Objective effectiveness of and indications for laser-assisted turbinectomy in brachycephalic obstructive airway syndrome.

OBJECTIVE: To evaluate the effectiveness of laser-assisted turbinectomy (LATE) in treating brachycephalic obstructive airway syndrome (BOAS) and to investigate the potential indications. STUDY DESIGN: Prospective clinical study. SAMPLE POPULATION: Client-owned pugs, French bulldogs, and English bulldogs (n = 57). METHODS: A BOAS index was obtained from whole-body barometric plethysmography before BOAS conventional multilevel surgery (CMS) and 2-6 months post-CMS. Dogs with BOAS index >50% and BOAS functional grades II-III after CMS were considered candidates for LATE. A BOAS index was repeated 2-6 months after LATE. Intranasal lesions and a measurement of soft tissue proportion at the rostral entrance of choanae (STC) were recorded on the basis of computed tomography images. Logistic regressions were used to assess the intranasal predictors for being LATE candidates. RESULTS: Twenty-nine of 57 dogs were candidates for LATE, all of which were pugs or French bulldogs. The median BOAS index of dogs that were operated on (20/29 candidates) decreased from 67% post-CMS to 42% after LATE (P < .001). Soft tissue proportion at the rostral entrance of choanae was the only predictor for candidacy for LATE. Pugs (P = .021; cutoff = 64%) and French bulldogs (P = .008; cutoff = 55%) with higher STC were more likely to be candidates for LATE. After LATE, 12 of 20 dogs had temporary episodes of reverse sneezing, and nasal noise was noted in 8 of 20 dogs when sniffing and excited. CONCLUSION: Laser-assisted turbinectomy was an effective treatment for dogs with intranasal abnormalities and a poor response to CMS. Soft tissue proportion at the rostral entrance of choanae was a predictor of candidacy for LATE in pugs and French bulldogs. CLINICAL SIGNIFICANCE: Computed tomography-based measurement of STC can be used to predict whether LATE is required in addition to CMS in pugs and French bulldogs with BOAS.

Endotracheal tube placement during computed tomography of brachycephalic dogs alters upper airway dimensional measurements.

Computed tomography (CT) is used to document upper airway lesions in dogs with brachycephalic obstructive airway syndrome. The presence of an endotracheal tube during CT scanning is often required for general anesthesia. We hypothesized that the endotracheal tube placement would change the soft tissue dimensions of the upper airway. The aims of this prospective, method comparison study were to evaluate the reliability of the previously reported upper airway CT measurements with endotracheal tube placement, and to propose measurements that are minimally affected by the endotracheal tube. Twenty brachycephalic dogs were included in this study. Each dog underwent head/neck CT with an endotracheal tube, followed by a second scan without the endotracheal tube. Ten measurements of the soft palate, nasopharynx, and trachea were performed. Tracheal dimension was significantly larger with the endotracheal tube compared to without, whereas the soft palate cross-sectional area was significantly smaller with the endotracheal tube than without the endotracheal tube. The influence of the endotracheal tube on the caudal nasopharynx cross-sectional (transverse-sectional) area varied with a mean proportional absolute difference of 35%. Rostral soft palate thickness, tracheal perimeter, and cross-sectional area of the rostral nasopharynx were the measurements least affected by the endotracheal tube (intraclass correlation coefficient = 0.964, 0.967, and 0.951, respectively). Therefore, we proposed that these three measurements may be most useful for future brachycephalic obstructive airway syndrome studies that require CT scanning of intubated animals. However, with endotracheal tube placement, measurements of soft palate length, caudal nasopharyngeal cross-sectional area, and trachea height and width may not be reliable.

Outcomes and prognostic factors of surgical treatments for brachycephalic obstructive airway syndrome in 3 breeds.

