Baytril injections

[tomy2ponds]

Duncan I seem to remember a while ago we spoke about Baytril injections and that it may no longer be correct to inject E.O.D but leave three days between injections,if memory serves.Could you refresh my memory please.

[Duncan]

i would have to go look for the reasearch again

will get on it

dunc

[tomy2ponds]

Thanks Duncan I think the info will help a lot of members on here

[Duncan]

useful piece of research on of Enrofloxacin. (Baytril). Pharmacokinetics (the absorption and distribution and effectiveness of)

Baytril is a synthetic antibiotic and while being a broad spectrum antibiotic it does not kill directly nor stun bacteria It inhibits an enzyme which is important for bacterial replication. Baytril is especially effective against (quote) “gram negative bacteria,such as Aeromonas salmonicida (causing furunculosis), Renibacterrium salmoninarum (causing bacterial kidney disease), Vibrio anguillarum (causing enteric red mouth disease), and intracellular organism, such as rickettsia, chlamydia and mycoplasma. Enrofloxacin is widely used in ornamental fish although there is a few pharmacokinetic information” (end quote) (Stoffregen et al.,1997).

All these are very relative infections to koi carp particularly Chlamydia a strain of which is the bacteria responsible for epitheliocystis and I believe is may be what’s causing all these blisters we are currently seeing. All these intracellular bacterium I believe may ultimately be responsible for a whole host of skin conditions we are witnessing at the moment in koi.

The research conducted trials of all possible routes of administration but at a greatly reduced dose to that which is normally used in ornamental carp 10 and 5 mg/kg of body weight where as the norm is 25 mg/kg of body weight.

Important: of the three hundred or so test fish non were infected with anything they were healthy fish. samples were taken after exposure to Baytril at controlled points in time the extracted serum was sperated out then used to see how much effective Baytril was left in the blood stream to carry on inhibiting bacteria by subjecting this extraction to a known bacterium Bacillus subtilison on agar and Standard enrofloxacin and plasma samples Plates were incubated at 37°C for 24 h and diameters of inhibition zones were recorded

In other words a known bacteria was grown on agar and this was subjected to the sirum containing whatever was left of the Baytril in the fishes blood, after it had been kicked around for a few hours/days this was the method used and applied to determine how effective and long Baytril would stay in the system

I’ll skip to the pay off, the so what! Before I go over the top. The research concluded that of the many ways to administer Baytril the most effect was the IP route (intraperitoneal) by a good bit, while IM (Intramuscular) and oral gavage (PO) ( in food) were next with there being very little in the difference in effectiveness. While adding to a bath coming last

Of the IP and IM route it showed the M.I.C of Baytril was around 100 hours which means we can revise our Baytril repeat injections to every 4-5 days rather than every day for three then EOD for two more and may further explain why in some cases one shot may suffice to effect a “cure” .

dunc

[Gazza]

Hi Dunc,

How about a topic on A/B injections in general as this is something not looked at very much and many either have no idea or are worried about such things ?

[Koiette]

How I have longed for a forum where you can put stuff and people are going to think about stuff and you are not going to get slagged off!

Antibiotics interest me, always have done. I was very ill as a child with an enlarged heart and nephritis, the doctors advised my parents that not much could be done for me, but the only thing they could try was to overdose me on penicillin, which they did, injections and tablets daily and a six month stay in hospital. Obviously I am still here, so it worked.

I know chickens and fish are different creatures, but AB's still treat infection (stay with me on this one)!

Chickens are a bit of an unknown quantity (like Koi) insomuch as you have to find an avian expert/exotic expert to often diagnose/treat chickens.

I often get people bring sick chickens to me that have been seen by a vet as they are ill, and the vets have not got a clue about what to do, so dish out Baytril in liquid (oral) dose, often it does not work and the bird gets sicker.

Chickens hide their illnesses, or they get bullied and picked on, so generally speaking by the time it is brought to me, a sick chicken is normally really sick/or dying.

I inject into the breast with twice the recommended does of baytil, administer oral liquid baytril too, again twice the recommended does. Meanwhile, Tylan (an different spectrum AB) is put in the water for the bird to drink. The baytril I administer in both methods for 10 days (with the recommended dose), each day (vets recommend 7 days, and an oral dose every other day). And I keep them warm. Most of these birds look like they are about to die anyhow, so I always feel it's worth giving them a chance.

Out of the 20 or so birds brought to me, 18 went home. One had peritonitis and the other had eaten rat bait and grit, and subsequently bled to death as it had scratched it's crop.

I am sure my vet would have a fit if he knew what I was doing, but it seems to work.

Now I am not saying try overdosing a Koi with AB. I have killed a large fish of Glenn's years ago using 10% baytril and not 2.5%. The koi died, I think it's fin swelled up so much as it was an overdose of PH (apparently the AB is high in PH).

It just makes me wonder, there is alternatives to Baytril, and they say inject Koi three days apart, has a trial ever been done using an AB with low PH/one not recommended for Koi, and injecting a koi everyday, and why do you not inject a koi everyday, is it just so as not to stress the koi?

Hope all this makes sense.

