Thinking about Foreign Animal Disease

Dr. Terry Whiting, Veterinary Services Branch

The two major foreign animal diseases of pigs are foot and mouth (FMD) currently sweeping Britain and Hog Cholera (Classical Swine Fever). The year of 1997 marked a period of major upswing in serious disease in world swine production areas of the globe. Foot and mouth disease swept through Taiwan (Taipei China) in March 1997 with immediate ramifications on Pacific Rim trade in pork. The estimated impact of this outbreak was an immediate expense of $1.6 billion US and the country has not recovered disease free status. Taiwan had previously held a major share of the Japanese fresh pork market.

In the Netherlands, hog cholera was isolated in February 1997 with rapid spread throughout the core swine producing area of Holland. This outbreak was difficult to contain and spread to Spain and Italy. The cost to contain this outbreak was near $2.4 billion US, however Holland has regained its disease free status. These events have served to remind pork producers everywhere of the importance of foreign animal disease control to the assurance of access to foreign markets.

On Aug 4th, 2000 hog cholera was identified in Britain. All controls relating to the 16 outbreaks of classical swine fever which occurred in Great Britain between 4 August and 3 November 2000 were lifted on 30 December 2000.

Although limited to just 16 confirmed cases, the necessary and widespread measures taken by the UK government to prevent the spread of the disease are expected to have far reaching consequences. Not only did the various restrictions placed on the pig sector detrimentally effect output for the five months it took to eradicate the disease, but the disruption to the UK breeding program is expected to affect national pig meat production for up to two years. The long period of swine fever controls in East Anglia, as a direct consequence of the disease, about 50,000 pigs that normally would have been marketed were slaughtered on farms where swine fever was found. In addition, 25,000 pigs were slaughtered on farms considered dangerous contacts and additional 190,000 pigs were removed from entry into the food chain. This outbreak was very small compared to the current FMD outbreak in Britain.

Risk and Time Periods There are four time periods that contribute to the overall final cost of a Foreign Animal Disease (FAD) outbreak. Prevention Period (P$) is the time during normal industry operations when other countries in the world have highly contagious diseases and we don't. We are incurring some costs during this time in preventing the entry of the disease, and substantiating that we are free of the disease while also reaping the benefits of market access. High Risk Period-1 (HRP1) is the time between when a disease like foot and mouth enters the disease free country and when the veterinary authority identifies it as present. High Risk Period-2 (HRP2) is the period of time from when you know you are infected until the veterinary authority successfully controls the herd to herd transmission of the agent. The Recovery Period-$ (RP$) is the time it takes to reestablish your area as free of disease and re-establish market access.

The final cost of an outbreak are largely dependent on HRP1 + HRP2 + RP$. Currently in Canada there are agencies and organizations contributing to minimizing the impact of each risk period. The Canadian Food Inspection Agency (CFIA) through trade negotiation and import controls is largely to credit with the prevention of entry of FAD to Canada (P$). The length of HRP1 or the early detection system has many components, veterinary practitioners, farmers the CFIA reportable disease system. In addition we are fortunate to have the national FAD diagnostics service laboratory, the laboratory able to confirm foot and mouth or hog cholera here in Winnipeg at the National Centre for Human and Animal Health on Arlington Street. Of crucial importance to the early warning system is the penetration of veterinarians into rural food animal practice, suitable diagnostic laboratory support in Provincial or commercial laboratories and live animal inspection at slaughter facilities.

The HRP2 or response period probably gets the most attention. Activities in stamping out the disease include tracing all animal movements, placing herds under quarantine and slaughter, disposal and compensation for producers. Placing geographic areas under movement restriction causes serious problems in swine production systems that are dependent on segregated production. In the January 2001 issue of the Canadian Cattleman Magazine there is a report of a recent simulation of FMD in the US, Canada and Mexico. According to this computer model Canada would have to resort to vaccination which would have extreme costs to our export market.

The recovery period RP$ probably is the least glamorous to talk about but, the most significant. Taiwan has been unable to recover from the 1997 outbreak and we will learn valuable lessons from the next couple of years in Britain.

As a producer you are key to early warning and first detection of foreign animal disease. By practicing good biosecurity on your farm in times of peace you will be prepared for the evil one.