My Oscar fish has Hole in the Head or an injury. How do I treat it?

Make sure the charcoal/carbon is removed from the filter/tank for the duration of treatment or it will remove/absorb the medication. Try using metronidazole and kanamycin. There is metronidazole in the Parasite Guard but it may not be an adequate dose. Monitor water quality and keep nitrates below 20ppm if possible. Use only aged/conditioned water that is temperature an pH matched to reduce or prevent stress. Raise the water temp to the upper limit for Oscars and add a multivitamin. You can soak pellets prior to feeding. If you can find it, use VitaChem (by Boyds). Make sure Tiger is eating a biologically appropriate diet.

It seems like there is an ulceration at the level of the gills. This may be related to a bacterial or fungal infection. Hole in the Head disease is possible as well. The exact cause of hole in the head fish disease has yet to be determined, but strong suspicion in terms of causes are parasite (Hexamita or Spironucleus infestation) or nutritional imbalances. Water quality must be checked and any abnormality corrected first. The treatment usually consists of taking a multi-faceted approach and includes includes the addition of the antibiotic metronidazole to the treatment tank housing the infected fish and making sure feeding is adequate. In cases where secondary bacterial infections are present, additional antibiotics such as Maracyn, Kanacyn, or Furan may be needed. When treating this or any disease, try to use a separate treatment tank and treat as soon as the first symptoms appear.

The addition of live prey may have introduced parasites into your aquarium. It is also possible it was pre existing and an unknown stressor may have triggered active infection. Regardless, now you have to treat. Check water quality first. Poor water quality is a major cause of illness and it can also complicate any condition. Test a sample at home with a kit or submit a sample for testing. Most pet stores or aquarists will do this for free or for a nominal fee. Ammonia and nitrites should be 0 ppm (parts per million). Nitrates should be 40 ppm or less but for HITH, try for 10ppm or less. Perform partial water changes using aged or conditioned water that is temperature and pH matched to prevent shock and further stress until water parameters are acceptable. Metronidazole is the treatment of choice for HITH. It will kill Hexamita which is the parasite associated with HITH. You can purchase metronidazole for tanks online or in the aquarium section of most pet stores. Follow label directions carefully. Remove the charcoal from the filter during treatment. A broad spectrum antibiotic should also be used to prevent secondary infection. If you have other fish in the tank, monitor them for similar symptoms. A proper diet is also critical. A vitamin and mineral deficiency may predispose a fish to this condition. Use a fortified pelleted diet. You can soak food in garlic juice (or GarlicGuard by SeaChem) to boost the immune system and stimulate the appetite.

Thanks for reaching out about Candoris and including photos. A veterinary visit is recommended as systemic antibiotics needed. Medications added to the water are not absorbed systemically and will not help with internal infections and will likely affect the biological filter. Check and correct water quality as pristine conditions needed to heal. Adding 1 gram non-iodized salt (aquariums salt) per 1 Liter, to decrease stress and osmotic load on the fish. Good luck.

Test the water or submit a sample to confirm proper chemistry. Most pet or fish stores will test water for free or for a nominal fee. Correct any imbalances with partial water changes (30-50%). Use only aged or conditioned water that is temperature matched to prevent further stress or shock. Metronidazole is an effective treatment for HITH (hole in the head) disease. You can feed medicated food, treat the tank or use it for medicated soaks. Look in the aquarium section of the local pet or fish store. Follow label directions carefully.

Maintain pristine water quality and stable chemistry. If the fish is not a scaleless fish, you can use plain aquarium salt as a general tonic. It will reduce stress, increase gill function, treat minor infection and aid in recovery. Dissolve 1 tablespoon of plain aquarium salt (NOT table or Epsom 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 of the injured fish. Partial water changes can be performed afterwards to reduce salinity. Use only aged or conditioned water that is temperature matched to prevent stress or shock.

Thanks for reaching out about Morty. Ich treatment need to be perfumed for several weeks at least. If mostly gone, means to continue treatments. Check water quality because high ammonia or nitrates can lead to corneal edema. A visit to a veterinarian might help with the diagnosis. Good luck.