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SEDATIVE ANALGESIC EFFECTS OF DETOMIDINE HCL (DOMOSEDAN) IN LANKA BUFFALOES
Proceedinps of the 4th International Con-
of Veterinaw Anaesthesia
SEDATIVE ANALGESIC EFFECTS OF DETOMIDINE HCL (DOMOSEDAN) IN LANKA BUFFALOES
D.D.N. de Silva. Department of Veterinary Clinical Studies, University of Peradeniya, Sri Lanka
Introduction In Sri Lanka indigenous Lanka buffaloes are reared mainly for draught purposes. They are considered as a cheaper substitute for tractors and other farming machinery. By nature these animals are aggressive and often need to be restrained by physical methods or by chemical means. Quite often the physical methods of restraint cause serious injuries to the handlers therefore, the chemical restraint is preferred. Also, with the recent trend to use lanka buffaloes and their crosses for milk production the need for taming and handling these "semi wild" species poses a challenge. In order to produce superior crosses between Lankan and Indian breeds numerous research programmes are under way and all these procedures demand safe handling of the animals with an effective sedative analgesic drug. In Sri Lanka, the availability of effective sedative analgesic drugs is limited and it was felt that it is worthwhile to investigate a newer drug. Therefore, a study of the sedative analgesic effects of a2 agonist, Detomidine HC1 on Lanka buffaloes was undertaken.
pulse rate and heart rate were measured prior to and at min 1,5, 10, 15,20,30,4 5 6 0 , 90, and 120 after the administration of Domosedan. The qualitative observations such as ptosis, head lowering, relaxation of the jaw, penis, muscles of the flank, ataxia, recumbency, salivation, urination, defecation, sweating, tear production, regurgitation, expiratory grunt, reactions to pinpricks at the base of the horn, interdigital space, coronet, flank, reactions to the handling of teats and vagina in females and penis and the scrotum in males were carried out at the above predetermined intervals after administration of the drug.
Results &t&d TemDerature No significant changes in the rectal temperature were observed with any of the dosages. m i r a t o r y Ratg There was no significant change in respiratory rate with the dosages of 0.1, 0.2 and 0.4 m1/100 kg. With 0.8 m1/100 kg the respiratory rate increased s w c a n t l y (P>O.O5) above the preinjection value from min 15 to 90 and then returned to a near normal rates at rnin 120.
Materials and Methods
Thirty two buffaloes (18 males and 14 females) whose ages ranged from 8 months to 8 years were divided randomly in to 4 groups. The body weight ranged from approximately 100 to 550 kgs. Four dosages of Domosedan (10 mg/ml) namely 0.1 ml, 0.2 ml,0.4 ml and 0.8 ml/ 100 kg were a d m i t e r e d intramuscularly to the gluteal region. Rectal temperature, respiratory rate,
Heart Rate and Pulse Rate With all four dosages heart rate and pulse rate decreased significantly (i50.005)from the preinjection value at 1 min after the injection and with the last two dosages pulse rate could not be palpated in the coxygeal artery from min 5 to u) and 30 respectively after the injection. The 211
Proceedings of the 4th International Congress of Veterinary Anaesthesia
pulse rates never returned to normal even at 120 min with any of the dosages.
pricks at the base of the horn, interdigital space, coronet and flank were shown and also examination of the vulva and udder in females and penis and scrotum in males were not resented.
Sedation and Analgesix 0.1 m1/100 kg: There was slight ataxia after about 10 minutes. Animal became slightly sedated and could be aroused easily. Reactions to painful stimuli remained intact.
9.8 m1/100 kg There was marked sedation in min 1 to 5. Ptosis, head lowering, marked ataxia, and salivation were evident and recumbency in all the animals was observed in 10 to 20 minutes. A marked relaxation of the muscles of the flank, lack of reactions to needle pricks were observed and their muzzles were rested on the ground or on the flaxik (milk fever position). There was a prominent expiratory grunt, regurgitation and the animals remained recumbent for about 180 minutes. (Another study showed that it was possible to perform castration and vasectomy in young animals without local analgesia and major surgical procedures where muscle relaxation is needed (e.g. laparotomy) in adult in conjunction with inverted "L"block).
