Open Jou nal o Ve e ina y Medicine, 2014, 4, 29-34
Published Online Ap il 2014 in SciRes. h p://www.sci p.o g/jou nal/oj m
h p://dx.doi.o g/10.4236/oj m.2014.44004
How o ci e his pape : Ko honen, H.T. (2014) Seda ion o Mink (Neo ison ison) o Elec ophysiological P ocedu es. Open
Jou nal o Ve e ina y Medicine, 4, 29-34. h p://dx.doi.o g/10.4236/oj m.2014.44004
Seda ion o Mink (Neo ison ison) o
Elec ophysiological P ocedu es
Hannu T. Ko honen
MTT Ag i ood Resea ch Finland, Animal P oduc ion Resea ch, Fu Animals, Kannus, Finland
Email: [email p o ec ed]
Recei ed 24 Feb ua y 2014; e ised 24 Ma ch 2014; accep ed 31 Ma ch 2014
Copy igh © 2014 by au ho and Scien i ic Resea ch Publishing Inc.
This wo k is licensed unde he C ea i e Commons A ibu ion In e na ional License (CC BY).
h p://c ea i ecommons.o g/licenses/by/4.0/
Abs ac
The aim was o apply mede omidine seda ion o elec ophysiological measu emen s in mink (Ne-
o ison ison). Adul animals (N = 15) o s anda d ype we e used. Ini ially, seda ion wi h an i.m.
injec ion o mede omidine (Do bene 0.20 ml, 200 mic og ams) was used. Howe e , su icien se-
da ion was no eached. The nex s ep was o seda e wi h 0.8 ml o mede omidine (Do bene 0.80
ml, 800 mic og ams). These animals woke up and he expe imen needed o be in e up ed. The
nex animal was injec ed wi h 1 ml o mede omidine (Do bene 1 ml, 1 mg) bu i ne e go su i-
cien ly seda ed. The i h and six h animals we e seda ed wi h combina ion o 0.8 mg mede omi-
dine and bu o phanol (Bu ado ) (2 mg in one mink and 4 mg in ano he ). These animals go se-
da ed o some ex en so ha he elec oencephalog aphy (EEC) eco ding was possible. The u -
he animals (N = 9) we e sedaded wi h he combina ion o he 0.4 mg mede omidine (Do bene 0.4
ml, 400 mic og ams) and 10 mg ile amine wi h 10 mg zolazepam (Zole il 0.2 ml). The combina-
ion o Do bene (0.4 ml) and Zole il (0.2 ml) we e mixed wi hin one sy inge and injec ed in a-
muscula ly. The es o mink go he same combina ion o anes he ics and all animals eached he
su icien le el o seda ion o measu e p ope ly elec oencephalog aphy (EEC), elec oca diog a-
phy (ECG), espi a o y a e and b ains em audi o y e oked esponses (BAER).
Keywo ds
Mink, Anaes hesia P ocedu es, Elec ophysiology, B ain, Seda i es, Animal Wel a e
1. In oduc ion
The cen al ne ous sys em is he supe io o gan o o ganism. I is esponsible o i al o ganic unc ions and he
animal’s pe cep ion o he en i onmen . The cen al ne ous sys em is also he cen e o consciousness. Seda ion
is a mild o m o dep ession o he cen al ne ous sys em. The animal is awake, bu calm and ee o ne ous
H. T. Ko honen
30
ension. Anaes hesia, on he o he hand, is o al loss o sensa ion. I includes dep ession o he cen al ne ous
sys em, cha ac e ized by he loss o sensibili y and consciousness [1] [2].
The mink (Neo ison ison) is a small membe o he amily Mus elidae. I ypically has an elonga ed body
shape, sho legs and sexual dimo phism. Due o high su ace- o-mass a io, he mink has o sus ain highe es -
ing me abolic a e han o he animals o he same body size [3] [4]. This se s special demands o i s medical
ea men in labo a o y expe imen s. Seda ion and anae hesia a e mainly used o haema ological and clinical-
chemical examina ion and sho - e m su gical p ocedu es in he mink [1] [5] [6]. Any documen a ion is a aila-
ble on seda ion du ing elec ophysiological e alua ions in his species.
