Oiled Sea Otter Rehabilitation Course

Triage for Oiled Wildlife

A triage program allows the rehabilitation team to classify and treat contaminated wildlife in a systematic manner. If all members of the team are familiar with the criteria or priorities, it provides the basis for providing the best care for the largest number of animals. Some animals may require immediate lifesaving procedures, while others may benefit from a period of stabilization. Critically ill animals with little chance of survival may create an unreasonable demand on veterinary resources. In these cases, euthanasia should be considered.

It is the responsibility of the rehabilitation team to assign treatment priorities for the different categories of contaminated wildlife. The triage system described here was developed for subadult and adult animals. Because sea otter pups require specialized care, they should be directed to nursery areas for immediate, full-time attention (see Chapter 9). The criteria used for ranking adult animals in different triage categories are based on: 1) toxicity of the oil encountered, 2) degree of external oiling, 3) stability of the animal, and 4) general medical condition.

Factors for determining these criteria are presented in Chapter 4 and Chapter 5. The condition of each otter arriving at rehabilitation centers depends on many unknown factors, such as the duration of oil exposure and the animals’ general health before the spill. However, triage criteria necessarily are limited to physiological and behavioral assessments of the animal once it arrives at the center.

For evaluating adult otters, we recommend the five-category triage rating system established for the treatment of war casualties (Bowen and Bellamy, 1988): 1) urgent, 2) immediate, 3) delayed, 4) minimal, or 5) expectant.

Urgent

Animals in this category require urgent intervention to prevent continued contamination or death. Their survival will depend on quick and efficient treatment. Heavily oiled otters contaminated early in the spill are placed in this category. The primary goal is to remove oil quickly and to avoid systemic contamination due to dermal absorption, inhalation, or ingestion during grooming. Fresh crude oil often irritates the otters’ sensitive membranes; excessive biting and scratching can lead to permanent damage of the cornea and interdigital webbing of the flippers. Animals displaying hypoglycemic shock and hypothermia fall within this category regardless of the spill phase. Treatments include washing (Chapter 6) and immediate medical attention (Chapter 5). Rewarming hypothermic animals, cooling hyperthermic ones, and administering fluids are indicated when appropriate. If presented with several animals in this category, animals displaying emergency medical conditions should be treated first.

Immediate

This group requires immediate washing and treatment of minor medical problems. Usually, survivorship is high if treatment is quick. Heavily oiled animals contaminated late in a spill and showing few medical abnormalities fall into this category. Also, moderately oiled animals captured during all phases of the spill, and animals showing moderate respiratory distress, mild hypoglycemia, or hypothermia require immediate attention. These animals are temporarily stable and tolerate short waiting periods as long as they are supervised. They should await treatment in thermal environments that allow them to maintain normal body temperatures and do not induce panting or shivering. Because of complications associated with anesthetic agents (Chapter 3), they should not be fed unless treatment is delayed for more than three hours.

Delayed

These animals can tolerate and will probably benefit from a period of rest before treatment. Moderately oiled otters contaminated late in the spill and showing no clinical or behavioral signs of distress should be placed in the delayed category. Other animals in this category include lightly oiled or unoiled otters with minor clinical signs (periodic agitation or shivering, etc.). These animals often will accept food; food, water, and rest are recommended while they await treatment. The period of stabilization can range from twelve to twenty-four hours with little adverse effect. These animals are treated after Urgent and Immediate Care animals are handled.

Minimal

Animals in this category require minimal or no cleaning and often only require a general physical examination. A stabilization period of twenty-four to thirty-six hours is recommended. Food and water should be offered to alert animals every three hours throughout this period. The animals must be supervised during stabilization. Tests may be necessary to determine if the fur is oiled; treatment and washing will be based on the results of these tests. If the results for oiling are negative and the veterinary staff has determined that the animal is healthy, then we recommend moving these animals quickly to long-term holding areas. Lightly oiled and unoiled otters showing no clinical signs of distress comprise this category.

Expectant

This category includes all animals that behaviorally and clinically have little expected chance of survival. They should be made comfortable during a brief period of observation. The primary criteria for placement in this category is severe subcutaneous emphysema as determined by palpation. Usually the condition is irreversible and is associated with other severe medical conditions. During the Exxon Valdez oil spill (EVOS), otters with subcutaneous emphysema that displayed diaphragmatic and agonal breathing rarely survived twenty-four hours in the rehabilitation center. A veterinarian should be consulted to determine if euthanasia is the most humane alternative for animals in this category.