Quarantine & Disease — The System Facts (KHV & SVC)

What KHV and SVC are as regulated diseases, why notification and movement controls exist — without diagnosis or treatment.

Two diseases structure the koi world's rules. Koi herpesvirus disease (KHV) is a serious viral disease of carp listed internationally — the World Organisation for Animal Health (WOAH) maintains a dedicated chapter for it in its Aquatic Animal Health Code. Spring viraemia of carp (SVC) is the second: it is the disease behind the United States listing of koi as a susceptible species for import purposes.

The system facts a reader needs are institutional, not clinical. Suspected serious disease in koi is a matter for official notification routes in many countries; movements of fish can be restricted while authorities investigate; and quarantine of new arrivals exists precisely because healthy-looking fish can still be part of a disease picture.

This page deliberately stops there. It gives no symptoms key, no diagnosis, no medicines and no doses. If fish look unwell, the correct action is a veterinarian or your local fisheries authority — not a website, including this one.

Sources: Wikipedia (CC BY-SA — summary in our own words, credit only); All Japan Nishikigoi Promotion Association official; Ministry of Agriculture, Forestry and Fisheries (MAFF) and Finance Ministry trade statistics as published; Japanese Agricultural Standard (JAS) for nishikigoi variety names and definitions (2022); Niigata Prefecture, Ojiya City, Nagaoka City (Yamakoshi) and Nishikigoi no Sato official; Japan National Tourism Organization (JNTO) visitor statistics; USDA APHIS and Australian DAFF official import guidance. Checked 6 November 2026.