Porcine ear necrosis: characterization of lesions and associated pathogens

Assessment of Flurbiprofen Suspension and Composite Gel Pre- and Post Skin Perforation: Effectiveness in Managing Inflammatory Responses in Ear Tags and Periocular Piercings

(1) Background: Controlled skin perforations, such as ear tags, piercings, and microdermal implants, induce inflammation and stress in individuals undergoing these procedures. This localized trauma requires care to optimize healing, reduce inflammation, and prevent infections. (2) Methods: Two formulations were developed: an FB-suspension and an FB-gel. Their in vivo efficacy was evaluated, along with drug retention in porcine and human skin after 30 min of administration, chemical stability at different temperatures, cytotoxicity, histological changes induced via transdermal application, and irritative potential, assessed using the HET-CAM assay. (3) Results: Both formulations reduced inflammation when applied 30 min before perforation compared to the positive control. The FB-suspension demonstrated no cytotoxicity and exhibited greater efficacy than the free flurbiprofen solution, highlighting the advantages of using nanoparticle-mediated drug delivery. Moreover, the FB-gel maintained chemical stability for up to 3 months across a temperature range of 4 to 40 °C. Histologically, no significant changes in skin composition were observed. (4) Conclusions: The FB-suspension is viable for both pre- and post-perforation application, as it is a sterile formulation. In contrast, the FB-gel is a convenient and easy application, making it a practical alternative for use in both clinical and veterinary settings.

Observations on the associations between damaging and aggressive behaviors, related lesions, and their implications for the welfare of pigs in the grower-finisher period

Introduction

Pigs perform damaging and aggressive behaviors, but few studies investigated associations between behaviors and resulting lesions in intensive settings. We investigated such associations within and across production stages to understand implications for welfare, and interpreted cut-off values of behavior for use as warning signals.

Methods

Four batches of 419 pigs each (n = 1,676 pigs) were followed on arrival to a commercial grower-finisher unit at 12 weeks of age until slaughter. Pigs had docked tails, were managed according to routine practice and housed in 48 mixed-sex groups in eight rooms [35(±2) pigs/pen; 6 pens/room/batch]. Ear and tail lesions were assessed when pigs arrived to grower stage I [24.9 ± 5.33 kg of body weight (BW)], after 2 weeks when transferred to grower stage II (33.3 ± 7.04 kg BW), and after 4 weeks when transferred to the finisher stage (60.2 ± 7.74 kg BW; 18 weeks of age). All occurrences of damaging (ear, tail, and flank biting) and aggressive behaviors were recorded for 5 min per pen from the week after pigs arrived for 11 weeks.

Results

High variability existed between pens for behaviors and percentage of pigs that developed new ear or tail lesions on arrival to grower II and finisher stage. There were significant correlations among the behaviors only within grower stage II (all behaviors: 0.65 ≤ rs ≤ 0.80, p < 0.05), while the only correlations across production stages were ear biting (grower II and finisher rs = -0.29, p < 0.05), flank biting (grower II and finisher rs = 0.70, p < 0.05), and aggression (grower I and II rs = 0.37, p < 0.05). This suggests a sensitive period during grower stage II but also that performance of behaviors changes over time. The frequency of ear and tail biting did not need to be high for new lesions to develop, but thresholds changed depending on stage, behaviors, and lesion type.

Discussion

This underscores the intricacies in developing cut-off values for warning signals and may relate to the cumulative effect of different risk factors. Thus, early identification and multifaceted management strategies tailored to specific pens are needed to address behaviors with adverse implications for pig welfare. This highlights the challenges and complexities of improving pig welfare within current intensive production settings.

Porcine ear necrosis in nursery piglets is preceded by oral manipulations of the ear

BACKGROUND

Porcine ear necrosis (PEN) is characterized by dry crusts on the ear tip. The crusts often progress to moist and bloody lesions and may lead to partial loss of the ear tissue. The cause and pathophysiology of PEN are unknown. Skin infections, systemic infections, or ear biting have been suggested as a cause of PEN, but no proper evidence has been shown. The behavioural factor has not yet been investigated, therefore this study evaluated the importance of oral manipulations in the occurrence of PEN in nursery pigs. Three farms affected by PEN were visited weekly, and the prevalence and severity were recorded. Video recordings of the animals were performed, and the behaviour was evaluated. The presence of pathogens in the lesions and histological alterations were also analysed.

