Untersuchungen über den Einsatz von Schmerzmitteln zur Reduktion kastrationsbedingter Schmerzen beim Saugferkel

Investigation about the use of analgesics for the reduction of
castration-induced pain in suckling piglets. This study is intended
to investigate the implementation of analgesics in order to reduce
pain induced by the castration of suckling piglets. Serum Cortisol
and postoperative behaviour are used as parameters. Additionally,
the influence on the healing process of the castration wounds is
evaluated. 320 four to six day old male piglets with a good general
condition and a birth weight over 1000g, are randomly allocated to
group 1 to 15. The injections for the animals of group 12 to 15 are
blinded. group number of animals application of the agent
castration Cortisol 1 Handling NaCl 35 0,3 ml Saline Solution
(0,9%) i.m. no 2 Handling Meloxicam 25 0,4 mg Meloxicam/kg wt i.m.
no 3 Handling Flunixin 26 2,2 mg Flunixin-Meglumin/kg wt i.m. no 4
Handling Detomidin 25 40 μg Detomidinhydrochlorid/kg wt i.m. no 5
Castration NaCl 28 0,3 ml Saline Solution (0,9%) i.m. yes 6
Castration Meloxicam 25 0,4 mg Meloxicam/kg wt i.m. yes 7
Castration Flunixin 26 2,2 mg Flunixin-Meglumin/kg wt i.m. yes 8
Castration Metamizol + Skopolamin 25 50 mg Metamizol and 0,4 mg
N-Butylscopolaminiumbromid/kg wt i.m. yes 9 Castration Metamizol 25
50 mg Metamizol/kg wt i.m. yes 10 Castration Carprofen 15 1,4 mg
Carprofen/kg wt s.c. yes 11 Castration Detomidin 25 40 μg
Detomidinhydrochlorid/kg wt i.m. yes Behaviour 12 Handling NaCl 10
0,3 ml Saline Solution (0,9%) i.m. no 13 Castration NaCl 10 0,3 ml
Saline Solution (0,9%) i.m. yes 14 Castration Meloxicam 10 0,4 mg
Meloxicam/kg wt i.m. yes 15 Castration Flunixin 10 2,2 mg
Flunixin-Meglumin/kg wt i.m. yes 15 to 30 minutes after
administering the substances, piglets are either castrated (groups
5-11 and 13-15) or only restrained for about 30 seconds (groups 1-4
and 12). They are returned to their box immediately afterwards. 2-3
ml blood is taken from all animals of the cortisol-groups before
the application of the agents including 30 minutes, one hour, four
and 24 hours after castration/fixation, and the concentration of
cortisol in the serum is measured. The behaviour of all animals in
groups 12 to 15 is observed individually for 20 minutes in the
first and third hour after castration. Additionally, all piglets
are scanned every 60 seconds for certain behaviours. On the first,
fourth, seventh and 14th day after castration, wound healing and
general condition are assessed and a “clinical score” is
determined. The results of the cortisol measurement show that
handling the animals has little influence on the cortisol level,
while castration leads to a significant rise of the cortisol
concentration that is still present four hours later. All of the
tested non-opioid analgesics reduce the rise of the cortisol
concentration after castration and a considerable reduction is
especially noticeable after one hour. Group 6 “Castration
Meloxicam” and group 7 “Castration Flunixin” show the lowest
cortisol response to castration. The concentrations of cortisol in
those two groups are significantly lower 30 minutes, one and four
hours after castration than the concentration of group 5
“Castration NaCl”, and already after one hour they do not differ
significantly from the corresponding handling groups. Irregardless
if animals are castrated or only restrained, the use of Detomidin
(group 4 and 11) leads to higher values of cortisol after
castration/fixation compared to the values after the application of
NaCl (group 1 and 5). A conspicuous impact on the postoperative
behaviour is obvious when non-opioid analgesics are used. The
frequency of occurrence of castration-induced signs of pain,
drooping the tail and changing the position is explicitly reduced
when Meloxicam and Flunixin are injected before castration. The
effect of Flunixin is most clear. In this group, the incidence of
castration-induced signs is only higher for five minutes after
castration when compared to the Handling-group. Animals without
preoperative medication show an overall reduced activity at the
mammary glands and playing. Results indicate that non-opioid
analgesics, especially efficient anti-inflammatory drugs like
Meloxicam and Flunixin, are capable of reducing castration-induced
pain in piglets. The castration wounds of 76,5% of the piglets are
healed completely after 14 days. NSAIDs are incapable of improving
the healing process.