Intraosseous infusion in sea otters is a technique that can be used to administer fluids or drugs when subcutaneous and intravenous routes are unavailable or inefficient. It allows immediate access to the venous system via the sinusoids in the bone marrow that drain into the medullary venous channels, which then drain into nutrient and emissary veins. The emissary veins subsequently drain into the systemic venous system.

This procedure was applied to a male, juvenile sea otter that was presented 3/25/93 in a semi-comatose state. Routine treatment began which included administration of subcutaneous fluids. By 3/26/93, the SQ fluids were not being absorbed, possibly due to the severity of dehydration and hepatic insufficiencies which were indicated from the blood chemistries. An alternative route needed to be established to continue effective treatment. Intravenous catheter placement was unsuccessful due to the peripheral vein structure and size, the high motility of the skin, and the grooming behavior of the otter. Intraosseous cannulation was then elected and techniques were attempted and adapted from prior intraosseous catheter placement in cats and dogs.

The sagittal crest at the head of the IV metatarsal was the primary site, reasoned to be least invasive. An 18 gauge 3 1/2 inch spinal needle with styles was advanced through a sterile prepared area into the cortex with direct pressure and twisting motions. Lactated Ringer's Solution (LRS) was administered at a rate of 10-12 ml per hour. This flow rate was deemed unsatisfactory and a secondary site was prepared, the femur of the right leg. Again, a 18 gauge spinal needle was placed in the proximal end of the right femur through the trochanteric fossa, and marrow was aspirated for confirmation of placement and analysis. LRS was then administered at 100-120 ml per hour and considered satisfactory for rehydration and diuresis.

The ease of placement, stability of the catheter, and the effective administration of drugs and fluids make intraosseous catheterization an excellent therapeutic tool in the treatment of debilitated sea otters.