Major histocompatibility class II expression in the normal canine cornea and in canine chronic superficial keratitis

OBJECTIVE: To compare the expression of major histocompatibility complex (MHC) class II antigen in the corneas of normal dogs and dogs affected with chronic superficial keratitis (CSK). METHODS: MHC class II expression was determined in frozen sections of normal canine cornea and cornea from lesions of CSK by immunohistochemistry using a monoclonal antibody directed against the canine MHC class II molecule. Langerhans cell phenotype was determined morphologically and by histochemical determination of ATPase activity. To determine the influence of gamma interferon on expression of MHC class II molecules by corneal cells, corneal explants were cultured with the cytokine and MHC class II expression determined as above. RESULTS: Numerous MHC class II-expressing cells were demonstrated within the stroma and epithelium of the normal corneal limbus and conjunctival epithelium while very little MHC class II expression was detected in the central region of normal canine cornea. In limbal and conjunctival epithelium, cells expressing MHC class II antigen showed ATPase activity, suggesting that they were Langerhans cells. Corneas from dogs with CSK showed MHC class II expression associated with stromal cells, some of which exhibited a dendritic morphology while most were lymphocytic. Corneal epithelial cells within the lesion also aberrantly expressed MHC class II. Corneal explants expressed MHC class II to varying degrees after differing periods of incubation with the cytokine gamma interferon. CONCLUSIONS: While the normal central cornea has little MHC class II expression, aberrant expression occurs in CSK, associated with secretion of gamma interferon by infiltrating CD4-expressing lymphocytes. Although this change is likely to be a secondary feature of the CSK lesion, increased MHC class II expression may play a part in perpetuating the corneal inflammation seen in the disease.     

The Position and Shape of Osteophyte Formations at Canine Vertebral Endplates and its Influence on Radiographic Diagnosis

The relationship between the risk of missing osteophytes in lateral radiographs and their position was determined in a sample of German shepherd dogs (GSDs, n = 42) and dachshunds (DHs, n = 36). Only 10% of osteophytes which were not detected on radiographs were located in the ventral median area (position 1) and classified as type 1 (small spur with narrow base). The highest risk for being affected next to the intervertebral foramen and/or the dorsal area of the vertebral endplate (position 3) was noticed in the lumbar segment (95% CI: 5.2-9.8% in DHs; 11.9-17.7% in GSDs). The minimum risk of missing osteophytes in this position radiologically was 33.3% in the GSDs and 26.4% in the DHs. In the GSDs a higher proportion of type 2 osteophytes (spur with broader base of origin, tending to extend up to half the way along the disc space) was not visualized on radiographs. Peak incidences of osteophytes in positions 1 and 3 were located at the centres of spinal flexion and extension. Therefore, distribution patterns of osteophytes in these positions confirmed mechanical factors being important in pathogenesis of vertebral osteophytosis.     

MHC class II is an important genetic risk factor for canine systemic lupus erythematosus (SLE)-related disease: implications for reproductive success

Major histocompatibility complex (MHC) class II genes are important genetic risk factors for development of immune-mediated diseases in mammals. Recently, the dog (Canis lupus familiaris) has emerged as a useful model organism to identify critical MHC class II genotypes that contribute to development of these diseases. Therefore, a study aimed to evaluate a potential genetic association between the dog leukocyte antigen (DLA) class II region and an immune-mediated disease complex in dogs of the Nova Scotia duck tolling retriever breed was performed. We show that DLA is one of several genetic risk factors for this disease complex and that homozygosity of the risk haplotype is disadvantageous. Importantly, the disease is complex and has many genetic risk factors and therefore we cannot provide recommendations for breeders exclusively on the basis of genetic testing for DLA class II genotype.     

