Laboratory investigation of causes of bovine abortion and stillbirth in the Republic of Korea, 2014-2020.

Bovine abortion is a critical problem in the cattle industry. Identifying causes of abortion is key to establishing appropriate herd management and prevention strategies. We used pathology examinations, detection of etiologic agents, and serology to determine the cause of bovine abortions in Korea. We analyzed 360 abortion and stillbirth cases submitted to the Animal and Plant Quarantine Agency from December 2014 to January 2020. The putative cause of abortion was identified in 140 of 360 (38.9%) cases; 124 of the 140 (88.6%) cases were attributed to infections. The most common etiologic agents detected were bovine viral diarrhea virus (65 of 360; 18.1%), Coxiella burnetii (19 of 360; 5.3%), Leptospira spp. (13 of 360; 3.6%), Listeria monocytogenes (9 of 360; 2.5%), and Neospora caninum (8 of 360; 2.2%). Minor abortifacient pathogens included Brucella abortus (2 of 360; 0.6%), bovine alphaherpesvirus 1 (2 of 360; 0.6%), Akabane virus (2 of 360, 0.6%), and bovine ephemeral fever virus (1 of 360; 0.3%). Non-infectious conditions included congenital anomalies (7 of 360; 1.9%), goiter (7 of 360; 1.9%), and vitamin A deficiency (2 of 360; 0.6%). Our diagnostic rate in cases with placenta submitted (42 of 86; 48.8%) was significantly higher than in cases without placenta (98 of 274; 35.8%), which highlights the value of submitting placentas. Our results confirm the status of the large variety of causative agents associated with abortions in cattle in Korea.

Pine needle abortions in cattle due to consumption of Pinus ponderosa in Argentina: Case reports.

Two outbreaks of pine needle abortions in cattle are here reported for the first time in Argentina. The cases occurred in Chubut and Neuquén provinces in the Patagonia region, causing 29.6% and 9% of abortions in each herd respectively. In both outbreaks, the dams were in the last third of gestation, and, due to a period of cold, snow and lack of available forage, they gained access to Pinus ponderosa and Pinus contorta forests. No pathological lesions, serological, molecular, or microbiological evidence of infectious causes were observed in any of the six fetuses analyzed. Microhistological analysis of feces confirmed higher presence of fragments of Pinus spp. needles in the diet of affected dams than in that of non-affected ones (12.2 vs 3.0%). Moreover, toxicological analysis showed higher tetrahydroagathic acid in the sera of affected dams than in that of non-affected ones (10.05 vs 2.81 ppm). In addition, this acid was detected in different fetal fluids (3.6-8.1 ppm) of the six fetuses analyzed. Interestingly, isocupressic acid was detected only in needles of P. ponderosa, and its content was lower than that found in other areas of the world (0.31 and 0.5% in Chubut and Neuquén respectively). These results confirm that the consumption of P. ponderosa by dams could have been the cause of these abortion outbreaks, a fact that should be considered as differential diagnosis in abortions of cattle, especially in silvopastoral systems of Argentina.

Serological investigation and isolation of Salmonella abortus equi in horses in Xinjiang.

