I am not very familiar with koi fish but when I went to check on my pond, my female koi was upside down, missing scales and has injured fins. She barely swims but she is still breathing. What can I do to help her? How can I avoid this from happening next time around?
Hi Jorge this koi has not been roughed up breeding its far to early in the season for that to be happening .
But what your koi does have looks to be a bacterial most probably caused by "Aeromonas hydrophila", wich is the most common bacteria found in ponds which isnt normally a problem fot our koi as long as they are in good health .
When our koi become stressed be it though over crowding , temperature fluctations, poor water quality or other factors all which have the effect of stressing out our koi allowing the bacteria present in the pond to become a problem.
The symptoms of "Areomonas Hyrdophila", are as follows a build of of exessive mucus and areas of reddening over the body which we see in your photo .
This reddeing will lead to the lifting of scales and will if not sorted cause ulcers on the koi's body.
Now in some cases this lifting of the scales will spread to all over the body and this is when dropsy can occur, internal problems may also develope along with the external ones.
Popeye can also develope if this is left untreated, this is where they eyes ae pushed outwards from the koi's head.
You should take a swab and send it off to the vets for testing which should also give you the result of which bacterium is causing your problem .
Prior to winter can you tell me if you removed all the dead leaves and detritus from the bottom of your pond , did you also clen your filters at the same time.
The best way to prevent this in future is one buy a book on koi health issues and learn about our hobby in greater depth , run as clean a pond as you possibly can , you wont eliminate the bacteria totally , so it is vitally important you keep your ponds enviroment to the highest standard and ensue that stress levels are kept down to a minimum , by doing this your making it less likely to have an outbreak in the future.
Dependant on where you live is your access to drugs , here in the UK we need to go through a vet but in the US many drugs are available over the counter.
You'll need to treat the pond with a good anti bacterial treatment but refare back to the vets results before choosing which you need if this is not an option then a good off the shelf antibacterial may be added .
You could use Chlormonine T at a minimum dose of 1g = 1,000 ltre (220 gallons Imperial) or Potasium Permaganate at a dose of 1.5g per 1,000 ltre (220 gallons imperial) Acriflavine may be used along side these.
Dave