General condition
Start every examination with an assessment of the tiger’s general condition by feeling the amount of muscle covering the bones, and the amount of body fat present. Note any wounds, abnormal body shape or asymmetry, and external lumps and masses.Take a rectal temperature, note whether the tiger is dehydrated or not, and record its weight. (Weighing a large tiger in the field is not easy, but it can be done and is important as an indicator of general condition and to guide to the doses of medical treatments).
Rectal temperature measurement is mostly important for monitoring anaesthesia but will also indicate a body temperature that is excessively high (hyperthermia) or low (hypothermia). Both conditions need to be addressed without delay.
A standard digital rectal thermometer can be used to take the body temperature of a tiger, although for monitoring during anaesthesia a real-time thermometer is an advantage.
The normal rectal temperature of tigers is between 37.8 degrees C and 39.4 degrees C. (100 – 103 degrees F). Hyperthermia is considered to exist if the body temperature is above 40 degrees C (104 F) and hypothermia if the body temperature drops below 36 degrees C (~ 97 degrees F). Long induction times, excessive pre-anaesthetic activity or seizures in high ambient temperatures often result in hyperthermia. Click on these links for treatment options: hyperthermia, hypothermia.
NB: A body temperature of 40°C or above in a tiger that has had a smooth and calm induction to anaesthesia in moderate ambient temperatures may have pyrexia (fever) caused by infection or severe pain.
Assess level of dehydration by:
- Feeling inside the mouth for dryness
- Observing for sunken, dull eyes
- Pulling up the skin to assess elasticity and tenting (Skin tent test)
Skin tent test: The tiger’s skin should be pinched and pulled up over the shoulders. The skin should then be released, and how quickly it goes back into place gives a rough guide to the level of dehydration.
| Signs | % Dehydration |
|---|---|
| Skin goes back into place quickly (< 1 second) - no clinical signs | 0-5% |
| Skin goes back into place slightly slower than normal. | 5-6% |
| Skin goes back significantly slower; possible also dry mucous membranes | 6-8% |
| Skin fold persists; sunken eyes, dry mucous membranes; increased capillary refill time > 2 secs | 8-10% |
| Symptoms of shock. Death. | 12-15% |
Dehydration reduces the perfusion of all tissues, slows the elimination of anaesthetic drugs, and if severe can lead to hypotension and life-threatening shock. Therefore treatment of dehydration is essential to prevent shock.
A tiger with a weak and rapid pulse, pale or cyanotic (bluish) mucous membranes with prolonged capillary refill time, a rapid heartbeat, hyperventilation or shallow sporadic breathing, cold extremities and hypothermia is likely to be already in shock.
