What to do if my discus fish has a hole in its head and won't eat?

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.

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.

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.

Thanks for reaching out about your Oscar and including photos, but difficult to see the HLLE lesions due to too dark. The eye looks terrible and systemic antibiotics are recommended at the least. A veterinary visit is highly recommended to clean the wound and provide other possible treatments. The water quality must be kept pristine (pH, ammonia, nitrites, nitrates) to assist recovery. Antibiotics added to the water do not penetrate into the body, nor do fresh water fish drink, since osmotically water enters over mucous membranes (gills, mouth, skin) and antibiotics do not cross this barrier. HLLE causes can be multi-factorial including water quality, bacteria, parasites, carbon particles in activated charcoal (filters), low vitamin C, etc. Check and correct water quality, replace existing food if older than two months (vitamin C degrades quickly), see a veterinarian with fish experience. Good luck.

It looks like it may be some sort of fungal infection on Tiller. I would recommend to the the photo to a pet store and see if they agree. They can also sell you fungal medication to add to his water. Sometimes these infections can be serious. If you have a pet store in town that specializes in fish, they are your best reference. Best of luck!

Fin rot is commonly caused by poor water quality. Submit 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 she/he is in a tank larger than 2 gallons move her/him to a smaller tank if possible to make treatment easier. The best treatments for mild fin rot are frequent water changes and aquarium salt. Maintain the water the treatment tank between 76-78'F. Turn the light and filter off for the time being. Aquarium salt can be used at 1 teaspoon per gallon. Dissolve it in tank water before adding it. Perform daily 100% water changes, making a fresh salt solution each day. Treat for a maximum of 10 days.

Check water chemistry first. 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 nitrates at 20 ppm or less. Perform partial water changes, no more than 30% at a time, to stabilize chemistry and/or to improve water quality. Use only conditioned water that is temperature matched to prevent stress or shock. Check water temp as well. Any of these can drive a fish to the surface. The "flashing" (darting about) can be due to infection (bacterial, fungal or parasites). Consider a broad spectrum antibiotic or an "all in one" product to treat multiple infections. Look in the Aquarium section of the local Petco for options. Follow label directions carefully and remove the carbon filter insert during treatment if indicated.