In ou p e ious elec ophysiological s udy [7] we used mede omidine o seda ion in a med ox (Alopex la-
gopus). This d ug wo ked well p o iding ideal seda ion o measu emen s o elec oencephalog aphy (EEG),
elec oca diog aphy (EEC), and espi a ion. Mede omidine has been success ully used o induce immobiliza ion
in blue oxes, oo [8]. In he p esen s udy, he aim was o apply mede omidine seda ion o elec ophysiological
measu emen s in a med mink be o e and du ing eu hanasia.
2. Ma e ial and Me hods
Al oge he 15 adul male mink we e employed in he p esen s udy. Body weigh s o animals a ied be ween
1307 and 2298 g ams. All he animals we e as ed o e nigh be o e he ials, bu had ee access o wa e . The
use o expe imen al animals was e alua ed and app o ed by he Animal Ca e Commi ee.
The o oscopy we e pe o med in o de o e alua e he ex e nal ea canal and he ympanic memb ane. Ex-
pe imen al animal was placed in o he wooden-glass chambe (60 × 30 × 35 cm; L × W × H) wi h he openings
o he wi es o subcu aneous needle elec odes o eco ding o b ains em audi o y e oked po en ials (BAER),
elec oencephalog aphy (EEG) and elec oca diog aphy (ECG). B ains em audi o y e oked po en ials we e e-
co ded on e e y side wice be o e eu hanasia. Simul aneously EEG and ECG eco ding o 5 minu e du a ion
we e pe o med be o e eu hanasia wi h exhaus CO (concen a ion 4% in killing box) in o de o eco d he ali e
EEG pa e n [9] (Ko honen e al., 2011). The animal’s hea a e, b ea hing, palpe al, co neal and wi hd awal e-
lexes we e examined a e discon inua ion o he BAER, EEG and ECG eco dings and a e emo al o he
animal om he chambe .
3. Resul s
Acco ding o he ini ial plan he i s animal was seda ed wi h an i.m. injec ion o mede omidine (Do bene 0.20
ml, 200 mic og ams). Addi ional wo doses in he in e als o 5 minu es we e injec ed i.m. as su icien le el o
seda ion was no eached. Animal ne e go su icien ly seda ed and he e o e expe imen al measu emen s we e
no possible. Based on his knowledge he nex wo animals we e injec ed wi h 0.8 ml o mede omidine (Do -
bene 0.80 ml, 800 mic og ams) a once. Animals go su icien ly seda ed o make manipula ion, o oscopy and
placing o he subde mal elec odes possible, bu animals woke up a e 86 and 53 seconds o measu emen e-
spec i ely and he e o e he expe imen needed o be in e up ed. The nex animal was injec ed wi h 1 ml o
mede omidine (Do bene 1 ml, 1 mg) a once. Also his ou h animal ne e go su icien ly seda ed and he e o e
expe imen al measu emen s we e no possible. The i h and six h animals we e seda ed wi h combina ion o 0.8
mg mede omidine and bu o phanol (Bu ado ) (2 mg in one mink and 4 mg in ano he ) hese animals go seda ed
o some ex en so ha he elec oencephalog aphy eco ding was possible, bu BAER eco ding was no pe -
o med as animals did no ole a e sound and placing o elec odes.
As he ini ial planned seda ion p o ocol appea ed o be insu icien in he i s six pilo s udy animals he an-
aes hesia p o ocol was amended and in all he u he animals (N = 9) he combina ion o he 0,4 mg mede omi-
dine (Do bene 0.4 ml, 400 mic og ams) and 10 mg ile amine wi h 10 mg zolazepam (Zole il 0.2 ml) was used
ins ead. The combina ion o Do bene (0.4 ml) and Zole il (0.2 ml) we e mixed wi hin one sy inge and injec ed
in amuscula ly in all animals. All he es o mink go he same combina ion o anes he ics and all animals
eached su icien le el o seda ion in o de o allow manipula ion, o oscopy, placing o he elec odes and mea-
su emen s h oughou he expe imen . The u he desc ip ion will conce n he 9 mink whe e comple e mea-
su emen s we e possible and only hese animals we e included in he u he e alua ion.
The hea a e anged be ween 90 - 294 bea s pe minu e (mean 194) and b ea hing equency was 16 - 72
b ea hs pe minu e (mean 40). Palpeb al, co neal and wi hd awal e lexes we e absen in all animals be o e pla-
cing o hem in o he wooden-glass eu hanasia chambe .
