SUMMARY

The direct influence of piperazine adipinate, nilverm and atazole-forte on the eggs of Toxocara canis has been studied. It has been discovered, that these preparations don't render immediate ovicidal effect, although they delay the development of eggs.

INTRODUCTION

Nowadays the large quantity of anthelminthic preparations is applied for animal and human deworming in veterinary and medical practice. There are unitary data about direct influence anthelminthics on worms egg in existent literature. According to V.F. Melashenko and A.M. Kelina (1957), Ascaris lumbricoides eggs develop normally after oxygenotherapy. E. I. Malakhova (1958) and O.I. Plaan (1961) noticed that santonine, sodium fluoride and tetrachlormethane did not render any influence on the development and infestive properties of Ascaris suum and Parascaris equorum eggs after deworming. O.I. Plaan (1961) also noticed that Ascaris suum eggs matured to infestive stage in usual terms after faeces treatment with santonine, sodium fluoride, hexachloroethane or phenothiazine in 1:100-1:2000 proportions. According to H. Kutsumi and Y. Komiya(1965), thiabendazole renders ovicidal action on eggs of ascarides and whipworms in concentrations from 4 x 10^-4 to 3.9 x 10^-7 within 3 to 7 days. According to H. Maissoneuve and I.F. Rossignol (1985), albendazole renders high ovicidal effect on Ascaris lumbricoides, Ancylostoma duodenale and Trichocephalus trichiuris eggs.

Taking into account the above-mentioned circumstances, we decided to test in vitro the influence of several anthelminthic preparations, which were popular in veterinary practice in our country, on the eggs of Toxocara canis ( Werner, 1782 ), which is the most distributed canine roundworm in Armenia and all over the world.

METHODS AND AIMS

The researches were carried out in February - March, 2002, at the Department of Parasitology of the Armenian Agricultural Academy. As an object of researches Toxocara canis eggs were chosen because of wide prevalence of toxocariasis. Besides, this disease is also extremely dangerous for people. The eggs of T. canis were separated by the method of N. A. Romanenko and N. I. Khijnyak (1972) from faeces of intensively infested dogs. The eggs were at the zygote stage.

The experiments were carried out in vitro. The influence of following anthelminthic preparations on T. canis eggs was tested:

 1. 2.5% and 1% aquatic solutions of piperazine adipinate;

 2. 2% and 1% aquatic solutions of nilverm, the analog of tetramizole;

 3. 1% and 0.5% aquatic solutions of atazole-forte, the analog of albendazole.

The running water was taken as a control. Toxocara canis eggs were placed in solution of tested anthelminthics in proportions - 1000 eggs in 5 ml of solution. The prepared suspensions were poured out into the bottles and placed into thermostat at the temperature +30degreesC. The observations on the eggs were performed in dynamics during 14 days: the first 5 days- every day, and after that - day about.

RESULTS

The results of study of anthelminthics influence on T. canis eggs are adduced in the following table:

Table: Comparative dynamics of Toxocara canis eggs development under the influence of anthelminthic preparations

DISCUSSION

The table shows, that the development of T. canis eggs in aquatic solutions of anthelminthic preparations is considerably slowed down. However, the anthelminthics in above-mentioned concentrations do not result in eggs destruction.

The strongest ovostatical action render the aquatic suspensions of atazole-forte. In 1% and 0.5% aquatic suspensions of this preparation the eggs develop only to the morule stage, which is reached at 8th day. The death of eggs begins since 6th day.

Weaker ovostatical action render 2% and 1% aquatic solutions of nilverm. In 2% solution the eggs develop only to the thick larva stage and in 1% develop to 1st stage immobile larva, which is reached within 9th day. The death of eggs in solutions of nilverm is not noticed.

The weakest ovostatical influence has been noticed in 2.5% and 1% aquatic solutions of piperazine adipinate. The 1st stage larvae in 2.5% solution have been reached at 9th day and the 2nd stage larvae have been reached at 14th day. These solutions have not caused eggs destruction.

CONCLUSIONS

Therefore the tested anthelminthic preparations form following row by their ovostatical action:

atazole-forte(albendazole)- nilverm (tetramisole)- piperazine adipinate.

Besides the results of the researches show that T. canis eggs are capable to reach the 2nd stage infestive larvae in aquatic solutions of piperazine adipinate, and thus animals dewormed with piperazine adipinate, will be carried out with special precaution, and the animals will be forcedly tied, and their faeces will be disinfested after deworming.

REFERENCES

1.  H. Kutsumi, Y. Komiya. Effect of thiabendazole as an ovicide on helminth eggs in nightsoil // Jap. J. Med. Sci. Biol., 1965, v.18, #4, p. 203-224.

2.  H. Maissonneuve, I. F. Rossignol. Ovicidal effects of albendazole in human ascariasis, ancylostomiasis, and trichuriasis // Ann. Trop. Med. Parasitol., 1985, v.79, #1, p. 79-82.

3.  E.I. Malakhova., The influence of anthelminthics on parasitic worms eggs and larvae, eliminated from animals after deworming // NHIAS STI Bulletin. Moscow, 1958, #3, p. 48-55.

4.  V.F. Melashenko, A.M. Kelina. Ascarides eggs development after oxygenotherapy // Medical Parasitology and Parasitic Diseases. 1957, Suppl. to #1, p. 68.

5.  O.I. Plaan., In influence of some physical, climatic and chemical factors on Ascaris suum (Goese, 1782) eggs // "The Questions of Parasitology in Baltic Republics". Riga, 1961, p. 107-110.

6.  N.A. Romanenko, N.I. Khizhnyak. The helminth eggs pure culture separation method during evaluation of environmental sanitary conditions // Hygiene and Sanitation, 1972, #9, p. 72-75.