Laws and ethics
In spite of the narcosis and pain medication, the aftermath of castration remains a painful experience for
the awakening rat. Nor is narcosis in itself a risk free process. Some never wake up, or wake up only to drift
into the final sleep. Add that castration has a permanent effect on health and the mental state of the
animal. The tendency to overeat and gain weight is increased. Fat rats are more prone to heart- and
circulatory diseases as well as diabetes. Their spatial memory suffers. So how can one defend the
removal of the testicles from an ethical point of view?
In 2001 the Norwegian Rådet for dyreetikk - an independent, advisory
board on ethics, appointed by Landbruksdepartementet (the Department of Agriculture) - delivered a paper on
castration which, among others stated:
According to the view of the Board it is not right to remove body parts from healthy, normal animals just
to make them fit in with production or family life. Therefore castration should be forbidden. However,
one must consider the fact that our husbandry necessarily limits certain natural behaviours of the
animals. Many adult beasts in the care of humans will never be able to live out their sexual drive.
A general rule against castration will not lead to most animals following their sexual instincts, but
only that their sexuality is controlled by different means. This control could be a source of considerable
frustration for the animal. Undoubtedly, some animals could have a freer and perhaps better life as castrates,
for instance, a gelded ox may be let out to graze. If the decisive weight is to be placed on the integrity
and concern for the animal, in a specific situation these arguments could be used to support castration,
not to suppress the practise.
|
(translated by me)
 |
As examples of when castration could be in the best interests of the animal, the
statement mentioned aggression and the ability to move among its own species.
|
The Law on Animal protection did not follow the advice of the Board, to issue a general rule against
castration, but to allow castration when it was considered to be in the best interest of the animal.
A castration on a male rat is a surgical procedure that must be performed by a veterinary. Otherwise
there is no law against it. Still, many vets will want to know why you wish to castrate the animal.
The Law on Animal protection does state that animals should not be made to suffer unnecessarily.
Aggression, serious nervous problems, or a practical need to let a male animal co-habit with
females are deemed justifiable causes for the operation.
In Norway, castrating rats is not common unless the rat has behavioral problems. Some animal welfare
organisations routinely castrate their bucks before re-homing, but castration to prevent urine marking or
"buck smell" is uncommon. The ethical consideration is not the only
barrier. Surgery is costly. Most rat owners will not want to pay the expense until cheaper solutions
have been tried. Cynically, the operation costs more than euthanisation and a new rat pup.
Often castrating a rat is more expensive than castrating a cat. The work is the same, but the rat actually
require a higher dose of medication than the rat! On the other hand this piece of surgery is not more
expensive than removing a large tumor. For male rats with behaviour problems due to overproduction of or abnormal
sensitivity to
gonad hormones, this cut could be the cure that allows meaningful life.
|
Rat balls belonging to Labben, a now deceased Alpha. In elderly bucks it is not unusual for the rat to drag
them across the floor while walking. |
Anatomy of the rat testicles
Rat testicles (testes) are lung, tubular organs connected with the urethra by first the epidydermis and the
vas ductus (seminal ducts). The epidydermis are two lumps hanging by the testicles. The semen must pass
through them to ripen. If not they are not capable of aiding propagation. Parts of the surface of both the
testicles and the epidydermis are covered by a beautiful meandering pattern of fine seminal ducts.
Unfortunately I do not have any close-ups. My vet wondered if I wanted to bring home a trophy to display in
formalin. I was tempted but knew that the pharmacy would have to order the formalin and that the sample would
rot in the meantime. Besides, I suspected my husband and the boys might be made to feel a bit Freudian angst
if I had displayed my trophy on the mantelpiece. To make amends I've added a link to Kenyon College which has
a
photo of an opened rat showing
the anatomy. Unfortunately the details are not good enough to catch the beauty of the seminal duct pattern.
The testicles are located under the anal orifice and behind the penis of the male rat. As with the human
testicles they depend on a fairly narrow temperature range to produce high quality semen. The rat can regulate
their temperature by pulling the testicles into the body. In a fight the testicles can be retracted for
protection. The muscle which facilitates the withdrawal reacts to noradrenalin (norepinephrine). Noradrenalin
is a stress hormone which the rat produces when preparing for fight or flight. The testicles are also protected
by a thick layer of fat all around them.
The testicles not only produce semen. They also produce the hormones testosterone, oestradiol,
androstendione, and dehydroepiandrosterone (DHEA). These hormones have such a vast number of different
effects on the body that listing them all is not possible. Especially since scientists are still finding new
effects. It has been shown beyond doubt that a serious fall in the level of these hormones have a positive
influence on certain forms of aggression and anxiety in rats. There are other beneficial effects from
lowering the level of gonad hormones in the male rat. There are harmful effects too.