Annette

[greg]

One for me that i'm interested in is the % of the AB to be used.

You here of various strengths of Baytril (for example) - 2.5%, 5%, 10%

Now i prefer the 10% due to the smaller amount of fluid that is req'd to be injected into the koi. But i realize there are risks associated with this due to the nature of the Baytril and what i'd call "Burn" of the injection site. I seem to be able to limit / stop the "burn" by injecting slowly not allowing a build up of baytril fluid in the injection site area.

Now i normally inject into the pec Muscle and would do 3 days apart for doses alternating the pec i inject into.

What do others think of this? - Am i on the right track?

[Koiette]

We always inject into the muscle behind the front flipper.

Annette

[Brockp]

Normally in humans we base our dosing schedule on the plasma half lives which is itself dependent on the rate of breakdown of the drug normally by the liver and the rate of excretion normally by the kidneys and sometimes the gut.

Do we have hard data other than that which Duncan has shared with us on the rates of excretion/breakdown (plasma half life) of any of the other antibiotics we use in Koi?
I know we cannot extrapolate from human data (of which there are buckets for every approved antibiotic) and if there is none / little then we will have to rely on experience. Nothing wrong with that

And one last query what about synergy for instance we know that an aminoglycoside used with a beta lactam (penicillin like) antibiotic will have a 1+1=3 affect. Any evidence that this has been tried in Koi ?

Pete

[Duncan]

hi

i can do something on this for you but right now imn trying to finish and autopsy doc for this section i think you will all be impressed with and will help you

the big advantage of using 10 baytril is you have to use less of it but not for the reasons you think/?/

baytril has a pH value of around pH 12 and thats the reason less is better froma volume point of view so for a 2 kg fish using 2.5% per you would need 2 ml/cc thats a lot of fluid going into the muscle , not only will it tend to try and split the muscle but the localised pH change would turn the flesh nectrotic very fast, if you injected the same fish with 10% you would only need O.5ml thats a huge difference in volume

annette bayrtil was first used for chickens in fact 2.5 % has chickens on the bottle the reason it was developed for chickens is there is money in chickens there is no money at all in koi not from a drug companies point of view

dunc

[Gazza]

Hi Guys,

We always inject into the muscle behind the front flipper.

they must be big fish

I have done a few in injections in the past and i think most will go for the ball in the pec (IM intamusculary into the muscle) but depending on the problem it can be best to inject into the actual body cavity (IP intraperitoneally into the abdominal cavity) as when injecting into any muscle part of the fish the antibiotic goes around the organs and in doing so can get filtered down where as if you inject in the cavity the antibiotic will short circuit the organs first time round and in doing so the fish will get a better "shot".

I am sure if i have missed something i am sure Dunc will elaborate much better on the subject as said before its a great subject and one which is very really talked about.

[tomy2ponds]

Thanks for the info Duncan

[Brockp]

Hi Guys

Thank you Dunc for setting up this limited post. It allows us to ask the questions and get evidence based or esperienced based answers to the most pressing problems.... thanks, bold move.

I look forward to the next chapter.

Pete

[Duncan]

And one last query what about synergy for instance we know that an aminoglycoside used with a beta lactam (penicillin like) antibiotic will have a 1+1=3 affect. Any evidence that this has been tried in Koi ?

yes, there are lots of combinations that have been used with great effect amakacin + azactam ( aztreonam) and bayrtil plus gentamycin ar ethe combinations that i have used in both cases this uses an aminoglycoside and a none aminoglycoside

I have done a few in injections in the past and i think most will go for the ball in the pec (IM intamusculary into the muscle) but depending on the problem it can be best to inject into the actual body cavity (IP intraperitoneally into the abdominal cavity) as when injecting into any muscle part of the fish the antibiotic goes around the organs and in doing so can get filtered down where as if you inject in the cavity the antibiotic will short circuit the organs first time round and in doing so the fish will get a better "shot".

what Gazza is refering to is the pectoral girdle, which in fish is obviously between the pectroal fins this is an arterial shunt around the kidney that when injecting IP gives a once off bypass to the filter ( kidney) on the first circuit where as IM goes straight to the kidney this gives a big bang for the drug on the first pass as its not being filtered out.


what you will find and i curtainly was not different you will find learning to inject IP is a lot less traumatic than you think and a lot more beneficial and avoids many of the complications of IM , like muscle spitting localised necrosis at the injection site scales lifting at the site also

[Brockp]

Hi Again just a two pennyworth !

The other advantage of the IP route is it's almost like giving the drug IV. The surface area of the peritoneum is large allowing rapid absorption and high initial peak plasma levels this means in the acute situation we are much more likely to get above the MIC of the bugs. With antibiotics like amikacin which have a long half life this is ideal….get the levels high quickly to kill the bugs and then they stay up to ensure adequate duration of therapy.

IM injections tend to be slowly absorbed, particularly when blood flow is low and the fish are fairly inactive at low temps. This may have its advantages because the plasma concentration curve has a lower peak than IP but last for longer as the drug is more slowly absorbed over time. For antibiotics with a short plasma half life this could be a definite advantage as we don't want to be getting up at 4 am to give the next dose do we !

Pete