BACKGROUND: Salmonella enterica subspecies enterica serovar abortus equi (S. abortus equi) is one of the main pathogens that causes abortion in pregnant horses and donkeys, which was highly infectious and greatly restricts the healthy development of the horse industry. OBJECTIVES: In order to investigate the prevalence and biological characteristics of S. abortus equi in different regions and breeds of horses in Xinjiang. METHODS: This study conducted ELISA detection of S. abortus equi antibodies on serum samples of 971 horses collected from three large-scale horse farms and five free-range horse farms in Yili Prefecture and Bayingol Mongolian Autonomous Prefecture of Xinjiang from 2020 to 2023. On this basis, bacterial isolation, culture, identification, and drug sensitivity tests were conducted on 42 samples of aborted foal tissues and 23 mare vaginal swabs. RESULTS: The results showed that the positive rate of S. abortus equi antibody was as high as 20.91% in 971 horse serum samples. Among them, the positive rate in the Ili region (29.09%) was significantly higher than that in the Bayingole region (11.24%), and the positive rate in mares (22.45%) was higher than that in stallions (14.05%). In terms of horse breeds, the positive rates of self-propagating thoroughbred horses, half-bred horses, Ili horses and Yanqi horses were 43.22%, 28.81%, 14.72% and 11.24% respectively. In addition, S. abortus equi was more susceptible to juvenile and elderly horses, with positive rates of 70.00%and 41.86%, respectively, both of which were significantly higher than young (10.97%) and adult (19.79%) horses. Further, 9 strains of S. abortus equi were obtained through bacterial isolation, culture and identification, which were resistant to five antibiotics (Clarithromycin, Clindamycin, penicillin, Sulfamethoxazole and Rifampicin), and sensitive to 13 antimicrobial agents (Amoxicillin, Ciprofloxacin and Gentamicin, et al.). CONCLUSION: There was a high infection rate of S. abortus equi in Ili Prefecture and self-propagating thoroughbred horses, and juvenile or old mares were more susceptible, which will provide scientific basis for the prevention of S. abortus equi infection in different regions and breeds of horses in Xinjiang.

Higher livestock abortion burden in arid and semi-arid lands, Kenya, 2019-2020.

Tracking livestock abortion patterns over time and across factors such as species and agroecological zones (AEZs) could inform policies to mitigate disease emergence, zoonoses risk, and reproductive losses. We conducted a year-long population-based active surveillance of livestock abortion between 2019 and 2020, in administrative areas covering 52% of Kenya's landmass and home to 50% of Kenya's livestock. Surveillance sites were randomly selected to represent all AEZs in the country. Local animal health practitioners electronically transmitted weekly abortion reports from each ward, the smallest administrative unit, to a central server, using a simple short messaging service (SMS). Data were analyzed descriptively by administrative unit, species, and AEZ to reveal spatiotemporal patterns and relationships with rainfall and temperature. Of 23,766 abortions reported in all livestock species, sheep and goats contributed 77%, with goats alone contributing 53%. Seventy-seven per cent (n = 18,280) of these abortions occurred in arid and semi-arid lands (ASALs) that primarily practice pastoralism production systems. While spatiotemporal clustering of cases was observed in May-July 2019 in the ASALs, there was a substantial seasonal fluctuation across AEZs. Kenya experiences high livestock abortion rates, most of which go unreported. We recommend further research to document the national true burden of abortions. In ASALs, studies linking pathogen, climate, and environmental surveillance are needed to assign livestock abortions to infectious or non-infectious aetiologies and conducting human acute febrile illnesses surveillance to detect any links with the abortions.

Infectious sporadic bovine abortions: retrospective analysis.

Infectious sporadic abortions in cattle are mainly caused by opportunistic bacteria and fungi usually present in environmental or gastrointestinal and reproductive microbiota of healthy animals. A retrospective analysis was carried out to evaluate the main opportunistic microorganisms involved in bovine abortions recorded at INTA Balcarce (Argentina) from 1997 to 2023, accounting for 2.2% of the total diagnosed etiologies of bovine abortion. The opportunistic agents identified as the cause of abortion in 29 fetuses were bacteria (90%) and fungi (10%). Escherichia coli (n = 8), Trueperella pyogenes (n = 5), and Histophilus somni (n = 4) were the bacterial species most often identified as causing infectious abortions, whereas Aspergillus spp. (n = 3) was implicated in all fungal abortions identified. Pure culture of bacteria or fungus was achieved from abomasal content and/or lung essential. Main microscopic findings were bronchopneumonia, myo- and epicarditis, meningitis, and portal hepatitis. Herein, we highlight the importance of detecting potential infectious bacteria in cultures to improve etiological diagnosis of bovine abortions associated with compatible microscopic findings to confirm the etiology.

Campylobacter species abortion in sheep.

This focus article was prepared by Jasmine Smith of the APHA Small Ruminant Species Expert Group. Data extraction and analysis was done by Anna Brzozowska of the APHA Surveillance Intelligence Unit and Leanne Dempsey from APHA Thirsk.

Overview of the causes of abortion in horses, their follow-up and management.