Expanded dog leukocyte antigen (DLA) single nucleotide polymorphism (SNP) genotyping reveals spurious class II associations

The dog leukocyte antigen (DLA) system contains many of the functional genes of the immune system, thereby making it a candidate region for involvement in immune-mediated disorders. A number of studies have identified associations between specific DLA class II haplotypes and canine immune hemolytic anemia, thyroiditis, immune polyarthritis, type I diabetes mellitus, hypoadrenocorticism, systemic lupus erythematosus-related disease complex, necrotizing meningoencephalitis (NME) and anal furunculosis. These studies have relied on sequencing approximately 300 bases of exon 2 of each of the DLA class II genes: DLA-DRB1, DLA-DQA1 and DLA-DQB1. In the present study, an association (odds ratio=4.29) was identified by this method between Weimaraner dogs with hypertrophic osteodystrophy (HOD) and DLA-DRB1?01501. To fine map the association with HOD, a genotyping assay of 126 coding single nucleotide polymorphisms (SNPs) from across the entire DLA, spanning a region of 2.5 Mb (3,320,000-5,830,000) on CFA12, was developed and tested on Weimaraners with HOD, as well as two additional breeds with diseases associated with DLA class II: Nova Scotia duck tolling retrievers with hypoadrenocorticism and Pug dogs with NME. No significant associations were found between Weimaraners with HOD or Nova Scotia duck tolling retrievers with hypoadrenocorticism and SNPs spanning the DLA region. In contrast, significant associations were found with NME in Pug dogs, although the associated region extended beyond the class II genes. By including a larger number of genes from a larger genomic region, a SNP genotyping assay was generated that provides coverage of the extended DLA region and may be useful in identifying and fine mapping DLA associations in dogs.     

Upregulation of major histocompatibility complex class II antigens in hepatocytes in Doberman hepatitis

Major histocompatibility complex (MHC) class II antigen expression in hepatocytes and its correlation with mononuclear cell infiltration into the liver were studied using immunohistochemical techniques in 38 Dobermans with Doberman hepatitis (DH). Liver biopsy samples were obtained from 18 dogs at the subclinical stage. Autopsy samples were taken from 6 DH dogs euthanized for a reason other than DH, from 14 dogs euthanized because of advanced liver failure and from 6 control Dobermans. Upon examination of the control liver samples, no expression of MHC class II antigens was detected in hepatocytes. By contrast, in 15 of the 18 DH biopsies (83%) and in all 20 DH autopsy liver samples, hepatocytes expressed MHC class II molecules. MHC class II expression was either cytoplasmic or membranous and occurred in conjunction with lymphocyte infiltration. A correlation between the inflammatory reaction and the expression of MHC class II in hepatocytes suggests that the aberrant expression of MHC class II in hepatocytes is induced by cytokines. Hepatocytes presenting a putative MHC class II molecule-associated autoantigen could thus become the target of an immune attack mediated by CD4+ T cells. In addition, corticosteroid treatment was observed to significantly decrease MHC class II expression in DH hepatocytes. Inappropriate MHC class II expression in hepatocytes and mononuclear cell infiltration are suggesting an autoimmune nature for chronic hepatitis in Dobermans.     

Inheritance of pancreatic acinar atrophy in German Shepherd Dogs

OBJECTIVE: To assess the heritability of pancreatic acinar atrophy (PAA) in German Shepherd Dogs (GSDs) in the United States. ANIMALS: 135 GSDs belonging to 2 multigenerational pedigrees. PROCEDURE: Two multigenerational pedigrees of GSDs with family members with PAA were identified. The clinical history of each GSD enrolled in the study was recorded, and serum samples for canine trypsin-like immunoreactivity (cTLI) analysis were collected from 102 dogs. Dogs with a serum cTLI concentration < or = 2.0 microg/L were considered to have exocrine pancreatic insufficiency (EPI) and were assumed to have PAA. RESULTS: Pedigree I consisted of 59 dogs and pedigree II of 76 dogs. Serum cTLI concentrations were measured in 48 dogs from pedigree I and 54 dogs from pedigree II. A total of 19 dogs (14.1%) were determined to have EPI, 9 in pedigree I (15.3%) and 10 in pedigree II (13.6%). Of the 19 dogs with EPI, 8 were male and 11 were female. CONCLUSIONS AND CLINICAL RELEVANCE: Evaluation of data by complex segregation analysis is strongly suggestive of an autosomal recessive mode of inheritance for EPI in GSDs in the United States.     

