penicillin - is this too high a dosage???

[milkmaid]

So we have a cow here - not one of mine, thankfully - that showed up yesterday with bloody urine and a depressed attitude. I looked through my Merck Vet Manual, and, provided it's something logical and not a sign of some other disease, it could possibly be "Bovine Cystitis and Pyenlonephritis" aka bladder/kidney infection.

The vet manual says that one treatment of choice would be penicillin at 22,000 units/kg, twice a day. For greater than 3 weeks.

OK, so if I figure this is a 1400lb cow, that's 635kg. Doing the math... that comes out to 13,970,638 units twice a day. I have here Twin Pen (penicillin G benzathine and pencillin G procaine) with each mL containing 150,000 units of pen G benzathine and 150,000 units of pen G procaine.

Does that mean each mL contains 300,000 units of penicillin total?

If I work out the math, at 300,000 units of penicillin per mL on a 635kg cow, that's 46mL twice a day. :shock: That seems like a LOT!!! but then the vet manual does say the dosage, frequency, and length of administration is extra-label. Giving that much penicillin is fine - cow won't be getting milked in the tank for a l-o-n-g time, LOL - but I just need to know for sure if that's the right dosage of not. Can't get in touch with my vet right now.

Comments?
Thanks!

 

[Medic24]

You are correct.......it is 300,000 units total per ml.

This type of mixture is supposed to be longer acting...........may not need a daily does......every other day may do it.

As far as dosage...............46 ml is not at all to high for that size of cow........at my vet's insistance, I dosed a cow with 60 ml every other day for over a week to prevent infection due to barbed wire fence injuries. And this cow was not more then 1,100 lbs!

Just spread it out a bit, I would not inject more then 10 ml per site, and would do it all sub Q. just stay away from any lymph node areas too. And as always...Good Job, and good luck! :cboy:

 

[Texas PaPaw]

I concur with medic 24, your math is correct. Since that dosage is extra-label, I would suggest getting an ok from the vet.

Also suggest more than 1 clean test before milking into the tank. This gal could have residue for a while. Sure wouldn't want to risk a load of milk without extra caution. Cheaper to lose the cow than a load of milk.

Good luck & best regards

Brock

 

[TheBullLady]

That's a large dose when you have to inject all of that, but not unusual for pen. I've also given doses of 60+ ml. They get pretty pi$$ed off after about the second injection site! :roll:

 

[milkmaid]

Thanks for the responses.

I gave her 46cc's of Twin Pen (pen G benzathine and pen G procaine) tonight, and boss is going to follow up with the same in the morning. We're planning to treat her at this dose and twice a day for a few days, and then see where we're at. If she appears to be responding, we'll continue the penicillin - vet manual said more than 3 weeks - but may move to once a day treatment. (Comments on that?) If she's not responding, then we'll have to find a different drug. The Merck Vet Manual suggested a type of sulfa I haven't encountered before - sulfadoxine and trimethoprim - so that would be the next choice if penicillin doesn't appear to be working. I am quite certain that's not one of the legal sulfa drugs for dairy cattle, however.

So that does come out to just a touch over 90cc's - per day. Which is quite a lot! LOL. I'm thinking penicillin's a pretty safe drug, but I'm not entirely certain either. Anyone know where the safety level is on pen?

Also - the Merck Vet Manual said to give it IM - intramuscular. Anyone know WHY? I gave it subQ this evening, per the label, and also because I know it can kill a horse if it's given IM and you accidently inject it into a vein. Don't know if cows are the same way, but I don't want to find out the hard way, either!

The cow in question is about 160 days bred, so we may either put a calf or two on her for another 2 months, or else dry her off early. Yep- I'm sure this one is going to have residues for a looooonnng time. :lol:

Here's the info from the Merck Vet Manual for anyone who's interested...

Bovine cystitis is an inflammation of the urinary bladder of cattle that may ascend the ureters to cause infection of the kidneys (pyelonephritis).

The organisms attack or colonize the mucosal lining of the bladder and ureters usually after some traumatic insult (such as parturition or abnormal deformity of the vaginal tract). The stresses of parturition, peak lactation, and a high-protein diet (which increases the pH of the urine and is therefore conducive to colonization of the attacking organisms) are all contributing factors.

Early diagnosis and prompt, sustained treatment are needed for a successful recovery. The treatment of choice for pyelonephritis due to the C renale group is penicillin (22,000 IU/kg, IM, b.i.d.) or trimethoprim-sulfadoxine (16 mg combined/kg, IM, b.i.d.) for at least 3 wk. The dosage, frequency, and length of administration for both of these drugs is extralabel, and adequate precautions must be taken to prevent antibiotic residues from entering the human food chain.

http://www.merckvetmanual.com/mvm/index ... 130501.htm

Thanks again!

 

[DiamondSCattleCo]

I've treated a few bladder/kidney infections over the years, and at the advice of my vet, I followed the directions on the label of the penicillin, except for first dose which I always doubled. I've treated once per day, for 12-14 days and never lost an animal.

I don't know about IM vs SubQ. I checked the drugs I have here that are registered for both, and generally the IM injection amount is 1/2 the SubQ amount, but double the number of days. Dunno why the SubQ is allowed to be twice the dose. Perhaps a vet on the list can tell us?

Is that the online Merck vet manual you're looking at? If so, I've been unimpressed. Their treatment plans vs what vets have recommended to me for treatment plans for a variety common maladies have either been insufficient or way overboard.

And I don't think I'd be too concerned about ODing. I watched my neighbor who was new to cattle inject a month old calf with 90ccs of Pen and it was just fine. He did the math wrong and refused to listen :roll:

Rod

 

[msscamp]

I think I remember reading somewhere that IM is absorbed faster than sub-q, but not sure. Perhaps that's why their is a difference in the dosages?

 

[milkmaid]

And I don't think I'd be too concerned about ODing. I watched my neighbor who was new to cattle inject a month old calf with 90ccs of Pen and it was just fine. He did the math wrong and refused to listen :roll:

Rod

:lol: :lol: Well it's good to know it's pretty safe. :lol:

The information does come from the Merck Vet Manual. I have the 9th edition in hardcover form here, and also a few other various vet-type books. I think the Merck was the only one that gave me a dosage, but the others all gave basically the same info; same symptoms, same problem, and that prompt treatment was necessary and for quite a bit of time.

I guess we'll know in a few days if this cow is going to respond to penicillin, and if not, we need to figure out something else. Shucks, if this bacteria is at all succeptible, at the dose we're giving her, she'd better respond. LOL.

 

[Texas PaPaw]

Milkmaid

IMO, subQ is the way to go. If you treat this gal for several days IM there won't be enough muscle to go around. Also will damage losts of future meat & probably hold residue longer than subQ. For subQ, in addition to the neck area, you can use the flank area behind the front legs. Never heard of it, but probably the rear flanks could be used to spread out the trauma area. JMO

Good luck & best regards

Brock