Abortions in horses represent an important health and economic challenge for equine industry. Primary causes of abortion are divided in non-infectious and infectious. Non-infectious causes include abnormalities of foetal appendices (umbilical cord and placenta essentially), abnormalities of gestation, maternal and foetal origins. Infectious abortions are caused in almost cases by bacterial infections, followed by viruses, fungi and parasites. New abortive pathogens (as Leptospira, Neospora caninum, Coxiella burnetii, Chlamydophila abortus, and) have been confirmed in equines by comparison already known for their abortive properties in human or in other species. Despite an increasing number of autopsies and continuous improvements in diagnostic tools, in management and surveillance, 20%-40% of the causes of equine abortion remain unknown depending on the country. To increase the likelihood of a definitive diagnosis in cases of abortion and stillbirth in horses, new diagnostic approaches are needed.

Molecular investigation of Coxiella burnetii in the Middle and East Black Sea region in aborted bovine fetuses and investigation of the oxidant/antioxidant system.

Coxiella burnetii (C. burnetii) is a causative microorganism that causes the zoonotic Q fever disease, which is generally asymptomatic in animals, but causes reproductive issues such as abortion, stillbirth, and infertility. C. burnetii infection poses a threat to farm economies as it affects productivity in farm animals. The purpose of this research was to look into the incidence of Q fever in eight provinces in the Middle and East Black Sea region and to measure reactive oxygen and reactive nitrogen species as well as antioxidant levels in bovine aborted fetal livers infected with C. burnetii. The study material consisted 670 bovine aborted fetal liver samples delivered to Samsun Veterinary Control Institute from eight provinces between 2018 and 2021. C. burnetii was analyzed by PCR in these samples and 47 (7,01%) were positive while 623 negative. Nitric oxide (NO), malondialdehyde (MDA) and reduced glutathione (GSH) activities were analyzed by spectrophotometric method in both 47 positive samples and 40 negative samples as control group. In the C. burnetii positive and control groups, MDA levels were determined to be 2.46 ± 0.18 and 0.87 ± 0.07 nmol/ml, NO levels were determined to be 1.77 ± 0.12 and 1.09 ± 0.07 nmol/ml, and reduced GSH activity was determined to be 5.14 ± 0.33 and 6.62 ± 0.46 µg/dl, respectively. In C. burnetii positive fetal liver tissue, MDA and NO levels were higher than the control group, while reduced GSH levels were lower than the control group. As a result, C. burnetii caused changes in free radical level and antioxidant activity in bovine aborted fetus liver.

Invited review: Bovine abortion-Incidence, risk factors and causes.

The true incidence of bovine abortion (42-260 days of gestation) is unknown because of under-reporting. This is particularly true of the first half of gestation when most abortions occur. From research studies, it is estimated that the animal-level incidence of abortion between day 45 and term is approximately 10%, being lower in suckler than in dairy cows. While wide variation exists in herd-level incidence, up to 30%, it is estimated that less than 5% of farmers report high (>5%) observed abortion rates. Given these figures, veterinary practitioners and farmers tend to use investigation thresholds close to these values, ≥5 and ≥3%, respectively. Most of the risk factors for abortion are animal-level factors (e.g. parity), but there are also herd-level factors (e.g. enterprise type). Of the many risk factors for bovine abortion, only a small number are modifiable. While the causes of bovine abortion are often classified as noninfectious or infectious, in reality, this means diagnosis not reached (DNR) or infectious. Approximately 40% of abortions are diagnosed as infectious and the remaining 60% as DNR; DNR includes both infectious and noninfectious causes not diagnosed. Increasingly, genetic causes are being diagnosed and changes to current national genetic selection indices may be warranted. Of the infectious causes, Neospora caninum is now the most commonly diagnosed abortifacient internationally, followed by Trueperella pyogenes, BVDv and fungi. Both national eradication programmes and effective vaccination programmes can reduce the burden of some infectious abortifacients, but the control of sporadic, noninfectious and Neospora-associated abortions remains challenging.

Detection of Chlamydia abortus in aborted chorioallantoises of horses from Western Canada.