MHC class II expression by follicular keratinocytes in canine demodicosis--an immunohistochemical study

MHC class II proteins present fragments of extra cellular antigen to stimulate CD4(+) T lymphocytes. Aim of this study was the detection of MHC class II antigens on different cutaneous cells in canine demodicosis. Histopathological and immunohistochemical examination of skin biopsies from 44 dogs with demodicosis is reported. The control group consisted of skin biopsies taken from 10 necropsied dogs without obvious skin lesions. The immunohistological assessment of the MHC class II expression revealed MHC class II proteins on different cell types of infiltrating inflammatory cells, i.e. APCs (antigen-presenting cells), macrophages, T lymphocytes and B lymphocytes. The plasma cells, however, only showed expression in 32 (73%) of 44 cases. Generally it was noticeable that most plasma cells but never all of them expressed MHC class II. Neutrophils, mast cells and eosinophils were MHC class II negative. Furthermore, in 39 biopsies (89%) from dogs with demodicosis MHC class II positive follicular keratinocytes were found. The control group did not show MHC class II expression on epithelial cells. Concerning the endothelial cells, a total of 25 biopsies (57%) showed MHC class II expression in which different vascular plexuses were affected by staining. This examination shows that MHC class II expression in the skin of dogs suffering form demodicosis is elevated. Especially the MHC class II expression by follicular keratinocytes seems to be conspicuous. We hypothesize that this is in association with the development and the maintenance of follicular inflammation.     

Survey on giardiosis in shelter dog populations

Faecal samples from 183 dogs living in three different shelters in the Rome metropolitan area were randomly collected and examined for the prevalence of giardiosis. Giardia infections were detected by a commercially available ELISA test (ProspecT Giardia Microplate Assay). Overall prevalence was 55.2%. Prevalence rates in single shelters were 74.3, 35.5, and 20.9%, respectively. Using multivariate analysis, no association was found between Giardia-positivity and shelter or sex, breed, or diarrhoea. Giardia-positive dogs were more likely to be younger than 5-year-old (odds ratio [OR] = 2.87; 95% confidence interval [95% CI]: 1.07-7.77; p = 0.038), living together (OR = 2.58; 95% CI: 1.12-5.93; p = 0.026), and fed commercial wet food, both alone and combined with dry food (OR = 5.67; 95% CI: 1.59-20.24; p = 0.008). Correlation between Giardia infection and type of food has not been previously reported in dogs. Possible use of the ELISA test for detection of Giardia infection in dogs and zoonotic implications are discussed.     

Cardiomyocyte calcium cycling in a naturally occurring German shepherd dog model of inherited ventricular arrhythmia and sudden cardiac death

ObjectiveTo further characterize arrhythmic mechanisms in German shepherd dogs (GSDs) affected with inherited ventricular arrhythmias by evaluating intracellular calcium cycling and expression of calcium handling genes.AnimalsTwenty five GSDs, 9 backcross dogs, and 6 normal mongrel dogs (controls) were studied. The GSDs and backcross dogs were from a research colony of inherited ventricular arrhythmias. The control research dogs were purchased.MethodsAction potentials (APs) and pseudo-electrocardiograms (ECG) were recorded from left ventricular (LV) wedge preparations of GSDs and normal dogs. Midmyocardial (Mid) LV cells from GSDs and normal mongrels were isolated by enzymatic digestion. Cells were either field stimulated or voltage clamped and calcium transients were measured by confocal microscopy using the indicator Fluo-3AM. Expression of calcium handling genes was measured by quantitative RT-PCR.ResultsMean calcium transient decay (tau) was not different between affected GSDs and control dogs, but striking cell-to-cell variability for tau was observed within affected GSDs and between affected GSDs and controls (P < 0.0001 each); within-dog variability accounted for 75% of total variability. Calcium sparks and afterdepolarizations occurred in GSD but not control cells. ATP2A2/SERCA2a expression was significantly reduced (P = 0.0063) in affected GSDs and inversely correlated (P = 0.0006) with severity of ventricular arrhythmias.ConclusionsGerman shepherd dogs with inherited ventricular arrhythmias have electrophysiologic abnormalities in calcium cycling associated with reduced ATP2A2/SERCA2a expression. These animals provide a unique opportunity to study calcium remodeling at the genetic and molecular level in familial ventricular arrhythmias.     

Measurements on the lumbosacral junction in normal dogs and those with cauda equine compression

Comparative measurements on lateral plain radiographs of the lumbosacral junction in neutral position, in flexion, and in extension, were made of 41 clinically and radiographically normal dogs (21 German shepherd dogs [GSDs], 12 Bernese mountain dogs, eight labrador retrievers) and 58 GSDs with clinical signs of cauda equina compression due to malformation and, or, malarticulation. The comparison of these measurements between sexes, between normal and affected GSDs and between normal GSDs and the two other breeds of dogs showed several statistically significant results. One was that the affected GSDs showed a reduced flexion ability at this junction compared to the normal ones. However, no difference was observed in the degree of sub-luxation of the sacrum between normal and affected GSDs. It was concluded that plain radiographs of the lumbosacral junction in flexion could help in determining a reduced flexion ability, which could be a characteristic of the GSD with cauda equina compression.     

Multiple autoimmune diseases syndrome in Italian Greyhounds: preliminary studies of genome-wide diversity and possible associations within the dog leukocyte antigen (DLA) complex

A disorder manifested by multiple autoimmune disorders, and resembling autoimmune polyendocrine syndrome type 2 (APS-2) in humans, may exist in Italian Greyhounds. The incidence of this disorder is increasing and its potential impact on the health of the breed is becoming of great concern. The aims of the present study were to document the existence of this syndrome, conduct a preliminary assessment of genetic diversity across the breed and within affected and unaffected dogs, determine whether the disorder associates with the dog leukocyte antigen (DLA) complex, and demonstrate similarities to APS-2 of humans. To these ends, information on disease, pedigrees, and blood or buccal swab samples were collected from affected and healthy Italian Greyhounds and extracted DNA analyzed. Analysis of Y chromosome markers and mitochondrial DNA sequences showed that Italian Greyhounds evolved from a single patriline and two major and four minor matrilines. A panel of 24 highly polymorphic simple tandem repeat (STR) markers across 20 autosomes demonstrated that affected and unaffected dogs were not distinguishable from the population as a whole by heterozygosity, F-statistics, and principal component analysis (PCA). However, analysis of allele frequencies at each STR loci identified regions of increased or decreased disease risk on four chromosomes. A similar genetic analysis using 109 single nucleotide polymorphisms (SNPs) across the DLA region showed differences between affected and unaffected dogs. PCA and zygosity mapping of DLA SNPs from unrelated dogs demonstrated two distinct subpopulations among the affected individuals. One population was very homozygous and the other closely resembled unaffected dogs in its heterozygosity, suggesting the evolution of a disease prone bloodline as a result of non-random selection. Exon 2 sequencing of the DLA class II genes demonstrated 5-8 alleles at each locus and 14 three loci haplotypes. Two specific haplotypes containing DRB1*00203 or DRB1*02901 were associated with increased disease risk in about one-third of affected dogs. However, high density SNP association mapping across the DLA region and CFA12 did not corroborate the association.     

Immunocytochemical demonstration of lymphocyte subsets and MHC class II antigen expression in synovial membranes from dogs with rheumatoid arthritis and degenerative joint disease

The study describes the distribution of canine leucocyte antigens in synovial membrane biopsies from six dogs with canine rheumatoid arthritis (CRA) and from eight dogs with osteoarthritis (OA) secondary to spontaneous rupture of the cranial cruciate ligament (CCL) (n = 5) or patellar luxation (n = 3). Synovial membranes from five dogs without evidence of joint lesions were used as control tissues. In the subsynovium of dogs with normal joints CD5+, CD4+, CD8+ and alpha beta TCR+ lymphocytes were present only in low numbers. With monoclonal antibody (mAb) to MHC class II antigen, either none or up to 20-30% of synovial lining cells were immunoreactive. Furthermore, scattered MHCII+ stromal cells were seen in the deeper subsynovial layer. In synovial membrane biopsies from dogs with CRA numerous diffusely and perivascularly distributed CD5+ lymphocytes were found in the subsynovium. CD4+ cells outnumbered CD8+ cells and were more numerous in the perivascular areas. In all the CRA cases examined, there were markedly higher numbers of alpha beta TCR+ cells compared with gamma delta TCR+ cells. With mAb to CD21, low numbers of immunoreactive lymphocytes were demonstrated. In all the CRA cases, a marked increase of MHC class II antigen expression was noted. In the majority of samples, 50% or more than 90% of the synovial lining cells were strongly MHC class II+. Throughout the subsynovial layer there were numerous MHC class II+ cells and included those with dendritic morphology and inflammatory mononuclear cells. Furthermore, marked perivascular immunoreactivity for MHC class II antigen was found. In biopsies from dogs with OA, there were markedly lower numbers of subsynovial CD5+, CD4+ and CD8+ lymphocytes. T-cells were mainly diffusely distributed. In three of the eight OA dogs examined, there was an increased percentage of synovial lining cells expressing MHC class II. The majority of OA cases had subsynovial major histocompatibility complex (MHC) class II+ cells with a dendritic morphology.     

Noninfectious factors associated with pneumonia and pleuritis in slaughtered pigs from 143 farrow-to-finish pig farms

A cross-sectional study involving 143 farrow-to-finish herds was carried out to identify herd-level noninfectious factors associated with pneumonia and pleuritis in slaughter pigs. Data related to herd characteristics, biosecurity, management and housing conditions were collected by questionnaire during a farm visit. Climatic conditions were measured over 20 h in the post-weaning and finishing rooms where the slaughter pigs were kept. After these on-farm investigations, the finishing pigs were examined at slaughter for lung lesions. A sample of 30 randomly selected pigs per herd was scored for pneumonia and pleuritis. Herds were grouped into three categories according to their pneumonia median score (class 1: ≤ 0.5; class 2: 0.53.75). For pleuritis, a herd was deemed affected if at least one pig had a high pleuritis score (≥ 3). A multinomial logistic regression model was used to identify factors associated with pneumonia classes 2 and 3. A logistic regression for binary outcome was used to identify risk factors for severe pleuritis. An interval of less than four weeks between successive batches (OR=4.5, 95% confidence interval (95% CI): 1.5-13.6, p<0.01), large finishing room size (OR=4.3, 95% CI: 1.6-11.6, p<0.01) and high mean CO(2) concentration in the finishing room (OR=4.2, 95%CI: 1.6-11.3, p<0.01), significantly increased the odds for a herd to be in class 2 for pneumonia. The same risk factors were found for class 3 and, in addition, a direct fresh air inlet from outside or from the corridor in the post-weaning room vs an appropriate ceiling above the pigs (OR=5.1, 95% CI: 1.4-18.8, p=0.01). The risk for a herd to have at least one pig with a high pleuritis score was increased when the farrowing facilities were not disinsected (OR=2.7, 95% CI: 1.2-5.8, p=0.01), when tail docking was performed later than 1.5 days after birth (OR=2.6, 95% CI: 1.2-5.7, p=0.01) and if the piglets were castrated when more than 14 days old (OR=2.7, 95%CI: 1.1-6.8, p=0.03). A temperature range of less than 5°C for the ventilation control rate in the farrowing room (OR=2.7, 95% CI: 1.2-5.9, p=0.01), a mean temperature in the finishing room below 23°C (OR=3.0, 95% CI: 1.3-6.8, p<0.01) and large herd size (OR=3.1, 95% CI: 1.4-6.9, p<0.01) were also associated with increased risk of pleuritis. The factors affecting pneumonia and pleuritis seemed to be different. All rearing steps from farrowing to finishing must be taken into account in any health programme aimed at controlling pneumonia and pleuritis and lung health may be improved through several pathways, i.e. correcting managerial and hygienic factors, implementing an appropriate and well-functioning ventilation in order to offer favorable climatic conditions.     

