It's about consistent patterns of behaviour, not necessarily it happening every day. It just means that the problem has persisted for a while, it's not something which has come out of the blue for the last week or so, which might be a phase or a reaction to something temporary. Also if it's persisted for 6m+ then it likely means you've tried different ways to tackle it but they haven't worked.
It sounds consistent enough to approach your GP and/or the school SENCo for advice about assessment and any support that might be available. Sometimes for example they offer a parenting course first, which is worth doing as you can pick up some useful tips, plus if none of it works then it gives you something concrete to say "We tried X approach as taught in Y course and it didn't help".
The pattern of assuming behaviour will get better as the child gets older and it just getting worse instead is a pattern I recognise with my 2 DC who are diagnosed with ADHD. I understand the diagnosis of ODD is not so often given in the UK because it can be quite stigmatised.
In terms of what helps IME - the examples you give about the dog and stomping etc, these strike me as quite reactive/in the moment sort of corrections almost after the fact. And you also mention difficulty with routine tasks like washing, dressing and eating. This is not to criticise because sometimes it's hard to predict behaviour in advance and especially if you have quite a whirlwind of a child, they will often just do something completely inexplicable. But I find trying to chase after the behaviour like that just escalates it. What I find tends to be more successful is trying to take a more proactive approach whenever possible e.g. sit down with DH and write a list of your top 5 battles you would face during an average day/week.
Then for each item, reword it so that rather than describing the unwanted behaviour (or a statement with "stop", "no" or "don't") you are describing a replacement or incompatible behaviour instead. Consider whether this is even a reasonable expectation e.g. if she's angry and her default response is to hit, it's probably not reasonable to expect her just to take some deep breaths and stop being angry. But you might be able to help her remember to redirect her hitting to a pillow instead, which is a good first step and you can move on from there. For stuff like the dog, it might feel reasonable to expect her to walk but it's probably more successful if you could distract her with a game that will keep her close to you, far away from the dog, moving more slowly/quietly etc e.g. trying to avoid detection or spot wildlife etc.
Sometimes literally just thinking about what the positive replacement behaviour would be is helpful in itself, but if you have more time to devote to it you could consider how to encourage it too or how to best set her up for success, like thinking about skills to make into a game to practice at neutral/happy times, less stressful "practice situations", books to read together about the topic, supports in the environment (e.g. keep pillows nearby to hit, a visual schedule to show what to do when in the morning) role play with a toy etc etc.
Then if you have even more time to devote to it you could even look into underlying structures or skills which might help her such as a behaviour points chart targeting the wanted behaviour (rather than penalising the unwanted behaviour) or looking up what developmental skill/ability might be behind certain things.
The other thing which really transformed our home lives was learning about prioritising de-escalation and not getting drawn into reacting to the behaviour. It's quite a natural response to react by giving a firm instruction and then as the instruction gets ignored, or behaviour which has repeatedly been corrected is repeated, starting to express more frustration or annoyance about it. With most children, although it's not the best way to communicate, they would receive the message that their behaviour was unacceptable and it would form part of a deterrent. We all follow social conditioning like this, which is why it's an automatic response. The problem is if a child has ADHD or some other issue affecting impulse control, they get the disapproval but it won't allow them to change their behaviour as a result. Imagine if you are riding a bike where the brakes are faulty - you can squeeze as hard as you like on the brake lever but it won't actually slow down the bike. The disapproval is like squeezing the brake lever, and normal impulse control would act like a brake on the behaviour that the child realises will cause social disapproval. This can make them very anxious instead or almost reactive and playing up to the scenario because they know they're going to get told off anyway.