Dog-related deaths registered in England and Wales from 2001 to 2021.

OBJECTIVE: This study aimed to describe the incidence and demographics of fatal dog bites or strikes, as defined in English and Welsh mortality data (2001-2021). STUDY DESIGN: A descriptive analysis of the Office for National Statistics registered deaths data set. METHODS: Individuals whose cause of death was defined as 'bitten or struck by a dog' were identified. The average annual number of dog-related deaths and trends in incidence were calculated. Age and sex demographics of victims were described. RESULTS: In total, there were 69 registered deaths, a mean of 3.3 (95% confidence interval 0.3-6.3) dog-related deaths per year, and a mean annual incidence of 0.59 (95% confidence interval 0.06-1.11) deaths per 10 million population. There was no year-on-year change in incidence. Of victims, 59% were male, 10% were <5 years, and 30% were ≥75 years. CONCLUSIONS: Dog-related deaths are rare in England and Wales and have not increased between 2001 and 2021. Further contextual information about the incidents is needed to be able to develop public health strategies and interventions.

The prevalence of pulmonary hypertension in Cavalier King Charles spaniels compared with other breeds with myxomatous mitral valve disease.

INTRODUCTION: Pulmonary hypertension (PH) is a common consequence of myxomatous mitral valve disease (MMVD). Cavalier King Charles spaniels (CKCS) are frequently affected with MMVD and appear to have different disease progression compared to other dogs. This study aimed to determine if CKCS are more likely to develop PH as a result of MMVD than dogs of other breeds. A secondary aim was to explore whether breed or PH impacted survival. ANIMALS: A total of 187 dogs diagnosed with MMVD, 94 CKCS and 93 non-CKCS, were included in this study. METHODS: This is a retrospective review of dogs with MMVD. Data were analyzed for presence of PH, congestive heart failure (CHF) and echocardiographic variables including the ratio between mitral E wave velocity (E vel) and isovolumic relaxation time (E/IVRT) and were compared between CKCS/non-CKCS and dogs with/without PH. Survival analysis was also performed. RESULTS: American College of Veterinary Internal Medicine (ACVIM) stage (p < 0.001), CKCS (p = 0.005), left atrium-to-aortic ratio (LA/Ao) (p < 0.001), E vel (p < 0.001) and log10(E/IVRT) (p < 0.001) were significant at the univariate level for PH development. At the multivariate level, only ACVIM stage remained significant (p = 0.044), suggesting that worsening MMVD was the predominant determinant of PH development in this study. Pulmonary hypertension was associated with greater likelihood of CHF (p < 0.001) and death (both cardiac [p < 0.001] and all-cause mortality [p = 0.011]). Cavalier King Charles spaniels were more likely to experience cardiac death than non-CKCS (p = 0.004). CONCLUSIONS: In this study, development of PH was associated with worse MMVD, according to ACVIM stage.

Invited review: Examining farmers' personalities and attitudes as possible risk factors for dairy cattle health, welfare, productivity, and farm management: A systematic scoping review.

