Veterinary medicines have been widely used for disease protection, growth promotion, and feed efficacy development of animals. Along with development of livestock and pet industry, veterinary medicine market in Korea has increased up to 1 billion US dollar in 2021. The national post-market surveillance (NMS) assessment is important system to manage quality control of veterinary medicines that have reached the open market in Korea. In this study, post marketed veterinary medicines have been analyzed particularly for the active ingredient contents based on the rule, “Tips on animal pharmaceutical audit” and monitored the noncomplicant compounds for prevention of adverse drug event. 6,620 veterinray medicines were chosen by NVRQS-SE10-V1 software program which we developed annually in Korea during 2018-2021. The programe chooses veterinary medicines which is 70% were selected products with high sales in order, 20% were selected products with low sales randomly and 10% were noncompliant product from last year automatically, as we input year`s sales and noncompliant product data. The Animal and Plant Quarantine Agency (APQA) leads collection of veterinary medicines from manufacturing companies, drug stores, and hospitals. The NMS assay was analyzed particularly for the active ingredient ingredients performed using liquid and gas chromatography, titration, UV/Vis spectrophometer, pH, and bioassay in Korea Animal Health Production Association (KAHPA). A total of 129 cases were deemed noncompliant and the average noncompliance rate for veterinray medicines was 1.9%. Among noncompliant products violating regulations, the leading cause was insufficient quantity of major ingredients. The compounds found to be noncompliant most frequently were tylosin, spiramycin, ampicillin, amoxicillin and colistin, respectively In this study, we analyzed the results of post marketing surveillance assay from 2018 to 2021 particularly violation rate and pattern. The overall trend indicated gradually decreasing noncompliance rate from 2.7% to 1.6%, suggesting that the quality of veterinary medicines has improved according to the steadily NMS assay and settlement of Korea Veterinary Good Manufacturing Practice (KVGMP) system.

The objective of this study was to develop a simultaneous method for 8 amino acids including alanine, arginine, glutathione, lysine, ornithine, methionine, threonine and tryptophan in veterinary products using LC-MS/MS. To optimize MS analytical condition of 8 amino acids, each parameter was established by multiple reaction monitoring in positive mode. The chromatogram separation was achieved on a C18 column with mobile phase of 0.1% formic acid in D.W. and 0.1% formic acid in acetonitrile for green technology at a flow rate of 0.4mL/min for 5 min with gradient elution. The developed method was validated for mass accuracy, precision, linearity in veterinary products. Calibration curves were linear over the calibration ranges (0.5 – 10 mg/L) for all the analytes r2>0.99. Average recoveries were 92.96 – 105.61% and relative standard deviations (RSD) were 0.27 – 3.5%. The limit of detection (LOD) and the limit of quantification (LOQ) were 0.04 – 0.83 mg/L and 0.12 – 2.52 mg/L, respectively. All values were corresponded with the criteria ranges requested by CD 2002/657/EC. The application of this method will be helpful in quality control analysis of amino acids in veterinary products.

Korea had experienced second epidemic highly pathogenic avian influenza (HPAI), and there were the seven affected farms, including two breeder duck farms, from 22nd November 2006 to 6th March 2007. Here, we reported the clinico-pathological characteristics of domestic breeder ducks farms naturally infected with HPAI virus (H5N1). Clinically, the most ducks showed various signs from depression, decreased egg production and feed consumption to even, death. The most commonly gross changes were hepatomegaly, splenomegaly, petechial and ecchymotic hemorrhage on the liver surface, a white stripe on the cardiac muscle, and severely hemorrhagic and deformed eggs. The most significant histopathological changes were necrosis of various cells such as neuron, lymphocytes, cardiac myocytes, hepatocytes, blood vessels and pancreatic acinar epithelium. The viral antigen was mainly detected in the endothelium of blood vessels of various organs and tissues, peripheral nerves and neuronal cells. Based on the above results, we identified that HPAI H5N1 induced systemic infection in the adult breeder ducks.