Lessons / Medical & Fluid Math / Assessing dehydration
🧮 Medical & Fluid Math · 6 min
Assessing dehydration
Why this matters
Fluid therapy is one of the most useful things you can do, and it starts with an estimate you make by hand and eye.
By the end of this lesson you will be able to
- Perform and interpret a skin tent test
- Estimate percentage dehydration from clinical signs
Gloves, always
Even seemingly docile animals resent hands near their face and may bite without warning. Many diseases are transmitted from an animal's mouth to you.
Common signs of dehydration
- Persistent skin tent. Gently pinch a small amount of skin at the neck or along the back, lift, release, and watch how long it takes to lie flat. This takes practice: learn it from a veterinarian or a skilled rehabilitator.
- Sunken eyes.
- Pale, tacky mucous membranes. Easiest to assess at the gums in mammals and inside the mouth in birds. A dehydrated bird's mouth appears stringy, and its saliva is sticky.
- Cool extremities.
- Dry, wrinkly skin in birds. Move the feathers aside. A skin tent test works on a bird too, on skin normally covered by feathers.
| Signs in mammals | % dehydration |
|---|---|
| None | under 5% |
| Slight increase in skin tent collapse time (1 to 2 seconds) | 6% |
| Prolonged skin tent (2 to 3 seconds), sunken eyes | 6 to 8% |
| Very delayed skin tent (3 to 5 seconds), sunken eyes, dry and pale mucous membranes | 10 to 12% |
Death can occur at dehydration levels over 12%
This lesson is part of the NY Wildlife Rehabilitator Exam course. Open it in the course to answer the retrieval checks that go with it, track what you have read, and quiz the whole unit. Lessons, quizzes and the glossary are free.