What causes red spots or rashes on my goldfish's body and fins?

Thanks for reaching out about your fish. Red spot disease is a fungal infection and usually appear fluffy. Adding anti-fungal medication to the tank is not recommended as these can often cause more problems. A veterinary visit is recommended to assess. If you only have goldfish, no live plants, no invertebrates, you can try adding aquariums salt (not table salt) to the tank at 1 Tablespoon per 5 gallons, once daily for 3 consecutive days to slowly raise the salt concentration. Monitor appetite. If fish seem stressed, perform a partial water change. Good luck.

Thanks for reaching out about your fish and including a photo. This is a fairly large lesion and needs to be diagnosed and treated. Parasitic infestations and bacterial infections must be considered. Adding non-iodized salt at 1 tablespoon per 5 gallons for 3 consecutive days might provide some osmotic relief but is not therapeutic levels. A skin scrape and microscopic examination is needed to diagnose parasites is needed. Different parasites require different medications. Bacterial infections should be treated with systemic antibiotics through injections or oral medications, not water additives. Good luck.

This could be bacterial or parasitic infection. It is difficult to determine definitively since the image provided is not clear. Fish can be difficult to photograph. Basic care includes checking water quality and chemistry. This can be done using a home test kit or by submitting a water sample for testing. The local Petco may do this for free or for a small fee. There should be an absence of ammonia and nitrites with nitrates at 20-60 ppm. pH should be as close to 7 as possible, avoiding large swings. Koi can tolerate a wide range in temperature, but generally do best between 65 F and 75 F. Again, avoid large swings in temperature to prevent stress or shock. If necessary, a partial water change can be done to stabilize chemistry and/or improve water quality. If you have other koi, consider placing this one in a hospital tank to make treatment easier and to prevent spread if the condition is infectious. Plain aquarium salt (NOT table or Epsom salt) can be used to reduce stress, improve gill function, treat minor infection and aid in recovery. Dissolve 1 tablespoon per 5 gallons of water in a cup or two of tank water and gently pour it into the tank. Treat for 14 days then reassess the condition. If there is no change, consider a broad spectrum antibiotic or "all in one" treatment. Either can be found in the Aquarium section at Petco. Follow label directions carefully and remove the carbon filter insert during treatment if indicated. All that said, if the spots multiply and appear like tiny grains of salt, it could be an ich infection. In this case the entire tank will require treatment. There are several commercial ich medications that can be used. You will also need to thoroughly vacuum the substrate/gravel in the tank and wipe down all tank furniture.

Hi, and thanks for your question. This is a quite concerning presentation and it is likely to be related to water quality. Begin by submitting a water sample for quality testing. Most pet stores will do this for free or a nominal fee. Clinical examination should always include a water quality check, even if you have done so already. Water testing should be performed with a quality test kit, measuring NH4, NO2 and NO3. High ammonia levels, PH imbalances may be responsible for these signs. Oxygen concentration and quality of the filters should be determined as well. If water quality is good and there are no major imbalances, your fish should get examined to look for any sign of bacterial/fungal infection and eventually water should be treated. Hope this answer was helpful, but please do not hesitate to contact us again on the forum or by requesting a consultation if you have any more questions or to discuss it any further. If this answer was helpful please let us know, this will be used to improve our service!

Thank you for your question about your goldfish. I see the area that you are referring to in the photo, but it is a bit blurry so I can't see it completely clearly. If you feel that your fish is otherwise doing well - it is staying upright and balanced, it is eating well, the two fish aren't fighting, and it is swimming normally, then I would recommend to monitor for the time being. If any of this changes, then I would recommend taking your fish to a veterinarian who is familiar with fish. You can use the AAFV website to help identify one in your area if you don't know of any. Also, you can contact veterinarians in your area who see other zoological companion animals (such as ferrets, birds, and reptiles) and they, or someone they know, may also be able to examine your fish. I hope this gives you a place to start, and thanks for using Petco Pet Education Center, formerly Petcoach.

It could be an infection (bacterial or fungal) or it could be due to trauma from other fish or tank furniture. Confirm proper water quality and chemistry. You can try some plain aquarium salt (NOT table salt or epsom salt) as a general tonic. It may reduce stress, improve gill function, treat minor infection and aid in recovery. Dissolve 1 tablespoon of salt per 5 gallons of water in a cup or two of tank water and gently pour it into the tank. Treat for 10-14 days then reassess the condition. Perform partial water changes to decrease salinity afterwards. Use only aged or conditioned water that is temperature matched to prevent stress or shock. Goldfish are cold water fish and do best between 65 F and 72 F.

This could be ammonia burn. Check the water chemistry. Use a home test kit or submit a water sample for testing. The local Petco may do this for free or for a small fee. Aim for an absence (0 ppm) of ammonia and nitrites with a nitrate level of 20 ppm or less. Partial water changes will be needed to stabilize chemistry. Use only aged or conditioned water that is temperature matched to prevent further stress or shock. Goldfish are cold water fish and do best between 65 F and 72 F. When using an ammonia reducing product, be sure to test the water after treatment but before pouring the treated water into the tank.