Recent information on iodine deficiency in New Zealand sheep flocks

AIMS: To determine the value of pasture iodine, serum thyroxine (T4) and tri-iodothyronine (T3) concentrations and thyroid (g) to body weight (kg) ratios in lambs as criteria to predict and diagnose increased litter size and decreased perinatal mortality in response to iodine supplementation. METHODS: Results from ten iodine response trials in ewes using an oil-based intramuscular iodine preparation were reviewed along with results from investigations into goitre on five farms in the Manawatu. RESULTS: In two trials, litter size was increased by 14% and 21% in iodine-treated ewes. In only three of the 10 trials was there a significant reduction in perinatal mortality in iodine-treated ewes. CONCLUSIONS: Pasture iodine and serum thyroxine (T4) and tri-iodothyronine (T3) concentrations appeared to be unhelpful in predicting the occurrence of increased litter size and reduced perinatal mortality in response to iodine supplementation. New-born lambs from ewes not supplemented with iodine, that had a mean thyroid weight (g) to body weight (kg) ratio of 0.40 g/kg or greater, generally had a significant increase in perinatal mortality compared to lambs from iodine-supplemented ewes.     

The effects of iodine deficiency on ewe fertility and perinatal lamb mortality

AIMS: To substantiate a previous report of improved fertility and perinatal lamb mortality rate following iodine supplementation in a Manawatu Romney ewe flock. To contribute data which might be used to predict a response to iodine supplementation. METHODS: A controlled iodine supplementation trial was performed over 2 successive years. The possible confounding factor of different lambing paddocks on perinatal lamb mortality was removed by the reversal of the paddocks used by the supplemented and control ewes during the second year. RESULTS: During 2 successive years, iodine supplementation resulted in improved reproductive performance in a Manawatu Romney flock with 21% and 14% more lambs born to supplemented than to control mixed-age ewes in 1996 and 1997 respectively. Supplementation also resulted in improved perinatal lamb survival, although this effect was greater during the wetter 1996 Lambing season. Despite the production response during both years, a difference in lamb thyroid:bodyweight ratio was only noted following the drier 1997 winter. Ewe thyroid hormone concentrations before mating and during mid-pregnancy were poor indices of deficiency. CONCLUSIONS: Iodine deficiency should be included in the list of differential diagnoses for poor reproductive performance in ewes and in the investigation of high perinatal lamb mortality rates. CLINICAL SIGNIFICANCE: The annual cost associated with iodine deficiency in this Manawatu Romney flock is conservatively estimated at dollar 6.00 per ewe. This economic loss is considerably greater than the annual cost of iodine supplementation using iodised oil.     

ASVCP reference interval guidelines: determination of de novo reference intervals in veterinary species and other related topics

Reference intervals (RI) are an integral component of laboratory diagnostic testing and clinical decision‐making and represent estimated distributions of reference values (RV) from healthy populations of comparable individuals. Because decisions to pursue diagnoses or initiate treatment are often based on values falling outside RI, the collection and analysis of RV should be approached with diligence. This report is a condensation of the ASVCP 2011 consensus guidelines for determination of de novo RI in veterinary species, which mirror the 2008 Clinical Laboratory and Standards Institute (CLSI) recommendations, but with language and examples specific to veterinary species. Newer topics include robust methods for calculating RI from small sample sizes and procedures for outlier detection adapted to data quality. Because collecting sufficient reference samples is challenging, this document also provides recommendations for determining multicenter RI and for transference and validation of RI from other sources (eg, manufacturers). Advice for use and interpretation of subject‐based RI is included, as these RI are an alternative to population‐based RI when sample size or inter‐individual variation is high. Finally, generation of decision limits, which distinguish between populations according to a predefined query (eg, diseased or non‐diseased), is described. Adoption of these guidelines by the entire veterinary community will improve communication and dissemination of expected clinical laboratory values in a variety of animal species and will provide a template for publications on RI. This and other reports from the Quality Assurance and Laboratory Standards (QALS) committee are intended to promote quality laboratory practices in laboratories serving both clinical and research veterinarians.     

