A prospective epidemiological, clinical, and clinicopathologic study of feline leukemia virus and feline immunodeficiency virus infection in 435 cats from Greece

Feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV) are retroviruses causing significant morbidity and mortality in cats. The aim of this study was to describe the epidemiological, clinical and clinicopathologic aspects of FeLV and FIV infections in different populations of cats in Greece, including client-owned cats, stray cats and cats who live in catteries. A total of 435 cats were prospectively enrolled. Serological detection of FeLV antigen and FIV antibody was performed using a commercial in-house ELISA test kit. The results showed that 17 (3.9 %) and 40 (9.2 %) of the 435 cats were positive for FeLV antigen and FIV antibody, respectively, whereas 5 (1.1 %) had concurrent infection with FeLV and FIV. Factors that were associated with FeLV antigenemia, based on multivariate analysis, included vomiting, rhinitis, infection with FIV, neutropenia, decreased blood urea nitrogen and increased serum cholesterol and triglyceride concentrations. Factors associated with FIV seropositivity included male gender, older age, outdoor access, weight loss, fever, gingivostomatitis, skin lesions and/or pruritus and hyperglobulinemia. Various clinical signs and laboratory abnormalities were found to be significantly associated with retroviral infections, suggesting that current guidelines to test all sick cats should be followed, taking into particular consideration the high-risk groups of cats found in this study.

A cross-sectional study of the seroprevalence and flock-level factors associated with ovine and caprine brucellosis in southeastern Iran

This cross-sectional study was conducted to estimate seroprevalence and to identify flock-level factors associated with seropositivity to brucellosis in small ruminants in Kerman province, southeastern Iran. In October-November 2011, serum samples were randomly collected from 1767 sheep and 1233 goats, older than 18 months, from 300 flocks. The sera were initially screened for the presence of anti-Brucella antibodies using the Rose-Bengal test; those found to be positive were then examined by Wright and 2-mercaptoethanol Brucella agglutination tests. A questionnaire was used to collect data on flock-level factors likely associated with the within flock seroprevalence of brucellosis. The associations were statistically evaluated for significance in multivariable logistic models. Sixty three flocks (21.00%; 95% CI: 16.80-26.60) had at least one seropositive animal. The mean within-flock seroprevalence was 3.10% (95% CI: 2.60-3.90). The presence of newly purchased animals (OR=3.42; 95% CI: 1.35-8.65) was significantly associated with seropositivity. Our findings highlight the role of animal movement among flocks in the epidemiology of brucellosis in this region. Thus, a control program for brucellosis in the region is suggested to impose appropriate restrictions on animal trade and improve knowledge of livestock owners about quarantine principles for newly purchased animals.

Oestradiol concentration as a predictor of ovarian response in FSH stimulated ewe-lambs

We investigated the prediction of ovarian response using oestradiol determination, in 37 gonadotrophin stimulated Karagouniko ewe-lambs. Ovarian stimulation was induced by serial FSH administrations, and laparoscopic follicular aspiration (OPU) was conducted 12h after the last FSH injection. Oestradiol concentration was assessed in six blood samples collected prior to each FSH injection and in one sample collected prior to follicular aspiration. According to ovarian response, ewe-lambs were allotted in three groups: good, L1 (n=17); moderate, L2 (n=10); and poor, L3 (n=10). Based on the data obtained from 28 (75%) randomly selected animals, a statistical model was designed and tested on the remaining nine lambs for its ability to predict the probability of good ovarian response. From the 2nd sample, oestradiol concentration was constantly higher in group L1 in comparison with L3 lambs (all p-values for the contrasts were </=0.02), while this difference between L1 and L2 lambs was significant only in the 6th and 7th sample (both p<0.005). Using as criterion the oestradiol concentration of the 6th sample, the statistical model predicted all lambs that did not belong to group L1 and three of four lambs that belonged to group L1. Our results indicate that the moderate- and poor-donors could be safely predicted on the basis of oestradiol concentration 12h prior to the scheduled follicular aspiration. Moreover, poor-donors could be identified--and rejected from further manipulations--on the basis of their inability to exhibit increased oestradiol levels in response to gonadotrophin stimulus.

