The task of modern veterinarians is not only to ensure the development of animal husbandry, but also to reduce the harm of human and animal diseases and improve the hygienic quality of animal food (meat, eggs, milk, aquatic products, etc.). ) and improve environmental sanitation, thus directly serving human health.
Veterinary clinical diagnosis and treatment work is mainly based on expensive individual livestock or breeding animals, as well as some accompanying animals and ornamental animals. Generally, the prevention and control of livestock is mainly based on whole groups.
The rapid development of industrialized intensive livestock and poultry breeding has increased the responsibilities of veterinarians in the selection of breeding sites, the design of barns, the preparation of feed additives, the formulation and implementation of immunization procedures for environmental sanitation management, disease diagnosis and immune level monitoring, so as to improve the health level of livestock and prevent the occurrence of group diseases, including infectious diseases, parasitic diseases, poisoning diseases and nutritional metabolic diseases. Hundreds of such diseases have been discovered. Infectious diseases are the most harmful, but many of them have been eliminated.
By the end of 1986, the infectious diseases of livestock in developed countries were: Denmark 18, the United States and Japan 13, Britain 10, Australia 7, the Soviet Union and the Federal Republic of Germany 6. Rinderpest, which once killed hundreds of thousands or even millions of cattle every year in China, was eliminated in 1956.
But at the same time, many new diseases have emerged, such as viral infectious diseases (such as swine vesicular disease), toxic diseases caused by serious pollution of pesticides, fertilizers and industrial wastes, nutritional and metabolic diseases. Some of them have no effective prevention and treatment methods so far, while others (such as metabolic diseases and malnutrition) are related to one-sided pursuit of high yield. This puts forward a new topic for veterinary workers.
In order to prevent the occurrence of nutritional metabolic diseases at an early stage, the current veterinary work should not only observe whether the cattle have clinical symptoms, but also determine whether the expected production indicators can be achieved under certain conditions and whether the metabolism in the body is in a balanced state. Usually, the metabolic profile of high-yield cattle is tested by blood chemical analysis to predict recessive or subclinical cases of nutritional metabolic diseases.
In many European and American countries, because dogs and cats are regarded as pets, the diagnosis and treatment of accompanying animal diseases such as dogs and cats has become an important business of veterinarians in these countries, which has also promoted the development of small animal medicine; Ornamental animals, including wild animals kept in zoos and birds kept at home, have also increased greatly in recent decades; More and more wild animals with high economic value, such as foxes, minks, sika deer and musk deer, are raised artificially. Their diseases are not only various, but also very complicated, which also requires a lot of research work by veterinarians.
In addition, the cultivation of experimental animals puts forward stricter requirements for veterinary work. Some experimental animals need sterile animals or animals without specific pathogens to draw accurate conclusions in research experiments on immune mechanism, metabolic mechanism and pharmacology. Experimental animal science has become a new branch of veterinary science.
Infectious diseases originating from abroad can lead to the epidemic of the disease in China, resulting in huge economic losses. For example, contagious bovine pleuropneumonia introduced to the United States from abroad in 1980s 19 was finally put out after slaughtering a large number of sick cows and cows that had contact with sick cows. Porcine atrophic rhinitis and mycoplasma pneumonia introduced from Japan by buying breeding pigs from abroad spread to pig farms all over the country, and the infection rate reached 50 ~ 60% in severe cases.
Infectious diseases imported from abroad are also common in China. For example, when 19 19 bought cows from abroad, it brought contagious bovine pleuropneumonia to Shanghai. Atrophic rhinitis was brought into pigs when it was imported from 1963. Others such as bovine infectious rhinotracheitis, treponema suis dysentery, etc. It was also introduced by breeding animals bought from abroad. At the same time, domestic livestock pathogens may also flow abroad with the export of sick livestock. Therefore, it is one of the important tasks of veterinarians to carry out strict import and export quarantine according to laws and regulations, investigate the epidemic situation in the producing areas and eliminate various pathogens.
Veterinarians' main task in this respect is to implement the food hygiene laws and regulations promulgated by the state, such as health supervision and inspection of all links before and after the production of animal foods such as meat, eggs, milk, fish, etc., to prevent the spread of infectious diseases pathogens of livestock, including human and animal diseases and germs, and endanger human health.
Veterinary medicine and medicine have the same basic theory and treatment standard, and many human diseases can be manifested in some animals in extremely similar mechanisms and forms. This kind of disease is called the animal model of human disease and is often used in the study of human diseases. For example, the study of chicken viral tumor disease and chicken Marek's disease can be used for reference to study the occurrence of human tumors. Physicians and veterinarians often study some surgical operations based on animal diseases. In addition, preventive medicine and comparative medicine have become the disciplines of veterinary medicine and medicine, which are of great significance for preventing biological warfare, chemical warfare, atomic warfare and developing space medicine.
At present, with the new achievements of many related disciplines, veterinary medicine is increasingly applied to the study of livestock diseases, and develops to a higher level. The initial success of genetic engineering technology in developing vaccines for foot-and-mouth disease, rabies and diarrhea of young animals will open the way for developing subunit vaccines or synthetic peptide vaccines for epidemic diseases.
Monoclonal antibodies produced by cell engineering technology will make veterinary diagnosis more accurate and rapid. Computers and lasers have been used in veterinary medicine. The prevention and treatment of diseases of wild animals and ornamental animals is a field to be developed.
With the increase of air transport volume of livestock and poultry, the effects of air transport on physiology and pathology of livestock and poultry will be studied. At the same time, international cooperation in monitoring and prevention of epidemics will be further strengthened. Consistent with the above development, paying more attention to veterinary education and scientific research has become a common trend in many countries.