Sudden and severe aggressive behavior.

[V's puppy]

:(I have a ten year old beagle who has suddenly become very aggressive. She has always been the most dominant of our five dogs in the house, but in the past few weeks she has started fighting and at times attacking the other dogs.

She is in a good mood most of the time, but we’ve had to get rid of all the toys in the house because if she has one and another dog comes near her she attacks them. She’s also starts wrestling matches with the other small dog in the house and usually gets so aggressive that we have to pull her away.

It is really starting to scare us. She has not badly injured any of the other dogs yet, but she did accidently bit my brother when he was trying to pry her off of another dog. She also killed a squirrel in our backyard a few weeks ago.
The other dogs, who are usually very calm, are now starting to get upset and of course they can’t play as much because all of their toys are gone.

Please, does anyone have any suggestions? We are really starting to worry she might hurt one of the other dogs, especially our small one.

[Karen]

Get her to the vet. Sudden changes in behavior like this could be because of something medical, so you want to get her checked before anything else. After all, we are all a little more cranky when we're in pain ...

Can she be crated okay, so in the meantime the other dogs can have some play time safely?

Any other big changes in the household?

[V's puppy]

I cannot think of any major changes in the household recently.

She can be crated and we have been doing that often lately. We are a little worried that we are going to make her feel frustrated if she realizes she's missing out...but maybe that's over thinking things. :P

[Asiel]

Have to agree with Karen about the sudden change in behavior if there is no reason for it. I do think a vet visit is warranted for sure.

[Riptide]

It might be her thyroid. Thyroid problems are common in Beagles, and seem to pop up in a dog's senior years. Thyroid problems can cause behavioral changes so I'd get a test on her ASAP. Meanwhile I would keep them separated to avoid injury.

[conchitaroja]

She killed a squirrel a few weeks back? is it possible she was bitten by the squirrel?
What does anyone out there know about rabies, is it transmitted only by being bitten by an infected animal & not biting one? How can a dog be tested w/o killing it?
Oh, I pray she's ok & that this can be easily treated....
good luck to you

[Riptide]

She killed a squirrel a few weeks back? is it possible she was bitten by the squirrel?
What does anyone out there know about rabies, is it transmitted only by being bitten by an infected animal & not biting one? How can a dog be tested w/o killing it?

Killing the squirrel is a prey drive thing. All dogs could do it, regardless of how sweet or aggressive they are. Its just plain ol' instinct, not a matter of meanness. Chasing and killing prey is a fixed action pattern - it's as natural to dogs as breathing is to humans. This sort of behavior isn't an indicator of aggression, especially since she's a Beagle (hound - bred for hunting!).

As far as rabies goes, I highly doubt that's the issue. I don't believe it can be transmitted by biting an infected animal. My understanding is that the infected animal's saliva has to come into contact with the other animal's blood. There is no way to test an animal without killing it. That being said, again it is HIGHLY unlikely that's the problem considering the circumstances and that rabies is uncommon in pets these days because of vaccinations and whatnot.

[*LabLoverKEB*]

Here is a quick overview of rabies:
Rabies is an often fatal disease, shed through the saliva of an infected animal. Animals acquire rabies primarily via bite wounds from infected animals. Squirrels can carry the rabies virus. All mammals are affected by this disease. The rabies virus effects the neurological system. Neurological symptoms include aggression, depression, paralysis, seizures, excessive salivation, inability to swallow, and eventually death.
Diagnosis for rabies includes quarantine for 10 consecutive days to observe for above symptoms. Like Riptide mentioned, the only reliable test is the microscopic examination of the brain tissue. (By cutting of the head). Unfortunately there is no treatment for animals with rabies. But as far as prevention goes, there is the rabies vaccine. (There is even a rabies vaccine for humans, but the side effects make you really sick. As far as I know, all licensed veterinarians are required to get the rabies vaccine.

[DriftyAlison0]

Once clinical signs of Rabies appear there is nothing you can do because Rabies is always fatal. I would do a rabies test asap and if it is positive then you would need to have to put her to sleep. But if she had her rabies vac. then it could be due to age.

http://www.cfsph.iastate.edu/FastFacts/pdfs/rabies_F.pdf

[*LabLoverKEB*]

Unfortunately, you cannot do a rabies test unless you look in brain tissue. So obviously the animal has to be already dead. There is no blood test to check for the rabies virus.

[Alysser]

She is 10 years old, which is pretty old. She might be showing the early stages of dog alhemizers. I knew a dog who had that, she got it when she was 11 and it got progressively worse. She didn't remember her family members and became quite aggressive too. I am not vet, but this is a serious issue especially seeing as how it came up out of no where. I would get her to a vet.