Fish Diseases: Their Symptoms & How To Treat Them

Fish diseases can be even trickier to spot than in dogs or cats, but the important thing is to know what to look out for, and how to act quickly to nip them in the bud before they cause any long-term problems!

Here is the AllPetSolutions run down of the most common fish diseases, and what medicine for fish or treatment options are best to deal with them quickly:


  • Dropsy is a bacterial kidney infection which causes bloating, and protruding scales usually around the abdomen. These symptoms, along with slow movement and loss of appetite, are often indicative of dropsy.

Treatments include a parasite treatment, and usually, just one course is sufficient. Often the critical action is to check the aquarium conditions quickly, as an untidy aquarium is usually a factor, and more likely to cause illness in fish who are already poorly or have a compromised immune system.

That means checking the temperature, water quality, ammonia levels and making sure any stresses are removed to help your fish recover.

Ich (Ichthyophthirius)

  • These fish diseases are often caused by stress - such as sudden changes in temperature or fluctuations in pH levels.

White spot treatment is essential, and with a fast reaction, you can combat Ich quickly, and prevent it from recurring.

Symptoms include white spots, usually beginning on the head, fast breathing or gasping, clamped fins and glancing, where your fish itches itself due to the skin irritation.


  • A fish fungus can be extremely stressful for fish and must be treated quickly with a fungal treatment, often with several doses administered at regular intervals.

The fungus is often because of low water quality and decomposing material in the water, so cleaning your aquarium and checking on filters, pumps and water quality is essential.

Symptoms of fungus include white or grey areas of growth, and if left untreated can be fatal and extraordinarily unpleasant so immediate treatment is vital.

Remember, most fish diseases sound scary but are entirely treatable with the right medicine for fish, and by addressing any issues in water quality or aquarium conditions.


If in any doubt, contact your vet or speak with the AllPetSolutions aquatic team for advice on the best medicines to try.