After a surgical castration the testosterone stores in the body fat is gone after only a few hours.
The behavioral changes, on the other hand, may take two to three weeks. This is partially because of a storage pool
of testosterone esters. This storage pool takes about two weeks to deplete. Secondly, the regulation of the receptors
in the brain and other body parts takes time. Another quick drop in hormone level is seen in dihydrotestosterone
(gone from blood serum in 6 hour but remains longer in the bladder which contains the semen.)
Some effects of castration
The timing of a castration influences the effect of castrating a rat buck. Rats castrated before puberty
and before their bone growth is complete will behave differently and have a more "female" shape than if the
operation had been delayed. These changes happen no matter at what age the rat is castrated:
- Fertility disappears
Self evident - but it does not disappear right away.
- Less display of sexual behaviour
The rats can still copulate, but the interest vanes.
- Less prone to attack from other rats
If a castrated male rat receives a new cage mate, the male
cage mate is less likely to bite the castrate than an intact buck.
- Lowered aggression
Nearly all forms of aggression are reduced. I have seen it written that
castration does not cure male rat from killing baby rats. Well, it did not help them all, but the
castrated baby killers still had a lower probability of killing babies after being deprived of their
torpedoes.
- Less nervous problems
Unfortunately this is not true for all rats. Some become more afraid
afterwards because the testosterone used to make them feel more brave.
- Less tendency to scent mark
Urine marking normally decreases.
- Lowered blood pressure
The lack of testosterone leads to a decrease in the number of calcium
channels in smooth muscles.
- Lowered pain threshold
Castrated rats feel painful stimuli more strongly than intact rats.
- Less effective burning of fat
Castrates have a lower level of activity and
An increased tendency to gain weight.
- Changed effect of drugs
For some reason castrated bucks have less effect of morphia than intact
males. Otherwise the castrated rats usually receive a greater effect. Testosterone increases
the production of certain liver enzymes (cytochrome P-450 and N-demethylase) that have important roles in
the elimination of many drugs from the body.
- Changed uptake of nutrients
Castrated rats release less amylase in their saliva. This probably
means that they do not break down starch as effectively as before castration. The uptake of long chained
fatty acids changes too.
- Changes in fur quality
The coat of the castrated rat becomes more wooly.
- Lowered production of skin oils/tallow,
The production of skin fats depend on oestrogens and
testosterone.
- Decrease in muscular strength
The muscle levator ani is affected by the level testosterone.
- Changed tear fluid
The tear fluid of castrated males is more like the tear fluid of female
rats than intact males.
- Differences in receptivity of infections
Castrated bucks are less prone to infection by
hookworm than intact ones.
There are bound to be effects that I have not read about, and others that have not been discovered yet.
|
 |
Remember:
Castrates feel pain more strongly than intact males.
The medicinal dose for castrates often has to be changed to avoid poisoning or side effects.
|
|
Operation Throwing the Balls
Quoting from the Board of animal ethics:
It should be a non-negotionable demand that if an animal is castrated, this should always
be performed under anaesthesia and with the added benefit of post-operative pain relief.
(my translation)
As most rat owners never enter the operation room during procedure, there are probably people out there
wondering what is happening in there. There is more than one operation technique for castration, but
this is the most common one. I had better start by telling that castration is a fairly small and simple
procedure. This does not mean that the operation always runs on tracks. In Birk's case, however, it took
no more than 45 minutes from he received his anaesthetic injection, until I paid up and took him home.
Most vets insist that they keep the rat for a few hours before they are allowed to leave with their owner.
My vet says that is mostly done to save the owners the pain of watching an animal die post surgery. She
rarely manages to chase the Death of Rats* with a syringe of adrenalin/epinephrine if anything goes wrong.
Basically she has stopped trying. Besides, she feels most animals will be better looked after by a
stay-at-home mum than at a busy veterinary office.
* Death of Rats is a character from the Discworld books by Terry Pratchett. He has given the rats their own
Rat with a scythe.
At the very beginning Birk received narcosis by an injection in his belly.
NB! Already at the start
one of the dangers of the operation surfaces. Injections in the abdomen may give rise to internal haemorrhages.
A neck injection can be used. Unfortunately my rats become more stressed by a neck injection. After we started
injection by the abdomen we no longer need such high doses of medication, and the effect sets in earlier too.
As I trust her steady hands, and as my rats are far calmer when I hold them myself than if a stranger were to
restrict them, I have chosen the danger of bleeding in favour of the danger of giving too much medication.
Birk told us what he meant of the treatment by immediately dropping a couple of soft raisins and stepping in them.