Age, FSH Dose and Follicular Aspiration Frequency Affect Oocyte Yield from Juvenile Donor Lambs

Experiments were conducted to determine the effects of lamb age, frequency of follicular aspirations, and hormone stimulation by fixed or variable FSH dose, on the number of collected oocytes and their maturational competence. In trial 1, the characteristics of follicular population (number and diameter of follicles) were studied in 40 lambs which were slaughtered at the age of 30 days (S1), 42 days (S2), 60 days (S3) and 5-6 months (S4), each n = 10. In trial 2, 27 lambs were divided into four groups. group MF lambs (n = 6) had follicular aspiration (OPU) in four monthly intervals commencing from the age of 8-9 weeks (sessions MF1, MF2, MF3 and MF4). In groups SF2, SF3 and SF4 (each n = 6), OPU was conducted once during the 12-13, 16-17 and 20-21 week of age, respectively. Ovarian stimulation was conducted with fixed FSH dose (3.52 mg/animal). In trial 3, 10 lambs (group MV) were treated as those of group MF apart from the FSH dose, which was administered according to the body weight in a dose of 0.27 mg/kg. The number and the size of follicles, the number and the quality of collected oocytes and the maturational competence of the oocytes were compared between and within groups. In trial 1, the total number and the number of small follicles were greater in groups S1 and S2 compared with those of S3 and S4 (p < 0.01). Similarly, the follicular population was greater in group MF1 than in group SF3 (p < 0.01). In sessions MF2, MF3, MV2, MV3 and MV4, more oocytes were collected in comparison with those from the respective once-aspirated age mates (groups SF2, SF3 and SF4). In total, more (p = 0.02) oocytes per donor were collected from group MV (15.2 +/- 5.5) than from group MF (9.0 +/- 3.2). An absolute maturational failure was observed in oocytes collected from groups SF2 and SF3. Maturational competence varied between 16.7% and 58.3% (p = 0.017) among sessions of group MF, but it was more uniform among sessions of group MV (range 12.5-42.9%, p > 0.05). Our results indicate that firstly, the number and the quality of harvested oocytes from juvenile lambs can be much improved if follicular stimulation regime is adjusted to the body weight. Secondly, in terms of follicular population and oocyte quality, 3 and 4-month-old lambs are naturally bad oocyte donors, but this characteristic can be reversed by a previous follicular ablation.

Application of a semi-dependent latent model in the Bayesian estimation of the sensitivity and specificity of two faecal culture methods for diagnosis of paratuberculosis in sub-clinically infected Greek dairy sheep and goats

In this study, we compared the frequency of isolation of Mycobacterium avium subsp. paratuberculosis (MAP) from faecal samples grown on Herrold's egg-yolk medium (HEYM) or on Lowenstein-Jensen (LJ) medium and estimated the sensitivity (Se) and specificity (Sp) of the methods separately in sub-clinically infected Greek dairy sheep and goats, using latent-class models and Bayesian estimation procedures. Faecal and blood samples were collected from 400 animals > or =1 year old in April-May 2002. The HEYM supported growth of MAP better than the LJ method and their agreement was very poor (weighted kappa=0.062 (95% CI: -0.098, 0.222)). There was no evidence of dependence between the Ses whereas the Sps were positively correlated. Thus, a semi-dependent model that assumed independence of Ses and accounted for the dependence of Sps was adopted. Under this model, the parallel interpretation of the results of the two methods gave median estimates and 95% credible intervals (CrIs) for Se(par), Sp(par) of 15% (CrIs: 3, 45%), 96% (92, 98%) in sheep and 16% (6, 36%) and 97% (94, 99%) in goats.

Bayesian estimation of sensitivity and specificity of serum ELISA and faecal culture for diagnosis of paratuberculosis in Greek dairy sheep and goats

Latent class models were used to estimate the sensitivity (Se) and the specificity (Sp) of a serum ELISA and a faecal culture (FC) method for the diagnosis of paratuberculosis separately, in sheep and goats. The estimates were obtained by a Bayesian method. Possible dependence of diagnostic errors was investigated by comparing models where independence was assumed to models allowing for conditional dependence given the true disease status. ROC analysis for the serum ELISA was also performed and optimized cut-off values based on the misclassification cost term were determined. No evidence of conditional dependence was found. Assuming independence, posterior medians and 95% credible intervals for the Se(ELISA), Sp(ELISA), Se(FC) and Sp(FC), were 63% (42, 93%), 95% (90, 98%), 8% (2, 17%) and 98% (95, 100%) in goats and 37% (10, 80%), 97% (93, 99%), 16% (2, 48%) and 97% (95, 99%) in sheep. AUC was calculated 0.702 for sheep and 0.847 for goats. For the serum ELISA, there is need of species- and purpose-specific cut-off selection. For instance, with 20% prevalence situation and assuming equal and five-fold cost of a false negative to a false positive test result, the optimal cut-off is 0.3 and 0.05 in sheep, respectively, while it is 0.6 and 0.1 in goats, respectively. Serum ELISA performed better in goats than in sheep. Lowering the cut-off, in relation to the one recommended by the manufacturer, improved Se(ELISA) without seriously compromising Sp(ELISA), in either species.