We aimed to determine how research regarding farmers' personalities and attitudes as risk factors is reported (methodological approaches to assessing, extracting, and processing data and analyzing risk factors) and to explore evidence for the effect of farmers' attitudes and personalities on dairy cattle health, welfare, productivity, and management. Therefore, we conducted a systematic review of studies on personality and attitude as risk factors for dairy cattle health, welfare, productivity, and farm management. Database searches captured 1,144 records, and 38 were finally included in the review. Thirty-three manuscripts assessed farmers' attitudes, 1 assessed their personalities, and 4 assessed both as risk factors. These potential risk factors were checked for relationships with more than 50 different outcome variables regarding farm management (17 manuscripts), animal health (13 manuscripts), animal productivity (11 manuscripts), and animal welfare (4 manuscripts). The approaches to assessing risk factors and processing and interpreting data varied greatly; thus, drawing conclusions regarding the effects of attitude and personality as risk factors is impeded because manuscripts are difficult to compare. Our findings highlight the need for harmonization of attitudes and personality assessments in future research. Furthermore, researchers should carefully consider which depth of detail to apply when planning and evaluating related research. Nevertheless, results highlight the importance of the effect of personality and attitude on outcomes. Farmers' personality and attitudes are associated with dairy cattle health, welfare, productivity, and management. In general, attitudes indicating higher degrees of technical knowledge, affection with problems, perceived responsibility, perception of control of a situation, a better human-animal relationship, or a positive evaluation of the benefits of management decisions tended to affect outcomes in a beneficial way. "Agreeableness" and "conscientiousness" were shown to promote better farm performance, whereas "neuroticism" had a negative effect. Therefore, further research on attitude and personality and their consideration by professionals and decision-makers within the dairy sector and politics is strongly recommended. This might provide the chance to better understand the needs of dairy farmers and therefore develop tailored advice and support strategies to improve both satisfactory and constructive cooperation.

Usefulness of pulsed-wave tissue Doppler imaging at the mitral annulus for prediction of new-onset atrial fibrillation in dogs.

INTRODUCTION: The time from the onset of the P wave on electrocardiogram to the peak of late diastolic wave signal (PA-TDI interval) recorded by left atrial pulsed-wave tissue Doppler imaging (PW-TDI) is a surrogate of the total atrial conduction time, and it can predict the development of new-onset atrial fibrillation (AF) in people. This study investigated whether PA-TDI interval measured with PW-TDI at the level of lateral aspect of the mitral valve annulus could identify dogs which developed AF within 6 months after echocardiography. ANIMALS: Forty-two dogs with different cardiac diseases were included; 21 dogs developed AF within 6 months after echocardiography (AF group) and 21 dogs did not (non-AF group). Each AF case was matched with a non-AF case for body weight and left atrium:aortic root ratio. METHODS: This was a retrospective study. Review of signalment, underlying disease and echocardiography data were included. PA-TDI interval was measured offline from acquired PW-TDI images. PA-TDI interval and standard echocardiographic variables were compared between groups. Receiver operator characteristic curves were used to identify the best AF predictor. Univariate and multivariate regression were used to evaluate predictors of PA-TDI interval. RESULTS: The AF group had significantly greater 2D left atrial maximal diameter, left-ventricular (LV) end-diastolic volume, M-Mode LV internal diameter and LV end-systolic volume index. PA-TDI was significantly longer in the AF group, and it was superior to other echocardiographic variables in predicting AF development within 6 months (AUC = 0.896). CONCLUSIONS: PA-TDI interval measured with PW-TDI at the lateral mitral valve annulus may identify dogs at risk of developing AF.

Eliciting preferences for attributes of Newcastle disease vaccination programmes for village poultry in Ethiopia.

Newcastle disease (NCD) is an important disease of poultry, directly affecting the livelihoods of poor farmers across developing countries. Research has identified promising innovations in NCD vaccine development and field trials among village poultry have been promising. However, NCD vaccination is not currently part of village poultry extension programmes in many developing countries. Understanding the preferences for, and relative importance of, different attributes of potential vaccination programmes to prevent NCD will be crucial in designing acceptable and sustainable prevention programmes. This research employed the discrete choice experiment approach to elicit farmers' preference for attributes of NCD vaccination programmes for village poultry in rural Ethiopia. The choice experiment survey was conducted on 450 smallholder farmers. The relative importance of attributes of NCD vaccines to farmers was estimated using a random parameter logit regression model. The preferred NCD vaccine programme had greater bird-level protection (i.e. greater capacity to reduce mortality should NCD occur in a flock), was delivered by animal health development agents, and could be administered via drinking water. Results from simulations on changes in attribute levels revealed that bird-level protection capacity and delivery of vaccine by animal heath extension affect farmers' preferences more than other attributes. These findings suggest that it is important to ensure NCD vaccine programmes offer reasonable capacity to protect against mortality. It also suggests the need to understand farmers' preferred vaccine delivery mechanisms and route of vaccine administration for a wider acceptance of vaccine.

