Những bệnh ký sinh trùng phổ biến ở gia cầm, lợn và loài nhai lại việt nam phần 3 bệnh ký sinh trùng thường gặp ở trâu, bò, dê

Chircmg BENH KY SINH TRUNG THUONG GAP TRAU, BO, DE nnnii i i i iii • • ~r • nn iw a ia a M a w a a M « iita » iiiii:! catiD iiB iaiiinininiiiiffiiffirrfsgfroa^ D c o o o i nionnoniaaaDDnDinnai^ ^ ^ ^ ^ M a a s a B s a a a a ^ M a a rinrriw i ^ ^ BENH GIUN XOAN DA MUI KHE (Trichostrongylidosis) • ■ r f / Benh giun xoan da mui khe la benh rat bien a gia sue nhai lai (trau, bo, de) a khap cac vung mien ca nude Benh nhieu giong loai giun tron thuoc ho Trichostrongylidae gay Cac loai giun tron co von^ ddi phat trien true tiep, khong qua ky chu trung gian Giun trudng dinh duong bang mau ky chu, d6ng thbi tiet chat chong dong mau, lam cho gia sue nhai lai bi mat rat nhieu mau, nhat la co so luqng ldn giun ky sinh Benh thay nhieu a sue vat nhai lai duoi nam tu6i, gay thiet hai Ion cho chan nuoi trau, bo, de a nuoc ta f \ y y G IU N X O A N D A M U I K H E K Y SINH G IA SUC N H A I LA I 1.1 Vi tri cua giun xoan da mui khe phan loai dong vat hoc Theo Skijabin va cs (1963), Nguyen Thi Le va cs (1996), Urquhart va cs (1996), giun xoan da mui khe co vi tri he thong phan loai dong vat hoc nhu sau: Nganh Nemathelminthes Schneider, 1873 Lap Nematoda Rudolphi, 1808 Phan lap Rhabditia Pearse, 1942 Bo Strongylida Railliet et Henry, 1913 Phan bo Strongylata Railliet et Henry, 1913 Sieu ho Trichostrongyloidea Cram, 1927 Ho Trichostrongylidae Leiper, 1912 Phan ho Trichostrongylinae Leiper, 1905 Giong Trichostrongylus Looss, 1905 Loai T colubriformis (Giles, 1892) Loai T axei (Cobbold, 1879) Loai T probolurus (Railliet, 1896) r Giong Ostertagia Ransom, 1907 Loai O ostertagi (Stiles, 1892) Chuvng B$nh ky sinh trung thutmg g$p d trSu, bd, d§ 231 Loai O circumcincta (Stadelmann, 1894) Giong Marshallagia Orloff, 1933 L oaiM marshalli (Ransom, 1907) Phan ho Haemonchinae Skijabin et Schulz, 1952 Giong Haemonchus Cobbold, 1898 Loai H contortus (Rudolphi, 1803) Loai H similis (Travassos, 1914) Phan ho Cooperinae Skijabin et Schikhobalova, 1952 r Giong Cooperia Ransom, 1907 Loai C curticei (Giles, 1892) Loai C punctata (Linstow, 1906) Phan ho Nematodirinae Skijabin et Orloff, 1934 r Giong Nematodirus Ransom, 1907 Loai N oiratianus (Rajevskaia, 1929) Loai N skrjabini (Mizkewisch, 1929) Giong Mecistocirrus Railliet et Henry, 1912 Loai M digitatus (Linstow, 1906) Trinh Van Thinh va cs (1982), Johannes Kaufmann, (1996), Urquhart G M va cs (1996) cho biet: Giun xoan ky sinh d dudng tieu hoa gia sue nhai lai nhung loai giun thuoc ho Trichostrongylidae gay Co giong bien gom tren 100 loai, la cac giong: Haemonchus, Mecistocirrus, Trichostrongylus, Ostertagia, Marshallagia, Cooperia, Nematodirus r Gia sue nhai lai thucmg nhiem hon hop cac giong Trong do, cac giong gay tac hai Ion la Haemonchus va Mecistocirrus Cac tac gia va ngoai nude deu thong nhat rang, tap doan giun xoan a da day (chu yeu a da mui khe) cua trau, bo va cac thu nhai lai khac tucmg doi phong phu, gom nhieu loai giun thuoc ho Trichostrongylidae Leiper, 1912 mot nhung ho thuoc sieu ho Trichostrongylidae Cram, 1927 Bac diem chung nhat cua nhung loai giun la: Than hinh sgi chi to hoac nho Mieng a tan cung dau Xoang mieng khong co, d mot so giun co bao mieng nho nhung xoang mieng the hien ro va co the co rang d tren hoac d dudi day xoang C> due tui sinh due phat trien Bai da so thuy ben ldn, thuy lung the hien > yeu hoac khong co Co hai gai giao hop, co hoac khong co lai Am ho cua cai nam phia sau than Giun cai de trung theo phan ngoai (Skrjabin va cs, 1963 Rieng d gia sue nhai lai Viet Nam, nhieu tac gia da xac dinh: Haemonchus contortus (H contortus), Haemonchus similis (H similis), Trichostrongylus axei (T axei), Trichostrongylus colubriformis (T colubriformis) va Mecistocirrus digitatus {M digitatus) la nhung loai giun xoan bien ky sinh d da mui khe va gay tac hai f 232 W Nhung b$nh ky sinh trimg phd bien & gia cim, Ign