Predation by carpet pythons (Morelia spilota) is an important cause of mortality in a free‐living koala (Phascolarctos cinereus) population in South East Queensland

Koalas (Phascolarctos cinereus) are experiencing significant declines across the northern part of their range. However, unbiased, population‐level estimates of mortality are rarely reported, as it's difficult to quantify causes of mortality robustly in this cryptic species. We aimed to determine the relative importance of carpet python (Morelia spilota) predation in a free‐living koala population and describe the characteristic pathological findings during necropsy. In total, 503 koalas were captured, underwent veterinary examination and telemetric tagging, and were monitored after release over a four‐year period. Mortalities were detected when activity data reported by K‐Tracker® biotelemetry collars indicated low or zero activity, or during routine field monitoring events. Experienced koala veterinarians performed thorough, standardised necropsy examinations on retrieved carcasses to determine causes of death. The three, sometimes subtle, cardinal signs used to definitively diagnose carpet python‐caused deaths of koalas were a U‐shaped primary bite site, slicking of the fur by python saliva (particularly around the face), and diffuse, uniform pulmonary congestion. We found that carpet pythons were important predators of koalas, second only to wild dogs (dingoes and dingo hybrids (Canis familiaris dingo)), accounting for 11.6% of predation deaths and 7.2% of total deaths. Less than half (38%) of the koalas killed by carpet pythons were ingested. Though carpet pythons are known predators of koalas, their relative importance as a cause of mortality hasn't previously been recognised. Population viability analyses and conservation management plans benefit from robust cause‐of‐death data collected during longitudinal monitoring studies, requiring telemetry methods that facilitate rapid detection of mortalities.     

胎儿宫内发育迟缓的原因

胎儿宫内发育迟缓(intrauterine growth retardation,IUGR)在畜牧生产中发生率较高,导致新生儿死亡率增加,影响日后生长发育及健康。了解IUGR发生原因对降低其发生,提高畜牧业生产水平具有重要意义。作者综述了引起IUGR的主要因素。     

Effects of dietary dihydroartemisinin supplementation on growth performance,hepatic inflammation,and lipid metabolism in weaned piglets with intrauterine growth retardation

The aims of this study were to investigate the effects of dietary supplementation with dihydroartemisinin (DHA) on growth performance, hepatic inflammation, and lipid metabolism in intrauterine growth retardation (IUGR)‐affected weaned piglets. Eight piglets with normal birth weight (NBW) and 16 IUGR‐affected piglets were selected and fed either a basal diet (NBW and IUGR groups) or the basal diet supplemented with 80 mg/kg DHA (IUGR‐DHA group) from 21 to 49 day of age. Blood and liver samples were collected on day 49. DHA supplementation significantly alleviated the compromised growth performance and liver damage in IUGR‐affected piglets. Additionally, DHA supplementation decreased the activities of alanine aminotransferase and aspartate aminotransferase, as well as the serum levels of non‐esterified fatty acids (NEFA), very‐low‐density lipoprotein, and total cholesterol. In the liver, the concentrations of interleukin 1 beta, interleukin 6, tumor necrosis factor alpha, triglycerides, and NEFA were decreased. Fatty acid synthesis was decreased by DHA supplementation, whereas the activities of lipoprotein lipase, hepatic lipase, and total lipase were increased. Dietary DHA supplementation led to upregulation of the expression of AMPK/SIRT1 signaling pathway‐related genes, whereas that of inflammatory factor‐related genes were downregulated. In conclusion, dietary inclusion of 80 mg/kg DHA can alleviate IUGR‐induced impairments in piglets.     

Hepatitis E Virus Antibodies in Finnish Veterinarians

We investigated hepatitis E virus (HEV) infections in Finnish veterinarians engaged in different practice specialties and evaluated the effect of different background factors on HEV exposure by examining total HEV antibodies in samples collected from the participants of the 2009 National Veterinary Congress in Helsinki, Finland. Finnish veterinarians commonly have total HEV antibodies with seroprevalence of 10.2%. Of the non‐veterinarians, 5.8% were seropositive. Increasing age was associated with HEV seropositivity, and, surprisingly, the highest HEV seroprevalence (17.8%) among veterinarians was detected among small animal practitioners. Although no positive correlation between swine contacts and HEV seropositivity was found, 22.7% of veterinarians who had had needle stick by a needle that had previously been injected into a pig versus 9.0% of those who had not were seropositive, even though the finding was statistically non‐significant (P = 0.07). Our results suggest that, although contact with swine is a known risk factor for HEV infection, the sources of HEV infections are probably numerous, including travelling abroad and possibly also other reservoirs of HEV than pigs.     