The association of sub-clinical paratuberculosis with the fertility of Greek dairy ewes and goats varies with parity

Our cross-sectional study investigated the association of sub-clinical Mycobacterium avium subsp. paratuberculosis (MAP) infection with failing to produce a live offspring the season of lambing/kidding (November 2001 to January 2002) before testing (in April-May 2002), in four dairy-sheep and/or goat flocks in Greece (369 animals >or=1.5-year-old). From each selected animal 10 ml of blood and 10 g of feces from the rectum were obtained. The harvested sera were tested for antibodies to MAP with a commercial ELISA test kit; the feces were cultured on Herrold's egg-yolk medium supplemented with mycobactin J and antibiotics. An animal was considered sub-clinically infected when found either seropositive or culture positive. The true prevalence of sub-clinically infected animals, adjusted for the sensitivity and specificity of the parallel testing, was 14% (0.1-28%) and 35.9% (9.2-62.7%) in sheep and goats, respectively. The association of fertility of sheep and goats with sub-clinical paratuberculosis was investigated in random-effects logistic models. Sub-clinically infected animals (compared to uninfected) had OR for live offspring the previous year of 5.4 for parity <4, OR=0.05 for parity >6, and a non-significant OR for the middle parity category.

Prevalence of BVDV infection in Greek dairy herds

Thirty-nine Greek dairy herds, totalling 6333 cattle, enrolled in a voluntary bovine viral diarrhoea virus (BVDV) eradication programme based on the identification and removal of persistently infected (PI) animals. The aim of this study was to estimate the prevalences of BVD antigen-positive and PI animals, and investigate the significance of the associations between the prevalence estimates and herd size. Initially, all animals were bled and examined for BVDV, using an antigen ELISA. A second sample was collected from the positive animals, after a period of at least three weeks. Animals retested positive were classified as PI. Antigen positive and PI animals were detected in all herds. The respective mean prevalences, adjusted for the test's accuracy and the herd-clustering effect, were 14% (95%CI: 11-18%) and 1.3% (0.8-1.8%), respectively. Herd size was not associated with the prevalence of antigen-positive or PI animals.

Comparative methodology for the detection and differentiation of circulating microfilariae of Dirofilaria immitis in the dog

The sensitivities of the Knott's test (four 20-microl sediment aliquots), quantitative buffy coat capillary tube method (QBC tube, 111 microl of whole blood) and direct blood smear (DBS, 20 microl of whole blood) were evaluated for the detection of microfilaraemia in dogs. Undiluted whole blood samples taken from 70 Dirofilaria immitis antigen-positive dogs and 10 serially diluted microfilaraemic blood samples at concentrations of 400, 200, 100, 50, 25 and 12 microfilariae (mff) ml(-1) were examined. For filarial speciation, the buffy coat of QBC tubes was mixed with one drop of methylene blue-formalin solution and examined as a direct smear. In 52/70 microfilaraemic blood samples, the number of mff ranged from 12 to 321987 ml(-1) (median: 3199 ml(-1)). The diagnostic sensitivity of the Knott's test, QBC tube method and DBS in undiluted blood samples attained the 100%, 98% and 92.3% levels, respectively. Eighteen dogs tested amicrofilaraemic by all three methods. At concentrations of 400 mff ml(-1), a 100% sensitivity was found by all three methods, while at 200 mff ml(-1) the Knott's test, QBC tube and DBS were 100%, 100% and 90% sensitive, respectively. The relevant figures at 100 mff ml(-1) were 100%, 100% and 80%, at 50 mff ml(-1) 100%, 100% and 50%, at 25 mff ml(-1) 100%, 100% and 10% and at 12 mff ml(-1) 80%, 50% and 10%. At 50 and 25 mff ml(-1), the DBS was less sensitive compared to the other two methods, while at 12 mff ml(-1), only to the Knott's test. A significant correlation was found between the QBC tube method and Knott's test regarding mff speciation. Therefore, the QBC method may be considered a reliable alternative to the Knott's test for both the detection and speciation of mff in the dog.

