Noritsugu Abe

Evaluation of wound healing of the teatwith and without low level laser therapy in dairy cattle by laser doppler flowmetry in comparison with histopathology, tensiometry and hydroxyproline analysis

Perforated teat wounds in eight lactating Holstein-Friesian cows were closed by four suture patterns with or without low level laser therapy (LLLT). Wound healing was evaluated by laser Doppler flowmetry (LDF), tensiometry and hydroxyproline analysis, and compared with histopathological examination. The three-layer pattern provided the best healing of the entire teat. Mucosal hyperplasia was observed in Gambee and continuous two-layer pattern while eversion of the skin, presence of suture tracts and a greater amount of granulation tissue were observed with the continuous and interrupted two-layer patterns. The epidermis in LLLT groups more closely resembled the normal epidermis, and collagen fibres were denser, thicker and better arranged in LLLT than in non-LLLT groups. LDF, tensiometry and hydroxyproline analysis correlated well with histopathological examination. The results suggest that LDF, a more rapid, less invasive and painless procedure, can replace tensile strength measurement or hydroxyproline analysis to assess the progress of teat wound healing.

HISTOPATHOLOGICAL EFFECT OF LOW-LEVEL LASER THERAPY ON SUTURED WOUNDS OF THE TEAT IN DAIRY CATTLE

Perforating wounds were made on the cranial surface of 32 teats in eight dairy cattle. The teats were distributed into eight groups with four kinds of suture patterns. The used suture patterns were Gambee in Groups A and E, continuous 2-layer (Cushing for submucosal layer, continuous horizontal mattress for intermediate layer and skin) in Groups B and F, separated 2-layer (simple continuous for mucosal layer, vertical mattress for intermediate layer and skin) in Groups C and G, and 3-layer (simple continuous for mucosal and intermediate layers, simple interrupted for skin) in Groups D and H. The wounds of Groups E, F, G and H were subjected to 3.64 J/cm2 dose of low-level laser, using a helium-neon system with an output of 8.5 mW, continuous wave at 632.8 nm. Histopathologically, healing was different between various suture patterns and between low level laser therapy (LLLT) and non-LLLT-groups. The results suggest that the 3-layer pattern was the best and LLLT could accelerate healing of perforating wounds of the teat in dairy cattle.

Pressor Effects of Ephedrine in Cows with Segmental Lumbar Epidural Analgesia Induced by a Combination of Xylazine/Lidocaine.

健康なホルスタイン種成乳牛17頭を4頭ずつ5群に分けて, 計20回のキシラジン・リドカイン混合液 (XL) による腰椎分節硬膜外麻酔を行った (3頭は1週間間隔で2度用いた) 。エフェドリンを投与しなかったコントロール群では硬膜外薬液投与後30～120分で約20%の平均血圧の下降がみられた。他の4群にはXL液の硬膜外薬液投与10分前に4種類の方法 (0.2mg/kg静注, 0.2mg/kg硬膜外投与, 0.5mg/kg皮下注, 1.0mg/kg皮下注) でエフェドリンを投与した。0.2mg/kg静脈内投与した群および0.2mg/kg硬膜外投与群では, それぞれ約15および10%の平均血圧の下降がみられたが, 1mg/kg皮下注射した群では20%以上の血圧上昇と鎮静効果持続時間の短縮がみられた。0.5mg/kg皮下注射群では, 収縮期, 拡張期, 平均血圧ともbaseline値を維持し, XL液による腰椎分節硬膜外投与による鎮静効果にも影響を及ぼさなかった。

Segmental Lumbar Epidural Analgesia Induced by Xylazine and Xylazine/Lidocaine in Dorsally Recumbent Cows.

4頭のホルスタイン種乳牛に3種の薬液 (XL群: 2%キシラジン0.0025m1/kgと2%リドカイン4mlの混合液, X群: 2%キシラジン0.0025ml/kgと生理食塩液4mlの混合液, S群: 生理食塩液0.0025ml/kg+4ml) を1週間間隔で各牛に硬膜外投与した。硬膜外薬液投与は第13胸椎・第1腰椎間から硬膜外腔に刺入したTuohy針を介してカテーテルを20cm前方に向けて留置して行い, 硬膜外投与直後に牛を仰臥位保定とした。X群およびXL群では左右体側壁で最大第7胸神経から第3腰神経支配領域の鎮痛効果が得られ, また, 薬液投与後5～30分に第四胃変位整復手術部位である剣状軟骨と臍の中央20×20cm部分の体壁 (正中部) の鎮痛効果が発現した。しかし, X群の2例およびXL群の1例で正中部頭側部分の鎮痛効果が不十分であった。X群およびXL群では硬膜外薬液投与後20および30分に平均血圧が約20%程度下降したが, S群では血圧の変動はみられなかった。すべての群で硬膜外薬液投与10～60分でPaO2の低下がみられたが, 60分で仰臥位保定を解除したところ牛は即座に起立し, 起立10分後にPaO2はbaseline値に復した。