Association between alleles of the ovine major histocompatibility complex and resistance to footrot

Variation in natural resistance to footrot may be genetically derived, implying that genetic markers for resistance may exist and allow selection of superior animals. In this study association between variation within the ovine MHC class II region and resistance to footrot was investigated in two trials. Half-sib progeny were subjected to a field challenge with footrot and their condition subsequently recorded. The animals were then typed at their MHC class II loci to investigate associations between inherited paternal haplotype and footrot status. In the first trial an association between MHC haplotype and footrot status was observed across all animals (P = 0.005), when the self-curing and resistant animals were combined (P = 0.002) and when the self-curing animals were excluded from the analysis (P = 0.001). No association was observed in the second trial, a result attributed to the dry weather conditions which led to poor disease transmission and unreliable disease classification.     

The influence of the swine major histocompatibility genes on antibody and cell-mediated immune responses to immunization with an aromatic-dependent mutant of Salmonella typhimurium.

Eighty-two major histocompatibility complex (MHC) swine leukocyte antigen (SLA) defined miniature pigs from 16 litters were examined for serum agglutinating antibody titer and O-polysaccharide (O-ps) specific peripheral blood lymphocyte blastogenesis following two parenteral vaccinations with 1 x 10(8) aromatic-dependent (aroA) Salmonella typhimurium and following oral challenge with 1 x 10(12) virulent parent S. typhimurium. Least mean squares analysis allowed separate determinations of the effects of MHC genotype, dam, sire and litter. In most cases only litter significantly influenced both lymphocyte blastogenesis and antibody titer before and after vaccination and following challenge. However, pig SLA haplotype significantly influenced the degree of O-ps specific lymphocyte proliferation six days after the second vaccination (p < 0.004). Lymphocyte proliferation and serum agglutinating antibody response six days after primary vaccination were negatively correlated (r2 = -0.68, p < 0.001). In most cases, "dd" and "gg" homozygous and "dg" heterozygous pigs, having the same MHC class II region, behaved immunologically as a group distinct from the other genotypes.     

Antihistone Autoantibodies in Dobermans With Hepatitis

Background

Immune system involvement is suggested as an underlying cause for Doberman hepatitis (DH) based on female predisposition, lymphocyte infiltration, abnormal hepatocyte expression of major histocompatibility complex class II antigens, and homozygosity for dog leukocyte antigen DRB1*00601.

Objective

To measure serum antinuclear antibodies (ANA) and serum antihistone antibodies (AHA) in Dobermans with hepatitis. To determine whether increased serum ANA or serum AHA could be used to support the diagnosis of Doberman hepatitis (DH).

Animals

Privately owned 25 subclinically and 13 clinically affected DH Dobermans and 17 healthy control Dobermans.

Methods

Case–control study. Indirect immunofluorescence (IIF) microscopy and line blot tests were employed for the ANA pilot studies and an enzyme‐linked immunosorbent assay (ELISA) assay for detection of IgG AHA.

Results

Indirect immunofluorescence revealed ANA‐positive cases, and line blot showed AHA reactivity. In ELISA, importantly increased concentrations of AHA were found in 92% (23/25) of dogs in the subclinical stage and 84.6% (11 of 13) of dogs in the clinical stage of DH compared with no control dogs (0/17) (P < 0.0005). The mean AHA absorbance values of the blood samples obtained from the 25 subclinical DH dogs (1.36 ± 0.60, mean ± SD) and the 13 clinically affected dogs (1.46 ± 0.49) were significantly higher than in 17 control dogs (0.51 ± 0.18; P < 0.0001).

