Table of Content

24 June 2025, Volume 50 Issue 3

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Prokaryotic Expression of the GAM56 Protein from Eimeria tenella Guangdong Strain and Preparation and Identification of Its Polyclonal Antibodies

JIANG Minghui, SONG Yongle, SU Guanzhi, CHEN Qingbiao, LI Juan, QI Nanshan, LIAO Shenquan, LV Minna, LIN Xuhui, CAI Haiming, ZHANG Xu, SUN Mingfei

2025, 50(3):  1-7.  DOI: 10.19978/j.cnki.xmsy.2025.03.01

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To elucidate the biological functions of GAM56 protein in Eimeria tenella，the coding sequence of the gam56 gene was amplified from the cDNA of gametocytes isolated from the Guangdong strain of E. tenella. Subsequently，a truncated prokaryotic expression vector pET⁃B2M⁃GAM56 was constructed，and the recombinant GAM56 protein was expressed in E. coli expression system using IPTG induction. Polyclonal antibodies were generated in BALB/c mice immunized with purified GAM56. The antibody titer and specificity were analyzed using indirect ELISA and Western blot. Gametocyte⁃stage samples of E. tenella（GD）were collected for immunofluorescence assay to evaluate antibody performance. Results revealed that compared with the reference E. tenella（Houghton）strain，the gam56 gene of E. tenella（GD）exhibited a partial terminal deletion，presenting a 1 077 bp CDS encoding 358 amino acids （predicted molecular weight 41.3 kDa）. The truncated GAM56 protein containing conserved regions was predominantly expressed in inclusion bodies. Indirect immunofluorescence assay demonstrated specific recognition of the GAM56 protein at the gametocyte stage，with subcellular localization consistent with literature reports. This study provides critical materials for elucidating the biological functions of GAM56 in the E. tenella（GD）and establishes a foundation for functional investigations of sexual development⁃associated proteins in Eimeria species.

Effects of Corn Slurry Fermented Protein on Performance，Plasma Biochemical Indices，Muscle Quality，and Texture Characteristics#br# of Qingyuan Partridge Chickens#br#

WANG Yitong, XIONG Taidi, CHEN Liming, QI Zhihao, FAN Qiuli, YE Jinling, LIN Xiajing, HUANG Yunmao, JIANG Shouqun

2025, 50(3):  8-15.  DOI: 10.19978/j.cnki.xmsy.2025.03.02

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This experiment was designed to investigate the effects of corn slurry fermented protein on growth performance，plasma biochemical indexes，muscle quality and texture characteristics of Qingyuan Partridge Chickens. A total of 576 healthy 80⁃day⁃old Qingyuan Partridge Chickenss（1∶1 male⁃to⁃female ratio）were randomly allocated into 4 treatment groups，with 6 replicates in each group and 24 chickens in each replicate. Each treatment group was supplemented with 0%（control group），3% ，6% ，and 9% corn slurry fermented protein under isonitrogenous conditions. The results showed that the addition of corn slurry fermented protein to the diet had no negative impact on the growth performance of Qingyuan Partridge Chickens（P>0.05）. Compared with the control group，the 6% corn slurry fermented protein group significantly increased the breast muscle percentage and significantly reduced percentage of abdominal fat（P<0.05）. The addition of corn slurry fermented protein to the diet significantly increased the contents of plasma total protein（TP），albumin（ALB），and immunoglobulin G（IgG）（P<0.05）. Compared with the control group，the plasma blood glucose （Glu） levels of the 9% corn syrup fermented protein group was significantly reduced（P<0.05），and the plasma immunoglobulin A（IgA）levels of the 3% corn syrup fermented protein group was significantly increased（P<0.05）. The addition of 6% corn slurry fermented protein significantly reduced the drip loss rate and pH45min of breast muscle（P<0.05）. The addition of corn slurry fermented protein to the diet significantly improved the hardness，adhesiveness，and chewiness of breast muscle（P<0.05）. Conclusion： The addition of corn slurry fermented protein to the diet can improve the plasma immune function of chickens，reduce the drip loss and pH45min value of muscle，and improve the hardness，adhesiveness，and chewiness of breast muscle， and has no negative impact on growth performance. This shows that corn slurry fermented protein has an improving effect on carcass traits and meat quality of Qingyuan Partridge Chickens，and the best effect is achieved when the corn slurry fermented is added at a level of 3% - 6%.

