Method of deworming before development of clinical and pathological signs characteristic of late stage of acute ascariasis in group of piglets

Abstract

FIELD: agriculture.SUBSTANCE: used for early diagnosis and implementation of antiparasitic measures for acute ascariasis in piglets. The method includes a pathological autopsy of sick and forcibly killed piglets to study pathomorphological changes. If traces of larval migration are detected in the form of venous hyperemia of the liver with funnel-shaped depressions and point damage to the capsules, as well as ecchymotic subcapsular hemorrhages at the sites of implanted larvae, an early stage of acute ascariasis in piglets is diagnosed and deworming of the group is carried out against the larval stage of roundworms.EFFECT: prevention of mortality in groups of piglets.1 cl, 7 dwg, 2 ex

Description

[0001] The invention relates to agriculture, in particular veterinary medicine for early pathological diagnosis of acute (migratory) ascariasis in piglets for drawing up a plan of therapeutic and prophylactic antiparasitic measures aimed at reducing economic damage.

[0002] Piglets become infected by ingesting infective ascaris eggs. Larvae hatch in the intestines, and the eggs penetrate the intestinal mucosa and are carried by the bloodstream through the portal vein to the liver. The larvae then travel through the pulmonary circulation to the lungs and are swallowed in the oral cavity with saliva, where they develop into adulthood in the small intestine.

[0003] The disease is characterized by pneumonia (during the period of larval migration through the lungs), a sharp delay in the growth and development of piglets, accompanied by damage to the digestive tract and decreased resistance to various other diseases. Clinical signs of ascariasis appear primarily in piglets aged 2 to 6 months, which at this time have a difficult time coping with the infection [1, 2, 3, 4].

[0004] A known method for diagnosing acute ascariasis involves cutting the lungs of a dead or slaughtered piglet into small pieces in warm water, and using the Berman method, detecting ascaris larvae in the sediment. The data obtained serve as the basis for making a diagnosis and developing a plan for antiparasitic treatment and prophylactic measures [1,5].

[0005] A disadvantage of this method is that the larvae migrate from the intestines through the liver, diaphragm, and heart before reaching the lungs [1]. Therefore, acute ascariasis can only be diagnosed by this method in the penultimate stage of infection. Inflammatory processes and multifocal hemorrhagic infiltrates in the affected organs begin to develop early in the disease [2], when the larvae from the intestines reach the liver.

[0006] The purpose of the invention is to diagnose the early stage of acute migratory ascariasis in piglets, for antihelminthic treatment and preventive measures, and to prevent mortality and economic damage.

[0007] This goal is achieved by performing a postmortem examination of sick and forcibly slaughtered piglets to study the pathomorphological changes. If traces of larval migration are detected, such as venous congestion of the liver with funnel-shaped depressions and punctate capsule lesions, as well as ecchymotic subcapsular hemorrhages at the sites of larval penetration, the early stage of acute ascariasis in piglets is diagnosed and deworming is performed against the larval stage of ascarids.

[0008] Pathological changes (traces of parasite migration) are studied on the capsule of serous tissues, organ membranes, and the organs themselves, starting with the small intestine and continuing to the liver along the migration path of parasite larvae. Detected traces of larval migration in the liver serve as the basis for diagnosis in the early stages of acute ascariasis, before the development of clinical and pathological signs characteristic of the late stage of acute ascariasis. These changes are aimed at eradicating the pathogen, reducing metabolism, restoring productivity, and obtaining high-quality products.

[0009] The technical result of the claimed invention is the early diagnosis of acute ascariasis, the preparation of a plan of antiparasitic treatment and preventive measures with the optimization of their metabolism and natural resistance.

[0010] Among the sources of information available to the applicant, no method for early pathological diagnosis of acute ascariasis is known that would allow the specified technical result to be obtained; therefore, the claimed invention meets the patentability requirement of “novelty”.

[0011] The applicant is also unaware of a similar method for the early diagnosis of acute ascariasis that would disclose the distinctive features of the claimed invention and achieve the stated technical result. Therefore, the claimed invention meets the patentability requirement of "inventive step."

[0012] Examples of specific performance.

[0013] Example 1. At a pig fattening complex in a summer camp, 2 pens were allocated and 50 piglets were placed in each of them after adaptation, where adult pigs were previously kept, in which mass disease and significant mortality were noted; changes characteristic of chronic ascariasis were found during autopsy (Fig. 1-3).