OBJECTIVE: To determine prognostic indicators for the surgical treatment of brachycephalic obstructive airway syndrome (BOAS) and to compare the prognosis of 2 multilevel surgical procedures. STUDY DESIGN: Prospective clinical study. SAMPLE POPULATION: Client-owned pugs, French bulldogs, and bulldogs (n = 50). METHODS: Noninvasive whole-body barometric plethysmography (WBBP) was used to assess respiratory function before, 1 month and 6 months after upper airway corrective surgery. Postoperatively, BOAS indices (ie, ascending severity score generated from WBBP data, 0%-100%) that equaled to or exceeded the cut-off values of BOAS in the diagnostic models were considered to have a "poor prognosis." A multivariate logistic regression was used to assess predictors for prognosis. RESULTS: The median BOAS indices decreased after surgery (from 76% to 63%, P < .0001), although dogs with indices in this range would still be considered clinically affected. Age (odds ratios [OR] = 0.96, 95% confidence interval [CI]: 0.93-0.99, P < .05), body condition (OR = 0.06, 95% CI: 0.01-0.39, P < .01), laryngeal collapse (OR = 6.1, 95% CI: 1-37.22, P < .05), and surgical techniques (OR = 7.94, 95% CI: 1.17-54.01, P < .05) were associated with postoperative prognosis. The multivariate model suggests modified multilevel surgery (MMS) may have a better outcome than traditional multilevel surgery (TMS) (P = .034). The positive predictive value of the logistic model was 84% (95% CI: 68-94%) and the area under the receiver operating characteristic (ROC) curve was 89% (95% CI: 78-99%, P <.0001). CONCLUSIONS: Younger age, normal body condition, presence of laryngeal collapse, and treatment with TMS were negative prognostic factors after surgical treatment of BOAS. MMS is recommended, particularly in dogs with a higher probability of poor prognosis.

Histological and Histopathological Features of the Third Metacarpal/Tarsal Parasagittal Groove and Proximal Phalanx Sagittal Groove in Thoroughbred Horses with Racing History.

Information regarding the histopathology of the proximal phalanx (P1) sagittal groove in racehorses is limited. Twenty-nine cadaver limbs from nine Thoroughbred racehorses in racing/race-training underwent histological examination. Histological specimens of the third metacarpal/metatarsal (MC3/MT3) parasagittal grooves and P1 sagittal grooves were graded for histopathological findings in hyaline cartilage (HC), calcified cartilage (CC), and subchondral plate and trabecular bone (SCB/TB) regions. Histopathological grades were compared between (1) fissure and non-fissure locations observed in a previous study and (2) dorsal, middle, and palmar/plantar aspects. (1) HC, CC, and SCB/TB grades were more severe in fissure than non-fissure locations in the MC3/MT3 parasagittal groove (p < 0.001). SCB/TB grades were more severe in fissure than non-fissure locations in the P1 sagittal groove (p < 0.001). (2) HC, CC, and SCB/TB grades including SCB collapse were more severe in the palmar/plantar than the middle aspect of the MC3/MT3 parasagittal groove (p < 0.001). SCB/TB grades including SCB collapse were more severe in the dorsal and middle than the palmar/plantar aspect of the P1 sagittal groove (p < 0.001). Histopathology in the SCB/TB region including bone fatigue injury was related to fissure locations, the palmar/plantar MC3/MT3 parasagittal groove, and the dorsal P1 sagittal groove.

Comparison of cone-beam and fan-beam computed tomography and low-field magnetic resonance imaging for detection of proximal phalanx dorsoproximal osteochondral defects.

