Effects of ketamine, xylazine, and a combination of ketamine and xylazine were studied in 12 male Pekin ducks (7 to 12 weeks old; mean [+/- SD] body weight, 3.1 +/- 0.3 kg). After venous and arterial catheterization and fixation of a temperature probe in the cloaca, each awake duck was confined, but not restrained, in an open box in a dimly lit room. Blood pressure and lead-II ECG were recorded. Three arterial blood samples were collected every 15 minutes over a 45-minute period (control period) and were analyzed for pHa, Paco2 and Pao2. After the control period, each duck was assigned at random to 1 of 3 drug groups: (1) ketamine (KET; 20 mg/kg of body weight, IV), (2) xylazine (XYL; 1 mg/kg, IV), and (3) KET + XYL (KET 20 mg/kg and XYL, 1 mg/kg; IV). Measurements were made at 1, 5, 10, 15, 30, 45, 60, and 90 minutes after drug administration. All ducks survived the drug study. Cloacal temperature was significantly (P less than or equal to 0.05) increased above control cloacal temperature at 90 minutes after the administration of ketamine, and from 10 through 90 minutes after administration of ketamine plus xylazine. In ducks of the KET group, pHa, Paco2, and Pao2, remained unchanged after administration of the drug. In ducks of the XYL group, pHa and Pao2 decreased significantly (P less than or equal to 0.05) from control values for all time points up to and including 15 minutes after drug administration. In ducks of the KET + XYL group, pHa and Pa02 were significantly (P less than or equal to 0.05) decreased at all time points up to and including 45 and 15 minutes, respectively, after administration of the drugs. In ducks of the XYL group, Paco2 increased significantly (P less than 0.05) during the first 15 min. after drug administration, and for 45 min. after administration of KET + XYL. Results indicated that ketamine when given alone to ducks, was not associated with pulmonary depression.

The current study described the developmental sequence of the ventriculus of the post-hatching Muscovy ducks of both sexes ranging from 1-60 days old, by using gross-histomorphometic measurements and by using light microscope, scanning electron microscope and transmission electron microscope. The ventriculus was extended from the level of the 4th intercostal space to terminate behind the last rib at variable distances dependent on the age of the duck. The statistical analysis revealed that the length of the ventriculus from that of the stomach was decreased by the advancement of the age, while the weight was increased. At all developmental age-stages, the cuticula gastrica was composed of two layers; vertical rods and horizontal matrix. The vertical rods projected slightly as dentate processes beyond the surface of the mucosa at 30-60dys old. The type of the gizzard gland was different according to the age; it was simple tubular type lining by one type of cells (chief cells) at 1-15 days old, but were compound-branched type lining by two types of cells; chief and basal cells at 30-60 days old. By semithin sections, the secretory basophilic granules within the cells lining of the tubular glands were increased by ageing. Transmission electron microscopy exhibited that the chief cells had numerous large sizes electron dense and electron lucent secretory granules. In conclusion, there are wide variations in the morphometrical analysis and the structure of the ventriculus at the developmental age-stages of the duck.

Coinfection of goose parvovirus (GPV) and duck circovirus (DuCV) occurs commonly in field cases of short beak and dwarfism syndrome (SBDS). However, whether there is synergism between the two viruses in replication and pathogenicity remains undetermined. We established a coinfection model of GPV and DuCV in Cherry Valley ducks. Tissue samples were examined histopathologically. The viral loads in tissues were detected by qPCR, and the distribution of the virus in tissues was detected by immunohistochemistry (IHC). Coinfection of GPV and DuCV significantly inhibited growth and development of ducks, and caused atrophy and pallor of the immune organs and necrosis of the liver. GPV and DuCV synergistically amplified pathogenicity in coinfected ducks. In the early stage of infection, viral loads of both pathogens in coinfected ducks were significantly lower than those in monoinfected ducks (P < 0.05). With the development of the infection process, GPV and DuCV loads in coinfected ducks were significantly higher than those in monoinfected ducks (P < 0.05). Extended viral distribution in the liver, kidney, duodenum, spleen, and bursa of Fabricius was consistent with the viral load increases in GPV and DuCV coinfected ducks. These results indicate that GPV and DuCV synergistically potentiate their replication and pathogenicity in coinfected ducks.