Chlamydiae are reported to cause abortion in several species, however the association between Chlamydia sp. and equine abortions is poorly understood. A zoonotic transfer event of C. psittaci from aborted equine tissues in Australia has emphasized the need to better understand the prevalence of this pathogen in equine populations. The prevalence of chlamydia in equine abortions in North America has not been investigated thoroughly. We examined 99 formalin-fixed, paraffin-embedded placental samples submitted between 2009 and 2020 from equine abortions in Western Canada using chlamydia-specific 16S rRNA conventional PCR testing; 26 of 99 submissions tested positive for chlamydial DNA. Most of these submissions (n = 17) had no final diagnosis noted on their original pathology reports. DNA sequencing identified 22 of the 26 cases as C. abortus; 21 of the 22 C. abortus-positive samples were positive on chlamydial immunohistochemistry. These findings contrast with studies in Europe that found a low prevalence of chlamydiae using similar methodology. The high prevalence of the potentially zoonotic C. abortus identified in our study suggests that more substantial biosecurity protocols may be warranted for equine foaling, abortion, and stillbirth in Western Canada to prevent zoonotic transfer of the pathogen.

Detection of Anaplasma phagocytophilum in fetal and placental tissue of bovine abortions and perinatal mortalities.

BACKGROUND: Anaplasma phagocytophilum is a tick-borne zoonotic bacterium that is the aetiologic pathogen of tick-borne fever (TBF) in ruminants. In clinical bovine cases of TBF, abortion and stillbirth may be observed. However, in this regard, the pathophysiology of TBF has not yet been completely elucidated, and no clear guidelines to diagnose A. phagocytophilum-related abortions and perinatal mortalities (APM) are available. METHODS: This exploratory study aimed to investigate the presence of A. phagocytophilum in bovine cases of APM and determine whether placental or fetal spleen tissue has the greatest sensitivity for A. phagocytophilum identification. The placenta and fetal spleen of 150 late-term bovine APM cases were analysed using real-time PCR to detect A. phagocytophilum. RESULTS: A total of 2.7% of sampled placentas were positive for A. phagocytophilum, while none of the fetal spleen samples was. LIMITATIONS: No histopathology to detect associated lesions was performed. Consequently, no evidence of causality between the detection of A. phagocytophilum and APM events could be achieved. CONCLUSION: The detection of A. phagocytophilum suggests a potential role of this pathogen in bovine APM, and placental tissue seems to be the most suitable tissue for its identification.

Equine abortion and stillbirth in California: a review of 1,774 cases received at a diagnostic laboratory, 1990-2022.

Reproductive failure represents an important cause of economic loss for the equine industry. We reviewed the cases of equine abortion and stillbirth submitted to the California Animal Health and Food Safety Laboratory System, University of California-Davis from 1990 to 2022. A total of 1,774 cases were reviewed. A confirmed cause of abortion was determined in 29.2% of the cases. Abortion or stillbirth was attributed to infectious agents in 18.7% of the cases, with Streptococcus spp., equine herpesvirus 1, and Leptospira spp. being the most prevalent. Noninfectious causes of abortion were established in 10.5% of the cases, with umbilical cord torsion being the most common. In 70.8% of the cases, a definitive cause of abortion could not be established. Our study demonstrated the difficulties in establishing an etiologic diagnosis, even when following a standard diagnostic work-up. New diagnostic approaches are needed to improve the likelihood of reaching a final diagnosis in cases of equine abortion and stillbirth.

ABORTION AND NEONATAL MORTALITY DUE TO TOXOPLASMA GONDII IN BIGHORN SHEEP (OVIS CANADENSIS).