BACKGROUND: Dorsoproximal osteochondral defects commonly affect the proximal phalanx, but information about diagnosis on computed tomography (CT) and magnetic resonance imaging (MRI) is limited. OBJECTIVES: To assess CT and MRI diagnoses of osteochondral defects, describe the lesions and compare sensitivity and specificity of the modalities using macroscopic pathology as gold standard. STUDY DESIGN: Cross-sectional study. METHODS: Thirty-five equine cadaver limbs underwent standing cone-beam CT (CBCT), fan-beam CT (FBCT), low-field MRI and pathological examination. CT and MR images were examined for proximal phalanx dorsomedial and dorsolateral eminence osteochondral defects. Defect dimensions were measured. Imaging diagnoses and measurements were compared with macroscopic examination. RESULTS: Fifty-six defects were seen over 70 potential locations. On CBCT and FBCT, osteochondral defects appeared as subchondral irregularity/saucer-shaped defects. On MRI, osteochondral defects were a combination of articular cartilage defect on dorsal images and subchondral flattening/irregularity on sagittal images. Subchondral thickening and osseous short tau inversion recovery hyperintensity were found concurrent with osteochondral defects. Compared with pathological examination, the sensitivity and specificity of diagnosis were 86% (95% confidence interval [95% CI] 75%-93%) and 64% (95% CI 38%-85%) for FBCT; 64% (95% CI 51%-76%) and 71% (95% CI 46%-90%) for CBCT; and 52% (95% CI 39%-65%) and 71% (95% CI 46%-90%) for MRI. Sensitivity of all modalities increased with defect size. Macroscopic defect dimensions were strongly correlated with CBCT (r = 0.76, p < 0.001) and moderately correlated with FBCT and MRI (r = 0.65, p < 0.001). Macroscopic measurements were significantly greater than all imaging modality dimensions (p < 0.001), potentially because macroscopy included articular cartilage pathology. MAIN LIMITATIONS: Influence of motion artefact could not be assessed. CONCLUSIONS: Osteochondral defects could be visualised using both CT and MRI with sensitivity increasing with defect size. Diagnostic performance was best using FBCT, followed by CBCT then MRI, but CBCT-measured defect size best correlated with macroscopic examination. MRI provided useful information on fluid signal associated with defects, which could represent active pathology.

Three-Dimensional Imaging and Histopathological Features of Third Metacarpal/Tarsal Parasagittal Groove and Proximal Phalanx Sagittal Groove Fissures in Thoroughbred Horses.

Fissure in the third metacarpal/tarsal parasagittal groove and proximal phalanx sagittal groove is a potential prodromal pathology of fracture; therefore, early identification and characterisation of fissures using non-invasive imaging could be of clinical value. Thirty-three equine cadaver limbs underwent standing cone-beam (CB) computed tomography (CT), fan-beam (FB) CT, low-field magnetic resonance imaging (MRI), and macro/histo-pathological examination. Imaging diagnoses of fissures were compared to microscopic examination. Imaging features of fissures were described. Histopathological findings were scored and compared between locations with and without fissures on CT. Microscopic examination identified 114/291 locations with fissures. The diagnostic sensitivity and specificity were 88.5% and 61.3% for CBCT, 84.1% and 72.3% for FBCT, and 43.6% and 85.2% for MRI. Four types of imaging features of fissures were characterised on CT: (1) CBCT/FBCT hypoattenuating linear defects, (2) CBCT/FBCT striated hypoattenuated lines, (3) CBCT/FBCT subchondral irregularity, and (4) CBCT striated hypoattenuating lines and FBCT subchondral irregularity. Fissures on MRI appeared as subchondral bone hypo-/hyperintense defects. Microscopic scores of subchondral bone sclerosis, microcracks, and collapse were significantly higher in locations with CT-identified fissures. All imaging modalities were able to identify fissures. Fissures identified on CT were associated with histopathology of fatigue injuries.

Comparison of cone-beam and fan-beam computed tomography and low-field magnetic resonance imaging for detection of palmar/plantar osteochondral disease in Thoroughbred horses.

BACKGROUND: Palmar/plantar osteochondral disease (POD) of the metacarpal/tarsal condyles is a common pathological finding in racehorses. OBJECTIVE: To compare diagnoses, imaging details, and measurements of POD lesions between cone-beam computed tomography CT (CBCT), fan-beam CT (FBCT), and low-field magnetic resonance imaging (MRI) using macroscopic pathology as a gold standard. STUDY DESIGN: Cross-sectional study. METHODS: Thirty-five cadaver limbs from 10 horses underwent CBCT, FBCT, MRI, and macroscopic examination. CT and MR images were examined for presence of POD, imaging details of POD, and measurements of POD dimensions and areas. Imaging diagnoses, details, and measurements were compared with macroscopic examination and between modalities. RESULTS: Forty-eight POD lesions were seen over 70 condyles. Compared with macroscopic examination the sensitivity and specificity of diagnosis were 95.8% (CI95 = 88%-99%) and 63.6% (CI95 = 43%-81%) for FBCT, 85.4% (CI95 = 74%-94%) and 81.8% (CI95 = 63%-94%) for CBCT, and 69.0% (CI95 = 54%-82%) and 71.4% (CI95 = 46%-90%) for MRI. Inter-modality agreement on diagnosis was moderate between CBCT and FBCT (κ = 0.56, p < 0.001). POD was identified on CT as hypoattenuating lesions with surrounding hyperattenuation and on MRI as either T1W, T2*W, T2W, and STIR hyperintense lesions or T1W and T2*W heterogeneous hypointense lesions with surrounding hypointensity. Agreement on imaging details between CBCT and FBCT was substantial for subchondral irregularity (κ = 0.61, p < 0.001). Macroscopic POD width strongly correlated with MRI (r = 0.81, p < 0.001) and CBCT (r = 0.79, p < 0.001) and moderately correlated with FBCT (r = 0.69, p < 0.001). Macroscopic POD width was greater than all imaging modality (p < 0.001). MAIN LIMITATIONS: Effect of motion artefact in live horse imaging could not be assessed. CONCLUSIONS: All imaging modalities were able to detect POD lesions, but underestimated lesion size. The CT systems were more sensitive, but the differing patterns of signal intensity may suggest that MRI can detect changes associated with POD pathological status or severity. The image features observed by CBCT and FBCT were similar.

