"Rush out of the worm fence" pure dry goods! Those things about parasites inside and outside pigs

Moxidectin, also known as Moxystin, is a macrolide antibiotic produced by the fermentation of Streptomyces, which belongs to Milbemycin. It is characterized by a single ingredient, higher insect repellent activity, long-term effect, safety and so on.

First, chemical properties and pharmacokinetics

Moxyctin is highly lipophilic, so its distribution concentration in fat is extremely high. Studies have shown that 28 days after bovine is given, its concentration in fat is 10 times that of ivermectin, and it is widely distributed in various tissues and fluids such as mucosal fluid, bile, feces, skin, and plasma[1]. The concentration of moxiketin in the peritoneal and intestinal mucosal tissues is higher than in plasma. Jalees Afzal et al. studied its absorption, distribution, excretion and biotransformation in sheep with 14C and 2H-labeled moxyctin, and at days 1, 7, and 28, the concentrations of moxyxiktin in adipose tissue were 249, 305, 118 ng/g (the average of omental fat and dorsal fat), respectively, at the same time point, at the liver (135, 50, 17 ng/g), kidney (41, 22, <4 ng/g) and psoas muscle (25, 12, <4ng/g) are distributed in both [2].

Lanusse et al. studied the pharmacokinetics of moxidectin in bovine and compared it with IVM and dorameicin [3]. The results showed that the absorption rate of MXD was significantly faster than that of ivermectin and doramin, and the peak time of plasma concentration of moxyxidine was also faster than that of ivermectin and doramin. There is no difference in peak concentrations between them. The mean time of retention in plasma was the highest (14.6 days), followed by doramusin (9.09 days) and the lowest ivermectin (7.35 days).

Moxyctin is mainly excreted through bile and feces (about 5%), followed by milk, a small amount of self-urine (<1%), and the drug concentration in fat, target tissue and milk is significantly higher than that of ivermectin. From the detection of residues in tissues, fats and feces, moxyctin is the main form of residue.

Second, anti-insect spectrum and activity

In general, moxiqtin can be used to fight a variety of in vivo and in vitro parasites. Among them, the internal parasites are mainly nematodes, and the external parasites are mites, ticks and lice. At present, it is mainly used clinically for parasite control of cattle, sheep, pigs, horses and companion animals.

In terms of anti-helminth and mite killing, moxyctin and avermectin are more similar. For example, at 200 μg/kg, both are ineffective against cow skin flies. The activity of moxykidine is mainly anti-worm spectrum, and it can also repel horse toothless roundworm, common round nematode, three-toothed nematode, fly soft nematode, etc. [5,6]. Efficacy tests of moxiquetine have shown that there is a deworming rate of >9% in the larvae and adults of bovine gastrointestinal nematodes and lung nematodes, and the duration of efficacy is generally 5 to 6 weeks. Moxikkidine can also treat in vitro parasites in dogs and rabbits and is now approved for the treatment of scabies mites in dogs, but when used for parasitic diseases in dogs, the oral route is safer and has fewer side effects than subcutaneous injections [7]. Another study has shown that the recurrence time of eggs after medication is the 84th day of moxyxidine, and the ivermectin is excreted on the 42nd day, which indicates that the efficacy of moxicltin is more durable than that of ivermectin [8].

The deworming rate of moxikkidine 0.5% pouring agent on pigs can reach more than 98.9%. Moxiktin has a good killing effect on digestive tract nematodes and lung nematodes in pigs. The 0.5% moxikktin pourer was used in pigs at a dose of 0.75 mg/kg body weight, and the repellent effect on porcine roundworms, pig hairy nematodes, posterior roundworms, and toothed esophageal nematodes was 98% after 14 days [9].

Third, the dosage form used

The most used dosage forms of moxiqtin today are injections, pastes and pours. Several studies have shown that injecting moxyketin in recommended doses to cattle, sheep, and camels is effective and safe for the prevention and control of internal and external parasites [10]. Due to their long-lasting insect resistance, animal safety, and good insect repellent effect, the caster has been widely used worldwide, and its active activity and insecticidal efficacy have been frequently reported [11]. Stewart et al. used moxiqtin 0.5% pouring agent to conduct experimental observation of pig nematodes, and the results showed that for the cases of comprehensive infection, the deworming rate of moxiqtin pouring on a variety of pig nematodes reached more than 98.9%, and only the effect on pig hairy nematodes changed greatly. Vercruysse et al. also compared the efficacy of moxiqdin pouring and injection against Osteriasis and its eggs, and the study proved that the moxiqtin pouring agent had a shelf life of 6 weeks for repelling adult insects and inhibiting insect eggs, and the injection was 5 weeks, and the insecticidal efficacy of the injectable agent was higher than that of the injection.

Fourth, safety

As a new generation of avermectin-based drugs, moxyxiktin is safer than ivermectin, and moxiquetin generally does not have a toxic reaction within the normal dose range. Due to the high fat solubility of moxiquetine, the drug has a high content in fat and a long residence time, and milk is a very important way of excretion of moximesin, so in the production of meat and dairy products, it is necessary to pay attention to the drug residue of the drug and reasonably formulate the drug suspension period.

5. Concluding remarks

Although moxyxiktin, like other avermectin-based deworming drugs, only has a better deworming effect on parasites of certain species than the previous generation, it is superior to ivermectin and doramusin in terms of drug resistance, dosage and distribution of drugs in vivo, so it is a class of antiparasitic drugs worth vigorously promoting.