What are the basic principles for the rational application of antibacterial veterinary drugs?

The basic principles for the rational application of antibacterial veterinary drugs are:

(1) Have strict indications. Different antibacterial veterinary drugs have different indications. Penicillins, tetracyclines, chloramphenicol, erythromycin, etc. are mainly effective against diseases caused by Gram-positive bacteria, such as swine erysipelas, tetanus, anthrax, equine bubonic plague, streptococcal inflammation, septicemia, etc.; aminoglycosides , chloramphenicol, etc. are effective against diseases caused by Gram-negative bacteria, such as pasteurellosis, enteritis, and urinary tract inflammation; enzyme-resistant penicillin is effective against respiratory infections and sepsis caused by penicillin G-resistant Staphylococcus aureus. The drugs of choice; gentamicin, polymyxins, etc. are effective against wound infections, urinary tract infections, pneumonia, sepsis, etc. caused by Pseudomonas aeruginosa; sulfonamides are mainly effective against most Gram-negative and positive bacteria such as Streptococcus, Pneumococci, Salmonella, Corynebacterium pyogenes, etc. all have high inhibitory effects.

(2) Choose the appropriate dosage and course of treatment. When using antibacterial veterinary drugs, the dosage and appropriate course of treatment must be selected. Generally, a larger dose can be used when starting treatment, and after the blood drug concentration reaches a high level, the dose can be reduced according to the condition of the disease. The duration of medication depends on the type of disease and the condition of the animal. In cases of acute infection, the course of treatment should not be too long, and the drug can be stopped about 3 days after the infection is controlled. For some chronic infections, the course of treatment should be appropriately extended to consolidate the curative effect. Otherwise, blindly increasing the dosage will cause pharmaceutical and economic losses, and may also cause adverse reactions in affected animals. If the dosage is insufficient or the course of treatment is too short, the therapeutic effect will not be achieved and bacteria will develop drug resistance.

(3) The combined application of antibacterial veterinary drugs may produce synergistic, additive or antagonistic effects. If the combination of drugs is well chosen, synergistic and additive effects can be achieved to improve efficacy, reduce the dosage of antibacterial drugs, and reduce toxic reactions; if not well chosen, antagonism may occur. Therefore, the best drug combination should be selected for combined application. In general, two antibacterial veterinary drugs should be used in combination, and in special circumstances, three or more drugs should be used in combination. However, when using drugs in combination, attention should be paid to possible incompatibility:

① In infusion, some drugs often appear turbid, discolored, precipitated and have reduced antibacterial activity after mixing. For example, penicillin G should not be combined intravenously with tetracyclines, aminoglycosides, polymyxin E, amphotericin B, sulfonamide sodium salt and sodium bicarbonate, amino acids, vitamin C, norepinephrine, chlorpromazine, etc.

② Tetracyclines are incompatible with many drugs and are suitable for intravenous administration alone. It is not advisable to take it with drugs or feeds containing iron, calcium, aluminum, magnesium, bismuth, etc., because it can form a complex that is not easily soluble and affects absorption; it is also not suitable to take it with sodium bicarbonate, because the latter can increase the pH value and cause Reduce its solubility.

③ When the two drugs are used together, the toxicity may be aggravated. For example, the combination of aminoglycosides and cephalosporins can cause acute tubular necrosis; the combination of gentamicin and furosemide can enhance ototoxicity.

(4) There must be clear clinical indications to avoid the abuse of antibacterial veterinary drugs. When selecting appropriate antibacterial veterinary drugs based on the clinical diagnosis, the systemic condition of the affected animal and the severity of the infection, the following points should be noted:

① Those diagnosed with viral diseases or infected by viruses should not use them because general antibacterial veterinary drugs In particular, antibiotics have no antiviral effect.

② It should not be used in animals with unknown causes of fever, because use may make it difficult for pathogenic microorganisms to be detected, making clinical manifestations atypical, affecting correct diagnosis or delaying timely treatment.

③ Try to avoid local application on skin, mucous membranes, etc. to prevent allergic reactions or the development of drug-resistant bacteria.

(5) If an unexpected situation such as allergic reaction occurs, you should stay calm and choose appropriate drugs to rescue.