6 Ion choai va Ion trudng thanh, benh thudng th£ hien man tinh. Lem gay rdc, khdng tang trong, khi nudi dudng kem cd the’ ia chay, va chi cd Ion con mdi chet do benh cdu trung.
Theo Pham Sy Lang va cs (2006), Ion mac benh d th£ man tinh, tinh them an thay d6i khdng ldn, tdc dd suy ye'u co the cham. Lon nai va Ion trudng thanh tuy bj nhiem cdu trung nhung khdng bi£u hien trieu chumg lam sdng, do dd chung ld ngudn tang tri? va truydn ba mdm benh trong tu nhien.
3.3. Benh tich cua Ion bi benh cdu trung
Ki£m tra Ion chet do cdu trung thudng thdy: xac chet gdy com, bdn, niem mac nhot nhat, trdng bech hoac xanh tai.
M6 kham Ion chet thdy benh tich tap trung chu ye'u d dudng rudt, dac biet d doan ta trang, dudi ta trang va rudt gia. Benh tich thudng thdy la:
- Trong ruot non chiia mot chat nude long, mau da cam vdi nhung soi chdt nhdy. 7,
- O ta trang va dudi ta trang: niem mac ruot bi viem tir cataz den xudt huyet va hoai tu. Nao niem mac va kiem tra ruot ve mat md hoc, thdy bieu bi hdu nhu hoan toan duoc thay the' bdi mot ldp cdu trung.
7.
- O ruot gia: thanh ruot gia bi day len, niem mac ruot gia cd mang gia do hoai tu, mang gia cd the thay trong phan.
- Cac hach mang treo ruot sung. Ngoai ra, cung thdy nhung benh tich viem phoi, cd le ke phat do cac vi khuan sinh mu gdy ra.
Theo Kolapxki N.A. va cs (1980), mang niem mac ruot non viem cataz, khi bj benh keo dai co the bj viem xuat huyet khdng chi d ruot non ma ca d ruot gia. Tai chd ruot bj viem thay nhung not to bang hat ke, xem kmh hien vi cac not do thdy cd cac nang trung, cac the’ phan lap va the’ phdn doan.
Gay benh cau trung cho Ion roi mo kham Ion mdc benh, Nguyen Thj Kim Lan va Le Minh (2006 - 2008) cho biet, cdu trung ky sinh va gay benh tich d ruot non cua I o n , khong thay ky sinh va gay benh tich d ruot gia. Lam tieu ban vi the, tac gia nhan thay nhung bien doi benh ly vi the’ d rudt non 1cm do cau triing gay ra. Nhung bien doi chii yeu duoc ghi la id cac hinh 140, 141, 142, 143, 144, 145.
Hinh 140 Hinh 141 Hinh 144 _• ' W ». Hinh 145 ' Long nhung u y - f.;- t bi ton'^thucmg
4. MlfiN DICH HOC TRONG BENH CAU TRUNG 4.1. Nghien curu ve mi6n dich eau trung d vat nuoi
Tyzzer (1929) da chung minh bang thuc nghiem la co 2 muc midn dich trong benl cau trung: