G.C. Fthenakis

Prevalence and aetiology of subclinical mastitis in ewes of Southern Greece

In a field investigation of ovine mastitis in eight flocks in Southern Greece, a population of 760 dairy ewes was monitored during lactation. The prevalence of subclinical mastitis was 4.5% on the 1st sampling (at weaning of lambs), 11.2% on the 2nd sampling (2 to 3 weeks later) and 16.9% on the 3rd sampling (6 to 8 weeks after the second sampling). Although the prevalence of subclinical mastitis increased as the lactation period advanced, the risk rate of the disease decreased. Coagulase-negative staphylococci (Staphylococcus epidermidis, Staph. simulans, Staph. chromogenes, Staph. xylosus) were the main causal agents of the disease, but Staph. aureus, streptococci, Bacillus spp., Escherichia coli, Pasteurella haemolytica and Actinomyces pyogenes were also isolated from cases of subclinical mastitis. Of the 1084 milk samples collected, somatic cell counts more than 1.0 × 106 cells/ml were found in 97 (8.9%); 64 were bacteriologically positive, but 33 bacteriologically negative.

The effect of experimentally induced subclinical mastitis on milk yield of ewes and on the growth of lambs.

In each of two experiments, subclinical mastitis was induced by inoculating both mammary glands of Welsh-Mountain and Dorset-Horn ewes with a coagulase-negative staphylococcus; groups of control ewes were also included. After inoculation, the somatic cell counts of milk of the inoculated ewes increased (P less than 0.01) and the milk yield decreased (P less than 0.01). The lambs of the inoculated ewes had a poorer growth than lambs of the control ewes (P less than 0.01).

The past, present and future in scaffold-based tendon treatments

Tendon injuries represent a significant clinical burden on healthcare systems worldwide. As the human population ages and the life expectancy increases, tendon injuries will become more prevalent, especially among young individuals with long life ahead of them. Advancements in engineering, chemistry and biology have made available an array of three-dimensional scaffold-based intervention strategies, natural or synthetic in origin. Further, functionalisation strategies, based on biophysical, biochemical and biological cues, offer control over cellular functions; localisation and sustained release of therapeutics/biologics; and the ability to positively interact with the host to promote repair and regeneration. Herein, we critically discuss current therapies and emerging technologies that aim to transform tendon treatments in the years to come.

Treatment and Control of Peri-Parturient Metabolic Diseases: Pregnancy Toxemia, Hypocalcemia, Hypomagnesemia

The paper reviews treatment and control of pregnancy toxaemia, hypocalcaemia, hypomagnesaemia, the important peri-parturient diseases of small ruminants. Treatment of pregnancy toxemia benefits from early instigation, ie, upon timely diagnosis and is based on administration of energy sources to sick animals. Removal of fetuses, by induced parturition or caesarean section, should also be carried out. Individual cases within a farm require close monitoring of other animals and measures to avoid development of further clinical cases. Treatment of hypocalcemia is based on administration of calcium solution. Finally, hypomagnesemic animals need urgent treatment with calcium and magnesium solutions.

Health management of ewes during pregnancy

The objectives of health management of ewes during pregnancy are as follows: (i) successful completion of pregnancy at term, (ii) birth of healthy and viable lambs, with optimal birth and potential weaning bodyweight, (iii) optimum milk production during the subsequent lactation and (iv) improved management in relation to drug residues in animal products. Knowledge of the physiological background of pregnancy in ewes: changes, mechanisms and interactions, during pregnancy is important for the overall health management of ewes during pregnancy. Health management of pregnant ewes includes diagnosis of pregnancy and evaluation of the number of foetuses borne, which will support strategies for subsequent management of the flock. Nutritional management of ewes depends upon the stage of lactation and specifically aims to (i) prevention of pregnancy toxaemia and other metabolic diseases during the peri-partum period, (ii) formation of colostrum in appropriate quantity and quality, (iii) production of lambs with normal future birth bodyweight and (iv) support of increased milk yield during the subsequent lactation. At the end of lactation, udder management of pregnant ewes includes its clinical examination, culling of ewes considered unsuitable for lactation and, possibly, the intramammary administration of antibiotics; objectives of that procedure are (i) to cure infections which have occurred during the previous lactation and (ii) to prevent development of new mammary infection during the dry period. Management of abortions includes the correct and timely diagnosis of the causative agent of the disorder, as well as the strategic administrations of chemotherapeutic agents, aiming to prevent abortions in flocks with confirmed infection with an abortifacient agent, especially if no appropriate vaccinations had been carried out before the mating season. During the final stage of pregnancy, health management of ewes includes administration of appropriate anthelmintic drugs, aiming to eliminate gastrointestinal helminthes (thus, increasing production output of ewes) and preventing the built-up of parasitic burdens in the environment (thus, reducing infection of lambs during their neonatal period). Vaccinations of pregnant ewes aim to protect these animals, as well as their offspring, especially against diseases which are a frequent cause of neonatal mortality (e.g., clostridial infections). Health management also aims to prevent the main metabolic disorders of pregnant ewes (i.e., pregnancy toxaemia and hypocalcaemia), as well as to monitor flocks for development of these disorders. Health management of pregnant ewes is completed with application of husbandry practices before the start of the lambing season. Finally, in some cases, health management may include induction and synchronisation of lambings, which is a management or therapeutic procedure.

The effect of inoculation of coagulase-negative staphylococci into the ovine mammary gland.