Identification of Heterotopic Mineralization and Adjacent Pathology in the Equine Fetlock Region by Low-Field Magnetic Resonance Imaging, Cone-Beam and Fan-Beam Computed Tomography.

Heterotopic mineralization in equine distal limbs has been considered an incidental finding and little is known about its imaging features. The study aimed to identify heterotopic mineralization and adjacent pathology in the fetlock region with cone-beam (CB) computed tomography (CT), fan-beam (FB) CT, and low-field magnetic resonance imaging (MRI). Images from 12 equine cadaver limbs were examined for heterotopic mineralization and adjacent pathology and verified by macro-examination. Retrospective review of the CBCT/MR images from 2 standing horses was also included. CBCT and FBCT identified twelve mineralization's with homogeneous hyperattenuation: oblique-sesamoidean-ligament (5) without macroscopic abnormality; deep-digital-flexor-tendon (1) and suspensory-branch (6) with macroscopic abnormalities. MRI failed to identify all mineralization's, but detected suspensory branch splitting, and T2 and STIR hyperintensity in 4 suspensory-branches and 3 oblique-sesamoidean-ligaments. Macro-examination found corresponding disruption/splitting and discoloration. All modalities identified 7 ossified fragments showing cortical/trabecular pattern: capsular (1), palmar sagittal ridge (1), proximal phalanx (2) without macroscopic abnormality, and proximal sesamoid bones (3). On MRI, fragments were most identifiable on T1 images. All abaxial avulsions had suspensory-branch splitting on T1 images with T2 and STIR hyperintensity. Macro-examination showed ligament disruption/splitting and discoloration. Suspensory-branch/intersesamoidean ligament mineralization's were identified by CBCT in standing cases; 1 had associated T2 hyperintensity. Both CT systems were generally superior in identifying heterotopic mineralization's than MRI, while MRI provided information on soft tissue pathology related to the lesions, which may be important for management.

Genome-wide association study in RPGRIP1(-/-) dogs identifies a modifier locus that determines the onset of retinal degeneration.

Cone-rod dystrophy (CRD) is a form of inherited retinal degeneration (RD) causing blindness in man as well as in several breeds of dog. Previously, a 44 bp insertion in RPGRIP1 (retinitis pigmentosa GTPase regulator interacting protein-1) was associated with a recessive early-onset CRD (cone-rod dystrophy 1, cord1) in a Miniature longhaired dachshund (MLHD) research colony. Yet in the MLHD pet population, extensive range of the onset age has been observed among RD cases, with some RPGRIP1(-/-) dogs lacking obvious clinical signs. Phenotypic variation has been known in human homologous diseases, including retinitis pigmentosa and Leber congenital amaurosis, indicating possible involvement of modifiers. To explore additional genetic loci associated with the phenotypic variation observed in MLHDs, a genome-wide association study was carried out using Canine SNP20 arrays in 83 RPGRIP1(-/-) MLHDs with variable ages of onset or no clinical abnormality. Using these samples, comparison of 31 early-onset RD cases against 49 controls (15 late-onset RD and 34 normal dogs combined) identified a strong association (P = 5.05 × 10(-13)) at a single locus on canine chromosome 15. At this locus, the majority of early-onset RD cases but few of the controls were homozygous for a 1.49 Mb interval containing ~11 genes. We conclude that homozygosity at both RPGRIP1 and the newly mapped second locus is necessary to develop early-onset RD, whereas RPGRIP1(-/-) alone leads to late-onset RD or no apparent clinical phenotype. This study establishes a unique model of canine RD requiring homozygous mutations at two distinct genetic loci for the manifestation of early-onset RD.

