Bethany J. Wilson

Sinonasal and sino-orbital aspergillosis in 23 cats: Aetiology, clinicopathological features and treatment outcomes

Aetiology, clinicopathological findings and treatment outcomes were documented in 23 cats (1.5-13 years of age) with sinonasal (SNA, n=6) or sino-orbital (SOA, n=17) aspergillosis. Cases recruited retrospectively and prospectively were included if fungal hyphae were identified on cytological or histological examination and the fungal pathogen was identified by PCR and DNA sequencing (ITS1 or ITS1-5.8S-ITS2 regions, rDNA gene cluster). Fungal culture was positive in 22/23 cases. In cases of SNA, the fungal pathogen was Aspergillus fumigatus (n=4), Neosartorya fischeri or A. lentulus (n=1) or a non-speciated Neosartorya spp. (n=1). In all cases of SOA (n=17), the fungal pathogen was identified as Neosartorya spp. Nine cats had brachycephalic conformation. Cats with SNA were more likely to be infected with A. fumigatus and had a better prognosis than cats with SOA.

Selection against canine hip dysplasia: Success or failure?

Canine hip dysplasia (CHD) is a multifactorial skeletal disorder which is very common in pedigree dogs and represents a huge concern for canine welfare. Control schemes based on selective breeding have been in operation for decades. The aim of these schemes is to reduce the impact of CHD on canine welfare by selecting for reduced radiographic evidence of CHD pathology as assessed by a variety of phenotypes. There is less information regarding the genotypic correlation between these phenotypes and the impact of CHD on canine welfare. Although the phenotypes chosen as the basis for these control schemes have displayed heritable phenotypic variation in many studies, success in achieving improvement in the phenotypes has been mixed. There is significant room for improvement in the current schemes through the use of estimated breeding values (EBVs), which can combine a dogs CHD phenotype with CHD phenotypes of relatives, other phenotypes as they are proven to be genetically correlated with CHD (especially elbow dysplasia phenotypes), and information from genetic tests for population-relevant DNA markers, as such tests become available. Additionally, breed clubs should be encouraged and assisted to formulate rational, evidenced-based breeding recommendations for CHD which suit their individual circumstances and dynamically to adjust the breeding recommendations based on continuous tracking of CHD genetic trends. These improvements can assist in safely and effectively reducing the impact of CHD on pedigree dog welfare.

Erythrocytic pyruvate kinase deficiency and AB blood types in Australian Abyssinian and Somali cats.

OBJECTIVE To determine the frequency of the mutant pyruvate kinase (PK) allele, haematological parameters and AB blood types of Abyssinian and Somali cats in Australia. DESIGN Complete blood cell and reticulocyte counts, DNA PK mutation testing and blood typing were performed in all cats. RESULTS A total of 60 cats (36 Abyssinians, 24 Somalis) were included (37 females, 23 males). For the mutant PK allele, three female Somalis were homozygous (affected, 5%), 17 cats were heterozygous (carrier, 28%) and 40 cats tested negative (normal, 67%). Pedigree analysis revealed common ancestry of affected and many carrier cats. Of affected cats, two had regenerative anaemias and all had reticulocytosis (range 64-390 x 10(9)/L; P < 0.001 compared with normal or carrier cats). The only consistent historical sign was lethargy. One affected cat was euthanased 18 months after testing, because of anaemia, neutropenia, anorexia and weight loss. The mutant allele frequency was 0.19 overall (0.29 in Somalis, 0.13 in Abyssinians). All cats had blood type A. The commercial blood typing card method incorrectly identified 12 cats as having type AB blood. CONCLUSIONS The frequency of the mutant PK allele is high in Australia. Screening for PK deficiency is indicated before mating and in individual cats of these breeds, even in the absence of anaemia and especially when there is reticulocytosis. Although all cats in the present study had blood type A, blood type B is common in these breeds worldwide. Retyping of any AB typed cats by a laboratory technique is recommended.

Heritability and Phenotypic Variation of Canine Hip Dysplasia Radiographic Traits in a Cohort of Australian German Shepherd Dogs

Canine Hip Dysplasia (CHD) is a common, painful and debilitating orthopaedic disorder of dogs with a partly genetic, multifactorial aetiology. Worldwide, potential breeding dogs are evaluated for CHD using radiographically based screening schemes such as the nine ordinally-scored British Veterinary Association Hip Traits (BVAHTs). The effectiveness of selective breeding based on screening results requires that a significant proportion of the phenotypic variation is caused by the presence of favourable alleles segregating in the population. This proportion, heritability, was measured in a cohort of 13,124 Australian German Shepherd Dogs born between 1976 and 2005, displaying phenotypic variation for BVAHTs, using ordinal, linear and binary mixed models fitted by a Restricted Maximum Likelihood method. Heritability estimates for the nine BVAHTs ranged from 0.14–0.24 (ordinal models), 0.14–0.25 (linear models) and 0.12–0.40 (binary models). Heritability for the summed BVAHT phenotype was 0.30±0.02. The presence of heritable variation demonstrates that selection based on BVAHTs has the potential to improve BVAHT scores in the population. Assuming a genetic correlation between BVAHT scores and CHD-related pain and dysfunction, the welfare of Australian German Shepherds can be improved by continuing to consider BVAHT scores in the selection of breeding dogs, but that as heritability values are only moderate in magnitude the accuracy, and effectiveness, of selection could be improved by the use of Estimated Breeding Values in preference to solely phenotype based selection of breeding animals.

