Simple Summary: Digestive disorders are the main cause of economic damage in rabbit farms and, usually, antibiotic treatment is the first choice to control them. Nevertheless, a broad range of infectious agents can be involved in such disorders, as we have observed in our diagnosis work as a veterinary diagnostic laboratory. In this study, a global and updated overview of the frequency of detection of those etiological agents is provided. We have seen differences depending on the age of the affected rabbits, with young rabbits (<15 days old) being the most affected by enteropathogenic Escherichia coli strains, while in preweaning and growing rabbits, a coinfection of two or three pathogens is the most prevalent situation. Clostridium spiroforme and E. coli are the main bacterial agents detected in preweaning rabbits, but enterotoxigenic Bacteroides fragilis has just appeared as a new possible emergent pathogen. Coinfections between bacteria (C. spiroforme and E. coli), parasites (Eimeria spp.), and viruses (rotavirus) are much more frequent than simple infections in growing rabbits; for this reason, complete laboratory studies are required to establish on-farm disease control measures.Abstract: Digestive disorders are the main cause of economic damage to rabbit farms. This article provides a global and updated overview of the diverse etiological agents causing them, since 757 clinical cases were analyzed during 2018 and 2019-Ninety-five from young rabbits (<15 days old), 117 from preweaning rabbits (15-35 days old), and 545 from growing rabbits. Etiological diagnosis was carried out by bacteriological culture and a set of real time polymerase chain reaction (qPCR) tests for the detection of enteropathogenic Escherichia coli (EPEC), Clostridium spiroforme, C. perfringens, rotavirus A, Bacteroides fragilis, and Eimeria spp. Also, 40 EPEC and 38 non EPEC isolates were investigated for the presence of other colonization factors (afr2, ral, liftA, and paa) by qPCR. EPEC is the most prevalent agent in young rabbits, and although different virulence profiles have been found among EPEC isolates, the liftA+, ral+, and paa+ profile is the most prevalent. C. spiroforme and EPEC are the more frequently detected pathogens in preweaning rabbits, but B. fragilis appears to be a new possible emergent pathogen. In growing rabbits, diverse co-infections between C. spiroforme, Eimeria spp., EPEC, and rotavirus are much more frequent than infections due to only one of them. Other pathogens detected in very few cases are Salmonella spp. and Enterococcus hirae.
Four hundred and ninety-eight culled sheep received at the Ruminant Clinical Service of the Veterinary Faculty of Zaragoza, Spain, were examined in life and after humanitarian sacrifice in order to reach the final diagnosis of the cause of culling and to evaluate the presence of caseous lymphadenitis (CLA) lesions. One hundred and forty-seven of the 498 studied animals (29.52%) showed CLA compatible lesions that were subsequently confirmed by Corynebacterium pseudotuberculosis isolation. One hundred and seven of the 147 CLA affected animals presenting the visceral clinical form of the disease (72.79%), while only 32 animals were affected by the superficial form (21.77%). In addition, eight animals were found to be affected in both the visceral and the superficial presentations (5.44%). Eighty-four of the 147 CLA-affected animals (57.14%) did not show any concurrent disease, considering, in this case, CLA the main cause of culling (84/498: 16.87%). In the superficial presentation, the retropharyngeal lymph node, as a sole lesion, was the most frequently affected (13/32: 40.63%). Further, in the visceral form of the disease, 85.06% of the affected animals had the lesions located in the respiratory system (91/107: 85.06%). CLA was revealed as an important cause of culling in sheep production.
IntroductionInfectious abortions have a major impact on small domestic ruminant farms, i.e., sheep and goats, both in terms of profitability and health status. Therefore, rapid and sensitive diagnosis is essential to minimize losses. Currently, molecular techniques, such as qPCR, are routinely used for their diagnosis, which imply the need to manipulate all abortive material, with consequent biosafety risks. Here, we evaluate the frequency of the main abortifacient pathogens in small domestic ruminants in the Iberian Peninsula and also assess an alternative approach for the optimization of sampling for molecular diagnosis.ResultsA total of 392 clinical cases were analyzed from April 2020 to May 2021, evidencing that the main causative agents of abortion detected were Coxiella burnetii (49.0%), Chlamydia abortus (38.3%) and, to a lesser extent, Toxoplasma gondii (10.2%), Salmonella enterica (7.1%) and Campylobacter spp. (6.1%). An uneven distribution of these pathogens was observed between ruminant species, with a higher frequency (p < 0.05) of T. gondii, S. enterica and Campylobacter spp. in sheep than goat abortions, and among geographic areas, highlighting the higher frequency (p < 0.05) of T. gondii and Campylobacter spp. in the north compared to southeastern Spain. The alternative sampling method, consisting on the use of fetal tongues and placental swabs in replacement of the whole fetus and placental tissue, offered a very good agreement with the classical method for all pathogens, except for low concentrations of C. burnetii, which seems to have a doubtful role in abortion when its concentration in the abortifacient material is low.ConclusionsThis study reveals a high frequency of infectious etiology in abortions of small domestic ruminants in the Iberian Peninsula and validates for the first time an alternative sampling method for molecular diagnosis that will help to provide rapid and accurate results while minimizing biosafety risks.
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