Monitoring of the intra-dermal tuberculosis skin test performed by Belgian field practitioners

The present study aimed to monitor skin test practices as performed by veterinarian field practitioners in Belgium. For this purpose, an anonymous postal questionnaire was elaborated and dispatched to veterinarians involved in bovine tuberculosis detection. The questionnaire included items focusing on the skin test performance. International experts in the field of bovine tuberculosis were asked to fill the questionnaire and a scoring scale was built as follows: 0 = ‘ideal’ answer, 1 = acceptable answer, whereas 2 = unacceptable answer. Furthermore, experts were asked to rank the questionnaire’s items according to their possible impact on the risk of not detecting reactors. A global score was further calculated for each participant and a comparison of practices was carried out between the two regions of the country, i.e. Wallonia and Flanders. Significant differences were observed between both regions, a harmonization at the country level is thus essential. No veterinarian summed a null score, corresponding to the ideal skin test procedure, which suggests that skin-testing is far from being performed correctly. Field practitioners need to be sensitized to the importance of correctly performing the test. The authors recommend the questionnaire is suitable for application in other countries or regions.     

Influence of modifiable risk factors on the incidence of stillbirth/perinatal mortality in dairy cattle

Bovine perinatal mortality is defined as the death of a full-term calf before, during or up to 48 h after calving. Recent studies indicate that the prevalence of bovine perinatal mortality is increasing, particularly in Holstein primiparae. Factors leading to a greater incidence of dystocia are the most important modifiable variables influencing the risk of perinatal mortality. Modifiable predictors are largely (age at first calving, breeding method, sire, calving management, feto-maternal health status and gestational nutrition) or moderately (calf breed, sex, gestation length) under the control of the dairy farm manager. Unlike non-modifiable risk factors, such as primiparity and fetal plurality, these factors can be manipulated to reduce the incidence of perinatal mortality.     

Effects of dietary methionine supplementation on growth performance,intestinal morphology,antioxidant capacity and immune function in intra‐uterine growth‐retarded suckling piglets

This study investigated the effects of dietary supplementation with _L‐methionine (_L‐Met), _DL‐methionine (_DL‐Met) and calcium salt of the methionine hydroxyl analog (MHA‐Ca) on growth performance, intestinal morphology, antioxidant capacity and immune function in intra‐uterine growth‐retarded (IUGR) suckling piglets. Six normal birthweight (NBW) female piglets and 24 same‐sex IUGR piglets were selected at birth. Piglets were fed nutrient adequate basal diet supplemented with 0.08% _L‐alanine (NBW‐CON), 0.08% _L‐alanine (IUGR‐CON), 0.12% _L‐Met (IUGR‐LM), 0.12% _DL‐Met (IUGR‐DLM) and 0.16% MHA‐Ca (IUGR‐MHA‐Ca) from 7 to 21 days of age respectively (n = 6). The results indicated that IUGR decreased average daily milk (dry matter) intake and average daily gain and increased feed conversion ratio of suckling piglets (p < 0.05). Compared with the NBW‐CON piglets, IUGR also impaired villus morphology and reduced antioxidant capacity and immune homeostasis in the intestine of IUGR‐CON piglets (p < 0.05). Supplementation with _L‐Met enhanced jejunal villus height (VH) and villus area and ileal VH of IUGR piglets compared with IUGR‐CON piglets (p < 0.05). Similarly, _DL‐Met supplementation increased VH and the ratio of VH to crypt depth in the jejunum compared with IUGR‐CON pigs (p < 0.05). Supplementation with _L‐Met and _DL‐Met (0.12%) tended to increase reduced glutathione content and reduced glutathione: oxidized glutathione ratio and decrease protein carbonyl concentration in the jejunum of piglets when compared with the IUGR‐CON group (p < 0.10). However, supplementation with MHA‐Ca had no effect on the intestinal redox status of IUGR piglets (p > 0.10). In conclusion, supplementation with either _L‐Met or _DL‐Met has a beneficial effect on the intestinal morphology and antioxidant capacity of IUGR suckling piglets.     