The topology of between-herd cattle contacts in a mixed farming production system in western Kenya.

In many livestock production systems in sub-Saharan Africa, cattle are owned by individual keepers but regularly mix with animals from other herds while grazing communal land, at watering points or through the use of shared bulls for breeding and ploughing. Such contacts may have important implications for disease transmission and control but are not well documented. We describe between-farm contacts in Kimilili sub-county of Bungoma County, a mixed farming area of predominately smallholder farmers. Between-farm contacts occurring during grazing or at shared water points over the past four weeks were captured in seven randomly selected villages using a photo-elicitation tool. The use of shared bulls for breeding and ploughing and cattle introductions from farms within the same village in the past 12 months were also captured. Contact networks were constructed for each contact type in each village. In total 329 farms were included in the study. Networks resembled undirected scale-free graphs with a network density ranging between 9.6 and 14.0. Between 45.6 and 100% of the farms in each study village had been in contact over the past four weeks through grazing and watering contacts. Between 88.9 and 100% were considered to have been in contact over the past 12 months. The topology of the networks was heterogeneous, with some farms exhibiting a high degree of contact. The degree of farm contact and distances between farms were negatively correlated (Pearson correlation coefficient range -0.2 to -0.4). Effective disease control and surveillance must take into consideration the frequency and range of contacts that occur between farms within a single village. Cattle keepers are highly interconnected and pathogens that are transmitted through direct or indirect animal contact would be expected to spread rapidly in the study system. However, the observed heterogeneity in between-farm contact may present opportunities for interventions to be targeted to particular herds to limit infectious disease spread.

Respiratory disease and sero-epidemiology of respiratory pathogens in the working horses of Ethiopia.

BACKGROUND: Pathogens are frequently implicated in equine respiratory disease. In Ethiopia, respiratory disease is a frequent cause for presentation at veterinary clinics and a priority concern for users of working horses. However, there is little existing literature on possible aetiologies. OBJECTIVES: Determine prevalence of respiratory signs and exposure to major respiratory pathogens through a serological survey. STUDY DESIGN: Cross-sectional. METHODS: Systematically selected horses from 19 sites in central Ethiopia were examined clinically and sampled once (August-December 2013). A face-to-face interview collected data on horses' management and history. Serological testing targeted equine influenza virus (EIV), equine herpesviruses-1 (EHV-1) and -4 (EHV-4), equine rhinitis viruses A (ERAV) and B (ERBV), equine arteritis virus (EAV) and Streptococcus equi subspecies equi (S. equi). RESULTS: Owners reported a recent history of coughing in 38% of horses and nasal discharge in 7%. No animals were observed coughing during examination but 6% had a nasal discharge. Antibodies towards S. equi, were most prevalent (8%, 33/350). Antibodies to EAV were confirmed in one animal (0.3%). Low antibody titres to EHV-1/4 and ERA/BV suggested prior exposure but antibodies to EIV were not detected. Multivariable, multilevel logistic regression analysis for risk factors associated with S. equi serostatus showed higher odds of seropositivity in younger animals and those working less frequently. MAIN LIMITATIONS: A single serological sample cannot describe dynamic changes in antibodies. Sampling horses at the place of work may result in healthy-worker bias. CONCLUSIONS: S. equi may be endemic in this population and contributing, in part, to the occurrence of respiratory disease. Low prevalence of antibodies to viruses, with the exception of EIV, indicates these pathogens are present, but unlikely a predominant cause of respiratory signs and noninfectious causes of disease should also be investigated. Working horses in this region would be vulnerable to incursion of equine influenza.