The lack of proofreading activity of the viral polymerase and the segmented nature of the influenza A virus (IAV) genome are responsible for the genetic diversity of IAVs and for their ability to adapt to a new host. We tried to adapt avian IAV (avIAV) to the pig by serial passages in vivo and assessed the occurrence of point mutations and their influence on viral fitness in the pig’s body. A total of 25 in vivo avIAV passages of the A/duck/Bavaria/77 strain were performed by inoculation of 50 piglets, and after predetermined numbers of passages 20 uninoculated piglets were exposed to the virus through contact with inoculated animals. Clinical signs of swine influenza were assessed daily. Nasal swabs and lung tissue were used to detect IAV RNA by real-time RT-PCR and isolates from selected passages were sequenced. Apart from a rise in rectal temperature and a sporadic cough, no typical clinical signs were observed in infected pigs. The original strain required 20 passages to improve its replication ability noticeably. A total of 29 amino-acid substitutions were identified. Eighteen of them were detected in the first sequenced isolate, of which 16 were also in all other analysed strains. Additional mutations were detected with more passages. One substitution, threonine (T) 135 to serine (S) in neuraminidase (NA), was only detected in an IAV isolate from a contact-exposed piglet. Passaging 25 times allowed us to obtain a partially swine-adapted IAV. The improvement in isolate replication ability was most likely related to S654 to glycine (G) substitution in the basic protein (PB) 1 as well as to aspartic acid (D) 701 to asparagine (N) and arginine (R) 477 to G in PB2, glutamic acid (E) 204 to D and G239E in haemagglutinin and T135S in NA.

Derzsy’s disease and Muscovy duck parvovirus disease have become common diseases in waterfowl culture in the world and their potential to cause harm has risen. The causative agents are goose parvovirus (GPV) and Muscovy duck parvovirus (MDPV), which can provoke similar clinical symptoms and high mortality and morbidity rates. In recent years, duck short beak and dwarfism syndrome has been prevalent in the Cherry Valley duck population in eastern China. It is characterised by the physical signs for which it is named. Although the mortality rate is low, it causes stunting and weight loss, which have caused serious economic losses to the waterfowl industry. The virus that causes this disease was named novel goose parvovirus (NGPV). This article summarises the latest research on the genetic relationships of the three parvoviruses, and reviews the aetiology, epidemiology, and necropsy characteristics in infected ducks, in order to facilitate further study.

Repeated incursions of highly pathogenic avian influenza virus (HPAIV) H5 subtype of Gs/GD lineage pose a serious threat to poultry worldwide. We provide a detailed analysis of the spatio-temporal spread and genetic characteristics of HPAIV Gs/GD H5N8 from the 2019/20 epidemic in Poland. Samples from poultry and free-living birds were tested by real-time RT-PCR. Whole genome sequences from 24 (out of 35) outbreaks were generated and genetic relatedness was established. The clinical status of birds and possible pathways of spread were analysed based on the information provided by veterinary inspections combined with the results of phylogenetic studies. Between 31 December 2019 and 31 March 2020, 35 outbreaks in commercial and backyard poultry holdings and 1 case in a wild bird were confirmed in nine provinces of Poland. Most of the outbreaks were detected in meat turkeys and ducks. All characterised viruses were closely related and belonged to a previously unrecognised genotype of HPAIV H5N8 clade 2.3.4.4b. Wild birds and human activity were identified as the major modes of HPAIV spread. The unprecedentedly late introduction of the HPAI virus urges for re-evaluation of current risk assessments. Continuous vigilance, strengthening biosecurity and intensifying surveillance in wild birds are needed to better manage the risk of HPAI occurrence in the future.

Introduction: Laryngeal swab samples collected from three waterfowl slaughterhouses in central Taiwan were cultured and suspected isolates of Riemerella anatipestifer were identified by API 20NE and 16S rDNA PCR. Material and Methods: Serum agglutination was used for serotyping, and antimicrobial susceptibility was tested. Results: Seventy-six R. anatipestifer isolates were detected, and the prevalences in the ducks and geese were 12.3% (46/375) and 8.0% (30/375), respectively. The positive isolation rates were 65.6% for all arriving waterfowl, 76.0% for birds in the holding area, 1.6% for defeathered carcasses, but zero for degummed carcasses. A PCR examination detected R. anatipestifer in the slaughtering area frequently. Serotype B was dominant in both duck (34.8%) and goose (46.7%) isolates, but the wide serotype distribution may very well impede vaccination development. All isolates were resistant to colistin, and 79.7% were resistant to more than three common antibiotics. Conclusion: The results proved that most ducks had encountered antibiotic-resistant R. anatipestifer in rearing, which suggests that the bacterium circulates in asymptomatic waterfowl. It is worth noting that most waterfowl farms were found to harbour R. anatipestifer, and contaminated slaughterhouses are a major risk factor in its spread. Effective prevention and containment measures should be established there to interrupt the transmission chain of R. anatipestifer.