Phenotypic variation and genotype-phenotype discordance in canine cone-rod dystrophy with an RPGRIP1 mutation.

PURPOSE: Previously, a 44 bp insertion in exon 2 of retinitis pigmentosa GTPase interacting protein 1 (RPGRIP1) was identified as the cause of cone-rod dystrophy 1 (cord1), a recessive form of progressive retinal atrophy (PRA) in the Miniature Longhaired Dachshund (MLHD), a dog model for Leber congenital amaurosis. The cord1 locus was mapped using MLHDs from an inbred colony with a homogeneous early onset disease phenotype. In this paper, the MLHD pet population was studied to investigate phenotypic variation and genotype-phenotype correlation. Further, the cord1 locus was fine-mapped using PRA cases from the MLHD pet population to narrow the critical region. Other dog breeds were also screened for the RGPRIP1 insertion. METHODS: This study examined phenotypic variation in an MLHD pet population that included 59 sporadic PRA cases and 18 members of an extended family with shared environment and having six PRA cases. Ophthalmologic evaluations included behavioral abnormalities, responses to menace and light, fundoscopy, and electroretinography (ERG). The RPGRIP1 insertion was screened for in all cases and 200 apparently normal control MLHDs and in 510 dogs from 66 other breed. To fine-map the cord1 locus in the MLHD, 74 PRA cases and 86 controls aged 4 years or more were genotyped for 24 polymorphic markers within the previously mapped cord1 critical region of 14.15 Mb. RESULTS: Among sporadic PRA cases from the MLHD pet population, the age of onset varied from 4 months to 15 years old; MLHDs from the extended family also showed variable onset and rate of progression. Screening for the insertion in RPGRIP1 identified substantial genotype-phenotype discordance: 16% of controls were homozygous for the insertion (RPGRIP1(-/-)), while 20% of PRA cases were not homozygous for it. Four other breeds were identified to carry the insertion including English Springer Spaniels and Beagles with insertion homozygotes. The former breed included both controls and PRA cases, yet in the latter breed, cone ERG was undetectable in two dogs with no clinically apparent visual dysfunction. Notably, the insertion in the Beagles was a longer variant of that seen in the other breeds. Fine-mapping of the cord1 locus narrowed the critical region on CFA15 from 14.15 Mb to 1.74 Mb which still contains the RPGRIP1 gene. CONCLUSIONS: Extensive phenotypic variations of onset age and progression rate were observed in PRA cases of the MLHD pet population. The insertion in RPGRIP1 showed the strongest association with the disease, yet additional as well as alternative factors may account for the substantial genotype-phenotype discordance.

Disruption of chromosome 11 in canine fibrosarcomas highlights an unusual variability of CDKN2B in dogs.

BACKGROUND: In dogs in the western world neoplasia constitutes the most frequently diagnosed cause of death. Although there appear to be similarities between canine and human cancers, rather little is known about the cytogenetic and molecular alterations in canine tumours. Different dog breeds are susceptible to different types of cancer, but the genetic basis of the great majority of these predispositions has yet to be discovered. In some retriever breeds there is a high incidence of soft tissue sarcomas and we have previously reported alterations of chromosomes 11 and 30 in two poorly differentiated fibrosarcomas. Here we extend our observations and present a case report on detail rearrangements on chromosome 11 as well as genetic variations in a tumour suppressor gene in normal dogs. RESULTS: BAC hybridisations on metaphases of two fibrosarcomas showed complex rearrangements on chromosome 11, and loss of parts of this chromosome. Microsatellite markers on a paired tumour and blood DNA pointed to loss of heterozygosity on chromosome 11 in the CDKN2B-CDKN2A tumour suppressor gene cluster region. PCR and sequencing revealed the homozygous loss of coding sequences for these genes, except for exon 1beta of CDKN2A, which codes for the N-terminus of p14ARF. For CDKN2B exon 1, two alleles were observed in DNA from blood; one of them identical to the sequence in the dog reference genome and containing 4 copies of a 12 bp repeat found only in the canine gene amongst all species so far sequenced; the other allele was shorter due to a missing copy of the repeat. Sequencing of this exon in 141 dogs from 18 different breeds revealed a polymorphic region involving a GGC triplet repeat and a GGGGACGGCGGC repeat. Seven alleles were recorded and sixteen of the eighteen breeds showed heterozygosity. CONCLUSION: Complex chromosome rearrangements were observed on chromosome 11 in two Labrador retriever fibrosarcomas. The chromosome alterations were reflected in the loss of sequences corresponding to two tumour suppressor genes involved in cell-cycle progression. Sequencing of CDKN2B across many different breeds revealed a widespread polymorphism within the first exon of the gene, immediately before the ankyrin coding sequences.

