DeGroot*1, M.; Boix2, O.; Ballarà2, I.
1 HIPRA ANIMAL HEALTH Canada Inc. / 2 HIPRA, Amer (Girona), Spain.
*Corresponding author:

Sow mortality is a growing concern for pig farms in Canada. Many causes contribute to sow mortality including lameness, reproductive disorders, infection, and sudden death. One pathogen that has been shown to be an infectious cause of sudden death is
Clostridium novyi (C. novyi). C. novyi is an opportunistic bacteria, affecting sows that are metabolically stressed1. Most deaths due to C. novyi occur in late gestation or early lactation or in hot weather conditions, causing important economic losses for the farmers2
.Although C. novyi is recognized as a cause of sudden death in sows, the prevalence of this pathogen in Canada has never been established. This study assessed the serological prevalence of C. novyi in breeding sows on Canadian Farms.

A study was carried out on 112 sow farms with a stratified selection across 6 provinces based on the Canada census data. Farms were selected only if they had not previously vaccinated their sow herd against C. novyi. Each farm had 10 serum samples collected from sows at mid-gestation (70-90 days) across all parities, assuming a 30% minimum prevalence of C. novyi per farm. The samples were analyzed for antibodies against C. novyi toxin by ELISA testing at HIPRA Laboratories. The farm was considered positive if at least one sample of the farm was positive.

An overall C. novyi seroprevalence of 63% (95% confidence interval: 54.29% – 71.68%) across Canadian sow farms was detected in this study. All regions overcome 50% prevalence, except for Quebec (Table 1 and Figure 1).

Sow mortality has an economic impact on sow farms3. There are multiple causes behind it, including sudden sow death due to C. novyi. This study has established a baseline level for C. novyi prevalence of 62% on Canadian breeding farms with greater than 30% seroprevalence. This provides an indication that C. novyi is present on many Canadian sow farms and likely contributes to sow mortality. Considering Quebec as a high density area, more samples should be taken in the future in order to establish a more accurate prevalence of C.novyi in this region. Based on these results, implementation of prevention measures such as vaccination program against C. novyi would be beneficial to reduce sow mortality.

The authors acknowledge veterinarians for their support, and the Scientific Marketing Unit staff for the study design, monitoring and sample processing.

1. Taylor DJ. Clostridial infections. OM: Straw BE, D’Allaire S, Mengeling WL, Taylor DJ, eds. Diseases of swine.

2. Songer G. 2012. Diseases of swine, 10th ed: 717-718

3. Schultz R. 2001. A sow mortality study—the real reason sows die. Identifying causes and implementing action. AASV.