[0014] Three weeks after placing the gilts in individual pens, a clinical examination revealed that their body temperature was within normal limits, a decrease in appetite was noted, and uneaten feed remained in the feeders. Mortality began the following week. Necropsies of two dead piglets from Group 1 revealed areas of desquamation on the gastric mucosa, ecchymotic (small-point) hemorrhages, and delicate fibrin threads on the intestinal serosal surface. The liver showed venous congestion with funnel-shaped depressions and pinpoint lesions of the capsule, as well as ecchymotic hemorrhages at the sites of larval penetration (Figs. 4 and 5).

[0015] At the indicated locations, on the liver serous membrane, there are distinctive funnel-shaped pits with needle-like lesions in the capsule (Fig. 5). Autopsy data revealed migration of ascarid larvae. Piglets from the first group in pen #1 were treated with Ivermectin, at a rate of 1 ml per 33 kg of body weight, administered intramuscularly once.

[0016] Piglets in Group 2 in pen #2 were not dewormed. Changes in the diaphragm of the dead piglets appeared on the abdominal side. Mortality increased, and after a few days, needle-like hemorrhages also appeared on the diaphragmatic lobes of the lungs (Figs. 6, 7). Verminous bronchopneumonia with damage to the serous membranes then developed. The disease progressed in the gilts; later, single roundworms were found in the intestines during autopsy. After another 2 weeks, a high intensity of ascariasis infestation was noted. Ascaris larvae blocked the bile ducts and bronchi. Some animals had damage to the walls of the small intestine (perforation), as shown in the first figure. Of the 50 gilts, 26 died, with the population in this group decreasing by 52.0%. After deworming, as indicated in the 1st group, the condition of the animals improved and the mortality of the piglets stopped.

[0017] Deworming after diagnosing the early stage of acute ascariasis in piglets based on the migration patterns of young parasite forms allowed to save up to 99.9% of piglets, in contrast to the late stage of acute ascariasis diagnosed using the larvascopic method according to Berman and the chronic stage based on coproovoscopy data.

[0018] Example 2. The use of early pathological diagnosis of acute ascariasis was tested on other pig farms by a methodological committee. A pig fattening farm weaned piglets. After adaptation, fattening groups were formed. After some time, piglet mortality was noted. Autopsies of the dead piglets revealed traces of larval migration on the diaphragmatic surface of the liver, similar to those shown in Figures 4-7. Deworming was immediately administered to combat the larval stage of the roundworm.

[0019] As a result, the condition of the animals improved, a sharp decrease in mortality and an increase in productivity were noted.

[0020] Conclusion. Therefore, diagnosis based on traces of larval migration in the early stages of migratory ascariasis allows for the diagnosis to be made based on traces of larval migration in the early stages of migratory ascariasis in the form of venous hyperemia of the liver with funnel-shaped depressions and pinpoint lesions of the capsule, as well as ecchymotic subcapsular hemorrhages at the sites of larval penetration, before the development of clinical and pathological signs characteristic of the late stage of acute ascariasis using the Berman larvascopic method.

[0021] Deworming after diagnosing the early stage of acute ascariasis in piglets based on the migration patterns of young parasite forms allowed to save up to 99.9% of piglets, in contrast to the late stage of acute ascariasis diagnosed using the larvascopic method according to Berman and the chronic stage based on coproovoscopy data.

[0022] It is recommended to implement the methodology of early stage acute ascariasis for the development of antiparasitic treatment and preventive measures, which will sharply reduce economic losses in the livestock production industry.

[0023] Literature

[0024] 1. Akbaev, M.Sh., et al. Parasitology and invasive diseases of animals [Text] / M.Sh. Akbaev, A.A. Vodyanov, N.E. Kosminkov [et al.] edited by M.Sh. Akbaev. - M. Kolos, 1998. - P.365-368. - (Textbooks and teaching aids for students of higher educational institutions).

[0025] 2. Zharov, A.V. Pathological anatomy of animals [Text] / A.V. Zharov Textbook. - 2nd ed., revised and enlarged. - St. Petersburg. Publishing house "Lan", 2013. - P.542-544, ill. (+ insert, 12 pp.). - (Textbooks for universities. Specialized literature).

[0026] 3. Safiullin R.T. Spread of helminthiasis in pigs in different types of farms / / Proceedings of VIGIS.1992. Vol.31. Pp.117-123.

[0027] 4. Safiullin R.T. Economic damage from helminthiasis of pigs / / Proceedings of VIGIS.1992. V.31. P.124-143.

[0028] 5. Safiullin R.T. Parasitic diseases of pigs: means and methods of control: monograph / edited by M.V. Arisov, E.N. Indyukhova. - VNIIP - branch of FSBSI FSC VIEV RAS; Publishing House ''Science'', 2023. - 423 p.

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