Effect of Chocolate Powder on the Performance and Anti⁃diarrhea Effect of Piglets

TANG JianPing, LONG Hongrong, HE YiPing, YUAN Kun, CAO Xiaojian

2025, 50(3):  16-19.  DOI: 10.19978/j.cnki.xmsy.2025.03.03

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This study aimed to investigate the effects of chocolate product on the performance and anti⁃diarrhea of piglet. 66 piglets were randomly divided into 2 groups with 3 replicates of 11 pigs each. The Piglets were fed the control diet or the control diet with 5% chocolate product instead of 2.5% low⁃protein whey powder for 14 days. In this study， compared to the control，dietary supplementation of 5% chocolate product significantly increased the average body weight gain（P<0.01），while dietary supplementation of 5% chocolate product significantly reduced the feed/gain ratio of the Piglets（P<0.01），as well as the diarrhoea rate decreased by 74%. In conclusion，dietary supplementation of 5% chocolate product can improve the growth performance of piglets and reduce the diarrhea rate of piglets. As an alternative to whey powder，chocolate product has great potential.

Comparative Analysis of Egg 􀆼 Laying Interval，Egg Weight，and Birth Weight of Shiqi Pigeons Across Different Quarters

HAN Yuanhao, LIN Chuanghao, XU Haoze, LIN Suiyuan, LUO Yongquan, LI Zhipeng, HUANG Xiaohua, CHANG Kaiyue, WANG Ziying, SUN Hong, LIE Jiahui, WU Zhongping, CHEN Yitian, LIANG Yayan, ZHANG Xumeng

2025, 50(3):  20-25.  DOI: 10.19978/j.cnki.xmsy.2025.03.04

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Shiqi pigeons are one of the excellent local breeds of meat pigeons in China，known for their superior reproductive performance. This paper aims to elucidate the differences in egg weight，laying intervals，and birthweight among different quarters of Shiqi pigeons across the entire year. In this experiment，data on the laying intervals，egg weight，and birthweight of one⁃day⁃old squab pigeons from 300 pairs of two⁃year⁃old Shiqi pigeons over a complete year were measured and analyzed. The results showed that the laying intervals was the longest in the second and third quarters，with significant differences among all quarters except between the first and second quarters（P<0.05）. The egg weight was the highest in the third quarter and the lowest in the second quarter，with a significant difference between the second and third quarters（P<0.05）. The birthweight of squab pigeons was the greatest in the third quarter and the lowest in the second quarter，and also showed a significant difference between the second and third quarters （P<0.05）. By comparing and analyzing the laying intervals，egg weight，and birthweight of squab pigeons across different quarters throughout the year，we can gain insights into the seasonal reproductive characteristics of Shiqi pigeons. This information can assist breeding enterprises （or households） in better formulating breeding plans， thereby improving production efficiency and economic benefits.

Structural Analysis of the Protein Encoded by PLA2G7 Gene in Chicken

WU Mingyin, XIE Lu, HE Jingyi, CHEN Yuting, XIE Chunlin, LUO Chenglong, JI Jian

2025, 50(3):  26-32.  DOI: 10.19978/j.cnki.xmsy.2025.03.05

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Abstract：Lipoprotein⁃associated phospholipase A2（Lp⁃PLA2），encoded by PLA2G7 gene，is mainly secreted by inflammatory cells and is associated with various metabolic and immune dysfunctions，as well as other related diseases. The sequence characteristics and physical and chemical properties of the protein encoded by PLA2G7 gene were analyzed to provide a theoretical basis for studying the mechanism of Lp ⁃ PLA2 protein in chicken growth， development and avian disease immunity. Here，bioinformatic methods were used to analyze the physical and chemical properties，hydrophilicity/hydrophobicity，protein structure，phosphorylation sites and transmembrane region of chicken PLA2G7 at the molecular level，and combined with protein interaction network analysis for comprehensive evaluation. The results showed that the chicken PLA2G7 gene was 1 923 bp in length and encoded a protein consisting of 641 amino acids，which was mainly distributed in the cytoplasm and belonged to a hydrophilic secreted protein； The secondary structure is mainly composed of irregular coil（48.36%），α ⁃ helix（31.36%），extended chain （12.79%）and β⁃Sheet（7.49%）. Functional prediction revealed that the protein has 46 potential phosphorylation sites，29 of which may be serine phosphorylation sites. Based on the STRING protein interaction network，four proteins involved in immune response and regulation of phospholipid metabolism were preliminarily analyzed. Conclusion：the sequence characteristics and structure of the protein encoded by PLA2G7 gene reveal that it may be closely related to the regulation of phospholipid metabolism and immune response in chickens. This finding provides a theoretical basis for further exploring the functional mechanism of Lp⁃PLA2.

Effects of Delayed Activation and Different Treatment Methods on the In Vitro and in Vivo Development Efficiency of Porcine Somatic Cell Cloned Embryos#br#

LUO Lvhua, ZHOU Rong, MAI Ranbiao, YU Wanxian, SU Qiaoyun, SHI Junsong

2025, 50(3):  33-38.  DOI: 10.19978/j.cnki.xmsy.2025.03.06

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The literature shows that electrofusion parameters，fusion methods and treatment methods of cloned embryos may affect the in vitro development efficiency of porcine cloned embryos.The effects of synchronous activation and delayed activation on in vitro and in vivo development efficiency of porcine cell cloned embryos were compared.All embryos were placed in PZM⁃3 culture medium containing 5 μg/mL of cytochalasinB（CB）for 4h after activation. There was no significant difference in the fusion rate between the two groups（P>0.05），but the cleavage rate and blastocyst development rate of delayed activation were higher than those of synchronous activation group.CB and histone deacetylase inhibitor are also commonly used in the treatment of activated cloned embryos. This study also compared the treatment with cytorelaxin B after delayed activation and the treatment with histone deacetylase inhibitor scriptaid，and found that the latter was more conducive to improving the efficiency of in vitro embryo development.The cloned embryos obtained by the above different methods were transferred，and the statistical results showed that the delayed activation method was more conducive to embryo development. After delayed activation，CB or scriptaid was used to treat the embryos，and the pregnancy rate and cloning efficiency after transplantation were significantly higher than those in the synchronous activation group.

Isolation，Identification and Antibiotic Resistance of Escherichia coli from Pigeons

HOU Gaowei, HUANG Ting

2025, 50(3):  39-45.  DOI: 10.19978/j.cnki.xmsy.2025.03.07

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To investigate the prevalence and drug resistance of Escherichia coli（E. coli）in a pigeon farm in Guangdong，E. coli was isolated and identified from the rectal contents of dead pigeons in this study，conducted antibiotic susceptibility tests on the isolates using agar dilution method，and also detected the drug resistance genes of the isolates using PCR. The results showed that 120 E. coli strains were isolated from 150 samples. The antibiotic susceptibility tests showed that the isolates were resistant to Ciprofloxacin，Ampicillin，and other antibiotics to varying degrees. Of the 120 isolates，74 strains had multiple drug resistance. The PCR detection revealed that the isolates with drug resistance phenotype carried 6 resistance genes，including qnrS、blaTEM、blaCTX⁃M、blaVIM 、aaC4 and sul1. These results indicated that the isolates are resistant to 13 antibiotics to varying degrees，with most of them having multiple resistance. Moreover，the isolates carry multiple resistance genes. This study could provide reference for the prevalence，antibiotic resistance status and clinical rational drug use of pigeon⁃source E. coli in Guangdong Province.

