Faculty of Agricultural Sciences, Institute of Animal Science, University of Hohenheim, Schwerzstr. 15/4, 70599, Stuttgart, Germany.
BMC Vet Res. 2022 Apr 27;18(1):152. doi: 10.1186/s12917-022-03254-z.
In animals, only few reports exist about the occurrence and causes of subconjunctival bleedings, especially in newborn calves. Most case reports and studies showed that the major risk factors for subconjunctival bleedings in animals are traumatic events such as birth trauma and traffic accidents, respectively. In neonatal babies, it is suggested that compression of the thorax and abdomen during delivery or forces generated in utero during labor may raise venous pressure to conjunctival vessels and can cause subconjunctival bleedings.
The incidence of bleedings in neonatal Holstein-Friesian calves was 2.4 per cent of 289 neonatal calves examined over a six-year period. In general, two types of subconjunctival bleedings were seen. One was usually in a semilunar fashion immediately outside the limbus of the eye. The other type was a stripe or macule of variable size at different positions of the sclera. The subconjunctival bleedings were not related to gestational time. In all cases, affected calves were born without assistance. Multiparous cows were more often involved in the calves with subconjunctival bleedings. Two calves examined haematologically did not show signs of anemia or thrombocytopenia.
Subconjunctival bleedings in neonatal calves appear not to be incidental findings. Main causes or associated conditions of subconjunctival bleedings were not found.
在动物中，仅有少数关于结膜下出血的发生和原因的报告，特别是在新生牛犊中。大多数病例报告和研究表明，动物结膜下出血的主要危险因素是创伤事件，如分娩创伤和交通事故。在新生儿中，有人认为分娩时胸部和腹部受压或分娩时子宫内产生的力可能会使静脉压升高到结膜血管，从而导致结膜下出血。
在 289 头经过六年检查的新生荷斯坦-弗里森牛犊中，出血的发生率为 2.4%。一般来说，有两种类型的结膜下出血。一种通常位于眼睛边缘外的半月形。另一种是巩膜不同位置的条纹或斑点，大小不一。结膜下出血与胎龄无关。在所有情况下，受影响的牛犊都是没有经过助产而出生的。经产奶牛在患有结膜下出血的牛犊中更为常见。对两只接受血液检查的牛犊没有发现贫血或血小板减少的迹象。
新生牛犊的结膜下出血似乎不是偶然发现的。未发现结膜下出血的主要原因或相关情况。
