AII 3000 A portable is a popular inexpensive and easy to use device to spot check O2 levels in intensive care unit cages used in veterinary clinics or animal clinics.

Animals that have been delivered to a clinic for a surgery or treatment will often be kept in ICU cages that allow specific controlled oxygen therapy. For conditions where there is a mechanical or physiological compromise of ventilation such as pre and post anesthetic oxygenation or fractured ribs the exposure of the animal to a higher than ambient oxygen is desirable. Other conditions where the alveolar oxygen exchange mechanism is compromised such as a longstanding obstructive airway disease or severely compromised e.g. serious lung contusion, or congestive cardiac failure require elevated oxygen exposure, sometimes to levels as high as 60%.

To achieve the desired therapeutic effect the selected oxygen levels have to be monitored with a simple and inexpensive instrument. Like many drugs, oxygen can be associated with toxicity and an excess amount of oxygen can be harmful to lungs (pulmonary endothelium). The use of inspired oxygen greater than 60% should be avoided if possible.