The aim of this study was to examine viruses associated with gastrointestinal illnesses in ducks collected from four governorates in Egypt (Sharkia, Gharbia, Dakahlia, and Qaliobia) during 2021-2022. These ducks underwent comprehensive clinical examinations and post-mortem analyses. All the flocks exhibited various forms of diarrhea. Additionally, 59.5% of the duck flocks manifested respiratory symptoms, while 57 % showed uneven growth, locomotory dysfunction (42.8%). Post-mortem findings consistently included enteritis in all examined flocks. To directly identify viruses associated with digestive illnesses, 42 aseptic intestine samples were obtained from recently deceased or sacrificed ducks. PCR analysis identified four positive samples out of the 42 (9.5%), with one containing Avian Rotavirus (AvRV) and three carrying Muscovy Duck Parvovirus (MDPV). Additionally, histopathological examination of the liver and intestine from PCR-positive flocks showed findings consistent with those typically observed in MDPV infections. This study concluded that the primary viruses associated with digestive illnesses in Egyptian ducks are MDPV and AvRV. Importantly, this research represents the first-ever detection of Rotavirus in ducks in Egypt.

An experiment was designed to investigate the effects of dietary supplementation of various concentrations of nanoselenium (NS) on the growth performance, immune status, antioxidant activity and hematological parameters of ducks. A total of 40 (1 day old) Pekin ducklings were equally divided into groups of 10 ducklings each. The 1st group was considered a control and was fed basal diet ad-libitum without nanoselenium (NS) supplementation; 2nd group (fed basal diet + 0.2 mg NS/kg diet); 3rd group (fed basal diet + 0.4 mg NS/kg diet) and 4th group (fed basal diet + 0.6 mg NS/kg diet). The selenium content of the unsupplemented control diet was 0.09 mg/kg during the starter period (0-2 weeks) and 0.07 mg/kg during the grower-finisher period (2-10 weeks). All feeds were formulated according to NRC (1994) to meet the nutritional needs of growing ducks. The experiment was extended for 10 weeks. Growth performance parameters such as body weight development, weight gain, feed consumption, feed-to-gain ratio, performance index and mortality were recorded. At the end of experiment, three randomly selected ducks from each group were selected to assess immune status, antioxidant activity, and blood biochemical parameters. The results showed that ducks fed on diets supplemented with different levels of nanoselenium had significantly higher body weight and weight gain (P<0.05) and consumed less feed than ducks fed the control diet. The third group had the highest body weight and weight gain and the lowest feed intake, followed by the second and fourth groups respectively. The NS supplemented birds had no mortality throughout the experimental period compared with control group which recorded highest mortality rate (20%). Different levels of NS supplementation improved the feed conversion ratio and performance index, the best values was achieved in 3rd group followed by 2nd and 4th groups, respectively. Addition of NS to duck diets significantly (P˂0.05) increased the serum immunoglobulins (IgA, IgG, IgM), glutathione peroxidase (GPx) and superoxide dismutase (SOD) levels, but decreased the malondialdehyde (MDA) levels compared to control. Concerning blood picture, NS supplementation significantly increased white blood cell and lymphocytic counts (P<0.05). However, no significant differences in other hematological parameters between tested groups. In conclusion, the present study found that supplementing duck diets with nano-selenium improved growth performance parameters, immune status, antioxidant activity, blood picture and 0.2-0.4 mg/kg is considered the optimum nano-Se supplementation level, and the maximum nano-Se supplementation level for ducks should not exceed 0.6 mg/kg.

A total of 65 Pasteurella multocida were isolated and identified from various animal’s samples received by Veterinary Research Institute (VRI) during the period of 2014 to 2016. These animals comprises of cattle, goat, pig, chicken, duck and rabbit. The serogroup of Pasteurella multocida were carried out using designation system of Carter’s capsular typing and molecular serogrouping method. Based on cases submitted to VRI, the prevalence of pasteurellosis in Malaysia ranging from 1.0% to 3.2% (2014 to 2016). It is low compared to previous reports and the pattern of predominant serogroups and animal hosts were found to be changing every year. In 2014, 80% (12/15) of the isolates were Pasteurella multocida Carter’s type D where all were isolated from goats. In 2015, the predominant serogroup changed to Pasteurella multocida Carter’s type A with a prevalence rate of 40.6% (13/32) which were mostly isolated from duck and cattle. While for Pasteurella multocida Carter’s type D, the prevalence in 2015 reduced to 21.9% (7/32) compared to the previous year and it was isolated from various animal species. Interestingly, in 2015 there was one isolate of Pasteurella multocida Carter’s type B isolated from goat with no reported history of outbreak. In 2016, the prevalence of Pasteurella multocida Carter’s type A increased to 72.2% (13/18), with a high percentage (92.3%) infection in young calves showing clinical signs with high mortality and morbidity in infected farms. Furthermore, during these 3 years of study, 3 isolates of Pasteurella multocida serogroup F were also identified each from pig, goat and chicken, respectively. In conclusion, this study revealed that pasteurellosis had become sporadic in Malaysia and the distribution of serogroups were diverse in all species of animal with no definitive host.