My 18 Mo Old Boy Is Aggressive to One of Our Dogs...

What do you mean by "aggressive" and "extreme" ? What exactly is your son doing?

At 18 months, children don't understand that what they might be doing to a pet could be hurting it - supervision, redirection, and sometimes separation is what is needed, but providing more details would be helpful. Spanking will not teach your child that hurting animals is wrong - it just teaches him its okay for bigger, stronger beings to cause pain to those who are smaller and unable to defend themselves.

Depending on what he is doing and how he is going about it I don't necessarily think punishment is the way to go.
He is very young. He has no idea how to treat the dog "nicely". He would have no idea what that even means. You have to teach him HOW to be nice to the dog... show him how to stroke the dog's fur by practicing on a stuffed animal. And explain light and hard touch and stroking vs. hitting or being rough and being gentle. He needs to be TAUGHT.

AND, he needs to be kept away from the dog when you are not right there supervising his every move. If he is annoying the dog, and isn't removed from the behavior, the dog will react at some point. Even the BEST dog will only take so much until they will bite to make it stop. Your son won't know that a little growl or getting up and moving away from him means "STOP/QUIT what you are doing; I don't like it!" Don't put your dog in that position. You must protect him/her from your son who doesn't yet know how to behave with the dog. If you fail to do that, then you are inviting the dog to act out against your son at some point and the results could be very very bad.

Extreme like trying to pull his eyeballs out, set him on fire, taking hammers to him, slamming him in the door (all which and more I've seen and heard of toddlers do or attempt to do to dogs - older children are much worse when they are extremely violent towards animals, and I won't go into that here... it's too vile) ... or normal things like hitting at/ kicking at/ hugging too hard/ falling on/ pulling fur/ears/tail?

If it's in the extreme range, you need professional help, pronto... because those (and others like them / worse things) are signs of *either* a disorder or that he is being abused.

If it's in the normal range:

Every single time a sharp NO! and then either

- IMMEDIATELY get gentle and smile and SHOW by holding his body (kindly) and directing his arms how to appropriately while talking calmly "Like THIS not with legs, not hitting (grabbing/pulling/ whatever roughness was going on) but like THIS."

or

- Scooped up and on timeout, or swat (since you use that as discipline) and remove him from the dog... and explain simply and repeatedly that x is not allowed... that that HURTS the dog, and we don't hurt animals/people unless we're defending ourselves or someone else or learning.

DO make sure to have a lot of "like this" so that acceptable behavior is understood right along with unacceptable behavior.

First, I would get a doggie gate for now. Separate them until everything is under control.
Next I would take your baby over to the dog, take his/or her hand and gently pat the dog and say "nice, nice dog" Do this often.
we are nice to the dog. Keep repeating with petting and being sweet.
If you catch your child pulling the ears, tail, hair, bopping with toys.....you simply say "no!" "We do not do that to our dog!" sternly...
and remove them from the situation immediately. Look at them again,
and say NO!" Be nice to the dog.
You must be very careful, because a dog can respond back and bite out of defense.
You don't want that to happen, so take precautions now.
If this is not working, I would call a dog trainer/and ask them
what to do.

I don't have any tips...we had this problem with our son torturing our cats when he was little. Needless to say we had no sympathy when he would get a little nip or scratch...and we would NOT allow him ot retaliate EVER.

It was a phase (Thank God) as I had visualizations of years of therapy and progression. We had a neighbor, Mikey, who brutalized my kitten in a bag against a brick wall when I was 5...so it is a very sore topic for which I have very little sympathy for kids....but he grew up and mellowed.

He is now one of the gentlest, kindest, animal loving kids I know...he always demands we leave money in the jars for animal organizations around town...and he does fundraising for animal organizations. We currently have 1 dog, 5 cats, 2 bunnies, and a guinea pig...and all is well!

I would venture to guess your child will also mature and learn to treat animals well.

I agree...it is a phase. We went through this for several months with our first son, although I think he was a bit younger probably around 9-15 months. We just kept on top of him all the time. Never let him in the room unsupervised with the dog. And if he even started to go near the dog we would be sure to be right there. We did a lot of modeling what acceptable touches were for the dog. We would pet him ourselves and say "niiiiiiice", then we would take his hand and show him how to pet while saying "niiiiiice". It definitely worked and sank in considering that every time he touches anything (pet/baby) he still says "niiiiiiiice" while he touches...and he is 2.5!! LOL

I am not opposed to spanking but when the problem is aggressive behavior then spanking may not be the best choice. I would remove him from wherever the dog is an put him someplace secure (play pen or something where he is restrained) for a 1 minute time out. They don't fully "get" the time out concept at that age but he will know being rough with the dog has a consequence. Also tell him being rough hurts the dog and demonstrate how to gently pet the dog instead. I used to hold my son's hand and use his hand to pet the cat gently (she was so soft!). My son had trouble being gentle with our cat until he was nearly 3 but my daughter has a calmer personality so it is much less of a problem.

I would not allow him to be around the dog unsupervised at all. I know this is hard when you are all living in one household but I say this because I was bitten by a dog when I was 3 (my aunt left the room for a few minutes). Maybe a baby gate will also work for the dog to keep them apart.

It is just his age and it is a phase. My son went through the same thing from about 18 months to maybe 2 and a half. We would remind him to be gentle and show him the right way to pet the dogs. But there were times when he would hit or kick (or try to) out of anger. He was expressing his frustration on the one being in the house that was "lower" than him on the totem pole. If he was upset about something he's sometimes try to take it out on the dogs. He would get reprimanded and have time outs for this. We got books talking about being nice to your pets. I forget the names of them now...Pets are not for Hitting...Be Nice to Your Furry Friends... Then when he was about 3 and a half we talked about him "training" the dogs and he was very excited about this. He (with my help) would make them sit or lie down to get treats. Or practice "stay". We would have him go out the door first, with the dogs sitting, and then he would say "ok" and they would run out. All those things they teach you in dog training classes. After doing this for the next year or so he really had a sense of ownership of the dogs and since then has always been kind to them.

I'm not sure exactly what your son is doing to the dog, but we have to keep our daughter away from our dog when she's sleeping in her bed. For whatever reason she wants to slap at her. (I think it's to wake her up, but she's an old dog and just wants to sleep) So we redirect her to other things than messing with the dog.

A lot of children also have a hard time understanding that a real animal has feelings and can be hurt, since they have so many stuffed ones. If our daughter hurts the dog, we make her say she's sorry and pet her or let her lick her hand (the dog's favorite thing).