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Simple Summary: Caseous lymphadenitis (CL) is an infectious disease clinically characterized by suppurative necrotic inflammation in superficial and internal lymph nodes and organs. This pathology is responsible for economic impacts in the sheep industry worldwide. In Morocco, where sheep farming is considered an important source of income for the rural population, CL causes significant economic losses to breeders due to the low prices and limited saleability of sheep showing superficial lesions. In this study, a 12-month longitudinal follow-up was carried out to evaluate the effect of seasons, the animals' age, sex, body score and shearing on the clinical incidence of CL, relapses and abscess location in sheep. As a result, both season and age showed significant effects on superficial CL incidence. A high incidence of CL in lambs and young sheep occurred between April and September, which coincided with the fattening periods and indoor housing. It appears promising to focus attention and preventive measures against CL on young animals during spring and summer to improve CL control strategies. Caseous lymphadenitis is an infectious disease that has a significant economic impact on sheep breeding. The objectives of this study were to evaluate the effect of season, animals' age, sex, body score and shearing on the clinical incidence of caseous lymphadenitis, relapses and abscess location in sheep from Settat province, Morocco. In this longitudinal study, 274 clinically healthy sheep were recruited in six flocks among 1451 inspected sheep and followed during 12 months to cover four seasons. The animals involved in this study were assigned to different age categories at continuous recruitment from February to July 2021 (lambs younger than 6 months, young sheep between 6 and 24 months and old sheep more than 24 months) and to sex categories. Selected animals were clinically examined every 2 months to detect superficial abscesses by palpation of superficial lymph nodes. Information about the number of abscesses and their locations was recorded and analyzed in multivariable statistical models. The results showed that 185/274 (67.5%) of the monitored animals developed superficial CL abscesses. The risk ratio (RR) of superficial CL was significantly higher between April and September compared to between January and March (RR~4.4; p < 0.0001). No significant difference was found between October and December compared to between January and March (RR = 1.2; p = 0.64). Regarding the effect of age, the results revealed that the RR was significantly lower in old sheep compared to lambs (RR = 0.45, p < 0.0001). No significant difference was detected between lambs and young sheep (RR = 0.7, p = 0.07). The prevalence of caudally located abscesses (prefemoral and popliteal lymph nodes, as well as in testicles, scrotum and mammary glands) was significantly higher in old sheep than in lambs (20% versus 3%; odds ratio = 7.8, p = 0.02). The sex, body score and shearing since the last examination did not show any significant effect on CL incidence (p > 0.1). Abscess relapse was significantly lower in old sheep than in lambs (IRR = 0.4, p = 0.003). The highest clinical CL incidence was observed in young animals between April and September and was likely due to indoor intensive rearing management. To conclude, both season and age had significant effects on superficial CL incidence. Farmers, veterinarians and technicians should focus attention and preventive measures against CL on young animals during spring and summer. [ABSTRACT FROM AUTHOR]

Simple Summary: Caseous lymphadenitis is one of the main infectious problems affecting sheep rearing areas worldwide. In Morocco, sheep farming constitutes an important socioeconomic activity and is considered to be a source of income for the local rural population. However, breeders are facing considerable economic losses due to caseous lymphadenitis. This negative impact is mainly due to the low prices and limited saleability of sheep with superficial abscesses, particularly for religious celebrations. In the present study, investigations were realised at the flock and slaughterhouse levels to determine the prevalence and risk factors implicated in caseous lymphadenitis. As a result, the form of rearing management adopted was found to impact the dissemination of caseous lymphadenitis. In conclusion, improvement of ventilation in sheep barns and implementation of periodic control of abscess cases, including their treatment with adequate procedures, are a must. Two surveys were conducted to assess the prevalence and risk factors of ovine caseous lymphadenitis (CL) and explore the association between its superficial and visceral forms in Sardi sheep in Settat province, Morocco. A total of 1521 sheep, including 318 lambs < 6 months, 572 young sheep aged 6–24 months, and 631 adult sheep > 24 months, were examined from 57 flocks. Superficial CL prevalence levels were as follows: 69/318 in lambs, 292/572 in young sheep, and 114/631 in adult sheep. Additionally, 2124 sheep, including 1813 young and 311 adult sheep, were inspected in slaughterhouses ante- and post-mortem. Among all infected animals, the prevalence of visceral abscesses was notably higher in adult sheep (83%, OR = 9.8, 95% CI = 5.5–17.2) compared to young sheep (35%). Data on flock size, sex, age, body condition score, rearing methods, and hygienic measures were collected. Suspected CL cases were confirmed using quadruplex-PCR. Poor barn ventilation, lack of abscess control, and younger age were identified as key risk factors for CL. Additionally, a high percentage (89%) of animals with thoracic abscesses did not display superficial lesions. While age and abscess control have been reported in previous studies, barn ventilation appears to be a new, but important, risk factor. In conclusion, the identified risk factors in Settat province are linked to breeding management practices. Implementing regular abscess control measures and improving barn ventilation are essential for CL prevention. [ABSTRACT FROM AUTHOR]

Anthroponotic cutaneous leishmaniasis (ACL) due to Leishmania tropica is spreading to new areas in Morocco. Exposure to the vector, Phlebotomus sergenti, is the only proven risk factor. Our objective was to compare the densities and genetic characteristics of P. sergenti populations in two nearby localities in Morocco, one in an ACL endemic area (El Borouj) and another in a nonendemic area (Sidi Hajjaj). P. sergenti density was significantly higher in the endemic area than in the nonendemic town (p = 0.032). A different predominant P. sergenti mitochondrial lineage was evidenced in each one of the two localities, and for the first time, the P. sergenti lineage acting as a vector of L. tropica has been identified. Bioclimatic differences were detected between both localities. In conclusion we found differences in both the density and the mitochondrial lineage of P. sergenti populations that may explain the different epidemiological situation. Given that the density of P. sergenti in the locality without ACL cases seems sufficient to allow transmission, the main factor that would justify its nonendemic character could be the absence of P. sergenti Lineage IV, which seems to prefer warmer and drier climates. [ABSTRACT FROM AUTHOR]