The Gambian epauletted fruit bat shows increased genetic divergence in the Ethiopian highlands and in an area of rapid urbanization.

The Gambian epauletted fruit bat (Epomophorus gambianus) is an abundant species that roosts in both urban and rural settings. The possible role of E. gambianus as a reservoir host of zoonotic diseases underlines the need to better understand the species movement patterns. So far, neither observational nor phylogenetic studies have identified the dispersal range or behavior of this species. Comparative analyses of mitochondrial and nuclear markers from 20 localities across the known distribution of E. gambianus showed population panmixia, except for the populations in Ethiopia and southern Ghana (Accra and Ve-Golokwati). The Ethiopian population may be ancestral and is highly divergent to the species across the rest of its range, possibly reflecting isolation of an ancient colonization along an east-west axis. Mitochondrial haplotypes in the Accra population display a strong signature of a past bottleneck event; evidence of either an ancient or recent bottleneck using microsatellite data, however, was not detected. Demographic analyses identified population expansion in most of the colonies, except in the female line of descent in the Accra population. The molecular analyses of the colonies from Ethiopia and southern Ghana show gender dispersal bias, with the mitochondrial DNA fixation values over ten times those of the nuclear markers. These findings indicate free mixing of the species across great distances, which should inform future epidemiological studies.

The Finnish lapphund retinal atrophy locus maps to the centromeric region of CFA9.

BACKGROUND: Dogs have the second largest number of genetic diseases, after humans. Among the diseases present in dogs, progressive retinal atrophy has been reported in more than a hundred breeds. In some of them, the mutation has been identified and genetic tests have allowed the identification of carriers, thus enabling a drastic reduction in the incidence of the disease. The Finnish lapphund is a dog breed presenting late-onset progressive retinal atrophy for which the disease locus remains unknown. RESULTS: In this study we mapped the progressive retinal atrophy locus in the Finnish lapphund using a DNA pooling approach, assuming that all affected dogs within the breed share the same identical-by descent-mutation as the cause of the disease (genetic homogeneity). Autosomal recessive inheritance was also assumed, after ruling out, from pedigree analysis, dominant and X-linked inheritance. DNA from 12 Finnish lapphund cases was mixed in one pool, and DNA from 12 first-degree relatives of these cases was mixed to serve as the control pool. The 2 pools were tested with 133 microsatellite markers, 3 of which showed a shift towards homozygosity in the cases. Individual genotyping with these 3 markers confirmed homozygosity for the GALK1 microsatellite only (chromosome 9). Further individual genotyping with additional samples (4 cases and 59 controls) confirmed the association between this marker and the disease locus (p < 0.001). Closely related to this breed are the Swedish lapphund and the Lapponian herder for which a small number of retinal atrophy cases have been reported. Swedish lapphund cases, but not Lapponian herder cases, had the same GALK1 microsatellite genotype as Finnish lapphund cases. CONCLUSION: The locus for progressive rod-cone degeneration is known to be close to the GALK1 locus, on the telomeric region of chromosome 9, where the retinal atrophy locus of the Finnish lapphund has been mapped. This suggests that the disease in this breed, as well as in the Swedish lapphund, may correspond to progressive rod-cone degeneration. This would increase the number of known dog breeds having this particular form of progressive retinal atrophy.

