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.

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.

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.

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 minutes after drug administration, and for 45 minutes after administration of KET + XYL. Results indicated that ketamine when given alone to ducks, was not associated with pulmonary depression. There was drug-associated respiratory depression after IV administration of XYL or KET + XYL.

Objective: To determine the pharmacokinetic properties of 1 IM injection of ceftiofur crystalline-free acid (CCFA) in American black ducks (Anas rubripes). Animals: 20 adult American black ducks (6 in a preliminary experiment and 14 in a primary experiment). Procedures: Dose and route of administration of CCFA for the primary experiment were determined in a preliminary experiment. In the primary experiment, CCFA (10 mg/kg, IM) was administered to ducks. Ducks were allocated into 2 groups, and blood samples were obtained 0.25, 0.5, 1, 2, 4, 8, 12, 48, 96, 144, 192, and 240 hours or 0.25, 0.5, 1, 2, 4, 8, 24, 72, 120, 168, and 216 hours after administration of CCFA. Plasma concentrations of ceftiofur free acid equivalents (CFAEs) were determined by use of high-performance liquid chromatography. Data were evaluated by use of a naive pooled-data approach. Results: The area under the plasma concentration versus time curve from 0 hours to infinity was 783 h•μg/mL, maximum plasma concentration observed was 13.1 μg/mL, time to maximum plasma concentration observed was 24 hours, terminal phase half-life was 32.0 hours, time that concentrations of CFAEs were higher than the minimum inhibitory concentration (1.0 μg/mL) for many pathogens of birds was 123 hours, and time that concentrations of CFAEs were higher than the target plasma concentration (4.0 μg/mL) was 73.3 hours. Conclusions and Clinical Relevance: On the basis of the time that CFAE concentrations were higher than the target plasma concentration, a dosing interval of 3 days can be recommended for future multidose CCFA studies.

A single dose of digoxin was injected, IV, into 5 mature male turkeys (0.066 mg/kg of body weight), 8 male ducks (0.066 mg/kg), and 6 roosters (0.33 mg/kg). Twenty-three serial venous blood samples were collected before (baseline) and after the administration of digoxin to turkeys, ducks, and roosters. Plasma concentrations of digoxin were determined in duplicate by a radioimmunoassay that was validated for avian species. The plasma concentrations were best fitted by a 3 (turkeys, ducks)- and 2 (roosters)-compartment open model, with first-order elimination from the central compartment. Significant (P < 0.05) kinetic differences were determined among species. Mean half-life (t1/2) for ducks, roosters, and turkeys were 8.30 +/- 2.70 (mean +/- SD), 6.67 +/- 3.50, and 23.7 +/- 4.8 hours, respectively. The volume of distribution at steady state (V(SS)) was 14.7 +/- 2.9, 3.13 +/- 0.49, and 2.27 +/- 0.36 L/kg, and total body clearance (CL) of drug was 1.54 +/- 0.43, 0.461 +/- 0.187, and 0.136 +/- 0.022 L/h/kg for ducks, roosters, and turkeys, respectively. The mean residence time was 10.3 +/- 3.9, 8.37 +/- 4.97, and 16.8 +/- 2.2 hours, respectively. Volume of distribution at steady state and CL in ducks were several fold higher than that in turkeys. The terminal half-life of digoxin determined for ducks and roosters in this study was considerably shorter than those previously reported for several mammalian species.