Do Show Koi Need Extra Quarantine Precautions?

By KoiQuanta Editorial Team|Updated Mar 2026

Yes, considerably more. Koi shows expose fish to water shared with hundreds of individuals from dozens of sources. KHV exposure risk is elevated at shows compared to almost any other koi-keeping situation. Your fish might not be sitting in the same tub as a diseased specimen, but show water systems often recirculate across display areas, and stressed fish shed pathogens at higher rates than fish in stable home ponds.

The standard 30-day quarantine applies to new fish from unknown sources. Show returnees need a different protocol because the risks are different, the exposure is known to have been broad, and the window of concern for KHV specifically needs to cover the viral incubation period at show temperatures.

TL;DR

The standard 30-day quarantine applies to new fish from unknown sources.
Key elements: Duration: Minimum 4 weeks, ideally 6 weeks if fish attended an international show or a show where multiple health concerns were reported.
KHV is most active and observable at 18-28°C.
Don't let fish cool below 16°C during this period, which would suppress KHV symptoms and extend the observation window needed.
The standard 30-day quarantine is appropriate for most show returnees from domestic shows.
For fish that attended large international shows or events where health concerns were raised, extend to 6 weeks.
Maintain the quarantine tank at 20-24°C throughout to ensure any KHV infection manifests within the observation window.

The Show Return Risk Profile

At a typical koi show, your fish:

Share recirculated water with hundreds of other koi
Are stressed by transport, handling, and unfamiliar conditions
Are exposed to pond water from multiple farms and hobbyist collections
Are handled by judges and other exhibitors
Return home immunocompromised

The primary diseases of concern post-show are KHV (which can incubate for 10-14 days at the right temperature), bacterial infections from handling abrasions, and parasites picked up through shared water contact.

Extended Post-Show Quarantine Protocol

KoiQuanta's show-return quarantine protocol extends the standard 30-day period and adds additional disease screening checkpoints for show-exposed fish. Key elements:

Duration: Minimum 4 weeks, ideally 6 weeks if fish attended an international show or a show where multiple health concerns were reported.

Temperature management: Maintain quarantine tank at 20-24°C through the protocol. KHV is most active and observable at 18-28°C. Don't let fish cool below 16°C during this period, which would suppress KHV symptoms and extend the observation window needed.

Screening checkpoints: Skin scrape at day 3 (establish a parasite baseline), repeat at day 14. Salt treatment at 0.3% from day 1. Praziquantel treatment in the first week for flukes. Daily observation with particular focus on lethargy, loss of appetite, and gill appearance.

Isolation from pond: Zero contact with your main pond collection until the full protocol completes clean.

Review the complete koi quarantine guide and your KHV management protocols before each show return.

Frequently Asked Questions

How long should I quarantine koi after a show?

A minimum of 4 weeks. The standard 30-day quarantine is appropriate for most show returnees from domestic shows. For fish that attended large international shows or events where health concerns were raised, extend to 6 weeks. Maintain the quarantine tank at 20-24°C throughout to ensure any KHV infection manifests within the observation window. A fish that looks healthy on day 14 but was exposed to KHV can still be incubating. Don't move show returnees back to your main pond based on how they look. Complete the full protocol.

What diseases are most commonly spread at koi shows?

KHV (koi herpesvirus) is the most serious concern and the reason extended quarantine is so important after shows. Parasitic infections, particularly gill flukes (Dactylogyrus) and skin flukes (Gyrodactylus), are also common show pickup because they spread efficiently through shared water. Bacterial infections from handling abrasions are common but tend to appear quickly and are treatable. Columnaris and Aeromonas infections are the typical culprits. Less commonly, SVC (Spring Viremia of Carp) has been associated with show transmission. A good skin scrape early in your post-show quarantine establishes what, if anything, your fish picked up.

Should I treat prophylactically when koi return from a show?

Yes, at minimum run salt at 0.3% and Praziquantel treatment. Salt provides osmotic support and reduces bacterial and some parasitic burden on stressed fish. Praziquantel at standard dosing treats monogenean flukes which are extremely common show pickups. Some experienced keepers also run a short potassium permanganate bath on show returnees on arrival to reduce surface parasite loads before the fish go into quarantine. Prophylactic antibiotic treatment is generally not recommended unless fish show specific signs of bacterial infection, as unnecessary antibiotic use can disrupt your quarantine tank's biofilter.