Significance of respiratory diseases in the health management of sheep

Objectives of the present article are to review the financial significance of respiratory diseases and to indicate their relevance within the health management of sheep. In lambs, the principal adverse effects of the diseases are related to mortality, reduced carcass quality, veterinary expenses, decrease of average daily bodyweight gain and poor quality of lambs produced. In adult animals, financial losses are related to reduced production of affected sheep, need for early culling and death. Given the multi-faceted nature of these diseases, management practices (e.g., housing improvements, implementation of biosecurity provisions) need to be considered for their prevention; as environmental conditions also play a role in development of these diseases, they should be taken into account. Appropriate health measures (e.g., vaccinations) that improve animal immune response also will help control of the diseases

Detection of Cathelicidin-1 in the Milk as an Early Indicator of Mastitis in Ewes

The objective of the study was the investigation of the behaviour of cathelicidin-1 in the milk after experimental infection with two prominent bacterial pathogens (experiment 1: Mannheimia haemolytica, experiment 2: M. haemolytica and Staphylococcus chromogenes) as a potential early indicator for diagnosis of mastitis in sheep. In two experiments, after bacterial inoculation into the udder of ewes, bacteriological and cytological examinations of milk samples as well as proteomics examinations [two-dimensional gel electrophoresis analysis (2-DE) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometer (MALDI-TOF MS) analysis] were performed sequentially. Cathelicidin-1 was detected and spot densities obtained from PDQuest v.8.0 were recorded. Associations were calculated between cell content and spot densities as well as between presence of mastitis in a mammary gland at a given time-point and detection of cathelicidin-1 in the respective milk sample. All inoculated mammary glands developed mastitis, confirmed by the consistent bacterial isolation from mammary secretion and increased leucocyte content therein. Spot density of cathelicidin-1 in samples from inoculated glands increased 3 h postinoculation; spot density of cathelicidin-1 in samples from inoculated glands was higher than in samples from uninoculated controls. There was clear evidence of correlation between cell content and cathelicidin-1 spot densities in milk samples. There was significant association between presence of mastitis in the mammary gland and detection of cathelicidin-1 in the respective milk sample; overall accuracy was 0.818\u2014this was significantly greater during the first 24 h postchallenge (0.903) than after the first day (0.704). In conclusion, detection of cathelicidin-1 in milk was significantly associated with presence of mastitis in ewes. The associations were stronger during the first 24 h post-infection than after the first day. Cathelicidin-1 has the advantage that it can be a non-specific biomarker, as simply a \u201cpositive\u201d / \u201cnegative\u201d assessment would be sufficient

A detailed questionnaire for the evaluation of health management in dairy sheep and goats

The objective of this work was to develop, use and present a detailed questionnaire for the evaluation of health management in dairy small ruminants; it includes 442 questions organised in seven sections: general, infrastructure, animals, production characteristics, health management, nutrition, human resources. Consistency of replies was evaluated in 27 farmers, interviewed twice. Inconsistent replies were given by all farmers to 30 different questions (Cronbach’s coefficient alpha: 0.987). Then, interviews were performed in 444 farms around Greece. Mean duration of an interview was 63.6 min. Clarifications were requested by 273 farmers to 22 different questions (maximum per farmer: 8). The experience of the investigator, the primary language of farmers and asking clarifications by the farmers affected the duration of the interview. The questionnaire can be used for research work in the field, to record details in the farms under study. In accord with the needs of a particular study, it can be modified, by adding more specific questions or omitting others deemed of less importance. Moreover, it can also be used for routine monitoring purposes, as a useful means to record and maintain details of farms during clinical work. To the best of our knowledge, the questionnaire is the most extensive and detailed one available internationally for dairy small ruminants

Comparison of the Efficacy of Intramammary or Injectable Antibiotic Administration against Staphylococcal Mastitis in Ewes

