Gross and histopathological evaluation of human inflicted bruises in Danish slaughter pigs.
BACKGROUND
Human inflicted bruises in slaughter pigs are hampering animal welfare, are an infringement of the animal protection act, and are a focus of public attention. The aim of the present study was to evaluate the gross appearance of human inflicted bruises in slaughter pigs and to compare the inflammatory changes in two lesions as a basis for estimating the age of lesions in the same pig. Pigs with human inflicted bruises slaughtered at two major slaughterhouses in Denmark from November 2013 to May 2014 were evaluated. After slaughter, the bruises were examined grossly and skin and underlying muscle tissue from two similar but separate bruises (a and b) on each pig were sampled for histology.


RESULTS
Skin and muscle tissue from 101 slaughter pigs were subjected to gross evaluation. Eighty-one of these were also subjected to histological evaluation. Most frequently (51 out of 101 pigs, 50 %), bruises had a tram-line pattern due to blunt trauma inflicted with long objects such as sticks. Other bruises reflected the use of tattoo-hammers, plastic paddles, double U profiles and chains. Histological evaluation of two bruises from a pig with multiple lesions was found insufficient to assess the overall age of the lesions as substantial variation in the inflammatory response between bruises was present.


CONCLUSIONS
Grossly, the pattern of bruises often reflected the shape of the object used for inflicting the lesions. When determining the age of multiple bruises on a pig more than two lesions should be evaluated histologically.
Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Ridebanevej 3, DK-1870, Frederiksberg C, Denmark. krisb@sund.ku.dk.
Kristiane
http://orcid.org/0000-0002-0087-6649
K
Barington
Department of Large Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg C, Denmark.
Jens Frederik Gramstrup
JF
Agger
Department of Large Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg C, Denmark.
Søren Saxmose
SS
Nielsen
Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Ridebanevej 3, DK-1870, Frederiksberg C, Denmark.
Kristine
K
Dich-Jørgensen
Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Ridebanevej 3, DK-1870, Frederiksberg C, Denmark.
Henrik Elvang
HE
Jensen
D000003:Abattoirs; D000827:Animal Welfare; D000818:Animals; D003288:Contusions / Q000209:etiology / Q000473:pathology / Q000662:veterinary*; D003718:Denmark; D006801:Humans; D013552:Swine; D013553:Swine Diseases / Q000209:etiology* / Q000473:pathology
Age assessment; Bruise; Forensic; Pig