adrenal glands and emotions and ferrets

[alonewiththemoon]

Somebody posted about this article by Temple Grandin and Mark Deesing on the Ferret Health List today; although ferrets are not explicitly discussed, they are so prone to adrenal disease that the statements made here are of a lot of interest to ferret owners.  To wit:

Raising young animals in barren environments devoid of variety and sensory stimulation will have an effect on development of the nervous system. It can cause an animal to be more reactive and excitable when it becomes an adult. This is a long-lasting, environmentally induced change in how the nervous system reacts to various stimuli. Effects of deprivation during early development are also relatively permanent. Melzak and Burns (1965) found that puppies raised in barren kennels developed into hyperexcitable adults. In one experiment the deprived dogs reacted with ~diffuse excitement" and ran around a room more than control dogs raised in homes by people. Presenting novel objects to the deprived dogs also resulted in diffuse excitement." Furthermore, the EEGs of the kennel-raised dogs remained abnormal even after they were removed from the kennel (Melzak and Burns, 1965). Simons and Land (1987) showed that the somatosensory cortex in the brains of baby rats will not develop normally if sensory input was eliminated by trimming their whiskers. A lack of sensory input made the brain hypersensitive to stimulation. The effects persisted even after the whiskers had grown back.

Development of emotional reactivity of the nervous system begins during early gestation. Denenberg and Whimbey (1968) showed that handling a pregnant rat can cause her offspring to be more emotional and explore less in an Open field compared to control animals. This experiment is significant because it shows that handling the pregnant mother had the opposite effect on the behavior of the infant pups. Handling and possibly stressing the pregnant mothers changed the hormonal environment of the fetus which resulted in nervous offspring. However, handling newborn rats by briefly picking them up and setting them in a container reduced emotional reactivity when the rats became adults (Denenberg and Whimbey 1968). The handled rats developed a calmer temperament.

The adrenal glands are known to have an effect on behavior (Fuller and Thompson, 1978). The inner portions of the adrenals secrete the hormones adrenaline and noradrenaline, while the outer cortex secretes the gender hormones androgens and oestrogens (reproductive hormones), and various corticosteroids (stress hormones). Yeakel and Rhoades (1941) found that Hall's (1938) emotional rats had larger adrenals and thyroids compared to the nonemotional rats. Richter (1952, 1954) found a decrease in the size of the adrenal glands in Norway rats accompanied by domestication. Several line and strain differences have been found since these early reports. Furthermore, Levine (1968) and Levine et al. (1967) showed that brief handling of baby rats reduces the response of the adrenal gland to stress. Denenberg et al. (1967) concluded that early handling may lead to major changes in the neuroendocrine system.

It definitely makes one speculate whether the adrenal disorders ferrets are subject to later in life have anything to do with their early life history.  It's considered common wisdom in ferret circles that ferrets from private breeders are less subject to adrenal gland disease than those from big farms; there is no firm evidence or research to back this up, but it sounds like it could be the case--less handling as a kit means a more nervous ferret which means more general stress which means overactive adrenal glands which potentially leads to cancerous growth?  I don't know, I'm probably just educated enough about this stuff to be able to come up with theories but not to be able to come up with theories that actually hold water.  But it would be an interesting avenue for research.

The article also gave me insight into my ferret Cully, who passed away--gosh, more than six years ago now.  That's hard to believe.  But anyway, reading the article I could see him as an individual who was already predisposed to be flighty and nervous who then did not receive enough handling to develop much in the way of positive emotional reactions or enough environmental stimulation to be able to handle novelty well.  It is really amazing that he came as far as he did, to the point of trusting me and eventually M and not always drawing blood on strangers :-/  And I can see why he and Amelia just couldn't get along--they probably literally could not read each other's body language, except for the biting part.  He was at the limits of his brain structure, I think.  Maybe he had the ferret equivalent of autism...  I'm glad there was still enough receptivity in him that he was able to get along as well as he did in the second half of his life.  I'm very thankful that I was able to have the patience to work with him, and that M, who'd never interacted with a ferret before meeting me, is the kind of person that he is and was able to cope with what really could be a very trying ferret.

I might take a look at the rest of the book that article came from, or more of Temple Grandin's writings.  If they're written at about the pop-sci level of that article, I'd do fine with it.

Comments

[rojagato.livejournal.com]

God bless Temple Grandin.

You would probably like "Animals in Translation" (which focuses more on non-human animal (mainly large herd animal and dog) behavior) and "Thinking in Pictures" which focuses more on humans; both of which you can pick up relatively inexpensively through Amazon Marketplace. I don't quite buy into the "animals are autistic people, and vice versa" thing because I'm kinda squicked by anthropomorphism in general, but she obviously knows quite a bit about non-human animals and autism than I do.

Also, a wealth of her articles appear on the web -- you can tell from the title of the magazine/journal which of these might be more accessible to the layman, especially one as wikkid smaht as you are.

I don't have enough experience to extrapolate from the rat pup studies to my own and fostered ferrets. Polecat-derived Francine was obviously an outlierThe MF ferrets that I fostered were divided 65%/45% without middle ground between, respectively, the the absolutely docile and the scary-bitey (although maybe half of those "vicious" ones I could definitely put to earmites and general neglect); while what I thought might could be breeder ferrets (because they were intact and/or lacked the ear tattoo) were generally docile, if often pretty skanky. I never had any ferrets under my supervision, from any source, that had adrenal disease, but that may have been because lymphoma carried them off earlier than any adrenal symptoms started presenting, and earlier in any case, certainly, than I would have wished.

[rojagato.livejournal.com]

And by that, I mean to say, I don't have enough data points to say anything.

[saturniidae.livejournal.com]

Hmmm, maybe that is part of the reason Casey is such a nutter. Temple Grandin is supposed to speak at Tufts some time in April - she always attracts a big audience, but I'll let you know when it's announced.