The objectives of the work were (a) to compare the efficacy of two routes for antibiotic administration in the treatment of mastitis in ewes and (b) to assess the potential importance of the timing of the initiation of the therapeutic regime on the outcome of the treatment. The ewes were allocated at random into three equal groups; intramammary inoculation with a Staphylococcus simulans isolate was performed, and clinical mastitis developed. The ewes in groups T1 (n = 6) and T2 (n = 6) were treated by the intramammary administration of ampicillin and dicloxacillin (two administrations with a 12-h interval). The ewes in group T3 (n = 6) were treated by the intramuscular injection of ampicillin and dicloxacillin (0.75 mL per 10 kg bodyweight, three injections with a 24-h interval). In the ewes in groups T1 and T3, treatment started immediately when the clinical signs of mastitis were first detected during the periodic examination of the ewes; in the ewes in group T2, treatment started 24 h after the clinical signs of mastitis were first detected. The animals were monitored clinically; mammary secretion samples were collected for bacteriological and cytological examinations. The median duration of the clinical signs was 4.75, 7.13, and 4.75 d for T1, T2, and T3; significant differences in clinical severity between the groups were seen until the 7th day post-treatment. The median duration of bacterial recovery was 3.25, 8.00, and 8.00 d for T1, T2, and T3; significant differences in the frequency of bacterial recovery between the groups were seen until (64.1%, 94.9%, and 96.2% of the samples) and after (2.9%, 16.7%, and 11.8%) the 7th day post-treatment. The median period required for the complete cure (clinical, bacteriological, and cytological) was shorter in the T1 than in the T2 and T3 ewe groups: 20.0, 32.0, and 24.5 d, respectively. The findings cover a gap in the available literature regarding the treatment of clinical mastitis in ewes. Early treatment resulted in the improved cure of the infection. The comparison of the intramammary and injectable routes for antibiotic administration indicated some benefit for the former, primarily in the post-treatment somatic cell counts. © 2022 by the authors

Use of proteomics in the study of mastitis in ewes

The objective of this review is to describe the usage and applicability of proteomics technologies in the study of mastitis in ewes. In ewes, proteomics technologies have been employed for furthering knowledge in mastitis caused by various agents (Staphylococcus aureus, Staphylococcus chromogenes, Mannheimia haemolytica, Streptococcus uberis, Mycoplasma agalactiae). Studies have focused on improving knowledge regarding pathogenesis of the infections and identifying biomarkers for its diagnosis. Findings have revealed that ewes with mastitis mount a defence response, controlled by many proteins and over various mechanisms and pathways, which are interdependent at various points. Many proteins can participate in this process. Moreover, as the result of proteomics studies, cathelicidins and serum amyloid A have been identified as proteins that can be used as biomarkers for improved diagnosis of the disease. In the long term, proteomics will contribute to improvements in the elucidation of the pathogenesis of mastitis. Further in-depth investigations into the various proteomes and application of new methodological strategies in experimental and clinical studies will provide information about mastitis processes, which will be of benefit in controlling the disease. Improvement of diagnostic techniques, establishment of prognostic tools and development of vaccines are key areas for targeted research. © 2019 by the authors. Licensee MDPI, Basel, Switzerland

Treatment of bacterial respiratory infections in lambs

Objective of the present paper is to discuss treatment of bacterial respiratory infections in lambs. This should aim to control clinical signs, as well as to limit lesions in the lungs of the affected animals, and requires immediate action with mainly antimicrobial agents effective against the causal bacteria. In clinical practice, correct identification of affected lambs is important for administration of the appropriate treatment regime. Fluoroquinolones, tilmicosin, tulathromycin, chlortetracycline, doxycycline and oxytetracycline are effective against both Mannheimia haemolytica and Mycoplasma, which are the major causal agents of respiratory infections of lambs. Simultaneous administration of non-steroid anti-inflammatory drugs is also recommended. All lambs with clinical signs must undergo the full treatment schedule. The potential value of a metaphylactic treatment in clinically healthy lambs, within flocks with affected animals, should be assessed on a case-by-case basis. Treatment protocols of the disease should always include management changes in the flock to eliminate factors that contribute to development of the disease. © 2019 Elsevier B.V

