Veterinary Clinical Medicine-I (General and Systemic)

TEMPERATURE AND RELATED ILLNESS

• Measuring the internal body temperature is of great importance in obtaining a diagnosis and prognosis of diseases.
• Internal body temperature can be measured using a mercury blunt-bulb clinical thermometer or a digital thermometer.
• The range of most thermometers is 36-42 ^○C. The blunt-bulb thermometer is used to obtain the temperature through the rectum whereas the digital thermometer is used to obtain the body temperature of felines from the ear.
• In case of obtaining the temperature via the rectum, it should be evacuated from faecal matter.
• If the animal has had a long journey, it should be rested before obtaining its temperature.
• For in-patients, record the temperature twice daily (morning and evening) and record on a special chart.

Internal body temperature in different animal species

Animals	Range	Average	Animal	Range	Average
Horse	37.2-38	37.6	Camel	35-38.6	36.8
Foal	37.5-38.6	38	Pig	37.8-38.9	38.3
Ox	37.8-39.2	38.5	Piglet	38.9-40	38.4
Calf	37.8-39.8	39.2	Dog (small breed)	38.6-39.2	38.9
Sheep	38.9-40	39.5	Dog (large breed)	37.5-38.6	38
Goat	38.6-40.2	39.4	Guinea pig	37.5-39.4	38.4
Cat	39.9-40.5	39.8
Rabbit	37.8-39.2	38.5

• The values above are applicable only when animal is at rest in moderate environmental temperature and humidity.
• Physiological factors affecting internal body temperature
• Body temperature may be slightly higher in the following:
  • Females, pregnancy and during oestrous cycles.
  • Young animals.
  • Variation during the day with temperature being higher at mid-day.
  • Following feeding or exercise.
  • Excitement.
  • High atmospheric temperature
• Abnormal body temperature

Subnormal body temperature (hypothermia)

• Faulty technique (bulb not in contact with rectal mucosa).
• Administration of cold enemas.
• Pathological
  • Malnutrition
  • Acute rumenal impaction of cattle
  • Hypocalcaemia
  • Hypothyroidism
  • Haemorrhage
  • Anaemia
  • Shock

• Subnormal temperature occurs in fatal disease just before death.
• Elevated body temperature (hyperthermia).
• Elevation of body temperature above the normal range.

Fever

• Is elevation of body temperature accompanied by trembling, erected hair coat and cold skin.
• It occurs in various infectious diseases such as anthrax, rinder pest, septicaemia, pyaemia and malignant head catarrh.
• Uneven distribution of external body temperature.
• Accelerated pulse and respiration.
• Loss of appetite and impaired digestion.
• Depression.

Fever goes through the following stages

• Increment or onset, during which the internal body temperature is elevated but the skin capillaries remain constricted resulting in the animal feeling cold and starts to shiver.
• Fastigum or period of maximum body temperature, the body temperature remains elevated but shivering ceases.
• Decrement, the internal body temperature starts to fall.
• N.B. rapid reduction of fever with the temperature returning to normal within a few hours is termed a crisis whereas a slow decrease of temperature is termed lysis.
• A rapid reduction of fever with temperature returning to the subnormal level is called collapse.
• The fever maybe mild (1C above normal), moderate (1.7C) or severe (2C). It has different types, these are:
• Simple fever.