Low lamb recruitment can be an obstacle to bighorn sheep (Ovis canadensis) conservation and restoration. Causes of abortion and neonate loss in bighorn sheep, which may affect recruitment, are poorly understood. Toxoplasma gondii is a major cause of abortion and stillbirth in domestic small ruminants worldwide, but no reports exist documenting abortion or neonatal death in bighorn sheep attributable to toxoplasmosis. Between March 2019 and May 2021, eight fetal and neonatal bighorn lamb cadavers from four western US states (Idaho, Montana, Nebraska, and Washington) were submitted to the Washington Animal Disease Diagnostic Laboratory for postmortem examination, histologic examination, and ancillary testing to determine the cause of abortion or neonatal death. Necrotizing encephalitis characteristic of toxoplasmosis was identified histologically in six of eight cases, and T. gondii infection was confirmed by PCR in five cases with characteristic lesions. Other lesions attributable to toxoplasmosis were pneumonia (3/5 cases) and myocarditis (2/5 cases). Protozoal cysts were identified histologically within brain, lung, heart, skeletal muscle, adipose tissue, or a combination of samples in all five sheep with PCR-confirmed T. gondii infections. Seroprevalence of T. gondii ranged from 40-81% of adult females sampled in the Washington population in October and November 2018-2021, confirming high rates of exposure before detection of Toxoplasma abortions in this study. Of 1,149 bighorn sheep postmortem samples submitted to Washington Animal Disease Diagnostic Laboratory between January 2000 and May 2021, 21 of which were from fetuses or neonates, a single case of chronic toxoplasmosis was diagnosed in one adult ewe. Recent identification of Toxoplasma abortions in bighorn sheep suggests that toxoplasmosis is an underappreciated cause of reproductive loss. Abortions and neonatal mortalities should be investigated through postmortem and histologic examination, particularly in herds that are chronically small, demographically stagnant, or exhibit reproductive rates lower than expected.

Pregnancy and parturition in dromedary camels III. Incidence, timing and factors affecting abortions and perinatal mortality under intensive management.

In this study, the incidence, timing and risk factors associated with abortion and perinatal mortality (PM) were described in dromedary camels under intensive management. In addition, overall pregnancy losses were also summarized and weekly risk of pregnancy wastage was determined throughout gestation. Data were collected over 11 breeding seasons from September 2006 through June 2017 at the world's largest camel dairy farm. A total of 229 abortions were observed (5.05%) out of 4533 pregnancies after 60 days (d) of gestation. Most abortions were singleton (n = 199, 86.9%), but twin abortions were also recorded in 30 cases (13.1%). Abortions showed a pronounced seasonal distribution, with a peak in August. The age category (P < 0.01), breed or ecotype of the female (P < 0.05) and bull influenced the occurrence of singleton abortions. Dromedaries with twins tended to abort earlier than those with a singleton fetus (median = 232.5 d vs. 257 d, P = 0.053). Perinatal mortality was observed in 174 cases (3.84%) out of 4533 pregnancies after 60 d of gestation. The condition included the premature birth of non-viable calves after shorter than normal gestation (330-350 d, n = 26, 14.9%), the birth of well-developed but dead calves after normal gestation length (n = 120, 69.0%) and neonates that died within 48 h after delivery (n = 28, 16.1%). The frequency distribution of PM was parallel with that of parturitions. The most important predisposing factor for PM was difficult calving. Thirty-nine percent (68 out of 174) of these losses were associated with dystocia. In addition, age category (P < 0.05) and parity of the female (P < 0.01), month of delivery (P < 0.05) and breeding season (P < 0.05) also affected the incidence of PM. The cause of 60 cases of PM (1.4% of all deliveries) could not be determined and was considered idiopathic. In conclusion, one-third of total pregnancy losses occurred during mid to late gestation. Approximately 10% of pregnancies after Day 60 failed, and 90% resulted in the birth of a live calf that survived beyond 48 h. More than half of these pregnancy losses were abortions before 330 d of gestation, and approximately 40% were classified as PM. The weekly mean risk of pregnancy loss after 100 d of gestation remained only a fraction of that observed during the first 2-3 months.

Control measures to reduce Neospora caninum abortions in dairy farms: a pilot study in Iran.