Predisposing factors for bacterial mastitis in ewes

Objective of this review paper is the appraisal of predisposing factors for bacterial mastitis in ewes. Factors that predispose ewes to mastitis can be classified into non-animal-related factors (environmental and climatological factors, housing, nutrition, milking practices) and animal-related factors (anatomic, genetic, litter size—ethological factors, number and stage of lactation period, health problems). There are clear management—environment—animal interactions in mastitis development in ewes, which underline its multifactorial nature. Research and studies regarding risk factors are important, in order to develop strategies for their elimination, control or correction. Control measures for bacterial mastitis, which attempt to eliminate predisposing factors for infection, can thus be developed and implemented. © 2019 Blackwell Verlag Gmb

Ultrasonographic examination of the udder in sheep

Objective of the paper is to review work relevant to ultrasonographic examination of the udder of ewes. Udder structures that can be readily imaged ultrasonographically (B-mode or Doppler examination) are mammary parenchyma, the gland cistern, the lactiferous ducts, the mammary vessels, the teat and the supramammary lymph nodes. Conventional diagnostic approaches for mastitis (i.e., combination of clinical, bacteriological and cytological examinations) provide a good means for diagnosis of mastitis; hence, in diagnosis of mastitis, use of ultrasonographic examination has, in general, an ancillary role, for example during investigation of cases, in which clinical diagnosis alone can prove of little help, e.g., in animals with small-sized, deep mammary nodules. The technique can be used at the end of a lactation period as part of routine udder examination performed at that point, which would provide additional useful information, e.g., regarding presence of abcesses or of increased quantity of fibrous tissue. Further, estimation of the dimensions of gland cistern of ewes in a flock would support decisions regarding milking frequency to be applied. Finally, examination of the teat can provide indications regarding optimising use of the milking machine by applying the appropriate settings. © 2016 Elsevier B.V

Vaccination against Bacterial Mastitis in Sheep

The objective of this review is to discuss the application of vaccination for the prevention of bacterial mastitis in ewes, performed within the frame of health management schemes in sheep flocks. Mastitis is a multi-faceted infection, caused most often by staphylococci; hence, special emphasis is given to staphylococcal mastitis, also given that most relevant studies refer to vaccinations against that infection. Studies regarding various vaccines have been performed; most studies refer to vaccination by using a vaccine making use of cell-free surface polysaccharides in various vehicles, bacterial unbound cells or bacterial cells embedded in their biofilm matrix. Vaccination against mastitis should be better performed during the final stage of pregnancy to allow protection of ewes from lambing and should be considered as one of many control measures for the prevention of the disease. The expected benefits of mastitis vaccination in sheep flocks include the following: (a) reduced incidence risk of clinical and subclinical mastitis, (b) reduced somatic cell counts, optimum chemical composition, absence of staphylococci in milk, (c) increased milk production, (d) reduced dissemination of mastitis-causing pathogens and (e) reduction of antibiotic use in flocks. © 2022 by the authors

Anti-staphylococcal biofilm antibodies in ewes and association with subclinical mastitis

Objective of the present work was the investigation of anti-poly-N-acetyl b-1,6 glucosamine (PNAG) staphylococcal antibodies in ewes and the study of factors that may be associated with these. During a field investigation in subclinical mastitis in Greece, milk samples for bacteriological and cytological examination for detection of staphylococcal mastitis and blood samples for detection of anti-PNAG antibodies were collected from 355 ewes in 71 flocks. Prevalence of seropositivity was higher among ewes vaccinated against staphylococcal mastitis (0.750) than non-vaccinated ones (0.458). Mean antibody titres in samples from vaccinated ewes (13.64) were significantly higher than in samples from non-vaccinated ones (7.39). There was no association between identity of staphylococcal isolates recovered from milk samples and antibody titres in blood samples from respective ewes. Among vaccinated ewes, there was correlation (r = 0.922) between total number of genes relevant to biofilm-formation in mastitis staphylococcal isolates and antibody titres in blood samples from respective ewes; further, isolates from ewes with seropositive samples had higher median number of genes (4) than isolates from ewes with seronegative samples (3). In a multivariable mixed-effects model, vaccination emerged as the only significant factor for the prevalence of seropositivity of anti-PNAG antibody titres; when only unvaccinated ewes were included in the model, no factor was found of significance for that prevalence. © 2019 Elsevier B.V