Effects of Inulin on Growth， Fecal Score and Nutrient Apparent Digestibility in British Shorthair Cats

XIAO Zaili, ZHAO Shiyuan, TANG Chao, LIU Ruili, LI Huahao

2025, 50(3):  46-52.  DOI: 10.19978/j.cnki.xmsy.2025.03.08

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This experiment was conducted to investigate the effects of dietary 1% inulin supplementation on growth，fecal score and nutrient apparent digestibility of British shorthair cats. Sixteen healthy adult British shorthair cats aged 1⁃2 years were randomly divided into 2 groups with 8 cat per group. Cats in the control group were fed a basal diet，and those in the experimental group were fed the basal diet supplemented with 1% inulin. The pre⁃feeding period was 7 days and the formal test period was 28 days. The results showed as follows：Compared with the control group，1） Dietary supplementation of 1% inulin had no significant effect on body weight and feed intake of cats（P>0.05）. 2） Dietary supplementation of 1% inulin significantly increased fecal water content and fecal score（P<0.05）. 3）Dietary supplementation of 1% inulin significantly increased the apparent digestibility of crude protein in cat diet（P<0.05）， and tended to increase the apparent digestibility of dry matter，organic matter，calcium and total phosphorus. In conclusion，dietary supplementation of 1% inulin has no significant effect on body weight and feed intake of cats，but can significantly improve fecal water content，fecal score and crude protein apparent digestibility.

Study on the Immune Regulation of Porcine Intestinal Epithelial Cells by Reuterin and its Potential Application in Piglet Health

WU Qi, YANG Xi

2025, 50(3):  53-62.  DOI: 10.19978/j.cnki.xmsy.2025.03.09

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The weaning stage of piglets is confronted with challenges such as imperfect intestinal development， unbalanced microbial community，and an immature immune system，resulting in frequent intestinal diseases and severely affecting growth performance. The search for alternatives to antibiotics is urgent. In this study，Lactobacillus reuteri LR1 strain was isolated from the feces of healthy weaned piglets，and its biological characteristics were analyzed，and the effect of its metabolite reuterin on porcine intestinal epithelial cells（IPEC⁃J2）was explored. The results showed that the LR1 strain grew best at 39.25 ℃ and pH=6.387；reuterin had significant antibacterial activity against ETEC K88，and the inhibitory effect increased with the increase of concentration；it had a time ⁃ and concentration⁃dependent effect on the survival rate of IPEC⁃J2 cells，with cytotoxicity in the early stage and an increase in survival rate in the later stage；different concentrations of reuterin（2 μL/mL，20 μL/mL，50 μL/mL） induced the differential expression of interleukins and chemokines in IPEC⁃J2 cells. This study provides a theoretical basis for the application of reuterin as an antibiotic⁃free feed additive in piglet breeding and helps to promote the green and healthy development of the livestock industry.

Research Progress of Animal Embryonic Stem Cells Directed Differentiation Induction into Germ Cells

ZHU Jinxuan, JU Xianghong

2025, 50(3):  63-70.  DOI: 10.19978/j.cnki.xmsy.2025.03.10

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Embryonic stem cells（ESCs）are embryonic stem cells with self⁃renewal and unlimited differentiation potential，and they can theoretically differentiate into germ cells. At present，the differentiation of ESCs into mature sperm and oocytes has been reported in both human and mouse in vitro. In this paper，the endogenous and exogenous factors and methods of inducing ESCs to differentiate into germ cells in vitro were systematically summarized，and the latest research progress，prospect and application prospect of inducing embryonic stem cells to differentiate into germ cells both domestically and internationally were reviewed，hoping to provide references for researchers engaged in related research.

Nutritional Value of Non - conventional Oilseed Meal and Its Application of Fermented Feed in Broiler Production