vA loai nhai lai Vi$t Nam f y nghiem cho gia sue nhai lai (Drozdz va cs, 1967; Phan The Viet va cs, 1977; Trinh Van Thinh, 1978, 1982; N guy In Thi Le va cs, 1996; N guyln Van Due, 2000; Pham Sy Lang va cs, 2002; Phan Dich Lan va cs, 2005; Nguyen Thi Kim Lan va cs, 2008) 1.2 Dac diem hinh thai, cau tao mot so loai giun xoan da mui khe Theo Skrjabin K I va cs (1963), qua v l hinh thai chung, chung co than hinh sod chi khong phan dot, ca the doi xung hai ben Ben ngoai dugc che phu m ot lop kitin hay goi la lop b ilu bi, tren lop b ilu bi co cac van doc, van ngang hoac van cheo Trinh Van Thinh va cs (1982) cho biet: He tieu hoa cua giun xoan da mui khe gom co mieng, moi, tui mieng, thuc quan, ruot, hau mon He than kinh don gian, co vong day th in kinh thuc quan va cac gai cam giac toan than He bai tilt g6m hai ong bai tilt chay tvr phan sau cua co the len d in p h ln dau r li xuong va d l lo huyet He sinh due giun xoan da mui khe don tinh, co giun due va giun cai Co quan sinh due cua giun due va giun cai rieng biet, khong giong 1.2.1 Giong Haemonchus - Loai Haemonchus contortus: Theo Nguyen Thi Le va cs (1996), loai H contortus (Rudolphi, 1803) ky sinh a da mui k h l va ruot non cua trau, bo, de tren pham vi toan quoc va bien tren toan cau Tac gia da mo ta hinh thai H contortus (theo Kamenskii, 1929): Giun due dai 18,7 22,3mm, rong n h lt 0,352 - 0,416mm Tui sinh due co thuy (2 thuy ben dai, thuy sau khong doi xung) Cac suon ben huong ve phia sau, cac sucm bung cong ve phia trude Cac sudn ben chung mot goc ldn, m ut cuoi co su phan nhanh Gai sinh due mau nau, dai 0,448 - 0,544mm, phan duoi that nho nhanh va ket thuc bang m ot phan dac trung nhu chiec kim Gai dieu chinh dang thuyen, dai 0,250 - 0,312mm Giun cai dai 25,0 34,2mm, rong nhat 0,588 - 0,739mm Lo sinh due each m ut duoi 5,92 - 7,07mm Vung am mon co mot van hinh luoi cay, dai 0,750 - 1,068mm, rong 0,330 - 0,580mm Tui nhan tinh dai 0,80 - 1,16mm B ulng trung uon khuc hinh m ay xo Trung co vo mong, kich thude 0,080 - 0,085 x 0,040 - 0,045mm Hinh 122: Giun cai Haemonchus contortus Hinh 123: Giun dire Haemonchus contortus Chirong Benh ky sinh trOng thu&ng g$p & trSu, bo, db 233 Hinh 124: Giun Haemonchus contortus thu thap tir da mui khe bo Hinh 125: Tui duoi va gai giao hap cua Haemochus contortus Dac dilm hinh thai cau tao cua loai H contortus ma Nguyen Thi Le mo ta a tren phu hap vdi sur mo ta cua nhieu tac gia khac (Skijabin va cs, 1963; Trinh Van Thinh, 1978, 1982; Johannes Kaufmann, 1996; Urquharrt, 1996) - Loai Haemonchus similis: H similis than nho, mau vang sam, gai co rat ro, lo bai tiet b phia trudc each dau 0,231mm Tui mieng rat nho co rang, quanh mieng co moi bao boc, phan sau thuc quan phinh to (dai 1,260 - 1,407mm, rong 0,105 - 0,126mm) Giun due dai 8,000 11,000mm, rong 0,232 - 0,265mm Tui duoi chia thuy, thuy lung khong doi xung, suon lung ngoai nho va dai, sucm hong trude thing, suon hong giua va sau cong ve phia lung, chia lam nhanh, doan cuoi moi nhanh lai chia lam nhanh nho Co mot doi gai giao hop dai bang (0,370 - 0,420mm) va co moc nho nho ra, banh lai gai giao hop to, kitin hoa a phan giua, dai 0,168mm Giun cai dai 12,500 - 21,000mm, rong 0,315 0,378mm Am ho each duoi 2,772 - 3,034mm Am dao dai, tu cung u6n khuc Trung hinh bau due, kich thuac 0,073 - 0,079 x 0,031 - 0,042mm (Nguyen Thi Kim Lan va cs, 1999) Vo trung mong, co phoi bao (Trinh Van Thinh, 1982) - Loai Mecistocirrus digitatus: Loai M digitatus (Linstow, 1906) duqc phat hien a nhieu tinh (Ha Noi, Ha TTnh, Lam Dong) cua Viet Nam va b nhieu noi tren the giai (chau My, SNG, Indonesia) Giun ky sinh a da mui khe va da la sach cua trau, bo, de, cim Nguyen Thi Le (1996) da mo ta: Ca the giun manh, lop bieu bi mong co van ngang Nang mieng nho, co num cutin, tren co rang ldn Con due dai 17,8 - 27,8mm, r6ng 0,35 - 0,51mm Thuc quan dai 1,40 - 1,78mm, rong 0,130 - 0,168mm Tui sinh due co thuy: thuy ben lan va dky, thuy lung nho nhung d6i xung Tui sinh