Quote Originally Posted by tikeyas_mom
I have never heard of a thyroid panel before.
Here's a web page that talks about thyroid and behavior issues
http://www.doganswers.com/Thyroid.htm

Baby is sort of a rescue.. She was originally bought from a breeder in peachland British Columbia (sunset danes i think?)..Her dogs arnt all registered, or show quality.. She was sold with no papers, under the agreement that she would be a pet dog only. Her original owners couldnt keep her due to moving, so they gave her to us at 3 months old.. Tikeya and her got along great till she turned 2. Thenall hell broke loose.. We spayed her at 6 months, and she was NEVER abused.
It's not uncommon for same sex couples of dogs to get into it as a younger one matures. Males with males and females with other females. From the physiology and psychological aspect, neutering females does not reduce potential for this type of aggression. It doesn't happen in all cases. Dogs are individuals.

It has however been shown that sometimes neutering before maturity leads to agression. This is why Canine Companions for Independence and Guide Dog associations neuter at one year or later if it is possible. (not all puppy raisers will be able to cope with a first heat)

Yesterday I made the rounds at the California state capital to visit the offices of the Assembly Business & Professions Committee members to discuss AB 1634. I was accompanied by two police officers who discussed the harmful impacts AB 1634 would have on law enforcement. Also with us was the person in charge of the breeding and training program at Canine Companions for Independence (CCI), who discussed how AB 1634 would harm programs that assist blind and disabled Californians. He also represented Assistance Dogs International, Inc., an umbrella organization over many guide/service/hearing dog organizations.

Similar to guide dog programs, CCI breeds and trains dogs to assist disabled people. They use Golden Retrievers, Labrador Retrievers, and Golden/Labrador mixes. CCI breeds over 600 dogs a year.

My jaw nearly hit the floor when the CCI representative started describing research that CCI did in the early 1990s to understand spay/neuter impacts. CCI wanted to know if early s/n (less than 6 months of age) would yield results at least as good as their traditional spay/neuter age, which is usually over 12 months of age (typical is 17 months of age). So CCI did a controlled prospective research study... the gold standard of research to understand cause-and-effect.

CCI assigned half the pups in a number of litters to be s/n early, while the remaining pups in these litters were s/n at their traditional age. The results were very unexpected. The early-age spayed females were significantly more dog aggressive than the traditional-age spayed females. Urinary incontinence was a much bigger problem in the early-age spayed females compared to the traditional-age spayed females. The early-age neutered males were more fearful than the traditional-age neutered males. The bottom line is that the early-age spay/neuter dogs had a significantly higher failure rate in CCI's program... a smaller percentage of them grew up to be working dogs. As a result, CCI will not spay/neuter dogs before 6 months of age, and usually wait until dogs are more than 12 months old to spay/neuter. The CCI rep said this research has been repeated by others. I believe one of them may be Guide Dogs for the Blind, as I was told by one of their trainers that they recently stopped doing early spay/neuter owing to results they were seeing that they don't like.
See context from the middle of this post - http://petoftheday.com/talk/showthre...97710#poststop

I met two of her siblings, both male danes.. They are Both also very dog agressive.. maybe its in the genetics?
Could be. Are they also neutered? Do you know what age? Is there an unneutered sibling? what is the state of that sibling's reactivity? (this is a way to study the effect of neutering down a family line, just like the guide dog groups did).
Are the unneutered parents not so aggressive? (you might not know, I realize).

I think that very large breeds mature quite slowly and should only ever be placed in homes that can control the dog through early maturity (so that it doesn't get loose and BREED!) until it has reached at least a couple years of age before neutering.
http://petoftheday.com/talk/showthre...02199#poststop

But none of this information is helpful for your situation NOW. I think you could take the first link and read up, then see about having Baby's thyroid panel done. The vet may be able to recommend a behaviorist.