Neospora caninum plays an important role in abortion and economic losses in dairy industry worldwide. The main target of this work was to detect the infection rate of N. caninum in various hosts in dairy farms for identifying the risk factors and applying appropriate control programs to reduce the number of abortions. The study was conducted in dairy farms with high incidence of abortion in Hamedan province, West of Iran. After the primary assessment, we conducted a controlling program for reducing the Neospora­infection rate and associated abortions. Before implementing the control program, the seropositivity was 24.8% in cows (N=476 distributed in 10 farms) and 8.6% (N=185) in dogs. Abortion occurred in 3.57% of pregnant cows. 94.1% of aborted cows were positive for Neospora­infection. Based on molecular technique, the infection rate was detected in 7.3% of cats (N=41), in 25% of pigeons (N=19)and in 11.8% of rodents (N=51). After the implementation of neosporosis control programs in the farms, the seropositivity of N. caninum decreased to 8.2% in cows and 2.9% in dogs. After the one­year follow­up, no cases of abortions were reported in the farms. This was the first parallel evaluation of Neospora­infection and controlling programs in Iranian dairy farms. Regular control of rodents, retesting of seronegative animals and farm biosecurity measures are recommended for reducing the abortion incidence. The access of dogs to the herd and to aborted materials should be restricted.

Neospora caninum-associated abortions in cattle from Southern Brazil: Anatomopathological and molecular characterization.

This study aimed to evaluate the N. caninum associated abortions in cattle in the state of Santa Catarina, in the southern Brazil. Aborted bovine fetuses were necropsied, submitting organ samples for histopathological evaluation. Brain fragments were analyzed by polymerase chain reaction (PCR). The diagnosis of abortion due to N. caninum was established through histopathology and molecular analysis in 53.84% (28/52) of the cases, with PCR detection in 71.42% (20/28). The histopathological evaluation showed lesions in 75% of the cases, characterized by mononuclear necrotizing encephalitis, mononuclear myocarditis, mononuclear myositis, mixed placentitis, and mononuclear pneumonia. Neospora caninum was the primary etiological agent associated with causes of abortion in cattle in the present study.

Neospora-related abortions in sheep in Israel - A serological diagnostic challenge in an endemic area.

Abortions in sheep flocks is a common multifactorial problem, which affects animal productivity and welfare. Israel is endemic to several infectious abortifacient pathogens, with neosporosis identified as a prominent cause. High seroprevalence of N. caninum is present in the general sheep population, making complicate to associate it as the causative agent of abortion in sheep. Here we describe two investigations of abortion storms in sheep flocks with high seroprevalence of neosporosis. In flock A, higher anti-Neospora antibody titers were demonstrated in aborting versus non-aborting ewes, suggesting that it may be the cause of abortions. In flock B, several infectious abortifacients were identified, but only the seroprevalence of border disease differed statistically between aborting and non-aborting ewes. These reports highlight the difficulty of diagnosing the cause of abortion in a multifactorial situation, and confirm the necessity to assess paired samples from aborting and non-aborting ewes, for reliable interpretation of the results.

Investigation of the outbreaks of abortions and orchitis in livestock in Namibia during 2016-2018.

