VCP 411: Medicine Section

CATTLE

• In young calves, the CSF sampling procedures described for sheep can be employed successfully. A 1½ inch 19 gauge needle is used.
• In adult cattle, CSF samples are best collected from the lumbosacral site under local anaesthesia with the standing animal restrained in cattle stocks. The approach is a follows:
• A midline site midway between the last palpable lumbar vertebral dorsal spinal process (L5) and the first palpable sacral dorsal spinal process (S2) is chosen.
• First, a 5 cm 14 gauge needle is used to penetrate the skin, connective tissue and interarcuate ligament.
• This tract is then followed by a 10 cm 18 gauge spinal needle with stylet. Increased resistance to the direction of the needle can be appreciated between a depth of 3 to 6 cm when the interarcuate ligament is penetrated.
• With the needle point in the subarachnoid space, removal of the stylet allows CSF to appear at the needle hub within two to five seconds. (In approximately 25 per cent of cases gently syringe aspiration is necessary to obtain CSF.)
• Diazepam (0.05 mg/kg bodyweight) is a useful sedative for this procedure when dealing with uncooperative animals.