Estimated Breeding Values for Canine Hip Dysplasia Radiographic Traits in a Cohort of Australian German Shepherd Dogs

Canine hip dysplasia (CHD) is a serious and common musculoskeletal disease of pedigree dogs and therefore represents both an important welfare concern and an imperative breeding priority. The typical heritability estimates for radiographic CHD traits suggest that the accuracy of breeding dog selection could be substantially improved by the use of estimated breeding values (EBVs) in place of selection based on phenotypes of individuals. The British Veterinary Association/Kennel Club scoring method is a complex measure composed of nine bilateral ordinal traits, intended to evaluate both early and late dysplastic changes. However, the ordinal nature of the traits may represent a technical challenge for calculation of EBVs using linear methods. The purpose of the current study was to calculate EBVs of British Veterinary Association/Kennel Club traits in the Australian population of German Shepherd Dogs, using linear (both as individual traits and a summed phenotype), binary and ordinal methods to determine the optimal method for EBV calculation. Ordinal EBVs correlated well with linear EBVs (r = 0.90–0.99) and somewhat well with EBVs for the sum of the individual traits (r = 0.58–0.92). Correlation of ordinal and binary EBVs varied widely (r = 0.24–0.99) depending on the trait and cut-point considered. The ordinal EBVs have increased accuracy (0.48–0.69) of selection compared with accuracies from individual phenotype-based selection (0.40–0.52). Despite the high correlations between linear and ordinal EBVs, the underlying relationship between EBVs calculated by the two methods was not always linear, leading us to suggest that ordinal models should be used wherever possible. As the population of German Shepherd Dogs which was studied was purportedly under selection for the traits studied, we examined the EBVs for evidence of a genetic trend in these traits and found substantial genetic improvement over time. This study suggests the use of ordinal EBVs could increase the rate of genetic improvement in this population.

Symmetry of hip dysplasia traits in the German Shepherd Dog in Australia

Canine hip dysplasia (CHD) is a common and debilitating developmental condition of the canine coxofemoral (hip) joint, exhibiting a multifactorial pattern of inheritance. British Veterinary Association hip traits (BVAHTs) are nine radiographic features of hips used in several countries to ordinally score both the right and left hip of potential breeding candidates to assess their suitability for breeding. The objective of this study was to examine some aspects of the relationship between contralateral scores for each BVAHT in a cohort of 13 124 Australian-registered German Shepherd Dogs. Goodman and Kruskal gamma coefficients of 0.48-0.95 and correlation coefficients of 0.50-0.74 demonstrate that the association between right and left hip scores varies between moderate and strong for BVAHTs. Principal component analysis of scores detected a sizeable left-versus-right effect, a finding supported by symmetry and quasi-symmetry analyses which found that seven of the nine BVAHTs display significant marginal asymmetry. Dogs showing asymmetry for one BVAHT are significantly more likely to display asymmetry at other BVAHTs. When asymmetry is expressed as a binary trait (either symmetrical or asymmetrical), it displays low to moderate heritability. Estimates of genetic correlations between right and left scores are very high for all BVAHTs (>0.945), suggesting right and left scores for each BVAHT are largely determined by the same set of genes. The marginal asymmetries are therefore more likely to be of environmental and non-additive genetic origin. In breeding programmes for CHD, we recommend that scores from both hips be used to estimate breeding values, with a term for side-of-hip included in the model to account for score variation owing to asymmetry.

Empowering international canine inherited disorder management

The mapping of the canine genome and the study of canine breed genomic architecture has revolutionized the discovery of genetic tests for inherited disorders in dogs. As the genetics underlying complex disorders are revealed, canine breeders and their registering organisations will be required to understand genetics in a much more sophisticated way. To facilitate the management of genetic disorders in the era of new complex information, we consider how best to apply the results of new research and analytical techniques to benefit the wider canine breeding community with the aims of improving canine health and maintaining benevolent genetic diversity. If this is not done, there is a serious risk that expensive and valuable genetic research will remain unused or be misused to the detriment of breeds. In this review, we make a case for the formation of an international organisation that will exist as a central repository for breed-based genetic analysis and information sharing. This organisation (“Inter-Dog”) could be modelled on a similar organisation that is monitoring genetic improvement of dairy cattle. The formation of such an organisation will require the collaboration of international kennel management organisations, researchers, and agencies offering genetic testing services.

