Reliability of high‐ and low‐field magnetic resonance imaging systems for detection of cartilage and bone lesions in the equine cadaver fetlock

Reasons for performing study: To determine the reliability of 2 magnetic resonance imaging (MRI) systems for detection of cartilage and bone lesions of the equine fetlock. Objectives: To test the hypotheses that lesions in cartilage, subchondral and trabecular bone of the equine fetlock verified using histopathology can be detected on high‐ and low‐field MR images with a low incidence of false positive or negative results; that low‐field images are less reliable than high‐field images for detection of cartilage lesions; and that combining results of interpretation from different pulse sequences increases detection of cartilage lesions. Methods: High‐ and low‐field MRI was performed on 19 limbs from horses identified with fetlock lameness prior to euthanasia. Grading systems were used to score cartilage, subchondral and trabecular bone on MR images and histopathology. Sensitivity and specificity were calculated for images. Results: High‐field T2*‐weighted gradient echo (T2*W‐GRE) and low‐field T2‐weighted fast spin echo (T2W‐FSE) images had high sensitivity but low specificity for detection of cartilage lesions. All pulse sequences had high sensitivity and low–moderate specificity for detection of subchondral bone lesions and moderate sensitivity and moderate–high specificity for detection of trabecular bone lesions (histopathology as gold standard). For detection of lesions of trabecular bone low‐field T2*W‐GRE images had higher sensitivity and specificity than T2W‐FSE images. Conclusions: There is high likelihood of false positive results using high‐ or low‐field MRI for detection of cartilage lesions and moderate–high likelihood of false positive results for detection of subchondral bone lesions compared with histopathology. Combining results of interpretation from different pulse sequences did not increase detection of cartilage lesions. MRI interpretation of trabecular bone was more reliable than cartilage or subchondral bone in both MR systems. Potential relevance: Independent interpretation of a variety of pulse sequences may maximise detection of cartilage and bone lesions in the fetlock. Clinicians should be aware of potential false positive and negative results.     

百日鸡J-亚群禽白血病组织病理学与超微病理学研究

利用ELISA试剂盒,对百日鸡的禽白血病抗体和抗原进行了检测。在5个百日鸡父母代鸡群中,1个鸡群的ALV-J抗体阳性率为57.14%,其余鸡群皆为阴性;所有鸡群的ALV-A、B抗体均为阴性;ALV p27抗原除1个鸡群为阴性外,其余鸡群阳性率都较高。在百日鸡的J亚群禽白血病病例中,肝脏、脾脏和肾脏显著肿大,且有弥漫性分布的肿瘤结节;在其他脏器也呈现肿瘤结节。组织病理学观察,发现其脏器等组织中,有一定比例的胞质含红色嗜酸性颗粒的髓细胞样瘤细胞与成淋巴细胞,排列致密呈局灶性生长,正常的组织细胞被挤压或破坏。超微病理观察,在脾脏和法氏囊等组织中均看到病毒颗粒,有囊膜,直径约100nm。部分淋巴细胞核膜、细胞膜水肿或溶解破裂,线粒体和内质网也水肿或池变大、细胞质中出现很多空泡状结构。肿瘤细胞的增多以及细胞内和细胞间的水肿,可能是各脏器严重肿大的主要原因。     

Pathological fracture through a subchondral bone cyst in the proximal phalanx of a horse

A 12‐year‐old Morgan broodmare presented for a nonweightbearing right forelimb lameness. Radiography and computed tomography confirmed the presence of a pathological fracture of the proximal first phalanx through a large subchondral bone cyst (SBC) in the right forelimb and a large SBC in the proximal first phalanx of the left forelimb. Surgical repair of the large palmar medial eminence fracture of the proximal first phalanx fracture was performed using bone screws placed in lag fashion placed through stab incisions after debridement and bone grafting of the SBCs. Approximately 6 months after surgery the mare was ambulating comfortably at pasture. This case report describes a fracture through a large subchondral bone cyst in a horse despite chronicity and ongoing bone remodelling. Careful consideration regarding exercise or use should be considered in horses with large SBCs.     

Anise oil dosage and its effect on growth performance and jejunal lesions during a Clostridium perfringens challenge in battery trials,and growth performance in a floor pen trial,

