Commonly used deworming drugs and deworming methods for cattle and sheep
Internal and external parasitic diseases of cattle and sheep are a worldwide problem, which is not only serious in the middle and small cattle and sheep farms. Even in large cattle and sheep farms with good management, advanced equipment and deworming, parasitic diseases exist to varying degrees. Deworming of cattle and sheep is a must. It is often overlooked because it does not cause a significant number of deaths in most cattle and sheep farms or cattle and sheep herds. But such indirect losses can account for a significant portion of the economic benefits. It affects the quality and sales of cattle and sheep, and affects the rapid fattening and health of cattle and sheep. Nowadays, veterinary science has been very clear about the pathogens, life history, occurrence and infection rules of the main parasitic diseases of cattle and sheep, but many cattle and sheep farms have not been able to effectively control the parasitic diseases. Insufficient understanding of the hazards of parasitic diseases; the two are improper selection of drugs and imperfect control programs. Only by reducing the losses caused by bovine parasitic diseases to a minimum, can the production performance of cattle and sheep reach an ideal level, so it is necessary to do a good job in the prevention and control of cattle and sheep parasitic diseases.
1 Types and selection of deworming drugs for cattle and sheep
At present, the most widely used anthelmintics in my country mainly include the following categories:
1.1 Organophosphates are low-toxic organic phosphorus compounds, commonly used as insecticides and anthelmintics, mainly including trichlorfon, dichlorvos, and phosphatophos. Among them, trichlorfon is used more. Trichlorfon is a broad-spectrum anthelmintic, which can expel a variety of bovine digestive tract nematodes, such as bovine roundworm, hair head nematode, esophagus nematode, and external use can also kill external parasites, such as mites, lice, fleas, ticks etc. Trichlorfon is administered in a mixture of 80-100 mg/kg body weight each time. For external use, it can be rubbed or sprayed at a concentration of 1%. However, trichlorfon is highly toxic and has a narrow safety range, so be careful not to overdose when using it. Pregnant cattle and cattle suffering from gastroenteritis are prohibited, and should not be used in combination with alkaline drugs. Due to the toxicity and side effects of such drugs, and the deworming effect is not ideal. Therefore, the number of users has gradually decreased in recent years. The discontinuation period for this drug is 7 days.
1.2 Amidine compounds are synthetic contact broad-spectrum insecticides for external use, mainly using amitraz, which is a crystalline powder and hardly dissolves in water, so it is mostly used in emulsions. Such as amphetamine EC, special enemy grams. It has a killing effect on various mites, lice, ticks, flies, etc., and can affect the vitality of eggs, and is harmless to humans and animals. When used, it is formulated into a 0.05% solution, which is often used in cattle bodies and the ground and walls of livestock houses. The drug withdrawal period is 7 days.
1.3 Imidazoprothiazoles Currently, levamisole is mainly used in veterinary clinics. It is a broad-spectrum, high-efficiency and low-toxic nematode drug, which has a good expelling effect on bovine roundworm and esophagus nematode. The dose of oral administration or injection is 7.5 mg/kg body weight, injected subcutaneously or intramuscularly. The injection is irritating to the local area, and at the same time often causes symptoms such as lack of energy, salivation, and coughing. However, if the cattle are infected with bovine lung filariasis or strongyloidia, the salivation and coughing help to accelerate the excretion of the worms. The discontinuation period for this drug is 7 days.
1.4 Benzimidazoles are broad-spectrum, high-efficiency, and low-toxic anthelmintics. There are many kinds of such drugs, but the most widely used in veterinary clinics is albendazole, also known as prothiobendazole and antihelminth. There are also fenbendazole, mebendazole, etc. in clinical applications, and some are used in compound preparations. These drugs have expelling effects on many nematodes, flukes and tapeworms, and have a killing effect on the larvae of some nematodes, and also have an inhibitory effect on the hatching of eggs. The oral dose of albendazole to cattle is 10-30 mg/kg body weight. Albendazole has poor palatability. When mixed feeding is administered, it should be added less each time and administered in multiple doses. This drug has the possibility of teratogenicity, and a large number of continuous applications should be avoided. The discontinuation period for this drug is 14 days.
