📝 STANDARD DESCRIPTION:
Key Lymph Nodes (Ox):
• Superficial Cervical (Prescapular) LN — cranial to shoulder, deep to brachiocephalicus. Drains skin of neck, shoulder, cranial forelimb. Routine palpation in clinical exam + meat inspection.
• Axillary LN — in axillary space; drains deep structures of forelimb.
• Cubital LN — at medial elbow (small, inconstant).
Surface Veins for Venepuncture:
• Cephalic vein — dog/cat (cranial forearm).
• Jugular vein — cattle, horse, sheep (large animals).
• Milk vein (subcutaneous abdominal) — only in lactating cows when others fail.
📚 DETAILED DESCRIPTION:
LYMPH NODES OF THE FORELIMB & THORACIC INLET
1. Superficial Cervical (Prescapular) Lymph Centre: A long chain of 4-20 nodes lying on the cranial border of the supraspinatus, deep to the brachiocephalicus and omotransversarius. Afferents: skin of cranial half of body, neck, shoulder. Efferents: tracheal duct → venous angle. Routinely palpated during the physical exam in cattle and required for ante-mortem inspection in the abattoir.
2. Axillary Lymph Centre: deep to the proximal pectorals; drain deep structures of the forelimb. Efferents → caudal cervical or thoracic duct. Inaccessible to palpation in life — relevant only at necropsy/meat inspection.
3. Cubital (Brachial) LN: small, inconstant; medial elbow.
SURFACE VEINS FOR VENEPUNCTURE:
• Cephalic vein (Vena cephalica): runs on craniomedial aspect of forearm. Standard IV in dog and cat (catheter placement, sample collection, induction). Easily distended by occluding above the elbow.
• Median cubital vein: bridges cephalic to brachial — used for blood collection in dogs.
• Jugular vein: although technically a neck vein, it is the routine large-animal IV access (cattle, horse, sheep, camelid). Located in the jugular furrow between brachiocephalicus and sternomandibularis.
• Subcutaneous abdominal ('milk') vein: prominent under the ventral abdomen of high-producing dairy cows. Last resort when jugulars are scarred/thrombosed — risk of severe haematoma.
// COMPARATIVE ANALYSIS
| CATTLE |
Prescapular LN routinely palpated and used for meat inspection. Jugular = standard IV. |
| DOG/CAT |
Prescapular LN palpable in slim animals — generalized enlargement = lymphoma. Cephalic vein = first IV choice. |
| HORSE |
Jugular venepuncture in upper third of jugular furrow. Avoid lower third (close to common carotid). |
CLINICAL RELEVANCE
Bovine Lymphosarcoma: Persistent enlargement of prescapular LN is a key clinical sign.
Jugular Thrombophlebitis: Common after repeated rough venepuncture — leads to abscess and reduced venous return.
'Milk Vein' Bleeding: Severe haematomas occur if not properly compressed — avoid unless absolutely necessary.