Anise oil (AO) is a phytochemical with antibiotic properties and it reduces the growth of Clostridium perfringens in vitro, which is the main causal agent of necrotic enteritis. A series of battery experiments was conducted to determine an AO dosage to feed to broilers and its effect during 2 C. perfringens challenges, and a floor pen experiment to determine its effect in performance. Anise oil linearly reduced (P < 0.05) ADFI and ADG, but feeding broilers 500 to 2,000 mg/kg of AO resulted in similar performance with positive control (PC) fed broilers. Broilers were challenged on d 10 (Experiment 2) or on d 10 and 13 (Experiment 3). Broilers fed AO had lower (P < 0.05) ADFI and ADG compared with broilers fed PC from zero to 18 d (Experiment 2). Growth performance of broilers fed AO was not affected (P > 0.05) during Experiment 3. In both challenges, the jejunum of broilers fed AO had fewer and milder (P < 0.05) lesions compared with broilers fed PC or negative control (NC) diets. In a floor pen trial, 1,000 mg/kg of AO was fed to broilers from zero to 42 days. Broilers fed AO or PC had similar (P > 0.10) growth performance for the entire trial. Broilers fed PC or AO had greater ADG (P < 0.05) and tended (P = 0.07) to be heavier than broilers fed NC at the end of the trial. Breast yield percentage was similar (P > 0.10) among broilers fed any of the dietary treatments. Residues of AO were not present at detectable levels in breast meat.     

Response of pigs to recent isolates of Coxsackievirus B5

Coxsackievirus B5 (CB5) was serially passaged five times in pigs in an attempt to establish clinical disease. No clinical signs were seen although some pigs had a transient rise in rectal temperature. Viremia was not detected although virus was isolated from nasal swabs and fecal samples. No CB5 specific fluorescence or virus was detected in any tissues of five passages by immunofluorescent test and tissue culture methods, respectively.

Brain lesions were noted in all passages; extensiveness of lesions increased slightly up to the third passage although no evidence of increasing viral replication was found. No increase in brain lesions was found in the fourth and fifth passages. The development and progress of brain lesions were similar to but less extensive than those caused by swine vesicular disease virus (SVDV) in most pigs examined. Contact pigs also showed more brain lesions than inoculated pigs. In some passages, microscopic changes also were found in the heart. All pigs exposed to CB5 had positive neutralizing antibody titres against CB5 and SVDV but became ill after challenge with SVDV. There was an anamnestic response to both viruses following challenge.     

Horizontal and vertical distribution of airborne conidia of Botrytis cinerea in a gerbera crop grown under glass

The horizontal and vertical distribution of airborne conidia ofBotrytis cinerea in a gerbera crop in two glasshouses (100 m² and 350 m²) was studied during 18 months in 1988 and 1989. Conidia ofB. cinerea were caught in simple spore traps consisting of agar in Petri dishes placed in a regular pattern at three different heights in the glasshouse and counted as colonies, after incubation. Lesions due to conidial infection were counted on gerbera petals. The horizontal and vertical distribution of conidia ofB. cinerea in a gerbera crop grown under glass was fairly uniform in both distinct glass-houses. Conidia ofB. cinerea trapped in a glasshouse can originate from sources inside and outside the glasshouse. No significant interaction was found between location and time for the colony counts and for the log transformed (ln(N+1)) lesion counts. The results of this study suggest that spore trapping at one height and at a limited number of locations and dates is sufficient for efficient monitoring ofB. cinerea in a glasshouse.     

Spontaneous aortic lesions in fallow deer (Dama dama L)

In 19 out of 22 aortas from fallow deer, 15 months to 5½ years, aortic lesions were found. Three types of lesions were observed, fatty streaks were seen in 2, fibrous plaques in 15 and fibrous plaques with complicated lesions (calcification and acid mucopolysaccharides) in 2 of the aortas. Elastic tissue degeneration of the inner two thirds of the tunica media was frequently found in the aorta of the animals > 3½–5½ years of age. There was no statistical evidence for a correlation between age and frequency (P ~ 0.10) but a trend towards age dependence was seen. The percentage of involved surface was found to significantly increase (0.05 > P > 0.01) with age. Lesions were found to start in the abdominal aorta in young animals and to extend cranially to the thoracic aorta with age. The percentage of involved surface in different affected regions, comprising all age groups were, in the posterior abdominal portion, 10.5 %, in the anterior abdominal portion, 4.3 % and in the posterior thoracic portion, 1.04 %. The influence of hemodynamic flow upon the localization of the aortic lesions, the endothelial cell population density and the endothelial nuclear patterns were discussed.     

Foot lesions in lame cows on 10 dairy farms in Ireland

Background

Little is known about foot lesions in dairy cattle in Ireland, managed under a pasture based system with housing during the winter and grazing for the rest of the year. Ten Irish dairy herds, with a lameness prevalence ranging from 9 to 17 % were locomotion scored routinely during the 2013 grazing season. Lame cows were foot trimmed and foot lesions recorded.

Findings

11.8 % and 89.6 % of cows had lesions recorded on front and hind feet respectively. No lesions were found in 6.9 % of cows. Sole haemorrhage and white line disease were the most prevalent lesions, and overall 76.8 % of lesions affecting the claw horn were diagnosed on the lateral hind claw.

Conclusions

Treatment success, as measured by improved LS post treatment, was not significantly affected by the LS prior to foot trimming, the presence of lesions or the type of lesion identified. Exposure to both risk factors for lameness at housing and pasture may have resulted in the development of a combination of foot lesions typically associated with zero-grazing or all-year-round grazing management systems.