Effect of challenge dose and age in experimental infection of pigs with encephalomyocarditis virus

Two experiments were performed to compare the severity of encephalomyocarditis virus (EMCV) infection in pigs. The pigs were challenged with the Greek myocardial strain, at different ages and with different doses. In the first experiment, nineteen susceptible pigs, 40 days old, were divided into three groups and were experimentally infected with 10(6) TCID(50), 10(4) TCID(50) or 10(2) TCID(50) of the Greek EMCV strain. In the second experiment, 10 susceptible pigs, of either 20 or 105 days, were divided into two groups according to age and were experimentally infected with 10(6) TCID(50) of the Greek EMCV strain. In addition, five piglets, each one the same age as its experimental group, were used as uninfected controls. No clinical signs were observed after infection, except a transient temperature rise in some pigs. Another important observation was the difference in mortality between groups. The survival rate of the 40-day-old pigs was inversely related to the viral dose. In these pigs, a positive association between the viral dose and the severity of macroscopical and histopathological lesions of the heart was also evident. Viral isolations from various organs of the challenged 40-day-old pigs increased with the increasing dose level. When challenged with 10(6) TCID(50) of EMCV, there was no difference in the fatality rate of the 20- and 40-day-old pigs, but none of the 105-day-old pigs died. The severity of the macroscopical and the histopathological heart lesions was inversely related to the age of the pigs. Furthermore, viral isolations from the various organs were higher in 20- and 40-day-old pigs than in the older ones. In 40-day-old pigs, neutralizing antibodies linearly increased as the dose increased. These antibodies were consistently lower in 20-day-old pigs. Viraemia, and nasal and faecal excretions were detected in all groups and lasted 1-3 days, except for the 105-day-old pigs whose symptoms lasted for an additional day.

Herd-level risk factors for subclinical Salmonella infection in European finishing-pig herds

Our objective was to find herd factors associated with pigs testing seropositive for Salmonella. Data were collected from 359 finishing-pig herds in Germany, Denmark, Greece, The Netherlands and Sweden, between 1996 and 1998. Pigs fed non-pelleted feed (dry or wet) had 2- and 2.5-times lower odds of seropositivity, compared to pigs fed pelleted feed. The protective effect of non-pelleted feed over pelleted feed may be ascribed to the structure and composition. Also, pigs that were given whey (to drink or as the liquid part of the diet) had 2.6-times lower odds to test seropositive than pigs not getting whey. Pigs produced in batches in herds with hygienic-lock facilities had >3-times lower odds for testing seropositive compared to pigs in herds where only one or neither factor was present. In herds where the caretaker(s) washed hands consistently before tending to the animals, pigs had 1.5-times lower odds of seropositivity than pigs in herds where the caretaker did not. Pigs which were able to have snout contact with pigs in neighbouring pens (because pen separations were either open or too low) had 1.7-times higher odds to test seropositive compared to pigs for which such contact was prevented. Pigs in herds recruiting from more than three supplier herds had three-times higher odds to test seropositive than pigs in herds which breed their own replacement stock or recruit from a maximum of three supplier herds.

Recovery of Salmonella enterica from seropositive finishing pig herds

The aim of this study was to assess the probability of detecting Salmonella from pen faecal samples in seropositive classified finishing pig herds. The study involved 77 herds from Denmark (20), The Netherlands (20), Greece (17) and Germany (20). The serological herd status was determined by the blood-sampling of 50 finishing pigs. Bacteriological sampling was performed by 20 pen faecal samples per herd. Over-all, 47% of the blood samples had an OD% larger than 10 and 23% larger than 40. Salmonella was isolated from 135 (9.3%) pen faecal samples in 32 herds (42%). Twenty-eight of these herds (87.5%) had a within-herd seroprevalence larger than 50% at sample cut-off OD% > 10. In our study, there was an increasing probability of recovering Salmonella with increasing within-herd seroprevalence. However, this was only a moderate correlation. A correlation coefficient of 0.62 was found between the proportion of culture positive- and seropositive samples in a herd at cut-off OD%> 10 and of 0.58 at cut-off OD% > 40. Serology is a measure of historical exposure, which may or may not correlate closely to the microbiological burden at the time of sampling. Due to the low sensitivity of culture methods, apparent 'false-positive' serological results may well represent real infections not detected by bacteriological testing. For screening purposes, serological testing provides an indication of exposure to Salmonella, which forms the basis for targeted sampling, intervention and logistic slaughter procedures.