White blood cell differentials in dogs with congestive heart failure (CHF) in comparison to those in dogs without cardiac disease.

OBJECTIVES: To determine if dogs with congestive heart failure have different white blood cell differential cell counts than dogs without cardiac disease. MATERIALS AND METHODS: In total, 72 dogs with congestive heart failure and 143 controls were included in this retrospective study. Signalment, white blood cell differential counts and echocardiography data were retrieved. Basic statistical analysis was performed on white blood cell differential counts, and principal component analysis was used to compare these counts between cases and controls, with age, gender and case/control status as supplementary variables. Cases and controls were compared with binary logistic regression for the principal components identified and individual white blood cell differential counts. Principal component analysis of cases alone was conducted with age, gender, weight and mitral E wave:isovolumic relaxation time as supplementary variables. Linear regression analysis was used to explore the association between mitral E wave:isovolumic relaxation time and the principal components, weight, gender, age and diagnosis (mitral valve disease or dilated cardiomyopathy). RESULTS: Among cases and controls, the largest variance in data (component 1) was associated with neutrophils, band neutrophils, monocytes and case status (P<0·01). The odds of an individual being a case increased 2·5-fold (95% confidence interval: 1·4 to 4·4) for each unit increase in component 1. Among the cases, mitral E wave:isovolumic relaxation time was associated with neutrophil count and case/control category. CLINICAL SIGNIFICANCE: Dogs with congestive heart failure had a statistically significant increase in neutrophils, band neutrophils and monocytes in comparison with those without cardiac disease but the cell counts remained within normal reference intervals.

Small ruminant pasteurellosis in Tigray region, Ethiopia: marked serotype diversity may affect vaccine efficacy.

The aim of this study was to investigate the prevalent Bibersteinia, Mannheimia and Pasteurella serotypes, risk factors and degree of serotype co-infections in sheep and goats in the Tigray region of Ethiopia. Serum was collected from 384 sheep and goats from the Tanqua-Abergelle district of Tigray region using cross-sectional random sampling. An indirect haemagglutination test was used for serotyping. Risk factors for infections were evaluated by logistic regression. Potential clustering of multiple serotypes within individual animals due to common risk factors was evaluated by redundancy analysis. Eight serotypes were identified: all studied animals were serologically positive for at least one serotype. Overall, 355 (92·45%) of the animals were infected by four or more serotypes. Of the five risk factors studied, peasant association (PA), animal species, age (serotype A1), and bodyweight (serotype T15) were significantly associated with infection, but sex was not significant. Only PA explained a significant proportion of the variation (adjusted R 2 = 0·16) in the serological responses. After the effect of PA was accounted for, T3 and T4; A7 and Pasteurella multocida A; and A7 and T10 were positively correlated for co-infection, while T4 and T10 were less likely to be found within the same animal. Diverse serotypes were circulating in the Tigray region and could be a challenge in selecting serotypes for vaccine.

Owner reported diseases of working equids in central Ethiopia.

REASONS FOR PERFORMING STUDY: Working horses, donkeys and mules suffer from numerous diseases and clinical problems. However, there is little information on what owners perceive as important health concerns in their working animals. OBJECTIVES: To identify and prioritise with owners the diseases and other health concerns in working equids in central Ethiopia using participatory methodologies. STUDY DESIGN: Participatory situation analysis (PSA). METHODS: The study was conducted with carthorse- and donkey-owners in 16 sites in central Ethiopia. Multiple participatory methodologies were utilised, including ranking, matrices and focus group discussions. Owners' perceptions on frequency, importance, morbidity and mortality of volunteered diseases and the clinical signs that owners attributed to each disease were obtained; information regarding the impact of these diseases and health concerns was also sought. RESULTS: A total of 40 separate disease and health problems were volunteered by carthorse- and donkey-owners. Horse-owners volunteered a musculoskeletal syndrome (with the local name 'bird', clinical signs suggest possible disease pathologies including equine exertional rhabdomyolysis), colic and epizootic lymphangitis most frequently, whereas donkey-owners volunteered sarcoids, nasal discharge and wounds to occur most frequently. One problem (coughing) was volunteered frequently by both horse- and donkey-owners. Owners demonstrated knowledge of differing manifestations and severity of these problems, which resulted in differing impacts on the working ability of the animal. CONCLUSIONS: Although many of the diseases and clinical signs had been previously reported, this study also identified some previously unreported priorities such as rabies in donkeys, an unidentified musculoskeletal syndrome in horses and respiratory signs in both horses and donkeys. The information gathered during this participatory study with owners may be used to inform future veterinary and educational programme interventions, as well as identify future research priorities.

