A retrospective study of forensic cases of skin ulcerations in Danish pigs from 2000 to 2014

Immunohistochemical study of CD31 and α-SMA expression for age estimation of porcine skin wounds

Age estimation of wounds in veterinary forensic investigations is based on the presence and amount of granulation tissue. However, accurate age assessment is challenging and new time-dependent markers are warranted to support and improve the current procedure. The objective of this study was to evaluate the expression of CD31-positive blood vessels and α-smooth muscle action (α-SMA)-positive myofibroblasts in granulation tissue in order to evaluate their value as markers for porcine wound age estimation in a veterinary forensic context. Immunohistochemical expression of CD31 and α-SMA in 14 experimental porcine skin wounds of different ages (4, 6, 8, 10, 18, 27 and 35 days) and 11 forensic porcine wound specimens (of unknown age) were evaluated. CD31-positive blood vessels and α-SMA-positive myofibroblasts were present in the granulation tissue in the experimental wounds at all time points. A significant decrease in the mean blood vessel counts was found in wounds aged 18, 27 and 35 days compared with wounds aged 6 days (P < 0.001), when assessing both the superficial and deep part of the wound bed. α-SMA expression was lower at 27 and 35 days post wounding compared with 6-18 days post wounding. Combined assessment of three parameters (mean blood vessel counts in the superficial and deep wound beds and α-SMA expression) could approximately specify the age of the wounds as either 6-18 days or ≥27 days. In two of the forensic cases a combination of the three parameters yielded results that were similar to the experimental wounds, indicating a wound age of 6-18 days or ≥27 days, respectively. In the remaining forensic cases a combination of the three parameters did not show the same expression pattern as in the experimental wounds. The results indicate that in some forensic cases the application of CD31 and α-SMA markers appeared to support the current procedure for porcine wound age estimation, but this must be combined with pathological characteristics.

Forensic necropsies of cattle: a study of Danish cases from 2010 to 2021 and a guideline for forensic examination of cattle

Forensic post-mortem examinations of animals are carried out on suspicion of violation of European and national legislation. In Denmark, and probably also in other countries with large-scale cattle production, cattle are regularly submitted for forensic assessment. Unfortunately, only few studies of forensic pathology in cattle are available. This paper presents a retrospective study of forensic case files on Danish cattle from January 2010 to December 2021. The case files were characterized with respect to types of lesion, age assessments of lesions and other parameters such as age and sex. A total of 118 forensic case files had been archived and related to 132 cattle (14 weeks-20 years of age; 68% female, 30% male and 2% unknown sex) with 228 lesions. Locomotor disorders constituted the majority of lesions. However, cachexia/emaciation, skin ulcerations and overgrowth of cornual horn were also frequent. Most lesions were chronic (91%) and age assessments for more than 2 weeks were stated for 79% of the lesions. This indicates that in Denmark at least, there is a need to consider how cattle with locomotor disorders are treated in a timely manner in order to avoid prolonged futile treatment and, thereby, suffering. Grossly visible reparative granulation tissue and new bone formation were present in lesions of 1-2 weeks and longer duration. However, all age assessments were stated in broad time intervals due to the lack of scientifically based forensic studies of age assessments of lesions in cattle. Therefore, to improve age assessments in forensic cattle cases, studies concerning the chronology of tissue reparation in cattle are warranted. We also present a guideline for the forensic examination of cattle.

The rise of veterinary forensics

Veterinary forensics is rapidly emerging as a distinct branch of veterinary medicine, especially because of increasing mindfulness about animal cruelty, and of the link between acts of cruelty to animals and violence toward humans. Nevertheless, the application of forensic sciences in veterinary cases lags behind its application in medical cases. Although gaps persist in veterinarians' knowledge of forensics and in how to apply this field to medicolegal cases involving animals, continued research and publication in veterinary forensics are rapidly developing the evidence base in this area. Additionally, educational opportunities in veterinary forensics are also increasing at both undergraduate and postgraduate levels. Together, these changes will continue to improve veterinarians' abilities to investigate cases involving animals. To further strengthen these investigations, veterinarians should also collaborate with the appropriate experts in different disciplines of forensic science.

A porcine model for pathomorphological age assessment of surgically excised skin wounds

A porcine model of second intention wound healing was established and gross and histological changes needed for accurate assessing the age of wounds were determined. Twenty-five pigs were anesthetized before incision of four wounds on each. The wounds were left to heal from 1 h to 35 days when the pigs were euthanized. In 14 pigs, biopsies were sampled from two wounds between days 2 and 18. By histological evaluation the following characteristics were found useful for determining the age of wounds: neutrophil:macrophage ratio, angiogenesis, hyperplasia of fibroblasts, presence of hemosiderophages and granulation tissue. The latter was present from day 4 (n = 8 wounds, 100%), but by gross evaluation it was not recognized until day 5 (n = 4 wounds, 100%). From day 4 to 10, the thickness of granulation tissue increased by 1.2 ± 2.4 mm/day. The thickness of collagen fibers within granulation tissue increased throughout the study period, and complete epithelization was reached from day 18.

A Review of Pain Assessment in Pigs

There is a moral obligation to minimize pain in pigs used for human benefit. In livestock production, pigs experience pain caused by management procedures, e.g., castration and tail docking, injuries from fighting or poor housing conditions, “management diseases” like mastitis or streptococcal meningitis, and at parturition. Pigs used in biomedical research undergo procedures that are regarded as painful in humans, but do not receive similar levels of analgesia, and pet pigs also experience potentially painful conditions. In all contexts, accurate pain assessment is a prerequisite in (a) the estimation of the welfare consequences of noxious interventions and (b) the development of more effective pain mitigation strategies. This narrative review identifies the sources of pain in pigs, discusses the various assessment measures currently available, and proposes directions for future investigation.