Tick infestation of dogs in Thessaloniki, northern Greece

Ticks were collected from 249 dogs, admitted over a one-year period (1996-1997) to a Veterinary Teaching Hospital and four private veterinary practices located in the county of Thessaloniki, Greece. A total of 2812 ticks (Acari: Ixodidae) were collected, of which 2511 (89.3%) were Rhipicephalus sanguineus (Latreille) adults (1070 males, 1441 females), 156 (5.5%) R. turanicus Pomerantsev adults (35 males, 121 females), 100 (3.6%) Rhipicephalus spp. nymphs and 45 (1.6%) Rhipicephalus spp. larvae. Dogs living outdoors, in rural areas and in close proximity to farm animals, were infested with higher numbers of ticks than dogs living indoors. Tick attachment sites were recorded on 237 dogs, harbouring a total of 1711 ticks. The most heavily infested sites were, in decreasing frequency, the ear pinnae, neck, interdigital skin folds, trunk, head, ventrum, extremities and the tail. Cutaneous lesions at the attachment sites were noticed in 129 dogs and then mainly in the more severely infested animals.

Prevalence, distribution and factors associated with the presence and the potential for malignancy of cutaneous neoplasms in 174 dogs admitted to a clinic in northern Greece

One hundred and seventy-four dogs diagnosed with cutaneous neoplasms in the Animal Medical and Surgical Clinic, Faculty of Veterinary Medicine, Aristotle University of Thessaloniki, were studied. Thirty-one types of neoplasm were diagnosed, among which mast cell tumours (13.8%), hepatoid gland adenomas (9.8%), lipomas (5.7%) and histiocytomas (5.7%) were the most common. The prevalence of epithelial, mesenchymal, lymphohistiocytic and melanocytic tumours was 47.7, 40.8, 8.6 and 2.9%, respectively. Potentially malignant neoplasms were less frequently recorded than benign neoplasms. The tumours were single (80.5%) or multiple (19.5%) and located on the head and neck (18.4%), the body trunk (49.4%), the limbs (25.9%) or at multiple sites (6.3%). The factors evaluated in multivariable logistic regression models for possible association with the odds of a tumour's potential for malignancy included the age, the sex and the breed of the dog, as well as the histological type of the neoplasm. Dogs with mesenchymal tumours had two times higher odds of potential for malignancy than those with epithelial tumours. In contrast, dogs with either lymphohistiocytic or melanocytic tumours did not have increased risk of malignancy compared with dogs with epithelial tumours. The odds of tumour malignancy linearly increased with increasing age of the dog by a factor of 1.1 per year. Finally, the effect of the sex and the breed of the dog on the risk of developing cutaneous neoplasms was investigated in an age-matched case-control sample of 348 dogs by conditional logistic regression analysis. The odds of neoplasm presence were two times higher in pure bred dogs than in mongrels but did not differ between cross-breeds and mongrels.

A randomised, blinded, placebo-controlled clinical trial with allopurinol in canine leishmaniosis

A total of 45 non-uremic dogs, with clinical signs indicating leishmaniosis, entered the study. Diagnosis was confirmed by indirect immunofluorescence assay (IFA) on serum and polymerase chain reaction (PCR) on bone marrow samples. The dogs were randomly allocated into Group A (n=37) that received allopurinol (10mg/kg B.W., per os, twice daily) for 4 consecutive months, and Group B (n=8) that were placebo-treated. Clinical signs were scored just before and at monthly intervals throughout the study period, in a blinded and independent fashion. Complete blood count, serum biochemistry profile, urinalysis, lymph node and bone marrow parasitology, IFA and enzyme-linked immunosorbent assay (ELISA) serology and bone marrow PCR were carried out at the beginning and at the end of the trial. A total of three Group A and one Group B dogs died of end stage kidney disease that developed during the trial. In Group A animals that endured the trial there was a significant improvement in the general body condition, conjunctivitis, peripheral lymphadenopathy, splenomegaly, masticatory muscle atrophy, ulcerative stomatitis, epistaxis, exfoliative dermatitis, cutaneous ulcerations, blepharitis and nasodigital hyperkeratosis. The same observation was made for anemia, lymphopenia, hyperproteinemia, hyperglobulinemia, hyperphosphatemia, increased alkaline phosphatase activity and the low albumin/globulin ratio. By contrast, no improvement of any kind was seen in Group B dogs. Lymph node and bone marrow parasite numbers were significantly decreased in Group A animals. In Group B, that occurred only in the lymph nodes. Apart from remission of clinical signs and restoration to normal of clinicopathological abnormalities, allopurinol did not eliminate Leishmania organisms, as the PCR result on bone marrow was still positive in all the dogs that finished the trial.