Academic food-supply veterinarians: future demand and likely shortages

The future demand for and potential shortages of food-supply veterinarians have been the subject of much concern. Using the Delphi forecasting method in a three-phase Web-based survey process, a panel of experts identified the trends and issues shaping the demand for and supply of academic food-animal veterinarians, then forecasted the likely future demand and shortages of food-supply veterinarians employed in academic institutions in the United States and Canada through 2016. The results indicate that there will be increasing future demand and persistent shortages of academic food-supply veterinarians unless current trends are countered with targeted, strategic action. The Delphi panel also evaluated the effectiveness of several strategies for reversing current trends and increasing the number of food-supply veterinarians entering into academic careers. Academic food-supply veterinarians are a key link in the system that produces food-supply veterinarians for all sectors (private practice, government service, etc.); shortages in the academic sector will amplify shortages wherever food-supply veterinarians are needed. Even fairly small shortages have significant public-health, food-safety, animal-welfare, and bio-security implications. Recent events demonstrate that in an increasingly interconnected global economic food supply system, national economies and public health are at risk unless an adequate supply of appropriately trained food-supply veterinarians is available to counter a wide variety of threats ranging from animal and zoonotic diseases to bioterrorism.     

ACVIM consensus statement on the treatment of immune‐mediated hemolytic anemia in dogs

Immune‐mediated hemolytic anemia (IMHA) causes severe anemia in dogs and is associated with considerable morbidity and mortality. Treatment with various immunosuppressive and antithrombotic drugs has been described anecdotally and in previous studies, but little consensus exists among veterinarians as to the optimal regimen to employ and maintain after diagnosis of the disease. To address this inconsistency and provide evidence‐based guidelines for treatment of IMHA in dogs, we identified and extracted data from studies published in the veterinary literature. We developed a novel tool for evaluation of evidence quality, using it to assess study design, diagnostic criteria, explanation of treatment regimens, and validity of statistical methods. In combination with our clinical experience and comparable guidelines for humans afflicted with autoimmune hemolytic anemia, we used the conclusions of this process to make a set of clinical recommendations regarding treatment of IMHA in dogs, which we refined subsequently by conducting several iterations of Delphi review. Additionally, we considered emerging treatments for IMHA in dogs and highlighted areas deserving of future research. Comments were solicited from several professional bodies to maximize clinical applicability before the recommendations were submitted for publication. The resulting document is intended to provide clinical guidelines for management of IMHA in dogs. These guidelines should be implemented pragmatically, with consideration of animal, owner, and veterinary factors that may vary among cases.     

Stillbirth/perinatal weak calf syndrome in dairy heifers: results of a pilot study

A pilot study of 10 Dutch dairy herds was performed to investigate possible causes of stillbirth/perinatal weak calf syndrome in heifers. Possible causes and advice for further investigations on farms affected by this syndrome are discussed based on the results of investigations of blood and urine from pregnant young stock, postmortem examination of still-born calves, and a questionnaire held among farmers. Infections with Neospora caninum, Salmonella spp. or Leptospira hardjo, or a deficiency of iodine could be excluded.     

Digital imaging advances and the future.

Digitization of clinical data is becoming increasingly important in veterinary medicine. Current veterinary applications range from digital cameras to computed radiography. The opportunity for increased productivity and diagnostic capabilities makes the computerization of veterinary medicine especially exciting. Future trends seem to indicate that more veterinarians should have better technology available in their practices and more veterinarians should be connected to experts, clients, and each other.     

Occupational swine exposure and Hepatitis E virus,Leptospira, Ascaris suum seropositivity and MRSA colonization in Austrian veterinarians, 2017–2018—A cross‐sectional study

