Repeatability and intra- and inter-observer agreement of cervical vertebral sagittal diameter ratios in horses with neurological disease.

BACKGROUND: Sagittal ratio values (SRVs) of cervical vertebrae are used for ante-mortem diagnosis of cervical vertebral stenotic myelopathy, but intraobserver and interobserver variability in measurement may influence radiographic interpretation of vertebral stenosis in horses with neurological disease. OBJECTIVES: To determine intraobserver repeatability in SRVs, intra- and interobserver agreement in SRVs and whether or not agreement was influenced by animal age. ANIMALS: Forty-two horses (>1 year old) with neurological disease from which laterolateral computed radiographic images of C2-C7 were obtained. METHODS: Four observers made measurements from C2 to C7 for each horse and interobserver agreement for intra- and intervertebral SRVs was determined using Bland-Altman analysis (acceptable agreement: limits of agreement [LOA] ≤ 0.05) on all horses and those ≤3 (n = 25) and >3 (n = 17) years old. Each observer also made repeated measurements for 10 horses and intraobserver repeatability and agreement were determined. RESULTS: Adequate intraobserver repeatability was achieved for 6 sites. Within observers, paired measurements had a median difference ≤5.7%, but a large range in differences often occurred, most frequently at intervertebral sites. For C5, C6, C7, and C3-4, LOA ≤ 0.05 were achieved by at least 1 observer. With the exception of C5 for 1 pair, LOA were >0.05 for interobserver agreement, regardless of animal age. LOA were largest at intervertebral sites. CONCLUSIONS AND CLINICAL IMPORTANCE: Within and between observers, measurement error may limit the diagnostic accuracy of SRVs and result in discrepancies of diagnosis and treatment and warrants consideration when used clinically in horses with neurological disease.

Serological changes observed in horses infected with Anoplocephala perfoliata after treatment with praziquantel and natural reinfection.

The serological changes in two groups of horses known to be harbouring Anoplocephala perfoliata were studied; 12 were treated with 1.5 mg/kg praziquantel and 200 microg/kg ivermectin, and 14 were treated with 200 microg/kg ivermectin. Serological and faecal analyses were carried out on each animal at intervals for 758 days. The titres of antibodies specific for A perfoliata decreased from the day of treatment to day 28 in both groups, and continued to decrease in the group treated with praziquantel and ivermectin, with the first significant decrease from the other group at day 121. From day 151 to day 295 the first significant increase in antibody levels in the group treated with both drugs was observed; no A perfoliata eggs were detected in the faeces of these animals until day 295 when five of the 10 were positive.

Assessment of serum protein electrophoresis for monitoring therapy of naturally acquired equine cyathostomin infections.

Serum protein electrophoresis (SPE) has previously been suggested as a means of assessing cyathostomin burdens in horses, although SPE used for that purpose is supported by little evidence. This clinical research report describes a study that objectively evaluated the use of SPE on a population of 38 horses following the administration of different anthelmintics. The population was subdivided into three groups, Groups F, M and P: 7.5 mg/kg bwt fenbendazole was administered to Group F on day -12; on day 0 0.4 mg/kg bwt moxidectin was administered to Group M and 19 mg/kg bwt pyrantel was administered to Group P. Faecal worm egg counts were obtained on days -14, 0 and 10. Groups M and P acted as controls for the Group F faecal egg count reduction test (FECRT) in which a high level of benzimidazole resistance was demonstrated. Group F was then used as a control group for the FECRT for both Groups P and M. A high anthelmintic efficacy of moxidectin and pyrantel was detected. SPE was performed on venous blood collected on days 0, 10, 30, 56 and 80. As the cyathostomins infecting the horses had been shown to be highly resistant to fenbendazole, Group F then served as a control group for comparison of any changes in protein fractions. Serum proteins did not vary significantly between groups on any of the sampling dates. No significant changes in serum proteins were observed in any group and no patterns were apparent on qualitative assessment of SPE profiles. SPE was therefore concluded to be an insensitive tool for the monitoring of cyathostomin treatment in horses in a clinical environment.