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Dr. B.
Dr. B., Board Certified Veterinarian
Category: Vet
Satisfied Customers: 22591
Experience:  General practice veterinary surgeon with extensive experience in a wide range of species.
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Red blotches on skin

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red blotches on skin

Hello & welcome, I am Dr. B, a licensed veterinarian and I would like to help you with your wee one today.

How long has your dog had these signs?

Where on his skin are they?

Is he itching/scratching with this?

Any other changes to the skin (ie pustules, pimples, crusts/scaling, ulcers, or sores)?

Any diet change in the 2 months before this started?

Is he worse at any particular time of year?

What flea treatment did you use? When did you last apply it?

Can you take a photo of this? If you can do so and post them online, this will let me see what you are seeing. To post them, you can either use the wee paper clip on the tool bar above your text box. Or if you cannot see that on your computer/phone, then you can post them on an alternative site (ie Flickr, Photobucket, imgur, etc) and paste the web link here for me to check.

Customer: replied 2 years ago.

Please note, The crerature we are asking about is a Koi Carp and not a Dog. The red blotches on the scales has just started over its complete body. We had an identical carp that suffered the same symtons some 3 weeks ago and it died.

Thank you for clarifying, as your history was quite brief.

In that case, I do need to make a few wee changes to what I was asking.

So, have you tested your water yet?
What were your pH, ammonia, nitrites and nitrate readings?

Is he rubbing on the substrate or walls of the tank/pond?

Are the blotches on the fins and tail as well?
Are they raised?

As well, can you post a photo still so I can see what you are seeing here?
Customer: replied 2 years ago.

When the other Koi developed the symtams, i completely cleaned the filters and did a water changed so although i have no pH, ammonia or nitrate readings, I am sure the water quality is good. I also dosed the clean water twice with Malachite and Formalin as directed on the product labels.

The fish within the pond (4 very large and 6 small) have not been rubbing unduly on the walls.

The red blotches are also appearing on the fins.

The carp is black and white and the blotches are clearly visable. They do not appear to be on the other fish in the pond but most are coloured .

The fins appear normal (ie are they raised?) but look sore.

No picture is available i'm afraid.

Hi again,

Did you do a full water change or a partial?
Did you add any biofilter supplement if you also completely cleaned the filters?

Are the blotches raised (not the fins)?
Customer: replied 2 years ago.

Did 3000 gallons in a 5000 pond.

Washed the filter out in rain water and added a biofilter supplement

The blotches are not raised but appear to be below and in scales.

Have just notice that small white raised blotches are also present on head and back fins.

The other Koi that suffered the same symptoms did clear all blotches and we believed had recovered but then was found dead.

Thank you again,

First, I am glad to see that you did only a partial water change and did supplement your biofilter. Still, with any situations where we have superficial skin lesions, testing water parameters is still indicated and highly advisable. Therefore, I would strongly advise a full test via kit or via your local aquarium shop (who often will do this free of charge). It is especially important to ensure your ammonia levels are normal with red skin blotches.

Otherwise based on what your have described (and why I was keen to see a photo), this would raise concerns of bacterial vasculitis. This is a septic condition where bacteria gain access to the blood stream. And in this case the blotches are sites of inflammation within the blood vessels of the tissues. The white blotches (as long as not raised or removable material) are likely related.

Now in this situation, sepsis type disease can be quite serious. This fish should be isolated to a hospitalization take with great water quality. It will need close monitoring and you will need to either order in or speak to your local vet about antibiotics for this fish (since these are not as readily available at aquarium shops in the UK). Specifically, we tend to use Kanamycin (Kanacyn) in these cases. Alternatively, since Aeromonas (gram negative bacteria) is our most common culprit you can also use erythromycin (plain Maracyn) or tetracycline, but treat simultaneously with minocycline (your Maracyn-Two). Both kanamycin and minocycline are antibiotics which are considered not to be harmful to the biological filter. Still at high dosages, kanamycin can harm the bio filter so take the necessary precautions with your filter (while keeping a close eye on the water parameters as you treat). Also injectable antibiotics can be an option for treating this fish, but again this would require a prescription from a local vet (who has physically examined the fish).

Overall, based on what you have described, this would be my concern for this and the previous fish. So, we'd want to isolate this one, check water parameters to be safe, and then source antibiotics to treat and give him a chance of overcoming this suspect systemic infection.

I hope this information is helpful.

If you need any additional information, do not hesitate to ask!

All the best,

Dr. B.


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