Genetic Correlations among Canine Hip Dysplasia Radiographic Traits in a Cohort of Australian German Shepherd Dogs, and Implications for the Design of a More Effective Genetic Control Program

Canine hip dysplasia (CHD) is a common musculoskeletal disease in pedigree dog populations. It can cause severe pain and dysfunction which may require extensive medication and/or surgical treatment and often ultimately requires humane euthanasia. CHD has been found to be moderately heritable and, given its impact on welfare, should be considered an imperative breeding priority. The British Veterinary Association/Kennel Club scoring method is one of several measures used to assess the genetic propensity of potential breeding stock for dysplastic changes to the hips based on radiographic examination. It is a complex measure composed of nine ordinal traits, intended to evaluate both early and late dysplastic changes. It would be highly desirable if estimated breeding values (EBVs) for these nine traits were consolidated into a simpler, EBV-based, selection index more easily usable by breeders. A multivariate analysis on the phenotype scores from an Australian cohort of 13,124 German Shepherd Dogs (GSDs) returned genetic correlations between 0.48–0.97 for the nine traits which fell into two trait groups, Group 1 reflecting early changes (“laxity”) and Group 2 reflecting late changes (“osteoarthritis”). Principal components analysis of the ordinal EBVs suggested the same pattern, with strong differentiation between “laxity” and “osteoarthritis” traits in the second component. Taking account of all results, we recommend interim use of two selection indexes: the first being the average of ordinal EBVs for “laxity” traits and the second being the average of ordinal EBVs for “osteoarthritis” traits. The correlation between these two selection indexes (0.771–0.774) is sufficiently less than unity enabling the selection of dogs with different genetic propensity for laxity and for osteoarthritic CHD changes in GSDs; this may also be applicable in other breeds. Dogs with low propensity for severe osteoarthritic change in the presence of laxity may be of interest both in molecular research and breeding programs.

Felis Catus Gammaherpesvirus 1 DNAemia in Whole Blood from Therapeutically Immunosuppressed or Retrovirus-Infected Cats

Gammaherpesviruses are major co-pathogens of human immunodeficiency virus (HIV) infection, making the interactions between feline immunodeficiency virus (FIV) and Felis catus gammaherpesvirus 1 (FcaGHV1) pertinent to both human and veterinary medical research. FIV-infected cats are at increased risk of FcaGHV1 DNAemia and consistently harbor higher FcaGHV1 loads than FIV-uninfected cats. Whether immune deficiencies unrelated to FIV are associated with similar risks is unknown. Using whole blood FcaGHV1 qPCR, we found no difference in the frequency of DNAemia or DNA load in therapeutically immunosuppressed (P1, n = 18) or feline leukemia virus (FeLV)-infected (P2, n = 57) patients compared with age- and sex-matched controls (C1, n = 58; C2, n = 57). In contrast, FIV/FeLV-co-infected cats (P3, n = 5) were at increased risk of FcaGHV1 DNAemia compared to retrovirus uninfected controls (C3, n = 39; p = 0.0068), and had a higher median FcaGHV1 DNA load, although the latter was not significant. FIV/FeLV-co-infected cats (P3) had a similar frequency of FcaGHV1 DNAemia reported compared to FIV-infected controls (C4). In conclusion, we found no evidence that cats with therapeutic immunosuppression or FeLV infection were at greater risk of FcaGHV1 DNAemia or had higher FcaGHV1 DNA load in whole blood. The risk of DNAemia in FIV/FeLV-co-infected cats was similar to that documented previously in cats infected with FIV alone.

Whip Rule Breaches in a Major Australian Racing Jurisdiction: Welfare and Regulatory Implications

Simple Summary An evidence-based analysis of whip rule breaches in horse racing is needed to address community expectations that racehorses are treated humanely. The study provides the first peer-reviewed characterisation of whip rule breaches and their regulatory outcomes in horseracing, and considers the relationship between rules affecting racing integrity and the welfare of racehorses in a major Australian racing jurisdiction. Abstract Whip use in horseracing is increasingly being questioned on ethical, animal welfare, social sustainability, and legal grounds. Despite this, there is weak evidence for whip use and its regulation by Stewards in Australia. To help address this, we characterised whip rule breaches recorded by Stewards using Stewards Reports and Race Diaries from 2013 and 2016 in New South Wales (NSW) and the Australian Capital Territory (ACT). There were more recorded breaches at Metropolitan (M) than Country (C) or Provincial (P) locations, and by riders of horses that finished first, second, or third than by riders of horses that finished in other positions. The most commonly recorded breaches were forehand whip use on more than five occasions before the 100-metre (m) mark (44%), and whip use that raises the jockey’s arm above shoulder height (24%). It is recommended that racing compliance data be analysed annually to inform the evidence-base for policy, education, and regulatory change, and ensure the welfare of racehorses and racing integrity.