Introduction: The development of sustainable animal husbandry plays an important role in establishing food security, improving welfare, increasing the income of rural households, improving productivity, creating job opportunities, creating links with other economic sectors, and rural development. In Iran, the issue of sustainable development of the animal husbandry industry and creating sustainability is one of the most important issues of the country because the animal husbandry industry is one of the most important sub-sectors of the agricultural industry, which produces the most important basic food of the country, i.e., red meat. The main goal of this research is to identify and prioritize the obstacles and problems of sustainable animal husbandry development in Guilan province. The development of the agriculture and animal husbandry industry is necessary to access a sufficient amount of food and energy and to cover the ever-increasing demand due to the increase in the population. Guilan province has a suitable capacity for the development of animal husbandry activities. Paying attention to the existing research gaps, by summarizing findings in this field, using the opinion of animal husbandry industry experts, and the application of the multi-indicator decision-making model, this study identified the obstacles and problems for the development of sustainable animal husbandry in Guilan province. Materials and methods: Various criteria have been introduced in previous research as key factors for the sustainable development of animal husbandry, the most important of which included structural, institutional, economic, cultural, social, environmental, macro goals and strategies, the process and cycles of providing inputs, and selling livestock products. The decision tree was drawn using the findings of similar studies and the opinions of provincial experts in this industry. The data collection tool is a questionnaire for pairwise comparisons of decision tree criteria and sub-criteria. To determine the weight of the criteria and sub-criteria included in the decision tree, the opinions of 10 experts in this field in Guilan province were collected and analyzed using the Fuzzy Hierarchy Process (FAHP). Fuzzy set theory is a mathematical theory designed to model the ambiguity of processes related to human knowledge. The decision maker can freely choose the range of desired values. Also, the uncertain judgment of the expert can be expressed by a fuzzy number. In this method, fuzzy numbers are used for the pairwise comparison of options, and the decision maker can express the pairwise comparisons of the elements of each level in the form of triangular fuzzy numbers. The decision tree for this research has five main criteria including institutional, environmental, social and cultural, structural, and economic factors, and 31 different sub-criteria. FAHP is a systematic method that uses the concepts of fuzzy set theory and hierarchical structure analysis. The calculated weights are a suitable basis for prioritizing the main obstacles and problems in the sustainable animal husbandry industry development of Guilan province. Modeling and obtaining the results were done in the MATLAB software. Results and discussion: The results of the research showed that from the point of view of experts, institutional and economic obstacles with the weights of 29.71% and 19.23%, respectively, are considered to be the most important obstacles to the development of sustainable animal husbandry in Guilan province. On the other hand, the sub-criteria of low attention to the animal husbandry sector in the provincial policies from the institutional criterion, the inappropriateness of the materials used, considering the weather conditions from the environmental criterion, the low status and job position of animal husbandry from the social and cultural criterion, the lack of high-yielding breeds consistent with the conditions of the region from the structural criterion, and the lack of adequate insurance coverage from the economic criterion have the highest rank among the sub-criteria. Conclusions: The obtained results indicated the high level of obstacles and problems for the development of sustainable animal husbandry in Guilan province, which requires the attention of policymakers and the development of a policy package that fits the priorities determined in this study. [ABSTRACT FROM AUTHOR]