due dai 0,80 1,00mm, rong 0,70 - 0,85mm Hai gai sinh due rat manh va dai, chieu dai 6,32 7,59mm Con cai dai 22,3 - 39,2mm, rong 0,46 - 0,64mm Thuc quan dai 1,59 1,92mm, rong 0,14 - 0,18mm Lo sinh due dang ranh ngang, co ca day, each mut duoi 0,545 - 0,743mm Duoi hinh non, dai 0,170 - 0,248mm Trung hinh van, kich thude 101 - 120x51 -63 pm 234 Nhung benh ky sinh trung phd bien & gia cim , hyn va lo&i nhai lai Vi$t Nam 1.2.2 Mot so loai thuoc giong Trichostrongylus r \ \ f Giong Trichostrongylus gom nhieu loai, co mot so loai quan ky sinh b da mui khe va ruot non cua gia sue nhai lai - Loai Trichostrongylus axei (Cobbold, 1879) duqc phat hien d nhieu noi tren the gibi C) Viet Nam, cac nha khoa hoc da tim thay loai giun b cac tinh Quang Ninh, * Lang Son Nhieu tac gia da mo ta (theo Ransom, 1911): Giun due dai 3,4 - 4,5mm, rong nhat 0,05 - 0,07mm Subn bung ben cua tui sinh due manh Cac sucm bung sau, sucm bung giua va sucm ben co day nhu Sucm lung dai va manh, chia nhanh d cuoi, moi nhanh lai chia nhanh nho Gai sinh due mau vang nau, kich thude khac (chiec nho dai 0,085 - 0,104mm, chiec Ion dai 0,110 - 0,128mm) Mut cuoi gai sinh due co hinh tarn giac Gai dieu chinh dai 0,705 - 0,720mm Giun cai dai 4,6 - 5,5mm, rong 0,055 - 0,075mm Thuc quan dai 0,155 - 0,175mm L6 sinh due each mut duoi 0,800 1,072mm Duoi thang, hinh non, dai 0,06 - 0,09mm Non sinh due hep Kich thuoc trung 90 - 92 x 35 - 42pm (Drozdz va cs, 1967; Phan The Viet, 1977; N guyln Thi Le, 1996) Hinh 126: Gai giao hap cua Trichostrongylus axei Hinh 127: Tui duoi va gai giao hap cua Trichostrongylus axei Theo Johannes Kaufman (1996), T axei thay ph6 bien a khap noi tren the gioi Giun dire dai 2,6 - 6mm; giun cai dai 3,5 - 8mm Tning co kich thuoc 79 - 92 x 31 - 41 pm - Loai Trichostrongylus colubriformis (Giles, 1892): Theo nhieu tac gia thi loai giun bien o bo, de, cuu tren pham vi toan cau O nude ta, phat hien giun b da mui khe va ruot non bo, de a cac tinh phia Bac Giun due dai 4,0 - 6,0mm, rong 0,078 0,095mm Tui sinh due phat trien nhung khong can doi Cac sucm ben chung mot goc lbn va map horn cac sucm bung Sucm lung gan cuoi hoi phinh Hai gai sinh due dai bang nhau, hinh thuyen cong, dai 0,118 - 0,145mm, mut cuoi co mau hinh tarn giac Gai dieu chinh dai 0,065 - 0,078mm Giun cai dai 5,0 - 6,0mm; rong nhat d vung lo sinh due (0,080 - 0,100mm) Thuc quan dai 0,648 - 0,730mm Lo bai tilt each mut dau 0,092 0,129mm Lo sinh due dang ranh doc, co moi, each mut duoi 0,067 - 0,076mm Tui nhan tinh hinh cau, dai 0,375 - 0,500mm Trung co kich thude 73 - 76 x 40 - 43pm (Nguyen Thi Le va cs, 1996; Pham Van Khue va cs, 1996) Chuvng B$nh ky sinh trung thuvng g$p & trau, bd, d§ 235 - Loai Trichostrongylus probolurus: Theo nhieu tac gia thi loai giun bien a bo va ciru tren pham vi toan cau nuac ta loai giun xuat hien chu yeu a cac tinh mien nui phia Bac Theo mo ta cua Skijabin va cs (1934): Con due co thd dai 4,3 5,5mm, rong nhlt 0,78 - 0,87mm Tui sinh due phat tri6n, suon bung sau day horn sucm khac, sucm ben sau day hom suon ben giua Suon lung ng&n va co su phan nhanh nhu loai T colubriformis Gai sinh due mau xam toi, mot chiec dai 0,125 - 0,128mm, chiec dai 0,129 - 0,134mm; co mdu tarn giac cr mat bung Gai dieu chinh dai 0,072 0,080mm Con cai dai 4,5 - 6,5mm, rong nhdt 0,078 - 0,090mm Thuc quan dai 0,850 0,940mm Lo bai tiet each mut dau 1,089 - 1,325mm L6 sinh due thing hoac hod loi, each mut duoi 0,067 - 0,076mm Co the sau 16 huyet manh din, duoi ngin va tu, thing hoac cong ve mat bung Tui nhan tinh dai 0,272 - 0,375mm Trung co kich thuoc 0,076 0,092 x 0,037 - 0,046mm f r f 1.2.3 Giong Ostertagia - Loai O ostertagi (Stiles, 1892): Con due dai 6,5 - 7,5mm; rong nhat 0,130mm Vong than kinh each mut dau 0,265 0,280mm, lo bai tilt va cac num c6 0,300 va 0,340mm, tuorng urng Tui sinh due nho Cac cap suon ben day nhu nhau, chi co suon ben truac day hon mot chut Sucm lung dai 0,050 - 0,060mm, each goc 0,035 - 0,045mm phan nhanh manh va hep