“The pharmacokinetics of cytarabine in dogs when administered via subcutaneous and continuous intravenous infusion routes.”
Crook, Early, Messenger, Munana, Gallagher, Papich
J Vet Pharmacol Therap. 36, 408-411

A cross-over study comparing 50mg/kg SQ twice daily for two days (200mg/kg over 2 days) versus 25mg/kg/hour IV infusion (200mg/kg over 8 hours). Blood values are speculated to reflect BBB transition of the drug for effectiveness (more important than CSF levels). The ability to achieve and maintain a steady-state is proposed to be necessary for the most effective transfer across the BBB. This was achievable with IV infusion but not the SQ administration protocol.