Detection of infectious bronchitis virus 793B, avian metapneumovirus, Mycoplasma gallisepticum and Mycoplasma synoviae in poultry in Ethiopia.

A survey was conducted into respiratory infectious diseases of poultry on a chicken breeder farm run by the Ethiopian Institute of Agricultural Research (EIAR), located in Debre Zeit, Ethiopia. Oropharyngeal swabs were collected from 117 randomly selected birds, and blood was taken from a subset of 73 of these birds. A combination of serological and molecular methods was used for detection of pathogens. For the first time in Ethiopia, we report the detection of variant infectious bronchitis virus (793B genotype), avian metapneumovirus subtype B and Mycoplasma synoviae in poultry. Mycoplasma gallisepticum was also found to be present; however, infectious laryngotracheitis virus was not detected by PCR. Newcastle disease virus (NDV) was not detected by PCR, but variable levels of anti-NDV HI antibody titres shows possible exposure to virulent strains or poor vaccine take, or both. For the burgeoning-intensive industry in Ethiopia, this study highlights several circulating infectious respiratory pathogens that can impact on poultry welfare and productivity.

Development and Evaluation of a Molecular Diagnostic Method for Rapid Detection of Histoplasma capsulatum var. farciminosum, the Causative Agent of Epizootic Lymphangitis, in Equine Clinical Samples.

Histoplasma capsulatum var. farciminosum, the causative agent of epizootic lymphangitis (EZL), is endemic in parts of Africa. Diagnosis based on clinical signs and microscopy lacks specificity and is a barrier to further understanding this neglected disease. Here, a nested PCR method targeting the internal transcribed spacer (ITS) region of the rRNA operon was validated for application to equine clinical samples. Twenty-nine horses with signs of EZL from different climatic regions of Ethiopia were clinically examined. Blood samples and aspirates of pus from cutaneous nodules were taken, along with blood from a further 20 horses with no cutaneous EZL lesions. Among the 29 horses with suspected cases of EZL, H. capsulatum var. farciminosum was confirmed by extraction of DNA from pus and blood samples from 25 and 17 horses, respectively. Positive PCR results were also obtained with heat-inactivated pus (24 horses) and blood (23 horses) spotted onto Whatman FTA cards. Two positive results were obtained among blood samples from 20 horses that did not exhibit clinical signs of EZL. These are the first reports of the direct detection of H. capsulatum var. farciminosum in equine blood and at high frequency among horses exhibiting cutaneous lesions. The nested PCR outperformed conventional microscopic diagnosis, as characteristic yeast cells could be observed only in 14 pus samples. The presence of H. capsulatum var. farciminosum DNA was confirmed by sequencing the cloned PCR products, and while alignment of the ITS amplicons showed very little sequence variation, there was preliminary single nucleotide polymorphism-based evidence for the existence of two subgroups of H. capsulatum var. farciminosum This molecular diagnostic method now permits investigation of the epidemiology of EZL.

Changing risk of environmental Campylobacter exposure with emerging poultry production systems in Ethiopia.