Hai gai sinh due dai 0,220 - 0,230mm, mut cu6i mat co rang manh Gai dieu chinh hinh ovan, dai 0,040mm, rong 0,014mm Con cai dai 8,3 - 9,2mm; rong 0,160mm Vong than kinh each mut dau 0,260 0,295mm Lo sinh due each mut duoi 0,100 - 0,140mm Tui nhan tinh dang chiec banh mi, dai 0,200 - 0,260mm; trung dai 0,065 - 0,080mm, rong 0,030 - 0,040mm - Loai O circumcincta (Stadelmann, 1894): Con due dai 9,8 - 10,6mm; gai giao hop dai 0,40 - 0,42mm, phan sau cua moi gai ^ \ each 0,1mm phan lam hai nhanh bang nhau, ngoai co choi ngan a gan cho phan nhanh; banh lai suot dai 0,070mm r \ Con cai dai 12 - 13,5mm; duoi dai 0,18 - 0,19mm; am ho each mut duoi 2,37mm; trung dai 0,089 - 0,93mm va rong 0,050mm 1.2.4 Giong Cooperia y y f y Nhieu tac gia cho rang, cac loai thuoc giong Cooperia gay benh tren trau bo gom: C laterouniformis, C pectinata, C oncophora, C punctata va C surnabada Cac loai xuat hien a khap nod tren the giai, C punctata va C pectinata thucmg bien hem or cac vung on dai va can nhiet dai am ap, C surnabada va C oncophora bien hon a vung mat me Hinh thai cu the nhu sau: r i r r r •> ^ r f - Loai C laterouniformis (Chen, 1937), ky sinh chu yeu a da mui khe va ruot non cua trau bo Tai Viet Nam, benh xuat hien a cac vung Bac bo va Ha Tinh Theo mo ta 236 Nhung benh k f sinh trung phd bien & gia ciim, Ign va loiii nhai lai Vi$t Nam cua Chen (1937), C laterouniformis ca th6 thing, due phan truac ca the cong hinh 16 xo, co dau phinh Doc co the co nhieu tam lucre, phan truac ca the co 14 tim , phan sau 22 tam Khong co num duoi va num ben f Con due dai 4,8 - 5,5mm, rong nhat 0,071mm Phinh dau dai 0,013mm, rang 0,028mm Tui sinh due Ion, thuy ben to, thuy lung nho suan ben co klch thuac nhu va xuat phat tir than Ion Gai sinh due kitin hoa manh, dai 0,138mm Non sinh due Ion, phan bung co mau ben, phan lung kich thuac nhu phan bung nhung tron va khong co mau loi \ f \ \ Con cai dai 5,5 - 6,5mm, rong nhat 0,069mm Phinh dau dai 0,011mm, rong 0,023mm Thuc quan dai 0,297mm, rong 0,11 - 0,026mm Vong than kinh each mut dau 0,188mm Lo sinh due dang lucri liem doc va each mut duoi 0,20mm Tui nhan tinh dai 0,30mm Duoi dai 0,13mm Trung co kich thuac 0,073 x 0,030mm r - Loai C pectinata (Ransom, 1907): Ky sinh a da mui khe va ruot non cua trau bo Benh dugc phat hien tren toan the gioi C) Viet Nam benh xuat hien a cac tinh mi6n nui phia Bac Con due dai 6,5 - 7,5mm, rong nhat 0,130 - 0,160mm Phinh dau rong 0,032mm Thuc quan dai 0,40mm Vong than kinh each nut dau 0,280mm Cac suan ben truac va suan bung sau day hon cac nhanh suan lai Suon lung bao gom ca nhanh cuoi dai 0,180mm Hai gai sinh due dai 0,240 - 0,280mm Con cai dai 7,5 - 9,0mm, rong nhdt 0,110 - 0,135mm Phinh dau rong 0,035 0,050mm Thuc quan dai 0,360 - 0,400mm, vong thdn kinh each mut dau 0,250 0,280mm Phan sau ca the manh va thuong bi cong a cho gap lai cua buong trurng va tu cung Lo sinh due each mut duoi 1,60 - 2,00mm Duoi dai 0,175mm Trurng co kich thuac 0,070 - 0,080 x 0,036 - 0,042mm \ O fv > - Loai C punctata (Linstow, 1906): Ky sinh a da mui khe va ruot non cua bo Benh xuat hien tren toan the gioi CJ Viet Nam thay tai cac tinh phia Bac va Lam Dong Loai co phinh dau dai 0,032 - 0,039mm Thuc quan dai 0,260 - 0,360mm Con due dai 5,0 - 9,0mm, rong nhdt 0,080 - 0,140mm Suom lung manh, dai 0,060 0,071, hinh chu Y Suon ben sau manh hon cac suon ben khac nhung dai va thang, suon ben giua va ben truac dai bang Gai sinh due dai 0,125 - 0,145mm, mut duoi co hoc sau Co non sinh due Con cai dai 5,7 - 10,0mm, cho rong nhat 0,20mm Lo sinh due co dang ranh doc, each mut duoi 0,99 - 1,50mm Tu cung ngan va chua it trung Tir sau vung that lung ca the hai cong ve mat lung, nhung tir 16 huyet ca the lai cong ve mat bung Duoi dai 0,135 - 0,260mm Tui nhan tinh dai 0,480mm Chung toi (2008 - 2010) da nghien cuu ve benh giun xoan da mui khe a trau, bo cua tinh Thai Nguyen va xac dinh dugc loai giun ky sinh: H contortus, H similis, M digitatus Hinh anh loai giun