RESULTS

The highest percentage of pigs with PEN lesions in the farms ranged between 58 and 93%, with most lesions being of mild to moderate severity. The first ear lesions occurred about 1-2 weeks after an increase in the number of ear manipulations in the pens. The frequency of the ear manipulations clearly changed over time, and the number of oral ear manipulation behaviour significantly differed (P < 0.05) between pigs in pens with high and low PEN prevalence. Increased ear manipulation behaviour was significantly related to a subsequent increase in PEN lesions (OR = 4.3; P < 0.001). Metagenomic investigation of lesion scrapings revealed a variety of pathogens mostly with low abundance, where microscopic alterations were found mainly in the epidermis.

CONCLUSIONS

Oral manipulation of the ear pinnae by pen mates was followed by the development of PEN lesions one to two weeks later. This suggests that the behaviour played an important role in the PEN lesions formation in the nursery pigs of the three farms. Bacteria found in PEN lesions most probably were secondary to initial external skin damage, but their relevance needs to be investigated further.

Description of patterns of ear and tail lesions during the grower-finisher period in a commercial pig farm

BACKGROUND

Ear and tail lesions are prevalent indicators of impaired welfare observed in pig production with different multifactorial causes. Understanding the progression of ear and tail lesions over time is important to implement preventative strategies on commercial pig farms. Therefore, this case study aimed to provide a detailed account of patterns of ear and tail lesions in pigs on a single commercial farm during the grower-finisher period.

CASE PRESENTATION

A total of 1,676 12-week old pigs (n = 773 females and n = 903 males, all tail docked) were followed from arrival to the grower facilities until transferred to the finisher stage on a commercial pig farm in Ireland. Pigs were individually weighed and inspected for the severity of fresh ear and tail lesions (score 0-4) on transfer to the first grower (24.9 ± 5.33 kg, 12 weeks of age, n = 1,676 pigs), second grower (33.3 ± 7.04 kg, 14 weeks of age, n = 1,641 pigs), and finisher stage (60.2 ± 7.74 kg, 18 weeks of age, n = 1,626 pigs). Due to the low number of pigs with high scores, ear lesions were classified as no (score 0), mild (score 1), moderate (score 2) and severe (score ≥ 3) and tail lesions were classified as no (score 0), mild (score 1), and moderate-to-severe (score ≥ 2). Ear lesions were more prevalent than tail lesions at each inspection. There were approx. 19% of pigs with ear lesions at all three inspections but no pigs presented with tail lesions at all three inspections. When considering the specific severity categories, we observed 32 different ear lesion score combinations and 15 different tail lesion score combinations across the three inspections.

CONCLUSION

The high number of observed patterns of ear and tail lesions suggest large individual variability in lesion progression. Ear lesions were more of an issue than tail lesions and little is known about this health and welfare problem indicating that further research into causes and management strategies is needed.

Porcine ear necrosis is associated with social behaviours in weaned piglets

BACKGROUND

Porcine ear necrosis (PEN) is a worldwide health issue and its aetiology is still unclear. The aim of this study was to describe the prevalence and the severity of PEN in a commercial farm, associated with pig behaviour and health biomarkers measures. On two consecutive batches, PEN prevalence was determined at the pen level. PEN scores, blood haptoglobin concentration and oxidative status were measured on two pigs per pen (n = 48 pens) 9, 30 and 50 days (D) after arrival to the post-weaning unit. Social nosing, oral manipulation and aggression of pen mates and exploration of enrichment materials were observed on two to three pigs per pen twice a week from D9 to D50.

RESULTS

At the pen level, the higher the time spent nosing pen mates, the lower the percentage of pigs affected by PEN during both the early and the late post-weaning periods (P < 0.002) and, in the opposite, the higher the time spent orally manipulating pen mates during the late post-weaning period, the higher the percentage of affected pigs (P = 0.03). At the pig level, the higher the increase in hydroperoxides and haptoglobin during the early post-weaning period, the higher the PEN scores on D30 (P < 0.001).

CONCLUSIONS

This study suggests that a high incidence of social nosing, which can be an indicator of good social cohesion in a group, was significantly associated with less frequent lesions of PEN. In opposite, high incidence of oral manipulation of pen mates may increase the percentage of PEN-affected pigs. According to these observations, PEN is a multifactorial condition which may have social causes among others.