鼓脹症Bloat

急性鼓脹症(瘤胃鼓脹)Acute bloat (ruminal tympany)

p  由於無法打嗝，牛隻的瘤胃和蜂巢胃充滿發酵氣體(CO₂和CH₄)而鼓起Abnormal distension of the rumen and reticulum with fermentation gases (CO₂ and CH₄) from a failure to eructate

p  兩型Two types：

   ‧ 原發性(泡沫性)鼓脹Primary (frothy) bloat

   ‧ 繼發性(游離氣體)鼓脹Secondary (free gas) bloat

原發性(泡沫性)鼓脹 Primary (frothy) bloat

p  餵飼多汁、未成熟又生長快速的牧草 ─ 尤其豆科植物(苜蓿、紫苜蓿) Associated with feeding lush, immature, rapidly growing pasture – esp. legumes (clover, lucerne)

p  也與餵飼細磨的精料有關(開放式欄圈鼓脹) Also may be associated with feeding finely ground grain (feedlot bloat)

p  鼓脹的原因為瘤胃產生過量穩定、持續的泡沫狀氣體Bloat is caused by the excessive production and entrapment of rumen gases in a stable, persistent foam

p  牛隻改換危險飼料，易在1小時內發生鼓脹Cattle can begin to bloat within 1 hour of moving onto danger feed

原發性鼓脹 ─ 臨床症狀 Primary bloat – clinical signs

p  左旁腰窩鼓起(瘤胃內部壓力增加) Distension of the left paralumbar fossa (increased intraruminal pressure)

p  感到不適/腹痛Uncomfortable/ abdominal pain

p  發展成嚴重的呼吸窘迫Progression to severe respiratory distress

•      張口呼吸Mouth breathing

•      流涎Salivation

•      舌頭吐出Protrusion of the tongue

•      排便/嘔吐物有瘤胃泡沫狀內容物Expelling faeces/ vomiting frothy rumen contents

p  倒地不起並窒息死亡Recumbency and death from asphyxiation

Cow with primary bloat (Photo: Murdoch University)

原發性鼓脹 ─ 診斷Primary bloat – diagnosis

p  以病史和臨床檢查做為依據Based on history and clinical exam

p  只有1頭牛發生 ─ 很可能是氣體鼓脹所致One animal affected – probably gaseous bloat

p  多頭發生 ─ 可能是泡沫性鼓脹Multiple affected – may be frothy bloat

p  透過插入胃管可做區別Pass a stomach tube to determine difference

原發型鼓脹 ─ 死後剖檢 Primary bloat – post-mortem

p  腹部很明顯鼓大Abdomen very distended

p  血液從身體外孔/眼睛滲出，舌頭吐出Blood exudes from orifices/ eyes and tongue protruding

p  屍體前軀鬱血(胸腔的壓力) Anterior regions of carcass congested (pressure on thoracic cavity)

p  可從食道看到鼓脹線 ─ 前部到胸腔入口處鬱血May see bloat line on oesophagus – congested anterior to thoracic inlet

p  瘤胃內容物早期呈泡沫狀，但牛隻死後泡沫減少Rumen contents initially frothy but froth decreases after death

Cow dead from primary bloat (Photo: Murdoch University)

原發型鼓脹 ─ 治療 Primary bloat – treatment

p  症狀輕微的牛隻(尚未危及性命) Animals in mild distress (non life-threatening)

  ‧還能走到牧場中Walk to yards

  ‧將牛隻灌入鼓脹油(或與500毫升植物油混合)及少量洗潔劑Drench with bloat oil drench or mixture of vegetable oil (500mL) and small amount detergent

•      若因牛隻抑鬱而無法插入胃管，可將套針插進瘤胃，並用插管把油導入；但可能因泡沫狀物而受阻If stomach tube is unable to be passed because of animal distress, could pass trocar into rumen and put oil through cannula. May also get blocked with foam.

套針和插管     Trocar and cannula (Photo: E Bramley)

原發性鼓脹 ─ 治療 Primary bloat – treatment

p  極度痛苦的牛隻(已危及性命) Animals in severe distress (life threatening)

•      緊急瘤胃切開術(牛較痛苦) Emergency rumenotomy (stabbing)

•      使用銳利的刀(解剖刀)，刺入左側離最後一根肋骨及背骨下方1手掌距離的地方Using sharp knife (post-mortem knife), stab on left side, 1 hand’s span behind last rib and 1 hand’s span below back-bone

•      切開後，向旁扭轉，讓泡沫和氣體排出After stab incision is made, twist sideways to allow escape of foam and gas

•      必要時擴大切口Enlarge incision if necessary

•      在每次術後要縫合傷口Suture wound afterwards as per rumenotomy

•      沖洗腹部和給予全身性抗生素Flush abdomen and systemic antibiotics

•      牛隻仍會因腹膜炎而死亡Animal may still die from peritonitis

原發性鼓脹 ─ 預防/管控Primary bloat – prevention/control

p  補充品質良好的纖維來源Supplement with a good quality fibre source

p  確認精料無太細碎Ensure concentrate is not ground too fine

p  持續投與抗鼓脹膠囊Sustained release anti-bloat capsules

•      提供的膠囊能在進入牛食道後，緩慢(80~100天)的釋放孟寧素80%Capsules administered as a large plastic pellet down oesophagus containing slow release monensin (80-100 d)

•      成本雖高，但死亡率可降低Cost is significant but reduces deaths by 80%

p  將氫離子劑(Ionophores)做為精料餵飼(飼料比例) Ionophores fed as premixes (dairy rations)