Conformational risk factors of brachycephalic obstructive airway syndrome (BOAS) in pugs, French bulldogs, and bulldogs.

Extremely brachycephalic, or short-muzzled, dog breeds such as pugs, French bulldogs, and bulldogs are prone to the conformation-related respiratory disorder-brachycephalic obstructive airway syndrome (BOAS). Affected dogs present with a wide range of clinical signs from snoring and exercise intolerance, to life-threatening events such as syncope. In this study, conformational risk factors for BOAS that could potentially aid in breeding away from BOAS were sought. Six hundred and four pugs, French bulldogs, and bulldogs were included in the study. Soft tape measurements of the head and body were used and the inter-observer reproducibility was evaluated. Breed-specific models were developed to assess the associations between the conformational factors and BOAS status based on functional grading. The models were further validated by means of a BOAS index, which is an objective measurement of respiratory function using whole-body barometric plethysmography. The final models have good predictive power for discriminating BOAS (-) and BOAS (+) phenotypes indicated by the area under the curve values of >80% on the receiver operating curves. When other factors were controlled, stenotic nostrils were associated with BOAS in all three breeds; pugs and bulldogs with higher body condition scores (BCS) had a higher risk of developing BOAS. Among the standardized conformational measurements (i.e. craniofacial ratio (CFR), eye width ratio (EWR), skull index (SI), neck girth ratio (NGR), and neck length ratio (NLR)), for pugs EWR and SI, for French bulldogs NGR and NLR, and for bulldogs SI and NGR showed significant associations with BOAS status. However, the NGR in bulldogs was the only significant predictor that also had satisfactory inter-observer reproducibility. A NGR higher than 0.71 in male bulldogs was predictive of BOAS with approximately 70% sensitivity and specificity. In conclusion, stenotic nostrils, BCS, and NGR were found to be valid, easily applicable predictors for BOAS (+).

The complete mitochondrial genome of Epomophorus gambianus (Chiroptera: Pteropodidae) and its phylogenetic analysis.

The Gambian epauletted fruit bat, Epomophorus gambianus, is widely distributed across sub-Saharan Africa. Its assembled and annotated mitochondrial genome (GenBank accession no. KT963027) is 16,702 bases in length, containing 13 protein-coding genes, 22 transfer RNA genes, two ribosomal RNA genes and two non-coding regions: the control region (D-loop) and the origin of light-strand replication (OL). The average base composition is 32.2% A; 27.6% C; 14% G; and 26.1% T. The mitogenome presented a structural composition greatly conserved between members of the Pteropodidae family.

Bat trait, genetic and pathogen data from large-scale investigations of African fruit bats, Eidolon helvum.

Bats, including African straw-coloured fruit bats (Eidolon helvum), have been highlighted as reservoirs of many recently emerged zoonotic viruses. This common, widespread and ecologically important species was the focus of longitudinal and continent-wide studies of the epidemiological and ecology of Lagos bat virus, henipaviruses and Achimota viruses. Here we present a spatial, morphological, demographic, genetic and serological dataset encompassing 2827 bats from nine countries over an 8-year period. Genetic data comprises cytochrome b mitochondrial sequences (n=608) and microsatellite genotypes from 18 loci (n=544). Tooth-cementum analyses (n=316) allowed derivation of rare age-specific serologic data for a lyssavirus, a henipavirus and two rubulaviruses. This dataset contributes a substantial volume of data on the ecology of E. helvum and its viruses and will be valuable for a wide range of studies, including viral transmission dynamic modelling in age-structured populations, investigation of seasonal reproductive asynchrony in wide-ranging species, ecological niche modelling, inference of island colonisation history, exploration of relationships between island and body size, and various spatial analyses of demographic, morphometric or serological data.

Characterisation of Brachycephalic Obstructive Airway Syndrome in French Bulldogs Using Whole-Body Barometric Plethysmography.