dugc chung toi ghi lai nhu sau: Chuvng Benh ky sinh trung thu&ng gSp d trSu, bd, d§ 237 Hinh 128: Ba loai giun xoan da mui khe phat hien a> tinh Thai Nguyen Hinh 129: Dau, duoi, am mon giun H contortus Hlnh 130: Dau, tip cung va am mon giun H similis Hinh 131: Dau, duoi, am mon giun M digitatus 238 NhCrng benh ky sinh trung bien d gia cam, Ian va loai nhai lai Viet Nam 1.3 Vong doi cua giun xoan da mui khe 1.3.1 Vong deft cua loai Haemonchus contortus Vong dcri (chu ky sinh hoc hay chu ky phat trien) cua giun H contortus da dugc nghien cuu va co nhieu tac gia ghi nhan Dinaburg (1944), Silverman va Campbell (1959) da nghien cuu su phat trien cua trung va au trung Haemonchus Crofton (1963) va Levine (1963) nghien cuu ve sinh thai cua au trung tren dong co > \ 9 Skrjabin va cs (1963) cho biet: Giun cai de trung, trung dugc bai xuat cung phan moi trucmg ben ngoai Nhiet cua moi trucmg ben ngoai thich hgp cho trung phat trien tiep tuc la 20 - 30 C Trong phan, vao thu hai da thay co au trung giai doan I no khoi trung Nhung au trung an phan va s6ng phan mot thai gian, nhung khong cam nhiem dugc cho sue vat Q giai doan nay, au trung kem ben vung hon a cac giai doan sau: chung chet phai kho a nhiet tren 30°C Su thay doi ve nong va lanh cung lam cho au trung bi chet nhiet 15 - 20°C, au trung giai doan I chi sau dem > da a giai doan tiem sinh, keo dai 12 - 15 gia Trong thai gian nay, au trung lot xac, sau song tra lai va chuyen vao giai doan II 9 A 9 ? CJ giai doan II, au trung mat di kha nang an uong va cung khong the ky sinh dugc Qua mot sau, doi chua den ngay, au trung lai tra lai a giai doan tiem sinh lan thu hai Trong thai gian nay, au trung lan len, nhung tang cutin bao quanh van giu nguyen va tao nap Sau hinh nap thi au trung chuyen vao giai doan III Luc nay, au trung da co kha nang cam nhiem cho dong vat Tir trung ngoai den giai doan au trung cam nhiem can thai gian khong duoi - 9 \ 9 y ^ \ _ _ _ f* 9 Nhimg au trung cam nhiem dugc sue vat nhai lai nuot cung thuc an va nuac uong vao da day O day, chung "vut bo" vo va chuyen sang giai doan IV Thuc hien xong mot lan lot xac nua, au trung co kha nang ky sinh va hut mau ky chu Sau - tuan, Haemonchus tra thanh thuc, cai bat dau de trung y \ \ Thai gian song cua Haemonchus ca the gia sue nhai lai chua ro, nhung nguai ta cho rang, thai gian khong qua nam Cang ve sau, giun cang gia va mat di kha nang tiep tuc ky sinh X Urquhart G M (1996) lam ro them vong doi cua H contortus- Au trung cam nhiem vao ong tieu hoa sue vat nhai lai thuc hien hai lan lot xac ong dan tuyen Chi truac lot xac lan cuoi chung moi phat trien den giai doan lay mau ky chu tir nhung mao quan a mem mac Khi trucmg thanh, chung di chuyen tu tren be mat niem mac Thai gian hoan vong dai a de, cim la - tudn va a dai gia sue la tudn \ 9 1.3.2 Vong ddi cua mot s6 loai thuoegiong Trichostrongylus Cac loai thuoc giong Trichostrongylus co vong doi true tiep, khong can ky chu trung gian (nghia la khong co su thay doi ky chu) Trung giun theo phan ngoai, gap dieu kien thich hgp (nhiet va am do), sau 20 - 24 gicr na au trung ky I Au trung hinh gay, X Chuxmg B$nh ky sinh trung thut/ng gSp & trau, bo, de 239 thuc quan hinh ong va co ruot cau tao dcm gian, hoat dong manh Chung dung cac loai vi sinh vat a xung quanh lam chat dinh duong, sau - gid lot xac au trimg ky II to hon au trung ky I, cau tao tuong doi giong Au trimg hoat dong rat manh va cung lay vi sinh vat xung quanh nuoi song ban than Sau 12- 60 gid au trung ky III co sue gay nhiem Trade au trung ky III, au trung ky II khong lot xac, mang hoc ngoai trd mang ngoai cua au trimg ky III Luc au trung ky III khong the lay thuc an a ben ngoai ma chi song dua vao thuc an au trimg ky II tich luy lai a ruot t r r r r r r >v r r f / f Khi gia sue nhai lai an co, uong nude co au trimg gay nhiem, vao duong tieu hoa, au trimg mat mang ngoai, tiep tuc phat trien, lot xac au trimg ky IV, lai tiep tuc phat trien, lot xac au trimg ky V va phat