H. T. Ko honen
31
Figu e 1 shows an example o no mal EEG, ECG and espi a o y pa e n in seda ed mink. A e 39 sec om CO
gas inpu i s pa hological EEG changes we e seen (Figu e 2). Respi a ion and ECG a e s ill no mal he e.
Changes in ECG we e seen 120 sec om he gas inpu (Figu e 3). 100 and 190 sec om s a EEC and espi a-
ion, espec i ely, we e gone (Figu e 4). ECG showed s ill pulsless ac i i y and was inally gone since 168 sec
om he s a og gas inpu . In all p ope seda ed mink (N = 9), i s signs o EEG changes we e ound 42 ± 10
sec om gas inpu . EEG was o ally los 86 ± 35 sec. Co espondingly, i s sign o changes in espi a ion and
ECG we e seen 42 ± 17 and 105 ± 37 sec om s a o CO exposu e. Respi a ion and ECG we e o ally gone in
217 ± 53 and 292 ± 130 sec, espec i ely.
4. Discussion
The mink is a e y agg essi e animal ha equi e chemical immobiliza ion o anaes hesia o mos clinical p o-
Figu e 1. Example o no mal elec oencephalog aphy (EEG), elec oca diog aphy (ECG) and b ea hing pa -
e n in seda ed a m- aised male mink. Backg ound ac i i y is supe imposed wi h sleep spindles (see a ows
C3-C4). Ba : sensi i i y 50 uV/cm, 1 sec 3 cm.
Figu e 2. Fi s pa hological EEG changes. Bu s supp ession (a ow). Respi a ion and ECG a e no mal. Ba :
sensi i i y 50 uV/cm, 1 sec 3 cm.
H. T. Ko honen
32
Figu e 3. ECG changes. ECG ampli ude and equency is dec easing. EEG is no p esen (isoelec ic line)
and espi a ion has se e ely dec eased equency. Ba : sensi i i y 50 uV/cm, 1 sec 3 cm.
Figu e 4. EEG and espi a ion is no p esen (isoelec ic lines) and ECG shows pulsless ac i i y. Ba : sensi-
i i y 50 uV/cm, 1 sec 3 cm.
cedu es. Mos o he d ugs ha ha e been p e iously es ed ha e disad an ages which ende hem less sui able
in his species [5] [9]. The e o e, u he de elopmen o seda ion p ocedu es is essen ial.
The esul s o he cu en expe imen indica e ha he elec ophysiological eco dings a e possible o pe o m
in he mink in a simila way as in o he animal species [7]. I animal is adequa ely seda ed eco ding is echni-
cally s aigh o wa d. The beginning o ou expe imen showed clea ly ha he seda ion wi h pu e alpha 2 ago-
nis mede omidine is no su icien o mink species as wo animals ne e go seda ed a all and 2 animals go
seda ed oo supe icially and s a ed mo ing du ing he expe imen . In addi ion, he neu olep analgesia in com-
bina ion o mede omidine and bu o phanol is no su icien o manipula e he animals sa ely o he examine
and he animal. The e o e he seda ion p o ocol o he cu en expe imen needed o be amended and combina-
H. T. Ko honen
33
ion o seda i e (mede omidine), anquilize (zolazepam) and gene al anaes he ic ( ile amine) was needed o
adequa e anaes hesia. All nine animals we e su icien ly anes he ized [1] as documen ed by absen co neal,
palpeb al and wi hd awal e lexes in all animals and he i al pa ame e s such as b ea hing and hea a e s ayed
in e e ence ange.
Eu hanasia should esul in apid loss o consciousness ollowed by ca diac o espi a o y a es and he ul i-
ma e loss o b ain unc ion [7]. Essen ial he e is ha eu hanasia occu s wi h minimal pain and dis ess. Pain is
ha sensa ion ha esul s om ne e impulses eaching he ce eb al co ex ia ascending neu al pa hways [2]
Pain can be expe ienced only when he ce eb al co ex and subco ical s uc u es a e unc ional [2] [10]. The e-
o e, he unc ional s a e o b ain is essen ial o animal wellbeing du ing eu hanasia.