Brachycephalic obstructive airway syndrome (BOAS) is an important health and welfare problem in several popular dog breeds. Whole-body barometric plethysmography (WBBP) is a non-invasive method that allows safe and repeated quantitative measurements of respiratory cycles on unsedated dogs. Here respiratory flow traces in French bulldogs from the pet population were characterised using WBBP, and a computational application was developed to recognise affected animals. Eighty-nine French bulldogs and twenty non-brachycephalic controls underwent WBBP testing. A respiratory functional grading system was used on each dog based on respiratory signs (i.e. respiratory noise, effort, etc.) before and after exercise. For development of an objective BOAS classifier, functional Grades 0 and I were considered to have insignificant clinical signs (termed here BOAS-) and Grades II and III to have significant signs (termed here BOAS+). A comparison between owner-perception of BOAS and functional grading revealed that 60 % of owners failed to recognise BOAS in dogs that graded BOAS+ in this study.WBBP flow traces were found to be significantly different between non-brachycephalic controls and Grade 0 French bulldogs; BOAS- and BOAS+ French bulldogs. A classifier was developed using quadratic discriminant analysis of the respiratory parameters to distinguish BOAS- and BOAS + French bulldogs, and a BOAS Index was calculated for each dog. A cut-off value of the BOAS Index was selected based on a receiver operating characteristic (ROC) curve. Sensitivity, specificity, positive predictive value, and negative predictive value of the classifier on the training group (n=69) were 0.97, 0.93, 0.95, and 0.97, respectively. The classifier was validated using a test group of French bulldogs (n=20) with an accuracy of 0.95. WBBP offers objective screening for the diagnosis of BOAS in French Bulldogs. The technique may be applied to other brachycephalic breeds affected by BOAS, and possibly to other respiratory disease in dogs.

Continent-wide panmixia of an African fruit bat facilitates transmission of potentially zoonotic viruses.

The straw-coloured fruit bat, Eidolon helvum, is Africa's most widely distributed and commonly hunted fruit bat, often living in close proximity to human populations. This species has been identified as a reservoir of potentially zoonotic viruses, but uncertainties remain regarding viral transmission dynamics and mechanisms of persistence. Here we combine genetic and serological analyses of populations across Africa, to determine the extent of epidemiological connectivity among E. helvum populations. Multiple markers reveal panmixia across the continental range, at a greater geographical scale than previously recorded for any other mammal, whereas populations on remote islands were genetically distinct. Multiple serological assays reveal antibodies to henipaviruses and Lagos bat virus in all locations, including small isolated island populations, indicating that factors other than population size and connectivity may be responsible for viral persistence. Our findings have potentially important public health implications, and highlight a need to avoid disturbances that may precipitate viral spillover.

Multiple mechanisms contribute to leakiness of a frameshift mutation in canine cone-rod dystrophy.

UNLABELLED: Mutations in RPGRIP1 are associated with early onset retinal degenerations in humans and dogs. Dogs homozygous for a 44 bp insertion including a polyA(29) tract potentially leading to premature truncation of the protein, show cone rod degeneration. This is rapid and blinding in a colony of dogs in which the mutation was characterised but in dogs with the same mutation in the pet population there is very variable disease severity and rate of progression. OBJECTIVE: We hypothesized that this variability must be associated with leakiness of the RPGRIP1 mutation, allowing continued RPGRIP1 production. The study was designed to discover mechanisms that might allow such leakiness. METHODS: We analysed alternate start sites and splicing of RPGRIP1 transcripts; variability of polyA(n) length in the insertion and slippage at polyA(n) during transcription/translation. RESULTS AND SIGNIFICANCE: We observed a low rate of use of alternative start codons having potential to allow forms of transcript not including the insertion, with the possibility of encoding truncated functional RPGRIP1 protein isoforms. Complex alternative splicing was observed, but did not increase this potential. Variable polyA(n) length was confirmed in DNA from different RPGRIP1(-/-) dogs, yet polyA(n) variability did not correspond with the clinical phenotypes and no individual was found that carried a polyA(n) tract capable of encoding an in-frame variant. Remarkably though, in luciferase reporter gene assays, out-of-frame inserts still allowed downstream reporter gene expression at some 40% of the efficiency of in-frame controls. This indicates a major role of transcriptional or translational frameshifting in RPGRIP1 expression. The known slippage of reverse transcriptases as well as RNA polymerases and thermostable DNA polymerases on oligoA homopolymers meant that we could not distinguish whether the majority of slippage was transcriptional or translational. This leakiness at the mutation site may allow escape from severe effects of the mutation for some dogs.