trien giun truong (Skijabin, 1963; Pham Van Khue va cs, 1996) r r ? r t 1.3.3 Vong itefi cua loai Mecistocirrus digitatus \ \ r Nhieu tac gia cho rang vong doi cua giun M digitatus co ban giong vong doi cua H contortus Hoan vong doi ckn 59 - 82 (Fernando, 1965) Trung dupe bai xuat ngoai cung voi phan CJ nhiet 26 - 30°C, sau 24 - 84 gia trung no au trimg giai aoan I Qua ngay, au trung lot xac l^ i dau va bien au trung giai doan II Sau ke tir trung thai moi truong ben ngoai, au trimg lot xac lan thu hai va tro au trimg giai doan III co sue cam nhiem Khi gia sue nuot phai au trimg qua thuc an hoac nude uong se mac benh / \ \ f f r f ^ \ r p Tuoi tho cua giun la -12 thang (Pham Van Khue va, 1996; Phan Bich Lan va cs, 2005) 1.3.4 Vdng d&i cua cac loai thuoc giong Ostertagia Theo Skijabin K I va cs (1963), trung Ostertagia thai moi truong ben ngoai 16 32 phoi bao Khi co nhiet thich hop (24 - 30°C) va du dm au trimg giai doan I phat tnen nhanh chong, au trimg vong mot chui khoi vo trung O moi truong ben ngoai, au trimg lot xac lan hai va sau - dat den giai doan cam nhiem Trau, bo va loai nhai lai khac bi benh Ostertagiosis la nuot phai au trimg cam nhiem cua Ostertagia cimg voi thuc an hay nude uong Au trimg Ostertagia khong di chuyen theo mau co th l dong vat nhai lai, ma phat trien d da mui khe Tai day, chung trai qua hai giai doan lot xac va sau 21- 25 Ostertagia dat den giai doan 240 Nhung benh ky sinh trung biin drgia dm, Ign va loai nhai lai Viet Nam Phan Dich Lan (1994, 2004) cho biet, kiem tra d nhieu dia didm thdy hai loai mong T rubidus va T striatus mang tien mao trung vdi ty le 15,2% va 14,0%; ruoi hut mau Stomoxys calcitrans mang tien mao trung vdi ty le 12,5% CJ nhung vung dang co benh # \ tS* f tien mao trung, kiem tra ruoi va mong hut mau dd dang tim thay tien mao trung \ / f Sau theo mau vao voi hut ruoi va mong, tien mao trung van song den gib thu 53, thai gian hoat dong manh nhat la tir gia thu nhit den gia thu 34, trung binh la 24 gia Su hoat dong cua tien mao trung yeu dan tir gia thu 35 - 42 Tir 46 - 53 gia thi tien mao trung ngimg hoat dong Hinh thai tien mao trung d voi rudi, mong bien doi theo thdi gian: tir 34 gia co hinh thai, kich thudc binh thubng; 35 - 45 gid: tien mao trung co hinh dang thay doi, tang kich thudc chieu rong va tho dan; 46 - 53 gid: tien mao trung truang to, duoi thang, mdt kha nang di dong va ngimg hdn hoat dong Thuc nghiem da chung minh kha nang gay benh cua tien mao trung sau xam nhap vao mong Tabanus rubidus nhu sau: Thdi gian tir gid thu -x , tien mao trung co r * kha nang gay benh va lam chet chuot bach tuang tu nhu truyen thang mau co tien mao trung cho chuot; tir gid thu - chi 30% so chuot thi nghiem phat benh, thdi gian gay benh keo dai va thdi gian chet cua chuot cung dai Dieu co the giai thich la, doc luc cua tien mao trung giam dan va s6 luong tien mao trung hoat luc gay benh cung giam dan sau chung xam nhap vao mong Tabanus rubidus r \ * 2.1.2 Tudi vat chu, mua mac benh Trau, bo va cac loai gia sue khac d moi lua tuoi deu nhiem tien mao trung va deu phat benh, co the dan den tu vong hoac suy nhuac, thieu mau, giam sue de khang, giam kha nang sinh de va sue san xuat Phan Dich Lan (1994, 2004) da t6ng hgrp ket qua dieu tra 3.172 trau d cac tinh d6ng bang: trau dudi nam tuoi nhiem thdp nhat (3,2 - 6,1%), trau - tuoi nhiem cao han (10,6 - 12,7%), trau - tudi nhilm cao nhdt (12,9 - 14,8%), trau tren nam tuoi ty le nhiem giam thap han trau - nam tudi Theo Phan Van Chinh (2006), ty le nhiem tien mao trung cao nhat d - nam tudi (trau 12,71%; bo 5,77%), thap nhat la trau, bo dudi nam tudi (6,92% va 2,31%) Mua lay lan benh thucmg xay cac thang nong am, mua nhieu (tir thang - 9) Thdi gian dieu kien sinh thai thuan loi cho cac loai ruoi, mong phat trien, hoat dong manh, hut mau sue vat va truyen tien mao trung Theo Luckins (1988), sir xuat hien luong ldn ruoi, mong mua mua nong am luon co lien quan den tinh hinh dich te benh tien mao