There is disagreement about the value of orally administered tetracycline as a therapeutic agent in the treatment of systemic disease in killer whales.

This disagreement arises as a result of evidence suggesting that tetracycline is very poorly absorbed when orally administered. To begin to answer this question, a preliminary absorption study was done on three killer whales residing at Sealand of the Pacific in Victoria, British Columbia.

The whales were given single oral doses of tetracycline hydrochloride, then blood samples were taken at 0, 1, 2, 4, 8, 12, and 24 hours. These samples were then analyzed for tetracycline concentration.

A single killer whale that was on tetracycline for therapeutic reasons, was sampled at 12, 24, 48, 72 and 96 hours post treatment. These samples were also analyzed in hopes of shedding some light on the half-life of the drug.