Bovine leptospirosis causes economic losses and raises public health concerns. It is possible that there are peculiarities in the epidemiology of leptospirosis in regions with a semiarid climate, such as the Caatinga biome in Brazil, where the climate is hot and dry, and the etiological agent require alternative routes of transmission. This study aimed to close knowledge gaps to the diagnosis and epidemiology of Leptospira spp. infection in cows from the Caatinga biome, Brazil. Samples of the blood, urinary tract (urine, bladder and kidney) and reproductive tract (vaginal fluid, uterus, uterine tube, ovary and placenta) were collected from 42 slaughtered cows. Diagnostic tests included were the microscopic agglutination test (MAT), polymerase chain reaction (PCR) and bacterial isolation. Anti-Leptospira spp. antibodies were found in 27 (64.3%) of the animals analyzed using MAT at a 1:50 dilution (cut-off 50), while 31 (73.8%) animals had at least one organ/fluid where the presence of Leptospira spp. DNA was identified, and 29 animals (69%) were positive at bacteriological culture. The highest sensitivity values for MAT were obtained at the cut-off point of 50. In conclusion, even under hot and dry climate conditions, it is possible that Leptospira spp. can spread through alternative routes such as venereal transmission; moreover, a cut-off of 50 is recommended for the serological diagnosis of cattle from the Caatinga biome.

Leptospirosis is an infectious disease that affects domestic animals, wild animals, and humans. It represents a public health problem and has an important economic impact on livestock. This study aims to investigate the importance of genital and transplacental infection in the epidemiology of leptospirosis in cows maintained in Caatinga biome conditions, Northeastern Brazil, as well as reporting organs colonized by Leptospira spp. in embryos and fetuses. Blood, urinary tract (urine, bladder, and kidney), and reproductive tract (vaginal fluid, uterus, uterine tube, ovary, and placenta) samples were collected from 15 slaughtered pregnant cows. Two embryos and 13 fetuses were sampled. Central nervous system and choroid ovoid samples were collected from embryos. Blood, central nervous system, lung, peritoneal liquid, abomasal content, liver, spleen, urine, bladder, kidney, and reproductive system samples were collected from fetuses. Diagnostic methods included the microscopic agglutination test (MAT) using a collection of 24 serovars belonging to 17 different pathogenic serogroups of five species as antigens, as well as polymerase chain reaction (PCR). Anti-Leptospira spp. antibodies were found in 9 cows (60%), while 13 cows (86.67%) had at least one organ or urine with leptospiral DNA. No fetus was seroreactive. Among the embryos and fetuses, 13 (86.67%) presented leptospiral DNA, proving a high frequency of transplacental infection (100%). For cows, the most frequent biological materials regarding Leptospira spp. DNA detection were placenta (13 out of 15 samples; 86.7%), uterus (10 out of 15 samples; 66.7%), and vaginal fluid (5 out of 15 samples; 33.3%), while, for fetuses/embryos, the most frequent PCR-positive samples were choroid ovoid (1/2; 50%), spleen (6/13; 46.2%), kidney (5/13; 38.5%), and central nervous system (5/15; 33.3%). Sequenced samples based on the LipL32 gene presented 99% similarity with L. borgpetersenii. The results indicate that transplacental infection is an efficient way of spreading Leptospira spp. in cows maintained in Caatinga biome conditions. Therefore, prevention and control strategies must include actions that interrupt transmission through this alternative route.

Leptospirosis is a disease that causes economic and social impact, as it affects wild and domestic animals and humans. There may be peculiarities in the epidemiology of this disease in the Caatinga biome, Brazil, where the environment is adverse and the etiologic agent, Leptospira spp., requires alternative transmission routes. Considering that in bovine leptospirosis the genital carrier is constantly neglected and the lack of reports on the role of bulls in the epidemiology of the bovine genital leptospirosis (BGL) syndrome, mainly in semiarid conditions such as Caatinga biome, this study aimed to investigate bulls maintained in Caatinga biome conditions as genital carriers of leptospires. Urinary tract (urine, bladder, and kidney) and reproductive tract (vas deferens, cauda epididymis, and vesicular gland) samples were collected from 42 slaughtered bulls. Microscopic agglutination test (MAT), polymerase chain reaction (PCR), and microbiological isolation were included as diagnostic methods. Anti-Leptospira spp. antibodies were found in 17 (40.48%) animals, while 26 animals (61.90%) had at least one organ or urine with leptospiral DNA, and 10 animals (23.81%) were positive at bacteriological culture. Sequenced samples targeting the LipL32 gene showed 99% similarity with Leptospira borgpetersenii. Molecular analysis of samples from the vas deferens and cauda epididymis is recommended for the diagnosis of genital leptospirosis in bulls and, if it is impossible to collect these tissues, semen can be used. In conclusion, this study provides important information relating to bulls from the Caatinga biome, Brazil, as carriers of genital leptospirosis. The results indicate that, even under adverse environmental conditions, leptospires may survive and propagate, mainly due to the characteristic of genital carriers for the sexually spreading of adapted Leptospira species without influence by external variables. Thus, prevention and control strategies for bovine leptospirosis need to include actions aimed at the genital carrier.