1.5 Macrolides are relatively new broad-spectrum, low-toxicity and high-efficiency drugs. Their outstanding advantages are that they have a high killing effect on both internal and external parasites in livestock and poultry. Adult worms also have a killing effect on the developmental larvae of some nematodes at a certain stage. These drugs are represented by abamectins in livestock and poultry anthelmintics, mainly including abamectin, ivermectin and doramectin. As roundworms and scabies mites are the parasites with the highest infection rate and the most serious harm in all cattle farms, this kind of drug that can kill and kill the internal and external parasites that are the primary harm to cattle at the same time has a high Practical value. However, many cattle and sheep farms or cattle and sheep farmers have misunderstandings in the understanding of this drug or the use of technology, deworming programs, etc., so that this ideal deworming drug cannot give full play to its excellent effects. The following focuses on these drugs, so that they can be used correctly in the production of cattle and sheep.
2.1 The anthelmintic range of avermectins, avermectins have the advantage of simultaneously expelling internal and external parasites in cattle and sheep. Adults and most of the fourth stage larvae of bovine esophagus nematode, tuberculosis, and hairhead nematodes, whipworms, etc., as well as strong nematodes, lung worms, bovine crown nematodes, bovine kidney worms of lung nematodes Adults have repelling and killing effects, and also have a good killing effect on scabies mites and blood lice on cattle and sheep, but have no killing effect on their eggs. Avermectins have no effect on tapeworms and flukes, pouch ciliates, bovine coccidia, etc.
2.2 The selection of avermectin drugs and the deworming program. The dosage forms of avermectin dewormers include oral preparations, injections and external pouring agents. Oral dosage forms include powder, tablet, capsule, paste, etc. Among these different dosage forms, 0.2% or 1% oral premix made from pure powder is more commonly used, so it is more convenient to mix it into feed orally. However, the injection has the highest bioavailability, and the combination of the drug and the subcutaneous fat after subcutaneous injection can play a certain slow-release effect, so that it not only has the effect of killing and killing infected parasites, but also maintains the blood concentration for a long time. Longer, so it can also protect cattle from re-infection due to environmental pollution and parasites within a certain period of time, which has the dual effect of treatment and prevention. Ivermectin is improved on the basis of avermectin, and its advantage is to reduce toxicity, so ivermectin should be used as much as possible. However, the market price of ivermectin is slightly higher than that of avermectin. Ivermectin injection is usually 1% preparation for cattle. Generally, it can be calculated as 0.3 ml per 10 kg of body weight. It should be injected subcutaneously with a short needle, not into muscles or blood vessels; the local stimulation of domestic preparations is slightly greater than that of imported products. The procedure for the use of injections can generally be done once at the age of 40 days, before the breeding of the heifers, and 2 weeks before the birth of the pregnant cows. Breeding cows are also injected once during mating, and 3-4 times a year for breeding bulls. Breeding cattle, especially bulls, suffer from stubborn scabies. If there is thick scab on the local area and cannot be cured for a long time, the injection dose and frequency of medication can be increased. 1% ivermectin can be used for each course of treatment at a dosage of 0.4 ml per 10 kg of body weight. 1 injection every 5-7 days, continuous application until recovery. Oral powder usually uses 0.2% premix. For calf or one-time deworming, it is generally mixed into the feed at a dosage of 5 grams per 30 kilograms of body weight. If the whole field deworming plan is adopted and the deworming effect is improved, it is best to use the method of divided doses. It should be calculated by mixing 0.2% premix per ton of feed according to the age of the cattle. Cattle and breeding cattle are used in dosages of 1.5 kg, 2.0 kg and 2.5 kg respectively; the dosage for severely infected breeding cattle can be increased to 3.5 kg, and the above doses, if converted into pure powder, are about 0.1 mg per kg body weight, or Each kilogram of feed contains 2 mg, and the herds using the above doses should be fed with the mixture for 7 consecutive days. The time of administration should be 3 weeks before delivery of breeding cows and once before breeding, 1 time before breeding for heifers, 3-4 times per year for breeding bulls, and 1 time for beef calves transferred to finishing sheds. Special attention should be paid to the formulation and implementation of the deworming program. For the first deworming, all cows on the farm should be treated uniformly, except for milk and beef calves. At the same time, drugs should be administered to eliminate the source of infection. This can achieve twice the result with half the effort. According to the test, two strict full-field deworming can reduce the pollution rate of bovine roundworm in the environment from 70% to close to zero.
Post time: Sep-13-2022