Hovmand-Hansen Trine, Jensen Tina B, Nielsen Søren S, Vestergaard Kaj, Nielsen Mai Britt F, Leifsson Páll S, Jensen Henrik E
Department of Veterinary and Animal Sciences, University of Copenhagen, Ridebanevej 3, 1870 Frederiksberg C, Denmark.
SEGES Innovation P/S, Axeltorv 3, 1609 København V, Denmark.
Prev Vet Med. 2022 Jun;203:105621. doi: 10.1016/j.prevetmed.2022.105621. Epub 2022 Mar 21.
Clinical presentations of umbilical outpouchings (UOs) in pigs cover a variety of pathological manifestations. Pigs with UOs often do not reach the abattoir as they die due to complications or are euthanized for welfare concerns. The primary objective was to characterize the gross appearance of UOs in pigs with respect to the different types of pathological manifestations. Also the association between the pathological manifestation and presence of a wound on the UO was evaluated. Pigs (in different age groups, n = 444) with an UO were sampled in Denmark from different locations (two herds and at an abattoir) and examined post mortem. Tissue samples from animals with an enterocystoma or internal umbilical proliferations were collected for histological and immunohistochemical characterization. Hernia umbilicalis was the most frequent cause (72%, n = 320) of the UOs. It was the only diagnosis in 57% (n = 254) of the pigs, and in 15% (n = 66) of the pigs the hernia appeared in combination with other manifestations. Thus, 28% (n = 124) of the pigs were diagnosed with an enterocystoma, internal umbilical proliferations, subcutaneous abscess/ fibrosis or another diagnosis, presented alone or in combination. The distribution of diagnoses varied in the different age groups. Overall, 38% (110/291) of the pigs presented a wound on the UOs post mortem. The age of the pigs confounded the relation between the pathological manifestation and the presence of a wound. The odds that an UO had a wound were lower among pigs with a subcutaneous abscess/ fibrosis compared to pigs diagnosed with an umbilical hernia or enterocystoma (OR, 0.3; 95% Cl, 0.1-0.7). The odds of wounds were higher among weaners (OR, 4.3; 95% Cl 2.3-8.3) and finishers (OR, 6.5; 95% Cl, 3.4-12.7) compared with piglets from the farrowing unit. The area of wounds ranged from 0.03 to 78.5 cm and increased with age (P < 0.001). Histologically and immunohistochemically the enterocystomas and internal umbilical proliferations seemed to be lined with mesothelial cells and both had a content comparable with mesenchymal embryonic connective tissue. However, only the cavities of the enterocystomas were also lined with mesothelial cells. In conclusion, UOs in pigs are caused by complex pathological conditions with hernia umbilicalis as the dominating diagnosis. Knowledge clarifying the different pathological manifestations causing an UO and the presence of wounds on the UOs is essential for future prevention strategies.
猪脐部外突（UOs）的临床表现涵盖多种病理表现。患有UOs的猪往往因并发症死亡或出于福利考虑被安乐死，因此通常无法进入屠宰场。主要目的是根据不同类型的病理表现来描述猪UOs的大体外观。此外，还评估了病理表现与UOs上伤口存在之间的关联。在丹麦，从不同地点（两个猪群和一个屠宰场）采集了患有UOs的猪（不同年龄组，n = 444），并进行了死后检查。收集患有肠囊肿或脐内部增生的动物的组织样本，进行组织学和免疫组织化学特征分析。脐疝是UOs最常见的原因（72%，n = 320）。在57%（n = 254）的猪中，脐疝是唯一的诊断，在15%（n = 66）的猪中，疝与其他表现同时出现。因此，28%（n = 124）的猪被诊断为患有肠囊肿、脐内部增生、皮下脓肿/纤维化或其他诊断，单独或合并出现。不同年龄组的诊断分布有所不同。总体而言，38%（110/291）的猪在死后UOs上出现伤口。猪的年龄混淆了病理表现与伤口存在之间的关系。与诊断为脐疝或肠囊肿的猪相比，患有皮下脓肿/纤维化的猪的UOs有伤口的几率较低（比值比，0.3；95%置信区间，0.1 - 0.7）。与分娩单元的仔猪相比，断奶仔猪（比值比，4.3；95%置信区间2.3 - 8.3）和育肥猪（比值比，6.5；95%置信区间，3.4 - 12.7）出现伤口的几率更高。伤口面积范围为0.03至78.5平方厘米，且随年龄增加而增大（P < 0.001）。组织学和免疫组织化学显示，肠囊肿和脐内部增生似乎内衬间皮细胞，两者的内容物与间充质胚胎结缔组织相当。然而，只有肠囊肿的腔也内衬间皮细胞。总之，猪的UOs是由复杂的病理状况引起的，脐疝是主要诊断。明确导致UOs的不同病理表现以及UOs上伤口的存在情况的知识，对于未来的预防策略至关重要。