Acco ding o he p esen esul s p ope seda ion wi h combina ion o mede omidine, zolazepam and ile a-
mine p o ided no mal EEG, ECG and espi a ion pa e n. Example o his was gi en in Figu e 1. The mink
we e inally eu hanized du ing seda ion by using exhaus CO 4%. Follow-up o EEC, ECG and espi a ion pa -
e n du ing pa e n was success ul (Figu es 2-4), esul ing decline o hese pa ame e s wi h logical manne [7]
[9]. Ou conclusion he e is ha he p esen seda ion combina ion can be used o p ope measu emen o elec-
ophysiology in mink.
5. Conclusion
The animals we e success ully seda ed wi h he combina ion o he 0.4 mg mede omidine (Do bene 0.4 ml, 400
mic og ams) and 10 mg ile amine wi h 10 mg zolazepam (Zole il 0.2 ml). The combina ion o Do bene (0.4 ml)
and Zole il (0.2 ml) was mixed wi hin one sy inge and injec ed in amuscula ly. The es o mink go he same
combina ion o anes he ics and all animals eached he su icien le el o seda ion o measu e p ope ly elec-
oencephalog aphy (EEC), elec oca diog aphy (ECG), espi a o y a e and b ains em audi o y e oked es-
ponses (BAER).
Acknowledgemen s
This s udy was inancially suppo ed by he Minis y o Ag icul u e and Fo es y (Finland) and he Eu opean
Fu B eede s’ Associa ion (EFBA). Heli Lindebe g, Pekka Toikkanen, Pekka Eskeli and Juhani Sepponen a e
g ea ly acknowledged o hei aluable assis ance in ca ying ou hese expe imen s.
Re e ences
[1] Jepsen, Ø.R., Poulsen Di ch, J.S. and Jo gensen, G. (1981) Collec ion o Blood, Seda ion and Anaes hesia in Mink. A
Haema ological and Clinical-Chemical S udy. No disk Ve e ina y Medicine, S1, 99.
[2] A ma, A. (2007) Guidelines on Eu hanasia. Ame ican Ve e ina y Medical Associa ion, 2007, 27 (Fo me ly he Repo
o he AVMA Panel on Eu hanasia).
[3] B own, J.H. and Lasiewski, R.C. (1972) Me abolism o Weasels: The Cos o Being Long and Thin. Ecology, 53, 939-
943. h p://dx.doi.o g/10.2307/1934312
[4] Ko honen, H., Ha i, M. and Asikainen, J. (1983) The mo egula ion o Poleca and Raccoon Dogs: A Compa a i e
S udy wi h S oa , Mink and Blue Fox. Compa a i e Biochemis y & Physiololgy, 74A, 225-230.
h p://dx.doi.o g/10.1016/0300-9629(83)90592-3
[5] Aenemo, J.M. and Søli, N.E. (1992) Immobiliza ion o Mink (Mus ela ison) wi h Mede omidine-Ke amine and Remo-
biliza ion wi h A ipamezole. Ve e ina y Resea ch Communica ion, 16, 281-292.
h p://dx.doi.o g/10.1007/BF01839327
[6] Wambe g, S., S endsen, P. and Johansen, B. (1996) Acid-Base S a us and Ca dio ascula Func ion in Mink (Mus ela
ison) Anaes he ized wi h Ke amine/Midazolam. Labo a o y Animal, 30, 55-66.
h p://dx.doi.o g/10.1258/002367796780745009
[7] Ko honen, H.T., Cizinauskas, S. and Vii maa, R. (2009) E alua ion o he T adi ional Way o Eu hanasia o Fa med
Foxes om an Animal Wel a e Poin o View. Annales Animal Science, 9, 73-87.
[8] Jalanka, H.H. (1990) Medo imidine- and Medo imidine-Ke amine Immobikiza ion in Blue Foxes (Alopex lagopus) and
I s Re e sal by A ipamezole. Ac a Ve e ina y Scandina ica, 31, 163-169.
[9] Ko honen, H.T., Cizinauskas, S. and Jese nics, J. (2011) E alua ion o CO and CO2 Eu hanasia in Fa med Mink (Mu-
s ela ison): Elec ophysical S udy. Repo No:1, Kannus, 39.
H. T. Ko honen
34
[10] Hansen, N.E., C eu zbe g, A. and Simonsen, H.B. (1991) Eu hanasia o Mink (Mus ela ison) by Means o Ca bon Di-
oxide (CO2), Ca bon Monoxide (CO) and Ni ogen (N2). B i ish Ve e ina y Jou nal, 147, 140-146.
h p://dx.doi.o g/10.1016/0007-1935(91)90104-U