Then I put him in his traveller cage to calm him down, and to wait for the deep sleep of narcosis.
|
 |
When Birk no longer reacted to having his ears touched, nor the closing of his eyelids he was ready. I put him
on his back on a special pillow, with his tail against the veterinary. First he was shaved around the operation area
and the field of operation was drenched in spirits.
NB! The second peril is cooling. Some narcosis inducers affect the ability to regulate body temperature.
In any case the spirit will require energy to evaporate, and the operating table is at room temperature. The
pillow is used to lessen the loss of body heat during the operation.
Birk had Simplex eye ointment (a vaseline oil based product) to prevent his eyes from drying up.
The vet cut a hole in a small paper operating towel so that she could fasten it around his balls.
The paper was fastened with clips to the skin of his belly. Then the vet put one hand on his abdomen to push the
testicles downwards into his pouch. slik at hun kunne tre det rundt ballene til Birk.
Papiret ble festet med klemmer til mageskinnet hans. With the other hand she cut a small incision
in the skin over each testicle before she anchored it with a kind of forceps that could be locked in place.
According to vet this is a place where things can go seriously wrong. If the testicles disappear into the
body they are not easy to retract!
With one testicle fixated she could concentrate on the other: pulling it out by the opening while she
was loosening the thin membranes around it. Next came tying catgut above the place to cut. The organ was so much
longer than I had ever imagined!
NB! Tying off the testicle is probably the second most critical point during the operation, next to
proper management of the anaesthesia. If the thread is not tight enough, or slips off, the rat will have
internal bleeding and may die.
There are other types of suture thread. Normally the vet would not use catgut, but shortly before the castration
she had had to re-operate another of my rats who reacted to her ordinary filament. She was not keen to have yet
another re-operation on her hands in case Birk too was allergic, and chose catgut instead.
When the testicle was neatly bound it was cut beneath the ligature. The vet made sure both testicle and
epidydermis had come out. Then she repeated the process on the other side.
At last his pouch could be sewn up. The vet made a cross stitch on each side. They would have to be removed
after a week, unless Birk had removed them himself by then.
All that was left to do now was cleaning up with a bit of disinfectant. If the operation was a successful one
the rat should have lost very little blood, apart from what is already in the testicles. Cleaning up was quick. |
|
This is what my vet uses:
Catgut USP 2/0 EP 3,5 Serrag Wiessner
Prolene 3.0
Domitor vet 1 mg/ml 0,5 ml/kg rat
Ketalar 50 mg/ml 1,5 ml/kg rat |
After the operation
Ocular side effects of Ketalar:
Bulging eyes and a milky white spot |
|
Some vets use a second shot to reverse the narcosis. My vet does not. The philosophy is that if the animals sleep
for another six hours or so, that is six painless hours without movement. The wounds have a better chance of
healing and the rat is less distressed. As a consequence the rat needs a bit more attention
in the post-operative phase. I had brought a large, empty glass (formerly holding Dolmio tomato sauce) to the
vet's office. Now I filled it with hot water from the tap and wrapped it in an old cloth nappy. This worked
well as a hot water bottle for hours. When not in his cage, next to the bottle, Birk slept on my stomach,
in a felted wool cloth (boiled woolen sweater). I had to change the cloth a couple of times because he was widdleing
himself. I also made sure his eyes remained moist. When the eye ointment had worn away I used viscous tear drops
on him every hour. I could have bought the ointment, but with eight rats the single dose packed tear drops are
better value. The ointment only keeps for a month after opening.
Birk's eyes looked huge, but I did not think much about it at the time. However, during his next operation I realised I
was seeing a side effect of the Ketalar. The bulging eyes meant an increase of the intraocular pressure. Not only that:
Birk's normally clear eyes developed a milky white spot: a cataract. Two days later it was gone without a trace.
|
It is not unusual for a rat to start "snoring" when in narcosis. This has to do with an increase in the
secretion of mucus. None of my rats have been greatly troubled by it, but I do watch over them, and change
their sleeping position if they become noisy. Usually a new sleeping position is all that it takes to quiet
them. I do not know how rats behave if they have been awakened by an injection. All my rats have slept solid for
about eight hours (give or take a couple of hours) before the first signs of awakening. It usually starts with
small movements around their nose or eyes. Quite often these movements can be seen on and off for a couple of
hours before they start crawling around, totally disoriented.
I do not have a picture of Birk waking up. This is his brother Skorpan after his castration.
Here Skorpan just managed to drag himself half way inside the wine rack before he collapsed like a drunk.
| |
When Birk started crawling he had very little control of his legs. This is normal. Birk keeled over, slid,
and dragged himself around without fully knowing where he wanted to go. If the rat is lying on a bed at this stage
it will probably go over the edge. A cage without the possibility to climb is the best solution.