LEI Yuheng, Guo Zhaowen, SONG Min, MA Xianyong, CUI Yiyan, YU Miao

2025, 50(3):  71-81.  DOI: 10.19978/j.cnki.xmsy.2025.03.11

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Miscellaneous meal refers to the by⁃product from oil crops after extraction，including rapeseed meal， cottonseed meal，peanut meal and sunflower seed meal. It has high yield and low price，and is rich in protein，fat， and minerals，which make it a valuable unconventional feedstock. However，the high levels of anti⁃nutritional factors present such as crude fiber，tannins，phytic acid and thioglycoside in miscellaneous meal not only impede the digestion and absorption of nutrients but also have toxicological effects，severely constraining the feed utilization of miscellaneous meal. With the advancement and widespread adoption of biotechnological approaches in animal feed production，fermentation of feed raw materials offers a distinctive advantage. Microbial fermentation facilitates the reduction of anti⁃nutrition factors in miscellaneous meal and breaks down indigestible or poorly utilized components into readily absorbable small molecules，enhancing digestion and utilization efficiency of animals. Currently，lactic acid bacteria，bacillus，yeast，and mold are the predominant microorganisms employed in the fermentation of miscellaneous meals. Fermentation also generates valuable metabolites，providing a rich source of probiotics for animals.Reasonable utilization of miscellaneous meal not only save conventional feed resources，alleviate the shortage of domestic feed resources and the situation of“human and animal competition for food”，but also address environmental pollution caused by waste discharge. Miscellaneous meal has broad application prospects in animal production. This paper reviews the nutritional value of miscellaneous meal，changes in nutritional components and anti⁃ nutritional factors before and after fermentation，as well as the application effect of fermented feed in broiler production. It also summarizes the current challenges in the utilization of miscellaneous meal，in order to provide theoretical basis for the application of fermented miscellaneous meal in broiler production.

Application of Clostridium butyricum in Livestock，Poultry，and Aquaculture

CHEN Weijun, LUO Weitao, HUANG Jiaming, CHEN Chen, JIANG Yongjie, WANG Zhuoduo, ZHAO Limei, ZHANG Haitao

2025, 50(3):  82-89.  DOI: 10.19978/j.cnki.xmsy.2025.03.12

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As a Gram⁃positive probiotic capable of producing short⁃chain fatty acids such as butyric acid and acetic acid，Clostridium butyricum has shown significant potential in improving feed utilization，promoting digestion and absorption，supporting growth and development，improving intestinal health，and enhancing antioxidant capacity and immunity. This paper provides a comprehensive review of the application of Clostridium butyricum in livestock， poultry，and aquaculture，focusing on its effects on animal growth，immunity，antioxidant capacity，and intestinal health in order to provide a theoretical basis for practical production.

Research Progress on Mycobacterium Marinum in Fish

JIANG Mengyan, LUO Zhang, WU Yongjiang, SUN Hanchang

2025, 50(3):  90-95.  DOI: 10.19978/j.cnki.xmsy.2025.03.13

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Mycobacterium marinum，a typical pathogen causing zoonotic diseases in both humans and fish， exhibits a complex infection mechanism with diverse host characteristics. In recent years， the incidence of mycobacteriosis caused by this pathogen in global aquaculture has significantly increased. Additionally，the rise in human infection cases highlights its potential public health risk. This review systematically summarizes the genetic diversity of M. marinum，its host adaptation and evolutionary mechanisms，and its pathogenic features in fish and humans. Special emphasis is placed on the molecular mechanisms mediated by the ESX⁃1 secretion system，including immune evasion，lipid metabolism hijacking，and regulation of host cell death. Integrating the cutting⁃edge application of the zebrafish model in tuberculosis research，this paper proposes an innovative approach to address host⁃specific infections through the integration of multi⁃omics and synthetic immunological techniques，providing a theoretical basis for the prevention and control of aquaculture pathogens and the early warning of zoonotic diseases.

Development and Application of a Dual RT⁃qPCR Assay for Detection of Classical and Novel Goose Reovirus

YIN Zhenghao, WEI Wuque, LIANG Zhaoping, LI Yuze, XU Hang, LU Yongkun, MEI Kun, HUANG Shujian

2025, 50(3):  96-104.  DOI: 10.19978/j.cnki.xmsy.2025.03.14

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The Goose reovirus（GRV）comprises two distinct types：the classic（GRV）and the novel goose reovirus （NGRV）. These two types exhibit differences in their epidemiological characteristics and viral gene sequences. The lack of sensitive and specific assays for both types of viruses has resulted in difficulties in accurately diagnosing and timely intervening in cases. In order to distinguish GRV from NGRV，a dual RT⁃qPCR assay based on a dye ⁃ based method（SYBR Green I）was established. The results demonstrated that the method was capable of distinguishing GRV（79.5℃） and NGRV（86.5℃） based on their respective melting curves. Furthermore，no amplification was observed for any of the common waterfowl epidemics，the lowest detections were 6.466×101 copies/ μL GRV and 4.979 × 101 copies/μL NGRV. The results demonstrated that the dual RT⁃qPCR assay，based on a dye⁃ based method，could rapidly and accurately identify different types of GRVs in infected geese. The assay exhibited a high degree of precision，with coefficients of variation less than 0.55% for both intra⁃ and intergroups. This method has the potential to support early diagnosis，epidemiological monitoring and effective prevention and control of the disease.