In each of two experiments, the effect of inoculation of coagulase-negative staphylococci (C-NS) into the ovine mammary gland was studied. In the first experiment, ewes were inoculated with one of six different C-NS to study differences in the pathogenicity of the isolates. In the second, ewes were inoculated with Staphylococcus simulans to study the sequential histopathological features of the infection. The existence of subclinical mastitis was established by consistent isolation of bacteria, the demonstration of high somatic cell counts in milk and an inflammatory reaction in biopsy samples of mammary tissue. A variation in the pathogenicity of the different isolates was evident: one Staph. chromogenes isolate caused clinical mastitis, four Staph. simulans isolates caused subclinical mastitis and one Staph. xylosus isolate caused a transient increase of somatic cell counts. Neutrophilic infiltration was the predominant histopathological finding. Lysis of neutrophils, destruction of alveoli and, in late stages of the infection, infiltration of lymphocytes and fibrous tissue proliferation were also noted.

Efficacy of moxidectin against sarcoptic mange and effects on milk yield of ewes and growth of lambs.

Forty-eight dairy ewes and 45 lambs naturally infested with sarcoptic mange, were divided into three equal groups and treated with moxidectin 1% inj. sol. at a dose rate of 0.2 mg moxidectin kg(-1) bodyweight once or twice ten days apart. During the study, the skin lesions were scored and the number of mites recovered in facial skin scrapings from the animals were recorded. Moxidectin was found to be effective against ovine sarcoptic mange, when given twice; the percentage reduction of mites was 100% (p < 0.0001) and the skin lesions disappeared completely (p = 0.0001). In sheep treated once only, the percentage reduction of mites varied from 75% to 92%. Treated ewes produced up to 22.4% more milk than the infested ones (p = 0.0001). Treated lambs had up to 15% greater final weight and up to 23.7% more growth than infested controls (p = 0.0001). It is concluded that two injections of moxidectin 1% inj. sol. at a dose rate of 0.2 mg kg(-1) bodyweight, given ten days apart, were effective against ovine sarcoptic mange. Furthermore, it is considered that sarcoptic mange adversely affects the production of the infested animals.

Ultrasonographic appearance of clinically healthy testicles and epididymides of rams

The clinically healthy testicles and epididymides of 31 rams were imaged inside and outside the breeding period, by using a real time ultrasound scanner. A scanning technique based on multiple imaging planes from the caudal and the lateral surface of the genitalia was employed. Optimum imaging was achieved by using a 6.0 MHz frequency sector transducer. The testicular parenchyma appeared homogeneous with a coarse medium echo-pattern. The mediastinum testis was present in 87% of rams and 77% of testicles; its median echogenicity score was 2 (range: 0-3) among rams aged 13 months or older and 1 among rams aged less than 13 months (P = 0.001). The tail of the epididymis was always clearly visible; it appeared less echoic than the testicular parenchyma and with a heterogeneous structure. The epididymal body was not visible, whilst the epididymal head was consistently partially imaged. The pampiniform plexus was clearly imaged as a dome-shaped structure masking the upper part of the head of the epididymis. The scrotal septum was seen in lateral sonograms as a highly echogenic line between the testicles. The scrotal skin formed a thick hyper-echoic peripheral structure.

Incidence risk and aetiology of mammary abnormalities in dry ewes in 10 flocks in Southern Greece

In a field investigation of 10 flocks in Southern Greece, 3367 dairy ewes were examined twice, in order to estimate the incidence risk and the aetiology of mammary abnormalities during the dry-period. Abnormal secretion, lumps, nodules, diffuse hardness, abscesses and cysts were the abnormalities detected. The cumulative incidence of mammary abnormalities during the dry-period was 5.1% (95% confidence interval: 4.4-5.8%); 47% of the cases detected developed during the first three weeks after cessation of lactation. Despite variation in the flock size, there was no between-flock variation in the risk of a ewe developing mammary abnormalities. Staphylococci (Staphylococcus aureus and coagulase-negative isolates) were the most frequently isolated bacteria from mammary samples; Actinomyces pyogenes, Clostridium perfringens, streptococci and Escherichia coli were also isolated. Resistance was encountered among the staphylococcal isolates.

Phylogenetic analysis of strains of Orf virus isolated from two outbreaks of the disease in sheep in Greece.

BackgroundAlthough orf is endemic around the world, there are few descriptions of Orf virus strains and comparisons of these strains. We report the sequence and phylogenetic analysis of the partial B2L gene of Orf virus from two outbreaks of the disease in Greece. The first was an outbreak of genital form of the disease in a flock imported from France, whilst the second was an outbreak of the disease in the udder skin of ewes and around the mouth of lambs in an indigenous flock.ResultsPhylogenetic analysis was performed on a part (498 bp) of the B2L gene of 35 Parapoxvirus isolates, including the two Orf virus isolates recovered from each of the two outbreaks in the present study. This analysis revealed that the maximum nucleotide and amino-acid variation amongst Orf virus strains worldwide (n = 33) was 8.1% and 9.6%, respectively. The homology of the nucleotide and amino-acid sequences between the two Greek isolates was 99.0% and 98.8%, respectively. The two Greek isolates clustered only with Orf virus strains.ConclusionsWe suggest that there can be differences between strains based on their geographical origin. However, differences in the origin of strains or in the clinical presentation of the disease may not be associated with their pathogenicity. More work is required to determine if differing clinical presentations are linked to viral strain differences or if other factors, e.g., flock immunity, method of exposure or genetic susceptibility, are more important to determine the clinical presentation of the infection.