Even if a drinking bottle may be difficult for the rat to handle at this stage, do not leave the rat with a bowl of
water. Its first action will be to drag itself over to the bowl and fall into it. The rat will become wet and
cold, and the stitches will become wet too. In place of a water bowl I usually give the rat a piece of fruit or
vegetable with a high water content: a boiled potato, cucumber, water melon... Birk had a bite of a boiled
potato that was next to his snout when he woke up. He laboriously crawled the two centimeters, sank his teeth into
the spud, probably enjoyed the cool and moist feeling, and went back to sleep without swallowing. I lifted him
gently away from the food and got him better bedclothes than a cold potato. |
The next stage is when the rat finds out that he can walk again. Birk staggered around with a drunkard's balance
and Dutch courage. Having been through this before I did not put him in an ordinary bar cage. He would have tried
to climb the bars, definitely lost his balance and probably got a limb stuck in the bars when falling. That is why I
use a traveller's cage for a cat or small dog - a plastic shell - for rats who are in the process of waking up.
Soft food is still a good idea. I usually do not use painkillers until I have seen the rat swallow anything.
After the castration Birk was not interested in dry food pellets for 1 1/2 day, but he lapped up a great deal of
yoghurt and porridge. His weight loss was about 45 g during the reconvalescent period. That is more than the
weight of the testicles. They are on an average
4,26% of its body weight, that is 21,3g for a 500
gram rat. The weight difference is partly due to the fact that the layer of fat around the testicles, which is
removed with them, is not part of the testicle weight. When Birk weighed around 650 g before the castration
and ate less than normal for two days, the weight loss seems pretty normal.
Birk did go home with a course of antibiotics. I chose not to give it to him. This was partly because he
managed to spit out his entire first dosage. But the fact remains that the testicles and the pouch have an
excellent blood supply. Infections are rare. Abscesses are a fairly common complication of the procedure, but
reaching an abscess with oral antibiotics is a problem anyway. Had it been a different kind of operation, or
a rat in poor health I would not have hesitated to give the medication. As it was, Birk was a model patient.
He kept his wound clean, took it easy, and extracted the stitches himself when he felt the wound had knit. He
looks a bit odd with those shrivelled, raisin sized appendixes that remain. On the other hand he as stopped
using his balls like a dish rag to wipe his urine all over my hands...
| Castration is always a calculated risk. The most feared one is the death risk from the medication. For rats
with increased risk of haemorrages (Australian/English blue rats) I would not reccommend an intraperitonal
injection. Otherwise the procedure above appears to work well. I have had four rats castrated this way without
mishap. No deaths, no permanent disability and no wound abscesses! |
References
Statement, Norwegian
from Rådet for dyreetikk 2001 about castration
Fulltext
Human epididymal proteins and sperm function during
fertilization: an update
ANDREA LASSERRE et al.
Abstract Long-lived testosterone esters in the rat
W Borg, C H Shackleton, S L Pahuja, and R B Hochberg
Abstract
Changes in Testosterone and Dihydrotestosterone Levels in Male Rat Accessory Sex Organs, Serum, and Seminal
Fluid After Castration: Establishment of a New Highly Sensitive Simultaneous Androgen Measurement Method
BUNZO KASHIWAGI et al.
Abstract
Testosterone deprivation by castration impairs expression of voltage-dependent potassium channels in rat aorta.
P Zhou et al.
Abstract
Effects of Dehydroepiandrosterone (DHEA) on Pituitary Prolactin and Arcuate Nucleus Neuron Tyrosine Hydroxylase mRNA Levels in the Rat
Ester Garcia De Yebenes et al.
Abstract Territorial aggression of the rat to males castrated at various ages
Kevin J. Flannellya og Donald H. Thor
Fulltext Gender related differences in antinociceptive
properties of morphine after gonadectomy in male and female rats
Manzumeh-Shamsi Meimandi et al.
Abstract
Castration decreases amylase release associated with muscarinic acetylcholine receptor downregulation in rat parotid gland
Lucila Busch1 og Enri Borda
Abstract Sex differences in hepatic uptake of long chain fatty acids in single-pass perfused rat liver
Michael C. Kushlan et al.
Abstract Hormonal influence on the
secretory immune system of the eye: androgen regulation of secretory component levels in rat tears
D.A. Sullivan et al.
Abstract SEX-DEPENDENT DIFFERENCES IN DRUG METABOLISM IN THE RAT
II. Qualitative Changes Produced by Castration and the Administration of Steroid Hormones and Phenobarbital
S. EL DEFRAWY EL MASRY og G. J. MANNERING
Abstract Experimental studies on the effects
in helminthic infection, with special reference to the gonadectomy of the host.
Paik KH.
|