trung d trau, bo, de, lac da Tir cuoi mua thu, mua dong va dau mua xuan, trau bo nhiem tien mao trimg phai song dieu kien thdi tiet lanh, thieu thuc an nen sue de khang giam, benh thudng phat vao thdi gian ma trau bo bi dd nga hang loat r \ r r \ Tien mao trung co sue de khang yeu, dd chet tidp xuc vdi nude cat, edn va thudc sat trimg Chuvng B$nh ky sinh triing thuvng g$p & triu, bd, d§ 317 2.2 Dac diem benh ly va lam sang bfnh tien mao trung 2.2.1 Dac diem benh ly \ r \ Khi ruoi trau, mong d6t, hut mau va truyen tien mao trung vao trau, bo, ngua, tien mao trung xam nhap vao da, gay vet viem tren mat da Theo Luckins (1992), co the quan sat duoc phan ung viem b da cua tho, ciru, de va bo gay nhiem thuc nghiem tien mao trung, kich thuoc cho viem phu thuoc vao s6 luong tien mao trung duoc tiem truyen (uac chung khoang 10 tien mao trung co the gay viem da - a vi tri tiem truyen), mot so luong Ion tien mao trung phat trien b tai cho viem f 7 f Vao mau, tien mao trung nhan len theo cip so nhan b mau, bach huyet va b cac mo khac cua co the vat chu theo each phan chia theo chieu doc So luong tien mao trung mau khong phai luc nao cung nhu Mat tien mao trung thay doi theo Bieu song tien mao trung cho thay, xen ke giua nhung song tien mao trung manh la nhung dot song yeu Moi dot song tien mao trung bat dau bang su tang so luong tien mao trung mau, sau giam va kho phat hien thay IV f tien mao trung Moi dot tien mao trung tang len mau la bieu hien su xuat hien mot quan the tien mao trung co tinh khang nguyen be mat moi, quan the co the tiep tuc sinh san va ton tai mot thoi gian cho den co th i xuat hien khang the dac hieu voi chung 7 > > f / > ' f \ r > t \ > 7 f f Tien mao trung phat trien nhanh mau, tieu thu glucose va cac chat dam, chat beo va khoang chat mau ky chu bang phuomg thuc tham thau qua be mat co the de tri hoat dong va sinh san CJ sue vat bi benh, 1ml mau co the co 10.000 30.000 tien mao trung Voi so luong nhieu nhu vay, tien mao trung chiem doat dinh duong nhieu, lam cho sue vat benh gay com, thieu mau va mat dan kha nang san xuat sua, thit, mat dan kha nang sinh san va giam sue de khang voi cac benh khac / * > y f \ y f f t Song mau vat chu, tien mao trung tao doc to Trypanotoxin, doc to \ f f f t gom: doc to tien mao trung tiet qua mang than qua trinh s6ng va doc to f xac chet cua tien mao trung phan huy mau sau - / \ f Doc to cua tien mao trung tac dong len he than kinh trung uong lam roi loan trung khu dieu hoa than nhiet, gay s6t cao va gian doan (luc sot, luc h it s6t xen ke nhau) Khi sot thubng co roi loan vd than kinh (keu r6ng, run ray, nga vat xuong) Doc to cung pha huy hong cau, uc che co quan tao mau lam cho vat chu thieu mau va suy \ ^ r nhupc dan Doc to tac dong tdi bo may tieu hoa, gay roi loan tieu hoa, lam vat ia chay Hoi chung tieu chay thubng xay xuat hien tien mao trung mau vat benh Khi tang len voi s6 luong Ion mau, tien mao trung lam tac cac mao mach, lam tang tinh thdm mach, dan d in tao cac thuy thung chat keo vang dubi da 318 Nhung b$nh ky sinh trung phd biSn d gia cam, Ion vd lodi nhai l$i Vi$t Nam 2.2.2 Trieu chung lam sang Trau, bo bi benh the hien cac trieu chung lam sang chu y lu nhu sau: f \ \ - Sot cao va gian doan: sau 14 - 30 bi ruoi, mong hut mau truyen tien mao trung, trau bo thuong dot ngot len can sot (40 - 41,7°C) keo dai - roi giam, thoi gian sau nhiet lai tang len Thai gian gian doan giua hai can sot dai hay ngan theo the vat Khi sot, kiem tra mau thuong thay tien mao trung / < f - Hoi chung than kinh: a mot so trau, bo len can sot the hien hoi chung than kinh nhu dien loan, mSt ngau, hue dau vao tucmg, chay vong quanh keu rong len Truong/ hop nhe thay run ray tung con, m at tron ngugc roi nga vat xuong, sui r bot mep giong nhu trau bi cam nang Sau 20 - 30 phut vat lai dung day di lai dugc Nhung trau bo mac benh co trieu chung lam sang nhu tren thuong la mac benh a the cap tinh r f r f r Trau, bo bi benh man tinh thuong keo dai, co