ABSTRACT
Equine headshaking syndrome is a poorly understood neuropathic pain condition presenting as uncontrollable shaking, flicking, or striking of the head. Therapeutic options are limited, and treatments are only partially successful. Currently, epidemiological information on headshaking in the Southern Hemisphere is lacking. An online survey was circulated to Australian owners of headshaking horses to collect information on triggers, symptoms, seasonality, treatments, and perceived treatment efficacy. The responses (n = 216) showed the mean age at symptom onset as 9.6 (±4.7) years. More geldings were affected than mares (76% vs. 24%), and symptom onset occurred later in geldings compared to mares (10.1 ± 4.7 vs. 7.9 ± 4.0 years; p < 0.01). Bright sunlight, wind, and high pollen were the most commonly reported triggers (61%, 46% and 40%, respectively), and seasonal onset of symptoms was reported by 54% of respondents. In total, 71% of respondents reported using two or more treatments. The most common treatments were supplements (68%), nose nets (63%), light-blocking masks (48%), bodywork (48%) and pharmaceutical compounds (38%). Overall, treatments were considered ineffective by 33% of respondents. The findings were in agreement with surveys from the Northern Hemisphere. Of note was the perception of bright light as a primary trigger, alongside the reported low treatment efficacy of light-blocking masks. Seasonal intensification of symptoms and its relationship to day length merits further exploration.
ABSTRACT
The principal MHC class II molecules involved in the presentation of peptides to the antigen specific receptors on CD4+ T cells genes in sheep are derived from DR and DQ genes. Allelic nomenclature systems for the DRB1 and its partner DRA loci are available for Ovid's; however, no official nomenclature is available for the DQ genes which creates ambiguity within the research community. Ovine MHC haplotypes include at least two pairs of DQA and DQB genes, termed DQA1, DQB1 and DQA2, DQB2 and both sets are polymorphic and both seem to be functional. In a number of haplotypes, the DQA1 locus appears to be absent (DQA1-null) and is replaced by a second locus termed DQA2-like. Here, we identify families of alleles based on sequence similarity and phylogenetic clustering which correspond to each of the DQA and DQB genes identified in previous genomic and transcript analyses of homozygous animals. Using such criteria to cluster sequences, we have named 82 full-length and partial cDNA transcripts derived from domestic sheep (Ovis aries) which correspond to alleles at the Ovar-DQA1, DQA2, DQA2-like, DQB1, DQB2 and DQB2-like genes and provide associated sequence resources available to the research community through the IPD-MHC Database. This sets the basis for naming and annotation of DQ genes within the ovine MHC and may be used as a template for DQ genes in other ruminant species which will ultimately support research in livestock infectious disease.