This study investigated outbreaks of seemingly related abortions and orchitis which occurred in the Khomas, Omaheke and Otjozondjupa regions of Namibia from 2016 to 2018, affecting cattle, sheep and goats. Fifty-nine questionnaires were administered, and 48 were completed giving an 81.4% return. The outbreaks were limited to Namibia's east and central regions, mainly on farms rearing cattle, sheep and goats and on farms with a mixture of these species. There was no significant difference between Khomas and other regions on abortion reporting at the farm level [X2 (1, N = 48) = 0.0002, p = 0.987851]. However, there was a significant difference in the abortions at the animal level among the three regions [X2 (2, N = 6246) = 239.8339, p = .00001]. In addition, the proportions of abortions calculated at the animal level at each farm were significantly different when the Khomas region was compared to the other regions. Seventeen cattle sera, 35 sheep sera, 52 caprine sera, 18 bovine liver samples, one caprine liver, five aborted cattle foetuses, two cattle placentas, 18 testes (one bull, eight bucks and nine rams) and ten bull sheath scrapings were collected and tested. Histopathology, microbiology, serology, immunohistochemistry, real-time PCR and mineral analytical techniques were used to establish the aetiology of the abortion and orchitis outbreaks. The gross and histopathological findings on the 18 testicles were characteristic of chronic orchitis. In aborted foetuses, significant histopathological findings included meconium aspiration, funisitis and cardiomyopathy. Placentitis and endometritis were the primary pathologies observed in cows. The bacteria isolated from microbiological samples included Enterococcus spp. (65.5% [19/29]), Enterobacter spp. (6.9% [2/29]) and Streptococcus spp. (10.3% [3/29]), Trueperella pyogenes (3.4% [1/29]), Stenotrophomonas maltophilia (3.4% [1/29]), Staphylococcus epidermidis (3.4% [1/29]), Providencia rettgeri (3.4% [1/29]) and Acinetobacter lwoffii (3.4% [1/29]), mostly opportunistic bacteria. On mineral analysis, 28%, 33%, 83%, 33% and 17% (n = 18) of cattle livers were low in copper, zinc, manganese, selenium and iron, respectively. Twenty-three percent (12/52) of the caprine sera were positive for Brucella melitensis on the Rose Bengal and complement fixation tests. Thirty-five ovine sera were tested for B. melitensis, B. ovis and Coxiella burnetii, and the prevalence for each was 2.9% (1/35). PCR tests on foetuses were all negative for Brucella spp., Coxiella burnetii, Chlamydia spp., Listeria monocytogenes, Salmonella spp., Campylobacter fetus spp., Leptospira pathogenic strains, bovine viral diarrhoea virus, Rift Valley fever virus, Anaplasma phagocytophilum and bovine herpes virus 4 Campylobacter fetus spp. and Trichomonas foetus spp. The authors concluded that Brucella spp., Enterococcus spp., Escherichia coli, Streptococcus spp., Trueperella pyogenes and Coxiella burnetii could have contributed to this outbreak. Micronutrient imbalances and pathogenic abiotic nanoparticles were also identified as possible contributors to the abortion outbreaks.

Nocardioform placentitis in a sample population of mares foaling in southeastern Pennsylvania and northeastern Maryland in 2020.

Nocardioform placentitis (NP) has been associated with mid to late pregnancy loss in mares. To date, disease outbreaks have been described only in central Kentucky, although sporadic, isolated cases have been reported globally. This study describes a series of cases of NP that occurred in a sample population of 299 mares foaling in southeastern Pennsylvania and northeastern Maryland in 2020. These cases coincided with an outbreak of NP that occurred in Kentucky that same year. On farms that reported information on both normal and abnormal foalings, nocardioform organisms/DNA were isolated from 6.3% of placental samples based on aerobic culture and/or PCR. In cases with characteristic gross lesions of the chorion, 41% of cases were positive on aerobic culture and/or PCR. NP was confirmed in 16 mares that had not resided in Kentucky for breeding or any part of gestation. Characteristics of mares confirmed positive for NP, including age, gestation length, and problems during gestation are described. Standardbred mares bred by artificial insemination were less likely to be affected than Thoroughbred mares bred by natural cover. Affected mares had prolonged Stage III labor compared with normal mares. These findings suggest that regional increases in NP may occur outside of Kentucky, potentially in parallel with Kentucky outbreaks.

Causes of abortion in Iranian sheep flocks and associated risk factors.

Abortion is a major issue in sheep husbandry. It can result in significant economic losses and a severe public health risk. This survey assessed the infectious and non-infectious causes of abortion in Iranian sheep flocks and determined the main risk factors. In this cross-sectional survey, causes of abortion were evaluated in 757 sheep flocks, and risk factors were analysed. A checklist containing general animal information for each abortion outbreak evaluated was filled in. Data were analysed using univariate tests and multivariable binary logistic regression analysis. In this sense, parity, gestational age of the aborted fetus, vaccination protocol, mineral supplementation and history of stillbirth showed significant associations with abortion. Infectious agents such as Coxiella burnetti (22.7%), Chlamydia abortus (12.3%) and Brucella melitensis (10.4%) were the most frequently isolated in the investigated flocks, with more than 2% of abortion rates. On the other hand, non-infectious agents such as trauma, pregnancy toxaemia and vitamin E/Se deficiency were involved in those flocks with low abortion rates (less than 10%). Results revealed multiple causes of abortion outbreaks among Iranian sheep flocks, which need careful investigation to identify possible aetiology and risk factors. Further studies are necessary to evaluate if these factors are similar to other countries in the same region.