We investigated the prevalence of Hepatitis E Virus (HEV), Leptospira and Ascaris suum (A. suum) seropositivity, and of nasal methicillin‐resistant Staphylococcus aureus (MRSA) colonization among Austrian practising veterinarians, and assessed the association with occupational swine livestock exposure. The 261 participants completed a questionnaire on demographics, intensity of occupational swine livestock contact and glove use during handling animals and their secretions. Participants' blood samples were tested for HEV, Leptospira and A. suum seropositivity and nasal swabs cultured for MRSA. We compared swine veterinarians (defined as >3 swine livestock visits/week) to non‐swine veterinarians (≤3 swine livestock visits/week) with regard to the outcomes through calculating prevalence ratio (PR) and 95% confidence interval (CI). Furthermore, the relationship between occupational swine livestock contact and the study outcomes was examined by age (</≥55 years) and glove usage. The prevalence of nasal MRSA colonization was 13.4% (95% CI: 9.3–17.6), of HEV seropositivity 20.8% (95% CI: 15.8–25.7) and A. suum seropositivity 44% (95% CI: 37.7–50.2). The highest anti‐leptospiral antibodies titres were 1:200 (L. hebdomadis) and 1:100 (L. autumnalis, L. caicola) found in three non‐swine veterinarians. Compared to non‐swine veterinarians, swine veterinarians were 1.9 (95% CI: 1.0–3.4) and 1.5 (95%CI: 1.0–2.3) times more likely HEV seropositive and A. suum seropositive, respectively, and 4.8 (95%CI: 2.5; 9.3) times more likely nasally colonized with MRSA. Among glove‐using veterinarians, occupational swine contact was no longer a determinant for HEV seropositivity (PR 1.6; 95% CI: 0.8–2.9). Similar was found for A. suum seropositivity, which was no longer associated with occupational swine livestock contact in the subgroup of glove using, ≥55‐year‐old veterinarians (PR: 1.07; 95% CI: 0.4–3.3). Our findings indicate that >3 occupational swine livestock visits per week is associated with HEV and A. suum seropositivity and nasal MRSA colonization and that glove use may play a putative preventive role in acquiring HEV and A. suum. Further analytical epidemiological studies have to prove the causality of these associations.     

Chemical restraint-reversal with medetomidine and atipamezole in veterinary small animal practice: a survey on the opinions of the dog owners and veterinarians.

The opinions of animal owners and practising veterinarians concerning a new restraint-reversal medication (medetomidine-atipamezole) for dogs were obtained by two questionnaires in connection with a clinical study. Four alternative answers to each statement question scored as "completely agree", "somewhat agree", "somewhat disagree" and "completely disagree". The questionnaires were completed by 21 veterinarians and 245 dog owners. The overall response to the treatment was clearly positive. Both groups had a favourable attitude towards drug use with mean combined scores (from 1 to 4; 4 = most favourable) of 48.1 (max 56) for the dog owners and 39.2 (max 52) for the veterinarians. Only a little information was gained about the background of negative sentiments. Some pet owners (19%) opposed to medication on a priori grounds, some (26%) reacted strongly to the dizziness of their animals and some owners (21%) complained because of general anxiety before, during and after their pets were treated.     

Epidemiologic factors involved in perinatal lamb mortality on four range sheep operations.

Four shed-lambing operations in western Colorado were monitored during the 1984 spring lambing season to determine the causes and rates of perinatal lamb mortality. The number of lambing ewes per flock ranged from 513 to 1,712, and lambing percentages ranged from 131 to 180%. Overall perinatal lamb mortality ranged from 8.2 to 12.2%. Most lamb deaths occurred during parturition or within 24 hours after parturition. More than 85% of all lamb deaths were in lambs born to ewes having 2 or more lambs. The leading causes of lamb death were starvation, dystocia, stillbirth (unknown cause), and infectious diseases. A wheel model was used to categorize factors causing lamb deaths into 4 groups: physical, social, host, and biological, and to present data on perinatal lamb mortality in a simple visual model. In all flocks, social and biological factors resulted in most of the lamb deaths. On the basis of our findings, we suggest that interventions designed to improve ewe-lamb bonding and to reduce infectious agents and the incidence of prolonged parturition may reduce lamb mortality.     

Genetic and phenotypic variation in sources of preweaning lamb mortality

Information on causes of mortality to 8 wk weaning for 16,881 lambs of 10 line-breed groups by 594 sires born over a 5-yr period was analyzed by least squares procedures to estimate sire variance and covariance components within line and year-season. Heritability estimates were approximately 5% for total mortality in the binomial scale and near 10% when converted to a normal scale. Average heritability estimates in the binomial and normal scale were, respectively, 4 and 12% for perinatal and 3 and 7% for postnatal mortality. The heritability estimates for respiratory problems were inconsistent; binomial-scale estimates ranged from 0 to 7% in different populations. Regression adjustment for effects of variation in litter size and birth weight caused only minor changes in the heritability estimates. Comparison of covariances among half-sibs vs full-sibs indicated very large maternal effects on perinatal mortality but smaller and less consistent effects on sources of postnatal mortality. Phenotypic correlations among sources of mortality indicated a 26% greater influence of postnatal than perinatal mortality on variation in total mortality, but both the genetic and phenotypic correlations between those two components were slightly negative. These results suggest that the use of family and progeny test selection for transmitted effects on both perinatal and postnatal lamb viability should be effective.