Campylobacter is a leading cause of diarrhoea, and its presence in chickens is a significant risk for zoonotic infection. Poultry production is becoming increasingly intensive in Ethiopia and is incorporating more high-producing breeds into traditionally managed smallholdings, especially in peri-urban areas. This cross-sectional study sampled 219 household environments in one peri-urban and two rural areas of Ethiopia, and an additional 20 semi-intensive farms in the peri-urban district. Campylobacter was detected by polymerase chain reaction (PCR)-specific assays in 44 samples; 16 of which could be identified as C. jejuni. Flocks in the peri-urban area were at significantly greater odds of detection, including those which only kept indigenous birds under a scavenging system. It was also noted that scavenging flocks of exotic high-production birds (Rhode Island Red) were at slightly greater risk, perhaps as exotic birds are under more stress when kept under traditional management systems. We suggest that changes to the system of chicken production may alter the ecology and epidemiology of Campylobacter in the environment, chickens and people, which may drive emergence of new epidemiological patterns of disease. Further research is needed to determine the extent to which the current management intensification and the distribution programmes of exotic and/or improved indigenous birds may alter Campylobacter epidemiology, ecology and public health risk, before their widespread adoption.

Participatory appraisal of the impact of epizootic lymphangitis in Ethiopia.

Epizootic lymphangitis (EZL) is reported to have a significant impact upon livelihoods within resource-poor settings. This study used a participatory approach to explore peoples' experiences of EZL and examine the perceived impact of disease, owner knowledge and understanding of EZL, lay management of disease and, attitudes and strategies towards disease prevention. Focus-group discussions were held with 358 cart-horse owners and drivers recruited from 7 towns attended by SPANA (Society for the protection of animals abroad) mobile veterinary clinics and 2 unexposed towns where no SPANA clinics were available. Focus group discussions explored four main research questions: (1) Is EZL recognised by animal owners, and is this considered an important disease in equids? (2) What factors do animal owners associate with the development of disease? (3) What happens to an animal with clinical disease and how does this impact upon the owner/community? (4) Are measures taken to reduce disease occurrence? These key areas were explored using photographs, disease ranking, matrices and open discussion. Data were analysed using descriptive statistics and thematic analysis. The results are presented thematically and include: recognition and descriptions of EZL, treatment strategies used, disease priorities and ranking, impact of disease, disease transmission and attitudes and approaches to disease prevention. EZL was widely recognised and ranked highly as an important disease of equids. However, there was uncertainty around identifying early cases of EZL, and this could impact upon the timing of initiating treatment and separating potentially infectious animals. People had varying knowledge of effective methods for disease prevention and reported particular difficulties with isolating infected animals. The impact of EZL was multi-dimensional and encompassed effects upon the horse, the individual owner and the wider society. Working equids provide a vital utility and source of income to many people in resource-poor settings. Often, infection with EZL resulted in a reduction in working ability which had a direct impact upon the livelihoods of owners and their dependent family members. EZL also impacted upon the welfare of the horse as sick animals continued to be worked and, in advanced cases, horses were abandoned due to ineffective or unavailable treatment. This study conceptualises the importance of EZL due to the effects of the disease on the horse and its impact upon human livelihoods. Epizootic lymphangitis is a neglected disease that requires further investigation in order to develop practical and sustainable disease control strategies within endemic regions.

Effect of signs of oestrus, disease stressors and cow activity on pregnancy rate following artificial insemination.