Relaxation of the jaw was seen in 3 young animals and salivation was evident in all the animals after about 15 minutes. 0.2 m1/100 k g There was ptosis, lowering of the head with relaxation of the jaw and salivation in about 10 minutes after the injection. No reactions to painful stimuli from min 20 onwards and examination of the vulva and udder in all females, scrotum and penis in 75% of the males were possible. Ear flapping remained intact in all the animals through out the experiment.
Discussion The results showed that the first dosage (0.1 m1/100 kg) is of limited value for practical use. The dosage of 0.2 m1/100 kg was desirable for sedation for clinical examination, minor surgical interferences in standing animals in conjunction with local analgesia and for transportation of the animals. The third dosage in this study (0.4 m1/100 kg) was suitable for clinical examination and for major surgical interventions with local analgesia and for immobilization of the animals. The final dosage (0.8 m1/100 kg) was suitable for major surgical interventions and for complete immobilization of the animal. The fact that there was no sigdlcant change in rectal temperature with any of the dosages used suggests that the thermoregulatory mechanism of this species is not affected by Detomidhe. The respiratory rates also were not significantly
0.4 m1/100 k g
Animals showed signs of sedation (Ptosis, head lowering, respiratory grunt) in 5 to 10 minutes after the injection. There was relaxation of the jaw, muscles of the flauk and marked ataxia in about 10 minutes and 50% of the animals became recumbent. There was profuse salivation and in 2 animals there was regurgitation of ruminal contents after recumbency. The recumbent animals were resting their muzzles on the ground from 30 to 60 minutes and raised their heads but remained recumbent until 90 to 115 min after the injection. They stood up when forced and remained standmg but sedated until about 180 minutes. Two pregnant females ( 2 and 3 months of pregnancy) included in this group did not show any adverse changes during or after the experiment. No reactions to needle 212
Proceedinps of the 4th International Con-
altered with the first three dosages probably because of an adequate ventilation was maintained. But, with 0.8 m1/100 kg the tidal volume was probably low, thus, adequate ventilation had been maintained by compensatory increase in the respiratory rate. However, without measuring the corresponding tidal and minute volumes this hypothesis cannot be proved. With all the dosages the heart and the pulse rates were lowered together with the pulse pressure. Without measuring the mean arterial blood pressure in this study it is impossible to say how &Icant the hypotension was. There was no adverse effects at least on the first trimester of pregnancy but further studies have to be done to come to a defmite conclusion on its safety in pregnant animals.
of Vcterinarv Anaesthesia
from 8 months to 8 years and which were randomly divided in to 4 groups. Rectal temperature, respiratory rate, pulse rate and heart rate were measured prior to and at min 1, 5, 10, 20, 30, 45, 60, 90 and 120 after intramuscular administration of the drug in the gluteal region. Qualitative observations such as ataxia, drowsiness, salivation, relaxation of the jaw, recumbency and response to painful stimuli were also made at the above intervals after injection. The results indicated that the dosage of 0.1 ml/ 100 kg caused only a mild sedation which was unlikely to be of any practical use. Whereas, dosages of 0.2 ml and 0.4 m1/100 kg were useful to produce desirable sedative analgesic effects for clinical examination, pre-operative medication, minor surgical procedures and transportation. The final dosage of 0.8 m1/100 kg produced a very deep sedation and marked analgesia always associated with recumbency which was useful for complete immobilization of the animal. In general Detomidine cause bradycardia, reduced pulse pressure, salivation and with higher dosages regurgitation. Degree of sedation and analgesia were dose dependent.