Improvement of the Purification and Detection Method of Chicken White Dysentery

CHEN Huihong, CHEN Peng, MO Zhixin, GUO Zhaowen, XIE Chunlin, WU Mingying, HE Jingyi, LUO Xuehui, LUO Chenglong, JI Jian

2025, 50(3):  105-110.  DOI: 10.19978/j.cnki.xmsy.2025.03.15

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To investigate the impact of cryopreservation conditions on the detection of antibodies against Salmonella pullorum and the feasibility of using residual plasma after avian leukosis detection for pullorum disease detection，this study selected 3 860 three⁃yellow chickens for pullorum disease testing in batches. The detection results using different anticoagulants，cryopreserved blood samples，serum，and residual plasma were compared with the standard on⁃site whole blood plate agglutination detection. The results showed that the positive detection rates of lithium heparin anticoagulated blood，ethylenediaminetetraacetic acid dipotassium salt（EDTA dipotassium salt， EDTA ⁃ 2K）anticoagulated blood and residual plasma were highly consistent with the on ⁃ site whole blood plate agglutination detection results. The positive individuals detected by the on⁃site whole blood plate agglutination method could be completely detected in both cryopreserved and non⁃cryopreserved serum and residual plasma samples. The positive detection rate of serum samples was slightly higher than the standard method，and short⁃term cryopreservation had no significant adverse effect on the detection results. In addition，the actual application effect of using residual plasma for pullorum purification was evident.

Concept of Detection and Control Strategies for African Swine Fever Gene Type I Strains

LI Songchao, LIU Wen, JIANG Biao, SU Weitong

2025, 50(3):  111-114.  DOI: 10.19978/j.cnki.xmsy.2025.03.16

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There are significant differences in clinical manifestations between pigs infected with African swine fever genotype Ⅰ and genotype Ⅱ strains. In addition to ensuring biological safety on a daily basis，the testing plan of the breeding farm also needs to be adjusted according to the characteristics of the virus to ensure that the risks present on site can be detected as early as possible. A reasonable detection and prevention plan is crucial for the clinical prevention and control of African swine fever. The author will briefly discuss some ideas for clinical testing strategies based on the characteristics of genotype I strains，in order to provide reference for the scientific prevention and control of African swine fever.

A Case of Reverse Remodelling Secondary to Rupture of Chordae Tendineae in a Dog with Myxomatous Mitral Valve Disease

RUAN Qianhua, LIN Jiayan, Lin Shiqi, LI Ying, Liu Chuandun

2025, 50(3):  115-120.  DOI: 10.19978/j.cnki.xmsy.2025.03.17

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Abstract：usually results in severe mitral regurgitation as well as marked dilatation of the atria and ventricles. As compensation progresses in the hearts of dogs with tendon rupture，it can manifest as reverse cardiac remodelling， whereby the originally dilated heart becomes smaller or even returns to normal. A 10⁃year⁃old brown poodle came to the hospital with significant exercise intolerance. Echocardiography revealed a ruptured mitral tendon cable with significant systolic regurgitation and marked left atrial and ventricle dilatation. Reexamination of the affected dog（at 3⁃ and 9⁃months post⁃diagnosis）revealed a gradual improvement in the degree of cardiac dilatation to normal size， consistent with cardiac reverse remodelling features. The affected dog had a favourable prognosis and showed a significant decrease in the frequency of exercise intolerance. Cases of cardiac reverse remodelling are uncommon in clinical practice. The authors report the long⁃term echocardiographic follow⁃up and diagnosis of the affected dog in this case in order to provide diagnostic ideas and references for the clinical diagnosis and treatment of this type of reverse remodelling in MMVD dogs with rupture of chordae tendineae.