–113 kg 22 mg. (Each tenth 0.1 cc = 1.87mg).
I asked my pharmacist if I could buy a 1cc syringe (without the needle) to give my cat some medicine, & he slapped one down on the counter & said “no charge”.
I pulled the plunger out of my 1cc syringe & shot the paste in the back. Put the plunger back in and squirted out the excess to the dose for my little 200 lb pony, which worked out to around 0.9cc. My 1cc syringe can be overfilled by a couple tenths cc, which would bring a 22mg dose (1.17cc).
Hope this helps.
The dosage recommended by the FLCCC and others is the same for humans as horses: 0.2 mg/kg (0.2 mg of Ivermectin per 1 kg of body weight). Step 1: the conversion from pounds to kilograms is 1 lb = 0.454 kg. So a 250 lb horse (or human) weighs 250 x 0.454 = 113.5 kg. Step 2: 0.2 mg/kg of Ivermectin then is (0.2mg)x(113.5kg)=22.7 mg of Ivermectin dosage for a 250 lb horse. Step 3: The Durvet has 1.87% Ivermectin in a 6.08g tube, meaning it has (6.08g)x1.87% = 113.70mg of Ivermectin total in each tube. So 1mg of paste has 0.0187mg of Ivermectin. Since a 250lb horse needs 22.7mg of Ivermectin, that means it needs 22.7/0.0187 = 1,213.90 mg of paste, which is the same weight as 1.2139 grams of paste. That’s 1/5 of a tube of Durvet paste; however it’s best to actually weigh out 1.2139g (or 1213.9mg) of paste instead of trying to estimate how much is 1/5 of the tube. This requires a decent scale that is able to measure in milligrams. I happen to use a small digital scale that’s meant for weighing gunpowder, but any good scale meant for small weights should work as long as it is accurate. As a frame of reference, paste with 16mg of Ivermectin is only about 1/4 to 3/8 of an inch long, so it is not much paste. The full tube of Durvet with 6.08g paste (113.7mg of Ivermectin) is intended for a 1,250 lb horse, which is right at the 0.2mg/kg dosage for that weight. Obviously, you should verify and are responsible for doing your own math for that horse. FYI – despite the pleasant apple flavored smell, neither horses nor humans like the taste!
Hope that helps!
Your pony gets the same dose by weight as a bigger animal. Each tooth on the plunger is 50# so from whatever zero you start from count four teeth and dispense the paste. Have your pony take it more like a pill rather than peanut butter.
The one I’ve seen is Durvet and comes in a syringe with lines on it. You can’t measure anything below the bottom line. It has a plastic piece that slides up and down and that piece locks into place with a slight twist. If you move it to the bottom line and lock it in place then push out the paste you can discard whatever comes out as it can’t be measured. From there, there are small lines and a number at every 250 lbs. Each line if you divide it up to the ones that are marked end up being 50 lb. So for a 100 lb animal for instance you’d move the plastic locking piece up 2 lines, lock it in place and push the syringe to that point.
Interestingly I compared the dosage that is recommended for horses with the dosage recommended by Mayo clinic. Mayo had 2 different recommended dosages depending on type of parasite and the dosage recommended for horses happens to be the higher of the 2 protocols on the Mayo page. This also happens to be the same dosage that the COVID Critical Care Alliance folk are recommending for post exposure prophylaxis.
Anyway I’m in no way a doctor of any sort so read the directions carefully and ask your vet if you have questions. If I were treating a small horse I would probably round down instead of rounding up to the next 50 lb line to make sure it isn’t over the recommended dosage.
You can use the pound scale on the plunger because the strength of ivermectin in horse pounds is the same as that recommended for human pounds. Here is the calculation of the strength of ivermectin:
A full tube treats a horse of 1250 pounds. Converting this to kilograms:
1250 x 0.453592 = 566.99 kg
A full tube has 6.09 grams of paste (which is 6,090 milligrams), with ivermectin 1.87% of that paste.
6,090 x .0187 = 113.883 milligrams of ivermectin in a full tube.
113.883/566.99 = .201 mg/kg^2 , essentially the same as what the FLCCC recommends for humans.
Visit https://maximpulse.com/permethrin/ivermectin-calculating-a-dose.html , watch the video and read the text. You will find that the dosage is not that critical because the amount your body absorbs varies depending on how empty your stomach is. From that webpage, “Also, if you take ivermectin with a meal you can absorb 2.5 times as much ivermectin than if you took it on an empty stomach! So even if you are hype-picky about figuring and measuring your dose there is a huge range of how much your body will actually absorb!”
— Disco Bear
I put this table together. Please confirm. This is not medical advice and is dosage for your pony
Beautiful chart ironpuppy. For those who don’t have an accurate milligram scale to measure, we might consider the beauty of the metric system, where 1cc of water weighs 1 gram (1000mg).
This would mean 420mg of paste would be equal to 0.42cc of paste measured in a 1cc syringe (which may be more easily available). 1.07 grams of paste would be just over one full cc.
I’ve herd the carrier fluid in the paste is not entirely water, but may contain some propylene glycol & glycerin, which have specific gravities slightly different from water, but are still fairly close.
I expect either a milligram scale or 1cc syringe would be more accurate than trying to use the scale on the original horse sized syringe the paste comes in.
On this product, Bimectin (UK) the plunger is divided into 100kg body weight divisions and further sub-divided into notches for 25kg bodyweight each. For a 75kg horse that is 3 notches worth, for nearer 50kg two notches worth and four notches worth for 100kg. There is a screw on/off stopper to set before using the plunger. The concentration is 200mcg per kg of body weight Here is setting for 75kg bodyweight
Here is an updated table reflecting dose of horse paste by volume for your pony (thanks Bill). I find it easier to weigh the paste than to measure its volume, because it’s too thick to suck up using a syringe. The attached chart is for dosing your pony and is not medical advice, nor do I endorse it’s accuracy.