How Do I Treat My Injured Oscar? (Explained)

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When It comes to treating an injured Oscar, the first step is to make sure their water is clean so they don’t contract a bacterial infection. Next, consider adding an antibacterial and antifungal treatment to the water such as Maracyn by Frtiz. Finally, be sure to remove the cause of the injury, whether that is decorations or another fish

Oscars are without doubt one of my favorite fish in my fish room. I can’t remember a time when I didn’t have at least one aquarium with Oscars in it. Over the last 30 years, I have kept almost all the color strains available, but Lemon Oscars are probably my favorite strain.

There is no doubt if you are going to keep Oscars, there are going to be occasions when your Oscar gets injured, either through fighting with tank mates or because they are trying to rearrange the rocks and decoration in their aquariums. Oscars are well known to blunder around and knock rocks over.

Put Your Oscar In Solitary Confinement!

The first step to successful treatment is to place your oscar into a tank on his own. A dedicated hospital tank should comprise no substrate, no décor (except possibly a large terracotta pot to provide a cave), and no plants.

The tank just needs a filter and a heater, that’s it. I run my hospital tank with a simple air-driven sponge filter. It doesn’t have to be anything fancy, it just needs to keep the water clean and the ammonia levels down. If your oscar already lives alone, there is no need to move him to a different tank.

Now your oscar is in isolation, there is no danger of another fish picking on him or making his injuries worse. Take a few minutes to sit down and assess your oscar.

Are there any signs of infection? For example, does he have white, cotton wool-like fungus on him? If his injury has just recently been inflicted, he should be fungus-free, but if the injury occurred a few days ago and you’ve just noticed, it is possible he had an infection.

If your Oscar has white fungus on it, read my article White fungus on my Oscar (what it is and how to treat it?) or, if it has white spots, read my article titled Why Does My Oscar Have White Spots (and How do I Treat Them)?.

Don’t Reach For The Medication Yet!

If your oscar appears to be free of infection, you need to concentrate on providing him good quality food and super clean water. There is no need at this stage to start medicating your fish.

I would recommend feeding your fish little and often over the coming week or two and changing around 50% of his water every other day. Feeding him little and often helps prevent an ammonia spike.

Feeding your oscar good quality food, ideally including lots of live and frozen foods, will provide him with lots of vitamins and minerals to help repair his body and rebuild his strength. Live and frozen foods, by their nature, contain no fillers, which contribute to poor water quality.

Carrying out large water changes every other day over the next 10 to 14 days will mean your water is of the highest quality. When we keep injured or sick fish in poor quality water, infection and disease quickly take over the fish.

What To Do If Your Oscar Has An Infection

If you do find your oscar has an infection, it is important to try to diagnose the problem. Does your Oscars body have a white fungus on it? This fungus can grow around the site of the injury, around the Oscars mouth or gills, or on his fins.

Another common issue around an oscar injury can be ulcers. These ulcers are inflammation of the external tissues on your fishes’ skin. Ulcers are quite distinctive. They look like sores.

There are two courses of action to treat the infection. One, source an anti-bacterial fish medication. I have had really good luck with Maracyn from Fritz (I order mine from Amazon).

Maracyn (not the same as Maracyn2) contains erythromycin which is an effective antibiotic. Maracyn will provide your oscar relief from bacterial infections including body fungus, popeye, fin rot, and gill disease.

The second option, which seems to be ignored by many, is to add aquarium salt to your oscar tank. Yes, Oscars are freshwater fish, but that doesn’t mean salt will hurt them. Salt is great for treating your Oscars that are affected by either external parasites or bacterial infections.

I start off a course of treatment at 1 tablespoon of aquarium salt per 3 gallons of water. I let the Oscar sit in that water for 4 or 5 days (maintaining the salinity after water changes). If after that time the infection is getting worse, I increase the concentration to 2 tablespoons per gallon, again, maintaining the concentration during water changes.

Monitor your oscar over the next 7 to 10 days and you should start to see an improvement. I have in the past gone as high as 3 tablespoons per 3 gallons (that’s 1 tablespoon per 1 gallon), but this can be hard on your oscar. Remember, salt will kill plants, snails, and shrimp in a flash, so keep its use for the hospital or quarantine tank.

What To Do Once Your Oscar Is Better?

Assuming you have beaten any infection and your oscar has returned to full health, you need to make sure you don’t put him back in a situation where injury can occur again.

If your oscar was bullied and injured by another fish, you need to make sure the same thing doesn’t happen again. Ideally, don’t put him back in the original tank.

If, however, you have no choice but to return your oscar, try and change the tank a bit to see if you can calm the bully down. Rearrange the rocks and décor to ‘reset’ the territories.

Add additional rocks or terracotta pots to provide caves and hiding places. Try creating line of sight blocks with fake plants or pieces of bogwood. Adding a dither fish can mean the aggressor leaves the oscar alone to chase the dither fish. Just make sure the dither fish doesn’t become lunch.

If your Oscar injured himself on a piece of décor such as a sharp stick or piece of wood, look to either remove the offending item or rearrange the tank, perhaps pointing the sharp end towards the wall of the tank so your oscar can’t swim into it.

In Conclusion

Oscars can injure themselves or be injured by others. Don’t panic! Place your oscar into a tank where he is safe and stress-free. Make sure you feed him good quality food and change lots of water to keep his environment fresh and hopefully disease-free.

Oscars are hardy. Treated quickly, they will usually recover even if an infection has set in.

About the Author

I’ve been keeping, breeding, and showing tropical fish for nearly 30 years. Over that time I’ve done it all! I’ve had great success and I’ve made some really foolish mistakes (like the time I bought an Asain Walking Catfish). Read more…
Richard James

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