How to treat and prevent velvet in fish

What is velvet disease?

Despite its fancy name, Velvet is a common fish disease that can cause serious issues. Velvet is caused by a small parasite known as Oodinium which can latch onto the body, gills and fins of fish. It is sometimes also referred to as rust disease or gold dust disease.

Velvet affects all types of fish, but goldfish and zebra danios are generally more susceptible to the disease. Certain conditions may also put fish at higher risk of velvet due to stress. These conditions include a dirty tank, poor water quality, large fluctuations in water temperature, or mishandling.

Symptoms of Velvet Disease

Velvet can cause serious harm to fish so it’s important to keep an eye out for any changes to your fish’s appearance and behaviour. If you suspect that your fish has contracted velvet disease, monitor your fish for these symptoms.

Symptoms during early stages of velvet disease:

Fish may rub, scratch or flick its body on surfaces in the tank to dislodge the Oodinium parasite.
Velvet disease appears as yellow, rust or gold-dust coloured spots or film on the body of the fish which gives it a velvet-like appearance. These small specks are most commonly on the fins, body and gills of the fish but can sometimes be difficult to see. It may be more easily detected by shining a flashlight on the fish in a dark room.

Symptoms during advanced stages of velvet disease:

Rapid gill movement, difficulty breathing or rapid/laboured breathing patterns
A loss of appetite and weight loss
Fins clamped closely against the body
In more serious stages of velvet disease, the skin may peel off.

How to treat fish with velvet disease

Velvet is a highly contagious and virulent disease but there is a chance it can be cured if you start treatment during the early stages of the disease and manage your tank with care. If you believe your fish is suffering from velvet, it’s important to act fast with these steps:

Do a 30% to 50% water change
Check and monitor your water conditions and adjust if necessary. Test for factors like pH, temperature, chlorine, ammonia, nitrite and nitrate levels. You can test for these with a home water testing kit or head into your nearest Petbarn with a 100ml sample of your tank water for a free water test.
Slowly raise the water temperature to 29ºC over 24 hours (in tropical tanks). This will speed up the parasite’s life cycle and make it faster to treat.
Dim or turn off the lights during the treatment period to help eliminate the parasites. This is because the Oodinium parasite is dependent on light.
Remove the active carbon filter during the treatment period to ensure it does not interfere with the medication.
Add aquarium salt to your tank. This encourages the natural production of slime/mucus coating on fish which deters the parasites.
Treat with Blue Planet’s Multi-Cure

Products Recommended for Treating Velvet Disease

Blue Planet Multi Cure 125mL

$13.99

API Aquarium Salt 454g

$22.99

Aqua One External Digital Thermometer 1 Pack

$5.99

How to prevent velvet disease

Velvet can be quite difficult to treat and prevention is definitely better than a cure. The best way to prevent velvet disease is to keep your tank clean and maintain excellent water conditions. Other measures include:

Regular water changes keep your tank clean
Regular water testing can help you pick up any problems with water quality.
Do not overcrowd your tank with too many fish
When feeding your fish, feed small quantities of fresh, high-quality food. Feeding time is also a good time to carefully observe your fish’s behaviour. Keep a daily eye out for any changes to their fins, tail, body, appetite and behaviour
When introducing new tank mates to your aquarium, quarantine any new fish for 10 to 14 days to ensure they are healthy and will not bring in any parasites from external sources.