Nektarios D. Giadinis

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.

Evaluation of Precision Xceed® meter for on-site monitoring of blood β-hydroxybutyric acid and glucose concentrations in dairy sheep

The accuracy of the Precision Xceed® hand-held meter as an on-site method for measuring blood β-hydroxybutyric acid (BHBA) and glucose concentrations, for the diagnosis of pregnancy toxemia and ketosis in dry and lactating dairy sheep, was assessed. Five to eight hours after the start of the morning feed, blood was collected once from 193 clinically healthy sheep (143 dry and 50 lactating). BHBA and glucose analyses were performed with serum in the laboratory, and with whole blood with the Precision Xceed®. Overall, BHBA and glucose determinations by the two methods were not statistically different (P>0.05). Strongly significant positive correlations were found for glucose and BHBA concentrations between the Precision Xceed® and laboratory results (r=0.76, n=150, P<0.01 and r=0.99, n=193, P<0.01, respectively). The Precision Xceed® was highly sensitive (98.6%) and specific (98.2%), and had excellent test agreement for the detection of pregnancy toxemia and ketosis.

Surgical treatment of coenurosis (gid) in sheep

During the past six years 623 cases of coenurosis (gid) in sheep have been treated surgically. Cysts were removed successfully from 573 of them (92 per cent) and 517 (83 per cent) were able to return to their flocks, although 36 showed no clinical improvement. In 37 cases, the cyst could not be localised, and postmortem examinations showed that in nine cases the cyst was in the brainstem, and in 28 cases it was in the cerebellum. Fifty-six cases deteriorated gradually after surgery and in these cases more than one cyst was found postmortem. Thirteen cases died during surgery.

PRNP genetic variability and molecular typing of natural goat scrapie isolates in a high number of infected flocks

One hundred and four scrapie positive and 77 negative goats from 34 Greek mixed flocks were analysed by prion protein gene sequencing and 17 caprine scrapie isolates from 11 flocks were submitted to molecular isolate typing. For the first time, the protective S146 variant was reported in Greece, while the protective K222 variant was detected in negative but also in five scrapie positive goats from heavily infected flocks. By immunoblotting six isolates, including two goat flockmates carrying the K 222 variant, showed molecular features slightly different from all other Greek and Italian isolates co-analysed, possibly suggesting the presence of different scrapie strains in Greece.

Ovine and caprine brucellosis (Brucella melitensis) in aborted animals in Jordanian sheep and goat flocks.

Two hundred and fifty five biological samples were collected from 188 animals (81 sheep and 107 goats) during the lambing season from September 2009 to April 2010 from the Mafraq region of Jordan. Sampled animals belonged to 93 sheep and goat flocks that had abortion cases in the region. One hundred and seven (41.9%) biological samples were positive for the omp2 primers that were able to identify all Brucella species in the collected samples which were obtained from 86 aborted animals (86/188 = 45.7%). Using the B. melitensis insertion sequence 711 (IS711) primers on the 107 omp2 positive samples, only 61 confirmed to be positive for B. melitensis. These positive samples were obtained from 28 sheep and 33 goats. The prevalence rate of B. melitensis was 27.1% (51/188) among aborted animals. For differentiation between vaccine strain and field strain infection, polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method using PstI endonuclease enzyme was used. Vaccination with Rev-1 in the last year (OR = 2.92, CI: 1.1–7.7) and grazing at common pasture (OR = 2.78, CI: 1.05–7.36) were statistically significant (P ≤ .05) risk factors positively associated with the occurrence of brucellosis in sheep and goat flocks.

Ovine and caprine toxoplasmosis ( Toxoplasma gondii ) in aborted animals in Jordanian goat and sheep flocks

Two hundred and fifty-five biological samples (106 aborted foetal tissue samples and 149 blood samples from aborted sheep and goats) were collected from 188 animals during the lambing season from September 2009 to April 2010 from the Mafraq region of Jordan. The sampled animals belonged to 93 goat and sheep flocks that had cases of abortion. A total of 169 (66.3%) biological samples were collected from sheep and 86 (33.7%) from goats. Seventy-six (29.8%) biological samples (45 blood and 31 tissue samples) were positive for Toxoplasma gondii by PCR assay. The positive samples were obtained from 43 sheep and 23 goats. The overall toxoplasma-specific prevalence rate was 35.1% (66/188). Forty flocks (43%) had at least one T. gondii PCR-positive animal. The risk factors related to flock health status and farm management that are hypothesized to be associated with T. gondii PCR positivity were also assessed using multiple logistic regressions. The presence of cats (OR = 4.74), a large flock size (OR = 2.76) and the method of disposing the aborted foetuses (OR = 3.77) were all statistically significant (P < 0.05) risk factors that were positively associated with toxoplasma positivity in goat and sheep flocks.