In the Northeast of Brazil, goat breeding plays an important socioeconomic and strategic role in coexistence within the semi-arid region. The rural nature of the species and adaptations that are appropriate for the climate are some of the characteristics that favor the Northeast as the largest national producer of goats (93% of the national herd). In spite of this, sanitary deficiencies facilitate the appearance and diffusion of pathogenic agents that compromise the productivity, e.g., Corynebacterium pseudotuberculosis, which are widespread in the national herd and cause damages in the industry. The objective of this study was to characterize caseous lymphadenitis (CL) in lamb cuttings at semi-arid abattoirs. The research was carried out between March and August 2017 at the Municipal Abattoir of Patos, State of Paraíba, Brazil, where the caprines from this region are slaughtered. We studied 304 animals with no defined racial pattern, of both the sexes, characterized according to their age group as evidenced by their teeth, submitted to ante- and post-mortem examinations with microbiological confirmation. Cheek material was processed for diagnostic confirmation, using the techniques of isolation and microbiological identification (gold standard). The bacteriological examination confirmed the presence of the agent in 21.38% of the animals, in which 13.16% were females and 8.22% were males. Of those affected, 11.51% had the clinical form of the disease, while 9.87% had the subclinical form and 1.31% had both the clinical form as well as the internal impairment. The precrural (25.71%), mammary (11.43%), and prescapular (11.43%) lymph nodes were the most affected. Internally, the most affected were the liver (63.33%), lung (13.33%), and medium mediastinal lymph nodes (10%). The presence of skin lesion/scars (Odds ratio = 2.394, 95% CI = 1.371 - 4.182, p = 0.003) and sex (females) (Odds ratio = 1.845, 95% CI = 1.053 - 3.232, p = 0.044) were found to be risk factors. CL is present in goats from the intermediate geographical region of Patos, reinforcing the need for control measures, with attention to the inspection of animals in the slaughter line.

Caseous lymphadenitis (CLA) caused by the pathogenic bacterium, Corynebacterium pseudotuberculosis, results in economic loss in goat farming. Its prevalence in Brazilian herds varies from 5 to 50%, generating expenses with treatment, loss in production, carcass and organ condemnation, and reduced price of the hide. This study aimed to describe the distribution of lesions and quantify the loss associated with CLA in goat breeding due to condemnation in a slaughterhouse located in a semiarid region. The study was conducted at the municipal slaughterhouse of the city of Patos, State of Paraíba, Northeastern Brazil, where goats from this intermediate geographical region are slaughtered. In 2017, 3,662 animals were slaughtered, an average of 305 per month. During the study period, from March to August 2017, 304 goats of both sexes and different ages of undefined breed were assessed. In the ante-mortem examination, inspection and palpation of the superficial lymph nodes was done; in the post-mortem examination, organ and viscera were assessed. The caseous material collected was sent for microbiological analysis. Of the 304 individuals, 227 [74.67% (95% CI: 69.50-79.23)] did not have any lesions, while 77 [25.33% (95% CI: 20.77-30.50)] showed abscesses suggestive of CLA, which was confirmed in 65 goats [84.41% (95% CI: 76.30-92.50)]. Sex (P = 0.044) and age (P = 0.002) were associated with infection. While the sex of the animals affected carcass and viscera weights and carcass yield, their age affected live weight, carcass, organ, and viscera weights; conversely, the incidence of CLA did not affect these variables. The average price in Real (R$) of a kilogram (kg) of goat meat cuts and "offal" was used to calculate the economic loss. Considering the average carcass weight (11,485 kg), organ weight (1,085 kg), and viscera weight (2,013 kg), 4,433.232 kg of meat was produced, resulting in R$ 72,945.43. The condemnations resulted in the loss of 269.894 kg, which is equivalent to R$ 4,540.33. CLA is responsible for a negative impact of 6.09% on production. Implementing control measures for this disease is important to increase the financial return in goat farming.

In the Caatinga biome, leptospirosis in livestock has been widely investigated due to environmental characteristics that challenge the transmission and persistence of Leptospira spp. infection in this animal group. This study aimed to investigate evidence of Leptospira spp. exposure and carriage in slaughtered goats using the microscopic agglutination test (MAT) in serum samples and polymerase chain reaction (PCR) of the genital and urinary tracts samples, considering seasonal dynamics of the pathogen potential in the Caatinga biome. At a slaughterhouse located in the Caatinga biome region, fluid and organ samples were collected from 90 goats. Serum samples were submitted to MAT, whereas urine, cervicovaginal mucus (CVM), and tissue samples from the urinary and reproductive tracts (kidney, bladder, uterus, oviduct, and ovary) were subjected to PCR assay. In the MAT, a cutoff point of 1:50 was adopted, with 23 (25.6%) goats testing positive, with no significant difference between the dry and rainy seasons. The most frequent serogroup was Icterohaemorrhagiae. In the PCR assay, 16 goats [17.8%; 95% CI = 9.9–25.7%] tested positive, presenting at least one tissue or fluid sample positive for Leptospira spp. DNA, totaling 97/630 (15.4%) positive samples. The highest frequency of PCR positivity was observed during the rainy season and involved samples from both the urinary and reproductive tracts. The detection of pathogenic Leptospira spp. DNA in goats at the slaughter line suggests the possible presence of PCR-positive animals on the farms of origin. Furthermore, the identification of pathogenic Leptospira spp. DNA in fluids and tissues of the genital and urinary tracts suggests a potential occupational exposure risk, especially for slaughterhouse workers handling carcasses and offal of infected goats in the Caatinga biome.