鸡骨型白血病的放射学研究（第二报）

本文对一个骨型白血病阳性鸡群的112只成年蛋用鸡进行诊断性调查,普通临床检查法只检出3例阳性,但首次试用一侧后肢X线照相法检查,检出45例阳性,使检出率提高了16倍,并初步揭示被检鸡的发病率竟高达46.39％(45/97)。阳性病例的胫骨100％发生病变,而跖骨兼有病变者仅为24.44％。经对97只鸡后肢X线照片进行胫骨骨外径及骨皮质厚度测量,结果52例阴性鸡胫骨中部骨外径的正常值平均为6.16mm(5.5～7.0mm),正常骨皮质厚度平均为0.64mm(0.4～0.9mm)。45例阳性鸡中的42例(占93.33％)隐性型病鸡,骨外径在正常值范围内。其中之轻度患鸡骨皮质厚度平均为0.81mm;中度者为2.12mm。只占阳性鸡6.67％的3例临床型病鸡,胫骨中部外径超过7.5mm,以至14mm,骨皮质厚度超过1.5mm,以至9mm。

STUDIES ON RADIOLOGY OF OSTEOPATHIC LEUKOSIS IN CHICKENS (SECOND REPORT)

In this paper are reported the results of a diagnostic survey conducted on 112 adult layer chickens from a flock in which osteopathic leukosis (osteopetrosis) was occurring. Only 3 positive cases were detected on the basis of clinical signs,but on first attempt 45 positive cases were discovered by radiography of one hind limb. This represented a 16- fold increase in detection rate and revealed the incidence of the disease to be as high as 46. 39%(45/97). In the positive cases,lesions occurred in 100% of the tibiae examined whereas only 24. 44% of the metatarsi showed pathological changes. Measurements of tibial external diameter and bony cortex on radiographs of hind limbs from 97 chickens,showed that in 52 osteopetrosis-negative chickens,the mid -portion of the tibia had a normal average value of 6. 16 mm (5. 5-7. 0 mm) ,and that the normal average value for the thickness of the cortical osseous tissue was 0. 64 mm (0. 4 - 0. 9 mm). Of the 42 occult cases which accounted for 93. 33% of the 45 osteopetrosis-positive birds,the external diameter of the bone fell within normal values,but the average thickness of the cortical bone was 0. 81 mm (slight increase) and 2. 12 mm (moderate increase). In the 3 clinical cases which occupied 6. 67% of the affected chickens,the external diameter of the tibia exceeded 7. 5 mm,attaining even 14 mm,while the thickness of the cortical bone exceeded 1. 5 mm,reaching even 9 mm.