Conclusions and Clinical Importance

As the presence of AHA indicates autoimmune activity, our results favor an autoimmune background as one cause for DH. Antihistone antibody could represent a novel means for screening Dobermans with increased serum alanine transaminase concentrations and suspicion of DH.     

Prevalence of the group 1 Dermatophagoides allergens Der p 1 and Der f 1 in homes with no dogs, healthy dogs and Dermatophagoides-sensitized atopic dogs in Liverpool

Dermatophagoides farinae is a frequent allergen in canine atopic dermatitis despite its reported scarcity in the UK, and the aim of this study was to determine whether dogs were uniquely exposed to this species. Der f 1 and Der p 1 in dust collected from living room carpets, bedroom carpets and dog beds of 13 houses with no dogs, 13 with healthy dogs, and 16 with Dermatophagoides-sensitized atopic dogs were quantified by ELISA. Der p 1 levels (microg g(-1) house dust) were significantly higher than Der f 1 in living rooms (Der p 1 median = 1.9, 95% CI = 2.05-6.32, n = 42; Der f 1 median = 0.07, 95% CI = 0.01-0.06, n = 42), bedrooms (Der p 1 median = 4.35, SD = 5.52; Der f 1 median = 0.01, 95% CI = 0.001-0.1, n = 42) and dog beds (Der p 1 median = 1.04, 95% CI = 1.4-8.1, n = 29; Der f 1 median = 0.008, 95% CI = 0.01-0.04, n = 29) (P < 0.0001). Living rooms in houses without dogs had significantly greater Der p 1 levels (median = 7.0, 95% CI = 3.53-15.8, n = 13) than houses with healthy (median = 1.19, 95% CI = 0.44-3.49, n = 13) or atopic dogs (median = 0.78, 95% CI = 0.63-2.42, n = 16) (P = 0.0004). Environmental flea control in living rooms and washing dog beds was associated with significantly reduced Der p 1 levels. This confirms that D. pteronyssinus is common but D. farinae is rare in the sampling area. Apparent sensitization to D. farinae is probably due to cross-reaction. A combination of environmental measures could reduce allergen exposure.     

Serological survey of canine dirofilariosis in Chongqing, Kunming, Nanchang, Fuzhou, Guangzhou, Shenzhen, and Nanning in Southern China

The present study conducts a serological survey on the presence of canine dirofilariosis in domestic dogs using an enzyme-linked immunosorbent assay (ELISA) kit. A total of 310 household dogs (166 females and 144 males) in Chongqing, Kunming, Nanchang, Fuzhou, Guangzhou, Shenzhen, and Nanning in Southern China were examined. Of the 310 dogs, 42 (13.5%) were seropositive for dirofilariosis. No statistically significant difference was observed in terms of sex in the seroprevalence of dirofilariosis using the ELISA kit. The positive rates for dirofilariosis were 6.6% in the 0-1-year-old group, 13.8% in the 1-4-year-old group, and 21.6% in the less than 4-year-old group. The statistical analysis revealed that significant differences were observed in the 1-4-year-old group (P=0.037, OR=0.441, 95% CI=0.170-1.144) and less than 4-year-old group (P<0.001, OR=0.256, 95% CI=0.095-0.693). In the regional comparison, the shoreline city Shenzhen (18.8%) had a significantly higher prevalence than urban and mountain areas (P<0.05, OR=0.310, 95% CI=0.066-1.445). In conclusion, Dirofilaria immitis infection in domestic dogs was present in Chongqing, Kunming, Nanchang, Fuzhou, Guangzhou, Shenzhen, and Nanning. Therefore, heartworm treatment and/or chemoprophylaxis for the captured domestic dogs are necessary in these areas. To the best of our knowledge, the present study is the first using serological methods to examine D. immitis infection in domestic dogs in Mainland China in the recent years.     