the suy yeu, liet hai chan sau, ndm tu thg quy va khong di lai dugc Mac du nSm liet nhung van an va nhai lai cho den sap chet - Phu thung duoi da: phu thung thuong thay b vung thap cua co the nhu b bon chan (tir khbp khuyu trb xuong), phan y6m, nguc, bo phan sinh due f # / f r \ r f - Viem giac mac va ket mac mat: trieu chung thay b hau het trau, bo benh Mat co dir trang hay vang, chay lien tuc, neu nang thi mat sung ngau Khi khoi benh, mat co mang trang (cui nhan) keo che kin giac mac - Hoi chung tieu hoa: mot so trau, bo benh bi ia chay nang, phan long, mau vang, sau chuyen mau xam, co lin bot va chat nhdy Cac dgt ia chay tiep theo nhung com sot each quang Ia chay benh tien mao trung thuong dai dang va vat van an dugc - Gay yeu, suy nhugc: b the benh cap tinh trau, bo gay sut nhanh, chi sau - 14 tir phat benh vat da gay roc, mat trung sau Neu benh keo dai thi vat gay xo xac, long dung ngugc, da kho nhan nheo, niem mac mat nhgt nhat, long de rung, dan dan suy nhugc co the nang, mat kha nang cay keo va sinh san Neu gap dieu kien bat lgi nhu thieu an, ret m ubt thi trau, bo de chet Trong thuc te, co khoang 3% trau benh b ^ the an van beo khoe, lam viec binh thuong dugc chain soc nuoi duong tbt *) f f Tinh trang thieu mau the hien r5 benh T evansi gay Theo Silva Rams va cs (1995), Smith R D (1995), so lugng hong cau va ham lugng huyet sac to giam, sb lugng bach cau tang, phan bach cau thay doi: bach cau lympho, bach cau toan tang nhung bach cau trung tinh giam, protein tong so va albumin giam ro ret Hinh 212: Bo b| benh tien mao trung Chuvng B$nh ky sinh trung thuvng g$p & trSu, bd, d i 319 Pham Sy Lang, Le Ngoc My (1984), Stephen (1986) cho biet, protein tong so va albumin giam thi cac phan a , P va y globulin deu tang, chi so A/G < 0,5 2.2.3 Benh tich cua benh tien mao triing Trau, bo bi benh tien mao triing c h it gay xo xac, md kham thay co nhung bien doi benh tich dai the ro ret d he tudn hoan va ho hap: tim nhao, xoang bao tim tich nude vang; phoi xung huyet va tu mau tung dam nho; gan sung to, nhat mau; lach sung, mem nhun va nhat mau; hach lam ba sung va co tu mau hach; co nhao, mau nhat nhat, nhat cat ri nude; xoang nguc va xoang bung tich dich mau vang nhat; co nhung dam keo nhay vang dudi vung da thuy thung 2.3 Chan doan bfnh tien mao trung 2.3.1 Chan doan lam sang Cac bieu hien lam sang dac trung cua benh tien m ao trung d trau, bo, ngua khong phai luc nao cung phat hien dugc Rat nhieu gia sue m ang benh nhung kho phat hien cac trieu chung dac trung, nhat la doi vdi nhung gia sue mac benh tien mao trung m an tinh Doi vdi gia sue mac benh d thd cap tinh, cac bieu hien benh dac trung la sdt cao, bo an, co trieu chung than kinh (dien loan) va chet nhanh Trau bi benh m an tinh co the thay trieu chung: sot gian doan, gay com, thieu m au keo dai, viem giac mac, phu thung d bung va chan sau, c h it kiet sue (Pham Sy Lang, 1982) Trieu chung say thai co the th ly d trau, bo bi benh tien mao trung (Nguyen Dang Khai, 1995; Kashiwazaki, 1998) 2.3.2 Chan doan thinghigm Co nhieu phuang phap chan doan tien mao trung phong thi nghiem, muc dich la phat hien tien mao trung mau gia sue Tuy tung trudng hap benh, dieu kien ma co th i lam cung luc m ot so phuang phap hoac lua chon mot phuang phap phu hop va co chinh xac cao r - Phuang phap p h a t hien tien mao trung true tiep: M u ln phat hien tien mao triing true tiep, co the ap dung nhung phuang phap sau: Phuang phap xem tuoi (Direct smear): Khi sdt, mao quan ngoai vi cua gia sue m ic benh tien mao trung thudng co T evansi Vi vay, trudng hap nen lay mau vung ngoai vi de xem tuoi Cho giot mau nho len phien kinh, day lamen len giot mau de giot m au dan theo 7 lamen mdt lap mong Soi dudi kinh hien vi (do phong dai 10 x 20) de phat hien tien mao triing song N eu co, th ly hdng cau dat tir ben no sang ben kia, chung to t r > ' T evansi chuyen dong huyet tuong, lam xao dong cac hong cau 320 Nhung b$nh ky sinh trOng phd bien & gia d m , l