Table 8 Skin temperature, thermal threshold (TT) and thermal excursion (%TE) and ambient temperature following a single IV administration of saline, 0.25, 0.5 and 1.0 mg/kg meperidine HCl to 8 horses. Values are expressed as mean ± SD

Skin Temp (°C)

  Saline

24.6 ± 3.1

25.2 ± 3.1

26.3 ± 3.4^*

26.7 ± 3.2^*

27.3 ± 3.3^*

28.2 ± 3.1^*

29.3 ± 2.9^*

30.5 ± 1.9^*

32.0 ± 2.0^*

32.0 ± 2.0^*

  0.25 mg/kg

24.8 ± 1.7

24.8 ± 2.3

25.9 ± 2.5

26.2 ± 2.8

28.1 ± 3.3^*

28.5 ± 3.6^*

29.2 ± 4.0^*

28.8 ± 4.2^*

29.7 ± 4.0^*

30.6 ± 4.6^*

  0.5 mg/kg

25.4 ± 3.2

25.4 ± 3.7

27.4 ± 3.8^*

28.1 ± 4.0^*

29.7 ± 2.4^*

30.4 ± 1.6^*

31.3 ± 1.0^*

31.6 ± 0.9^*

32.1 ± 1.0^*

32.1 ± 1.4^*

  1 mg/kg

25.4 ± 2.3

25.9 ± 2.8

26.5 ± 3.3

27.5 ± 2.8^*

28.7 ± 1.7^*

31.3 ± 3.8^*

30.8 ± 1.0^*

30.3 ± 1.7^*

30.7 ± 2.1^*

32.1 ± 0.8^*

TT (°C)

  Saline

48.5 ± 4.9

50.0 ± 4.2

48.6 ± 6.9

46.7 ± 6.5

50.0 ± 7.8

47.6 ± 3.7

49.9 ± 3.7

50.0 ± 6.3

49.4 ± 4.8

50.6 ± 4.7

  0.25 mg/kg

49.6 ± 3.8

50.3 ± 3.2

46.9 ± 6.9

51.4 ± 4.3

51.0 ± 4.8

51.7 ± 4.3

49.5 ± 5.4

50.7 ± 5.0

51.4 ± 5.9

52.8 ± 3.3

  0.5 mg/kg

47.7 ± 6.0

51.7 ± 3.6^*

50.5 ± 4.5^*

50.8 ± 5.5^*

49.9 ± 4.0

47.4 ± 5.3

47.4 ± 4.3

48.7 ± 5.9

51.5 ± 4.0^*

49.7 ± 3.7

  1 mg/kg

49.0 ± 3.4

53.5 ± 2.6^*

51.3 ± 3.6

48.9 ± 5.6

50.4 ± 3.1

50.6 ± 5.5

47.8 ± 4.9

47.9 ± 3.1

49.3 ± 4.3

48.9 ± 6.4

% TE

  Saline

79.4 ± 15.2

83.4 ± 13.2

78.6 ± 21.8

70.5 ± 24.5

81.9 ± 28.3

71.6 ± 14.1

79.8 ± 14.6

78.9 ± 26.7

75.6 ± 21.4

80.2 ± 21.2

  0.25 mg/kg

82.1 ± 12.2

84.3 ± 10.8

70.6 ± 26.0

87.4 ± 15.1

84.2 ± 18.7

86.2 ± 17.6

76.4 ± 23.1

82.9 ± 18.5

84.9 ± 24.3

90.1 ± 14.3

  0.5 mg/kg

75.4 ± 20.9

88.6 ± 12.8^*

84.2 ± 15.7^*

84.9 ± 20.7^*

79.7 ± 16.0

69.3 ± 21.4

67.7 ± 18.3

73.1 ± 25.3

84.6 ± 17.9

76.8 ± 16.5

  1 mg/kg

79.7 ± 11.3

94.9 ± 8.9^*

87.3 ± 12.4

78.4 ± 19.0

82.4 ± 12.1

81.6 ± 23.0

70.2 ± 20.4

71.1 ± 12.5

76.6 ± 18.0

73.3 ± 27.2

Ambient Temp (°C)

  Saline

19.4 ± 1.2

20.0 ± 1.0^*

20.1 ± 1.0^*

20.3 ± 1.1^*

20.4 ± 1.0^*

20.8 ± 1.0^*

21.1 ± 1.1^*

22.2 ± 1.2^*

23.4 ± 1.4^*

25.8 ± 1.4^*

  0.25 mg/kg

20.9 ± 1.9

20.8 ± 1.8

20.9 ± 1.9

21.1 ± 1.9

21.1 ± 1.9

21.4 ± 2.0

21.8 ± 2.1^*

22.6 ± 2.2^*

23.6 ± 2.0^*

25.0 ± 1.3^*

  0.5 mg/kg

19.9 ± 2.1

20.2 ± 1.9

20.4 ± 2.0

20.7 ± 2.0

20.9 ± 2.0^*

21.4 ± 1.9^*

21.9 ± 1.9^*

22.9 ± 2.0^*

23.8 ± 2.0^*

24.7 ± 1.5^*

  1 mg/kg

20.5 ± 1.4

20.6 ± 1.2

20.8 ± 1.2

20.9 ± 1.2^*

21.1 ± 1.2^*

21.6 ± 1.2^*

22.1 ± 1.1^*

23.1 ± 1.2^*

24.1 ± 1.1^*

26.1 ± 1.4^*