Analysis of host genetic factors influencing African trypanosome species infection in a cohort of Tanzanian Bos indicus cattle

Trypanosomosis caused by infection with protozoan parasites of the genus Trypanosoma is a major health constraint to cattle production in many African countries. One hundred and seventy one Bos indicus cattle from traditional pastoral Maasai (87) and more intensively managed Boran (84) animals in Tanzania were screened by PCR for the presence of African animal trypanosomes (Trypanosoma congolense, Trypanosoma vivax and Trypanosoma brucei), using blood samples archived on FTA cards. All cattle screened for trypanosomes were also genotyped at the highly polymorphic major histocompatibility complex (MHC) class II DRB3 locus to investigate possible associations between host MHC and trypanosome infection. Overall, 23.4% of the 171 cattle tested positive for at least one of the three trypanosome species. The prevalence of individual trypanosome species was 8.8% (T. congolense), 4.7% (T. vivax) and 15.8% (T. brucei). The high prevalence of T. brucei compared with T. congolense and T. vivax was unexpected as this species has previously been considered to be of lesser importance in terms of African bovine trypanosomosis. Significantly higher numbers of Maasai cattle were infected with T. brucei (23.0%, p=0.009) and T. congolense (13.8%, p=0.019) compared with Boran cattle (8.3% and 3.6%, respectively). Analysis of BoLA-DRB3 diversity in this cohort identified extensive allelic diversity. Thirty-three BoLA-DRB3 PCR-RFLP defined alleles were identified. One allele (DRB3*15) was significantly associated with an increased risk (odds ratio, OR=2.71, p=0.034) of T. brucei infection and three alleles (DRB3*35, *16 and *23) were associated with increased risk of T. congolense infection. While further work is required to dissect the role of these alleles in susceptibility to T. brucei and T. congolense infections, this study demonstrates the utility of FTA archived blood samples in combined molecular analyses of both host and pathogen.     

COMPARISON BETWEEN SHOULDER COMPUTED TOMOGRAPHY AND CLINICAL FINDINGS IN 89 DOGS PRESENTED FOR THORACIC LIMB LAMENESS

Computed tomography (CT) is an established technique for detecting shoulder lesions in dogs, however the clinical significance of shoulder CT lesions often remains uncertain. The purposes of this retrospective study were to describe the prevalence of CT lesions in both shoulder joints for 89 dogs presenting with thoracic limb lameness and to compare CT lesions with clinical characteristics. For all included dogs, results of a full orthopedic examination, other diagnostic tests, and signalment data were available in medical records. Multilevel, multivariable logistic regression was used to test clinical significance of the most prevalent CT lesions and determine factors associated with their presence. Computed tomographic lesions were detected in one or both shoulder joints for 51/89 dogs (57.3%). Mineralization of one or more surrounding peri‐articular soft‐tissue structures was identified in 31.5% of dogs, with supraspinatus muscle/tendon mineralization being the most frequently identified (24.7%). The prevalence of humeral head osteochondrosis was 9 and 21.3% of dogs had shoulder osteoarthritis. Border collies (odds ratio [OR] 9.3; 95% CI 1.39–62.1, P = 0.02) and dogs with shoulder pain (OR 4.3; 95% CI 1.08–17.1, P = 0.04) had increased risk of osteochondrosis lesions. Border collies (OR 8.4; 95% CI 1.27–55.6; P = 0.03) and older animals (OR 1.04; 95% CI 1.02–1.1, P < 0.001) had increased risk of osteoarthritis lesions. Female entire dogs had an increased risk of supraspinatus mineralization lesions (OR 6.8; 95% CI 1.55–29.5, P = 0.01). Findings indicated that shoulder CT lesions are common in dogs with thoracic limb lameness, and that some CT lesions are not associated with shoulder pain.