The objective was to examine (a) how pregnancy rate on one farm (500 cows) was affected by signs of oestrus and disease stressors and (b) whether pregnancy rate could be maximised by considering cow activity. The signs of oestrus and timings were recorded at artificial insemination (AI), and cow activity was monitored by neck collars. Pregnancy rate tended to be higher in animals that displayed standing oestrus (35 v 26 per cent; P=0.06) but was 10 per cent lower in those cows with an elevated somatic cell count (SCC; >200,000 cells/ml milk) within 0-4 or 4-8 weeks prior to AI (P=0.01 and 0.05, respectively), irrespective of the incidence of clinical mastitis prior to AI. Cow activity data were available for 525 inseminations (from a total of 1299). The mean interval from increased activity to AI in all cows (11 hours 32 minutes; 95 per cent CI 10 hours 40 minutes to 12 hours 24 minutes) was not different for cows that did or did not establish a pregnancy (P=0.90). The pregnancy rate improved to the average of unaffected cows if AI was delayed by about eight hours in animals with an elevated SCC 0-4 weeks prior to AI (P=0.025), indicating that, in cows with prior elevated SCC, AI could be repeated approximately eight hours later to achieve maximum pregnancy rates.

Infection-interactions in Ethiopian village chickens.

Chickens raised under village production systems are exposed to a wide variety of pathogens, and current or previous infections may affect their susceptibility to further infections with another parasite, and/or can alter the manifestation of each infection. It is possible that co-infections may be as important as environmental risk factors. However, in cross-sectional studies, where the timing of infection is unknown, apparent associations between infections may be observed due to parasites sharing common risk factors. This study measured antibody titres to 3 viral (Newcastle disease, Marek's disease and infectious bursal disease) and 2 bacterial (Pasteurella multocida and Salmonella) diseases, and the infection prevalence of 3 families of endo- and ecto-parasites (Ascaridida, Eimeria and lice) in 1056 village chickens from two geographically distinct populations in Ethiopia. Samples were collected during 4 cross-sectional surveys, each approximately 6 months apart. Constrained ordination, a technique for analysis of ecological community data, was used to explore this complex dataset and enabled potential relationships to be uncovered and tested despite the different measurements used for the different parasites. It was found that only a small proportion of variation in the data could be explained by the risk factors measured. Very few birds (9/1280) were found to be seropositive to Newcastle disease. Positive relationships were identified between Pasteurella and Salmonella titres; and between Marek's disease and parasitic infections, and these two groups of diseases were correlated with females and males, respectively. This may suggest differences in the way that the immune systems of male and female chickens interact with these parasites. In conclusion, we find that a number of infectious pathogens and their interactions are likely to impact village chicken health and production. Control of these infections is likely to be of importance in future development planning.

Identification of inadequate maternal progesterone concentrations in nulliparous dairy heifers and treatment with human chorionic gonadotrophin.

Plasma progesterone concentrations were estimated for 381 nulliparous dairy heifers from eight farms on days 4-6 after insemination. Heifers were synchronised using two treatments of prostaglandin F2α (PGF2α) 11 days apart. Alternate heifers were treated with 1500 IU human chorionic gonadotrophin (hCG) at the time of sampling, and the pregnancy status assessed ~35 days after insemination. Heifers with no corpus luteum (CL; n-30) at the second PGF2α had lower progesterone concentrations (P<0.001) and pregnancy rates (PR; P=0.001) compared with heifers with CL (n=351, defined as cyclic). The risk of no CL increased in heifers <15 months of age (OR=7.5, P<0.001) and with body condition score <2.5 (OR=4.5, P=0.001). Those with no CL were removed from further analysis. The 20 per cent cyclic control heifers with progesterone concentrations ≤2 ng/ml on days 4-6 had lower PRs compared with those with higher concentrations (42 per cent vs 64 per cent, OR=0.3, P=0.01). There was no overall effect of hCG on PR compared with controls (51 per cent vs 60 per cent, P=0.10). However, heifers with high progesterone on days 4-6 (>2 ng/ml) had a lower PR after treatment (51 per cent vs 64 per cent, OR=0.6, P=0.02). Heifers inseminated with sexed (n=18) compared with conventional (n=333) semen had a decreased PR (33 per cent vs 57 per cent, OR=0.2, P=0.01). This study demonstrates that higher plasma progesterone concentrations as early as days 4-6 after insemination have a positive effect on first insemination PR, but there was no beneficial effect of hCG treatment on these days in dairy heifers.