Selenium and vitamin E effect on antibody production of sheep vaccinated against enzootic abortion (Chlamydia psittaci)

The effect of selenium (Se) and vitamin E (vit E) on antibody production of sheep vaccinated against Chlamydia psittaci (ovis) was investigated. Thirty-two sheep, one year old, seronegative to Chlamydia infection, vaccinated against enterotoxemia and dewormed were used. Injectable sodium selenite (0.1 mg/kg b.w.) was given twice to animals of the first group (gSe), with a three week interval. The sheep of the second group (gE) received 1 g vit E each orally, six times at weekly intervals. The animals of the third group (gSeE) were given Se and vit E in doses and routes of administration as in gSe and gE. The animals of the fourth group served as controls (gC) and injected normal saline. The first vaccination was made at the time that the second Se injection was given. Revaccination was made two weeks later. The experiment lasted 29 weeks. The results indicated that Se alone led to a significant increase of Chlamydia antibody response (P < 0.05), but not when it was given in combination with vit E. Animals that received vit E (gE) had much lower titres, just above of those of the controls.

Evidence of Schmallenberg virus circulation in ruminants in Greece.

During March 2013, we investigated the presence and the levels of Schmallenberg virus (SBV) circulation in three dairy cow herds and three sheep flocks in Central Macedonia, Greece. In two cow herds, a high number of abortions had been observed during the winter. Six bulk-tank milk samples and 147 individual sera were screened for SBV-specific antibodies by ELISA. Positive reactions were obtained from 5 out of 6 bulk-tank milk samples, 58 out of 90 sera from the 3 cow herds, and 2 sera from 2 of the 3 sheep flocks. Twenty-two ELISA-positive sera were tested by serum neutralization test (SNT). SNT confirmed the presence of neutralizing antibodies against SBV in all samples tested, with titers ranging between 1:32 and ≥1:256. No neutralizing antibodies against Akabane virus (AKAV) or Shamonda virus (SHAV) were detected, indicating that neutralizing antibodies against SBV do not cross react with AKAV or SHAV in SNT. ELISA testing of bulk-tank milk samples proved to be convenient and reliable. None of the tested sera was found positive for SBV by real-time RT-PCR, indicating that the sampling was conducted past the viremia stage. This is the first report of SBV circulation in Greece.

Perspectives of a scrapie resistance breeding scheme targeting Q211, S146 and K222 caprine PRNP alleles in Greek goats

The present study investigates the potential use of the scrapie-protective Q211 S146 and K222 caprine PRNP alleles as targets for selective breeding in Greek goats. Genotyping data from a high number of healthy goats with special emphasis on bucks, revealed high frequencies of these alleles, while the estimated probabilities of disease occurrence in animals carrying these alleles were low, suggesting that they can be used for selection. Greek goats represent one of the largest populations in Europe. Thus, the considerations presented here are an example of the expected effect of such a scheme on scrapie occurrence and on stakeholders.

Coenurosis in a beef cattle herd in Greece

toscoleces. Cysts of C cerebralis were identified according to Clapham and Peters (1941) and Wardle and McLeod (1952). The cysts were large, white, translucent structures, and had numerous protoscoleces attached to the wall. Microscopic examination of protoscoleces showed that each scolex had a double ring of 30 rostellar hooks. The large hooks were 150 to 160 μm long and the small ones 100 to 110 μm long (Fig 3). The most probable explanation for the development of coenurosis might be that the calves were infected after birth, acquiring the parasite’s eggs from the faeces of infected dogs and wild carnivores, as they were raised in a mountain area. This is supported by the fact that the clinical signs were first noted when the animals were six or seven months old, the approximate time a cyst needs to reach maximum size (Radostits and others 2000). This report describes the first proven cases of coenurosis in beef calves in Greece. According to the literature, coenurosis has been diagnosed in two calves in the UK (Greig and Holmes 1977); those authors also refer to six other cases in the UK. Coenurosis has also been diagnosed in a calf in Japan (Yoshino and Momotani 1988) and in a cow in Italy (Bozzetta and others 2003); a C cerebralis cyst has also been found in the retained placental membrane of a cow in India (Tirgari and others 1987). The clinical signs of the two affected calves suggested a space-occupying lesion of the central nervous system. The cysts were located in the lateral ventricles, as in the case in Coenurosis in a beef cattle herd in Greece