Seroprevalence and antibiotic sensitivity of serotypes of Salmonella enterica in Greek pig herds

Blood samples were taken from 50 pigs in each of 59 farrow-to-finish production herds and from 40 pigs in each of four of five registered multiplying herds. Samples of feed and faeces were also collected from 17 of the production herds and from the four multiplying herds. The sera were tested for antibodies to Salmonella enterica by the Danish mix-ELISA, and the organisms were isolated, serotyped and sensitivity tested by standard techniques. The average within-herd seroprevalence was 3.4 per cent and at least one pig tested seropositive in 21 of the 59 herds. In the multiplying herds, only a single seroreactor was detected. Salmonellae were isolated from only five of 95 feed samples, from two of the 17 herds sampled, Salmonella tennessee in four of five samples from one herd and an untypable strain in one of five samples from another. Four infected faecal samples were detected in four herds; they harboured Salmonella typhimurium, Salmonella bredeney or Salmonella london. No salmonellae were isolated from the samples of feed and faeces taken from the multiplying herds. The S london and S typhimurium had a low sensitivity to streptomycin, kanamycin and neomycin, and the S typhimurium also had low sensitivity to amoxycillin, ticarcillin, piperacillin, amoxycillin + clavulanic acid, cefalotin and cefoperazone. The other isolates were sensitive to all the antimicrobial agents tested.

Reproductive efficiency of three estrus synchronization schemes comprising fixed-time insemination in dairy cows

The objective of this field trial was to compare the odds of pregnancy at 25 days (P25) and at 60 days (P60), of embryonic death (ED) between 25 and 60 days, and of non-pregnant cows returning to heat 20-25 days after artificial insemination (AI). Three fixed-time insemination protocols involving combined administration of either double gonadotrophin-releasing hormone (GnRH) and prostaglandins (A) or GnRH, human chorionic gonadotrophin (hCG) and prostaglandins (B), or double treatment with prostaglandins (C) were used. Cows included in the trial were selected from five herds, comprising a total of 735 (herd size range 85-250, median 120) Holstein dairy cows. Animals used for the study were multiparous, 4-7 years of age, had expressed at least one overt postpartum heat, were between 60 and 120 days of lactation and had at least one palpable corpus luteum and no gross morphological anomalies of their reproductive tracts. They were randomly allocated to receive treatment A (n = 89), B (n = 93), or C (n = 65). Pregnancy of cows not observed in heat 18-24 days post AI was diagnosed by transrectal ultrasonography at 25-30 days and confirmed by rectal palpation at 60-75 days post AI. Those that were detected in heat in the normal period post AI were re-inseminated. No differences were detected among the three treatment groups concerning the odds of P25 (P = 0.5), P60 (P = 0.2) and ED (P = 0.13). In contrast, non-pregnant cows that were administered treatment A were less likely to exhibit estrous signs in the normal period post AI than those administered treatments B (P = 0.02) or C (P = 0.005).

A matched case-control study of factors associated with retention of fetal membranes in dairy ewes in Southern Greece

We defined retention of fetal membranes (RFM) in dairy ewes as failure to expel the placenta within 6h after lambing the last lamb and designed a matched case-control study to identify factors that affect the risk of retention. For each ewe with RFM, the next ewe in the flock that lambed and expelled the placenta in <6h after lambing the last lamb was selected as control. Data analyzed included 92 pairs of ewes from 25 flocks comprising a total of 7275 ewes (median flocksize 270 ewes). Factors investigated for associations with RFM were induction of lambing, obstetrical assistance because of dystocia, parity, the number of liveborn lambs, the occurrence of stillbirth(s), the mean weight of the litter on the third day post-lambing and the occurrence of neonatal death in the litter. Conditional logistic regression indicated (1) that the risk of RFM increased linearly with increasing number of liveborn lambs and (2) that the risk of retention was 4-fold higher in ewes that received assistance at lambing than those that lambed normally.

