My fish's mouth is stuck shut and he can't eat. What should I do?

Thanks for reaching out about Tennessee and including photos. If he can not open his mouth, he needs to see a veterinarian, the sooner the better. Concerns are an oral obstruction, fractured mandible or other problems. Check and correct water quality as pristine water parameters will be needed after a veterinary visit. Good luck.

eIf you can, look in the mouth for foreign bodies (gravel, food, etc), tumor or any redness, swelling or discharge. You should also check water chemistry. If ammonia or nitrites are elevated, perform daily partial water changes to stabilize chemistry and maintain water quality. Use only aged or conditioned water that is temperature matched to prevent further stress or shock. Goldfish do best in cooler waters, between 65F and 72F. Trauma is also a possibility. A fractured or dislocated jaw can be the result of hitting the glass or tank furniture or from bullying. Swelling from infection is also a possibility. Monitor for redness, bruising, lethargy or loss of appetite. A broad spectrum antibiotic can be used if necessary. Find one, such as maracyn or kanaplex, in the aquarium section of the local pet or fish store. Follow label directions carefully and remove the carbon filter insert during treatment if indicated. Maintaining adequate water quality and parameters will aid in any healing. Plain aquarium salt (NOT table salt) can be used as a general tonic. It will reduce stress, improve gill function, aid in recovery and may help treat minor infection. Dissolve 1 teaspoon per gallon of water in a cup of tank water and gently pour it into the tank. Treat for 10-14 days. When performing water changes, treat only the amount of water being replaced with salt, not the entire tank volume.

Thanks for reaching out about your cichlid and including photos. This is probably not an abscess that can be treated with simple antibiotics. A tumor or possibly a fractured mandible bone causing inflammation. A veterinary visit is recommended to assess, possibly requiring radiographs. If it can not open the mouth and can't eat, then it will starve. Check and correct water quality for pH, ammonia, nitrites and nitrates. Pristine water quality will be needed to assist in recovery. Good luck.

Thanks for reaching out about Felix. Any chance of ingested rocks or other material that can block the throat? Enlarged organs (goiter, heart) can also make swallowing difficult. A veterinary visit is probably needed to assess and provide a diagnostic/treatment plan. Good luck.

Check the water chemistry and quality first. Elevated ammonia or nitrite levels can be toxic. Partial water changes can be done to stabilize and improve water chemistry. Use only aged or conditioned water that is temperature matched to prevent further stress or shock. For goldfish, a range of 65F to 72F is recommended. Check the filter and rinse the sponge with tank water, not tap water, to spare beneficial bacterial populations and to maintain water quality. The tank may not be large enough to support 5 goldfish. Generally, 20 gallons should be allowed for the first goldfish then a 10 additional gallons should be provided for each additional goldfish. This is due to the larger than average bio load (wastes) they produce. Consider a larger tank or decrease the number of fish in one tank. Use a filter that is rated for at least twice the volume of the tank and add an airstone and pump for increased oxygenation. Plain aquarium salt (NOT table salt). Can be used as a general tonic. It will reduce stress, improve gill function, aid in any recovery and may treat or prevent minor infection. Dissolve 1 teaspoon of salt per gallon of water in a cup of tank water and gently pour it into the tank. Treat for 10-14 days. When performing water changes, add salt only to the amount of water being replaced, not the entire tank volume.

Thanks for your question, and I’m sorry that Oscar isn’t feeling well. Thank you for the photos as well - they are very helpful. I agree with you - it looks like his fins are shortened and I can appreciate the color changes you are seeing. Both of these changes can be caused by infections, including bacterial, fungal, and parasites. When these infections occur, the first thing that we evaluate is the water quality. I am not sure if you have done this or not yet, but you can take a sample of your water to a pet store for evaluation if you don’t have a kit at home. If the parameters are not ideal, this can make Oscar susceptible to diseases that he would normally be able to fight off. Once you have determined this, then you can either try to treat empirically with an over the counter medication, or you can seek veterinary advice for Oscar. Your veterinarian would take a sample from the skin surface and maybe the fins to evaluate for what is causing the changes. They would then prescribe medications that are tailored to what they find. I hope that gives you a place to start, and that Oscar feels better soon!

It could be Columnaris, aka cottonmouth. It looks like a fungal infection but is actually an infection caused by a gram negative bacteria. You can treat with kanamycin and nitrofuran. Both are antibiotics effective against this bacteria. Brand names are Kanaplex (by SeaChem) and Furan 2 (by API). You can find them online or in the aquarium section of the local Petco. Follow label directions carefully and remove the carbon filter insert during treatment if necessary. You will likely need to treat the entire tank since more than one fish is symptomatic.