Conclusion
In general it can be concluded that the sedation and analgesia with Detomidine was dose dependent. And for most clinical and practical purposes 0.2 m1/100 kg to 0.4 m1/100 kg are the most suitable dosage ranges. Although the highest dosage used caused complete immobilization and pronounced muscle relaxation there is a risk at aspirating regurgitated ruminal contents and, therefore, it should be used with caution. Summary Detomidine HCI (Domosedan) is a Imidazole derivative which acts upon a2-adrenoreceptors. In Sri lanka, the limited availability of an effective sedative analgesic drugs for intractable buffaloes, for various purposes such as restraint for easy handling, transportation, immobhtion, pre-operative medication and analgesia prompted the present study. Four dosages namely, 0.1, 0.2, 0.4 and 0.8 ml/ 100 kg body weight of 1% Detomidine HCI were tested in 32 male and female buffaloes whose ages ranged 213
of Veterinaw Anaesthesia
SEDATIVE ANALGESIC EFFECTS OF DETOMIDINE HCL (DOMOSEDAN) IN LANKA BUFFALOES
D.D.N. de Silva. Department of Veterinary Clinical Studies, University of Peradeniya, Sri Lanka
Introduction In Sri Lanka indigenous Lanka buffaloes are reared mainly for draught purposes. They are considered as a cheaper substitute for tractors and other farming machinery. By nature these animals are aggressive and often need to be restrained by physical methods or by chemical means. Quite often the physical methods of restraint cause serious injuries to the handlers therefore, the chemical restraint is preferred. Also, with the recent trend to use lanka buffaloes and their crosses for milk production the need for taming and handling these "semi wild" species poses a challenge. In order to produce superior crosses between Lankan and Indian breeds numerous research programmes are under way and all these procedures demand safe handling of the animals with an effective sedative analgesic drug. In Sri Lanka, the availability of effective sedative analgesic drugs is limited and it was felt that it is worthwhile to investigate a newer drug. Therefore, a study of the sedative analgesic effects of a2 agonist, Detomidine HC1 on Lanka buffaloes was undertaken.
pulse rate and heart rate were measured prior to and at min 1,5, 10, 15,20,30,4 5 6 0 , 90, and 120 after the administration of Domosedan. The qualitative observations such as ptosis, head lowering, relaxation of the jaw, penis, muscles of the flank, ataxia, recumbency, salivation, urination, defecation, sweating, tear production, regurgitation, expiratory grunt, reactions to pinpricks at the base of the horn, interdigital space, coronet, flank, reactions to the handling of teats and vagina in females and penis and the scrotum in males were carried out at the above predetermined intervals after administration of the drug.
Results &t&d TemDerature No significant changes in the rectal temperature were observed with any of the dosages. m i r a t o r y Ratg There was no significant change in respiratory rate with the dosages of 0.1, 0.2 and 0.4 m1/100 kg. With 0.8 m1/100 kg the respiratory rate increased s w c a n t l y (P>O.O5) above the preinjection value from min 15 to 90 and then returned to a near normal rates at rnin 120.
Materials and Methods
Thirty two buffaloes (18 males and 14 females) whose ages ranged from 8 months to 8 years were divided randomly in to 4 groups. The body weight ranged from approximately 100 to 550 kgs. Four dosages of Domosedan (10 mg/ml) namely 0.1 ml, 0.2 ml,0.4 ml and 0.8 ml/ 100 kg were a d m i t e r e d intramuscularly to the gluteal region. Rectal temperature, respiratory rate,
Heart Rate and Pulse Rate With all four dosages heart rate and pulse rate decreased significantly (i50.005)from the preinjection value at 1 min after the injection and with the last two dosages pulse rate could not be palpated in the coxygeal artery from min 5 to u) and 30 respectively after the injection. The 211
Proceedings of the 4th International Congress of Veterinary Anaesthesia
pulse rates never returned to normal even at 120 min with any of the dosages.
pricks at the base of the horn, interdigital space, coronet and flank were shown and also examination of the vulva and udder in females and penis and scrotum in males were not resented.
Sedation and Analgesix 0.1 m1/100 kg: There was slight ataxia after about 10 minutes. Animal became slightly sedated and could be aroused easily. Reactions to painful stimuli remained intact.
9.8 m1/100 kg There was marked sedation in min 1 to 5. Ptosis, head lowering, marked ataxia, and salivation were evident and recumbency in all the animals was observed in 10 to 20 minutes. A marked relaxation of the muscles of the flank, lack of reactions to needle pricks were observed and their muzzles were rested on the ground or on the flaxik (milk fever position). There was a prominent expiratory grunt, regurgitation and the animals remained recumbent for about 180 minutes. (Another study showed that it was possible to perform castration and vasectomy in young animals without local analgesia and major surgical procedures where muscle relaxation is needed (e.g. laparotomy) in adult in conjunction with inverted "L"block).
