Teaming up for animal health
The Prevalence of Spleen Atrophy in Slaughter Sows W.A.M. Poppe1,2, T.J. Tobias1, A. van Nes1, M.A.M. Houben2 Utrecht University, Faculty of Veterinary Medicine, Department of Farm Animal Health, Yalelaan 7, 3584 CL, Utrecht, the Netherlands 2 GD Animal Health, PO Box 9, 7400 AA Deventer, the Netherlands 1
Background and objectives Complete or partial spleen atrophy is frequently observed in slaughter sows as well as in sows submitted for necropsy to the GD Animal Health (GD). The exact relevance of spleen atrophy as well as the association with mortality or sow health is unclear. The prevalence of spleen atrophy in slaughter sows in the Netherlands was estimated at ± 2% in 1984, 1986 and 1991 (Van Leengoed, ESPHM, 2014), but risk factors nor the exact pathogenesis are unknown. To enable future pathogenesis and epidemiological studies this study aims to estimate the current prevalence of spleen atrophy in Dutch slaughter sows and in pigs (>1 year old) submitted for necropsy to GD.
Material and methods An observational study was performed in a Dutch slaughterhouse. During four days spleen sizes and shapes of sows at slaughter were scored as: 1) being completely atrophied (fig. 1 & 2), 2) ± 17 centimetres long (fig. 3), 3) ± 34 centimetres long spleen or 4) longer than 34 cm. In addition, a retrospective data analysis was performed on necropsy results of pigs submitted to GD in 2015 and 2016. Table 1 Results spleen scoring in the slaughterhouse (2016) and at necropsy (2015-2016) Sows
Score
Category
Size
Prevalence (%)
95% Confidence Interval (%)
Slaughter
1
Complete atrophy
-
2.49
1.66-3.31
Slaughter
2
Partial atrophy
<17 cm
1.10
0.54-1.65
Slaughter
3
Incomplete spleen
>17cm, <34 cm
4.75
3.62-5.88
Slaughter
4
Normal spleen
>34 cm
91.67
90.20-93.13
8.75
5.18-12.32
Necropsy
Complete or severe atrophy
Fig. 1 A completely atrophied spleen
Results The prevalence of spleen atrophy in sows at slaughter per day was very consistent. There was no significant difference in spleen scores per observation day. Occurrence of spleen atrophy could not be traced to the farm of origin. At necropsy: In total 8,75% of animals >1 year showed (partial) spleen atrophy. Fig 2. An atrophied spleen in the omentum majus
Conclusion and discussion The prevalence of spleen atrophy in sows at slaughter per day was very consistent, indicating that multiple farms experience this phenomenon. In sows submitted for necropsy (partial) spleen atrophy is diagnosed more often, suggesting a relation between sow mortality and spleen atrophy. Scoring in the slaughterhouse and GD were not performed with the same protocol. This could have an effect on the result.
Fig. 3 A spleen of approximately 17 centimeters
Acknowledgement We greatly thank Vion N.V. for enabling and assisting us in the assessment of sows in the slaughterhouse.
GD, P.O. Box 9, 7400 AA Deventer, the Netherlands, T. +31 (0)570-63 33 91, F. +31 (0)570-63 41 04 www.gdanimalhealth.com, info@gdanimalhealth.com
GDOV1057/04-17
contact: m.houben@gdanimalhealth.com