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.

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.

Asymptomatic bacteriuria in puppies with canine parvovirus infection: a cohort study

This study aimed to investigate the possible association between canine parvoviral enteritis and asymptomatic bacteriuria. Forty-three puppies that were admitted to the outpatient service of the Animal Medical Clinic with clinical signs compatible with parvoviral enteritis formed the exposed group. The clinical diagnosis was subsequently confirmed by a positive fecal ELISA test (CITE test: IDDEX Lab., Westbrook, ME). Twenty-three (53.5%) of these puppies were males and 20 (46.5%) were females. Their age ranged from 1.5 to 5.5 months. Forty-eight clinically normal and age-matched puppies, that had been admitted to the clinic for vaccinations and had a negative result in the aforementioned ELISA test, were randomly selected to form the unexposed group. Urine samples were collected by antebupic cystocentesis from all puppies and submitted for bacterial culture. In the parvovirus exposed group, 11 of 43 puppies had detectable bacteriuria. The isolates were Escherichia coli alone (8/11-72.7%) Staphylococcus aureus alone (1/11-9.1%) and mixed cultures of E. coli and S. epidermitis (2/11-18.2%). In the unexposed group there were three puppies with detectable bacteriuria, one isolate each of E. coli, Enterococcus durans and Corynebacterium spp. Puppies with parvoviral enteritis had five (95% CI: 1.3-19.8) times higher odds of developing asymptomatic bacteriuria than puppies without the disease. The observed increased risk of asymptomatic bacteriuria among puppies with parvoviral enteritis was probably due to the fecal contamination of the external genitalia and the neutropenia these puppies exhibited.

Financial evaluation of vaccination and testing alternatives for control of parvovirus-induced reproductive failure in swine

OBJECTIVE

To identify the preferable testing and vaccination strategy for control of porcine parvovirus (PPV) during a 6-month period.

DESIGN

Decision-tree analysis and computer simulations.

SAMPLE POPULATION

Computer modeling of 300-sow farrow-to-finish herd.

PROCEDURE

Serologic testing of 30 females to estimate herd PPV prevalence versus not testing any females was the initial decision alternative. On the basis of serologic test results, herds were classified into 1 of 3 PPV-risk categories: low (> or = 80% seropositive females), moderate (40 to < 80% seropositive females), or high (< 40% seropositive females). Vaccinating all females, only gilts, or not vaccinating was the second decision alternative.

RESULTS

For initial model assumptions (test sensitivity and specificity = 0.95; test cost = $5/female; vaccination cost = $0.30/dose; vaccination efficacy = 0.95; and foregone gross margin = $10.85/pig), vaccination of all females (with or without serologic testing) was preferable, but the financially preferable option was to omit serologic testing. Most profitable vaccination option varied with foregone gross margin, vaccination cost, and efficacy. For herds in which all sows were known to be immune, vaccinating only gilts was financially preferable, and serologic testing was not warranted. Variation is expected monetary losses was less in vaccination options than with nonvaccination.

CLINICAL IMPLICATIONS

For most herds in the United States, serologic screening for PPV prior to selection of a vaccination program is unlikely to be cost-effective, because vaccination is inexpensive ($0.30/dose) and effective (95%). At current profit margins ($10.85/pig), vaccination of all females has the least-risk and is the preferred option.

Herd risk factors for serological evidence of Aujeszky's disease virus infection of breeding sows in northern Germany (1990-1991)

The distribution of herd risk factors with respect to serological evidence of Aujeszky's disease virus (ADV) infection in breeding sows was studied using samples collected in the early phase of an area-wide eradication programme in two districts of Northern Germany (Schleswig-Flensburg and Nordfriesland). The odds of seropositivity in breeding females were 6.5-times higher for herds that purchased replacement gilts compared with herds that introduced gilts from their own inventory. Herds in which confirmed clinical Aujeszky's disease (AD) had occurred during the 1980s had 4.2-times higher odds of seropositive test results compared with herds without clinical outbreaks of AD. The log-odds of a herd having seropositive females increased, in a curvilinear pattern, with increasing herd size. The slope of the log-transformed herd-size line suggested that wind-borne transmission may have been an important route for among-herd transmission of ADV. It was concluded that, in areas with endemically-infected swine herds, the expected level of ADV infection will be highest in regions with large herds and previous clinical outbreaks of AD. This should be taken into account in the design of future area-wide AD-eradication campaigns.