Relaxation of the jaw was seen in 3 young animals and salivation was evident in all the animals after about 15 minutes. 0.2 m1/100 k g There was ptosis, lowering of the head with relaxation of the jaw and salivation in about 10 minutes after the injection. No reactions to painful stimuli from min 20 onwards and examination of the vulva and udder in all females, scrotum and penis in 75% of the males were possible. Ear flapping remained intact in all the animals through out the experiment.
Discussion The results showed that the first dosage (0.1 m1/100 kg) is of limited value for practical use. The dosage of 0.2 m1/100 kg was desirable for sedation for clinical examination, minor surgical interferences in standing animals in conjunction with local analgesia and for transportation of the animals. The third dosage in this study (0.4 m1/100 kg) was suitable for clinical examination and for major surgical interventions with local analgesia and for immobilization of the animals. The final dosage (0.8 m1/100 kg) was suitable for major surgical interventions and for complete immobilization of the animal. The fact that there was no sigdlcant change in rectal temperature with any of the dosages used suggests that the thermoregulatory mechanism of this species is not affected by Detomidhe. The respiratory rates also were not significantly
0.4 m1/100 k g
Animals showed signs of sedation (Ptosis, head lowering, respiratory grunt) in 5 to 10 minutes after the injection. There was relaxation of the jaw, muscles of the flauk and marked ataxia in about 10 minutes and 50% of the animals became recumbent. There was profuse salivation and in 2 animals there was regurgitation of ruminal contents after recumbency. The recumbent animals were resting their muzzles on the ground from 30 to 60 minutes and raised their heads but remained recumbent until 90 to 115 min after the injection. They stood up when forced and remained standmg but sedated until about 180 minutes. Two pregnant females ( 2 and 3 months of pregnancy) included in this group did not show any adverse changes during or after the experiment. No reactions to needle 212
Proceedinps of the 4th International Con-
altered with the first three dosages probably because of an adequate ventilation was maintained. But, with 0.8 m1/100 kg the tidal volume was probably low, thus, adequate ventilation had been maintained by compensatory increase in the respiratory rate. However, without measuring the corresponding tidal and minute volumes this hypothesis cannot be proved. With all the dosages the heart and the pulse rates were lowered together with the pulse pressure. Without measuring the mean arterial blood pressure in this study it is impossible to say how &Icant the hypotension was. There was no adverse effects at least on the first trimester of pregnancy but further studies have to be done to come to a defmite conclusion on its safety in pregnant animals.
of Vcterinarv Anaesthesia
from 8 months to 8 years and which were randomly divided in to 4 groups. Rectal temperature, respiratory rate, pulse rate and heart rate were measured prior to and at min 1, 5, 10, 20, 30, 45, 60, 90 and 120 after intramuscular administration of the drug in the gluteal region. Qualitative observations such as ataxia, drowsiness, salivation, relaxation of the jaw, recumbency and response to painful stimuli were also made at the above intervals after injection. The results indicated that the dosage of 0.1 ml/ 100 kg caused only a mild sedation which was unlikely to be of any practical use. Whereas, dosages of 0.2 ml and 0.4 m1/100 kg were useful to produce desirable sedative analgesic effects for clinical examination, pre-operative medication, minor surgical procedures and transportation. The final dosage of 0.8 m1/100 kg produced a very deep sedation and marked analgesia always associated with recumbency which was useful for complete immobilization of the animal. In general Detomidine cause bradycardia, reduced pulse pressure, salivation and with higher dosages regurgitation. Degree of sedation and analgesia were dose dependent.
Conclusion
In general it can be concluded that the sedation and analgesia with Detomidine was dose dependent. And for most clinical and practical purposes 0.2 m1/100 kg to 0.4 m1/100 kg are the most suitable dosage ranges. Although the highest dosage used caused complete immobilization and pronounced muscle relaxation there is a risk at aspirating regurgitated ruminal contents and, therefore, it should be used with caution. Summary Detomidine HCI (Domosedan) is a Imidazole derivative which acts upon a2-adrenoreceptors. In Sri lanka, the limited availability of an effective sedative analgesic drugs for intractable buffaloes, for various purposes such as restraint for easy handling, transportation, immobhtion, pre-operative medication and analgesia prompted the present study. Four dosages namely, 0.1, 0.2, 0.4 and 0.8 ml/ 100 kg body weight of 1% Detomidine HCI were tested in 32 male and female buffaloes whose ages ranged 213