They are descendants of Wolves after all :P believe it or not.
Actually this is still being disputed, whether it was wolves,
dholes or some other wild canid. For a start, dholes are easier to domesticate than wolves and are less aggressive towards humans.
Sorry to go off topic but I thought it might be necessary to clear up that it's not a set in stone fact that they came from wolves.
Just something to think about though, unrelated to the origin of dogs (and to keep this post on the topic at hand):
About microbial animals such as single-celled amoeba, for those who don't yet know they work by a bunch of cellular mechanisms that are both chemical and mechanical in nature (and sometimes even electrical). They have "organelles" which are their own equivalent to our organs - they are separate components that each have their own separate job within the organism, but are all essential and work in harmony to keep the organism alive. They are built from proteins encoded by its genetic information.
The way they work means that they have all the basic survival attributes you would expect in a macroscopic multicellular organism, such as the ability to sense and avoid danger, the ability to sense and seek food or other benefits and in many species the ability to exchange information with other organisms in its environment. All this is done by cellular mechanisms which, to us, seem rather robotic in nature because we can predict how they work as a series of mechanical and chemical reactions, each action triggering a reaction, which triggers another reaction, etc. Requiring no intelligence that we can identify, it's like the organism is on autopilot all the time.
However, something to think about is that, in truth, we work exactly the same way. There is no difference except we simply have more atoms in our bodies, with additional layers of complexity (such as cell organisation and differentiation). But our basic function is no less "robotic" as a microscopic multicellular tardigrade, or even unicellular amoebas, in the physical reality.
The main difference is that we are simply more intelligent, we even have an organisation of specific cells for storing and processing complex information (or brain). But does intelligence correlate to our ability to feel?
Looking back at the amoeba, first thing we notice in respects to intelligence and consciousness is the lack of a brain. They don't have one. They don't even have anything like one. Some might say the nucleus, but that's not true. It doesn't store and process information. It just provides the blueprints for making proteins - nothing more. It doesn't even decide which proteins should be made when. The cellular mechanisms do that, working together.
But is it right to say "decide"? They don't have a brain - they don't have intelligence, right? Well, to them, the closest thing they have to a brain is their cytoplasm and membrane and everything in it, pretty much everything but the nucleus. If they exhibit anything close to intelligence, they do have a facility for it, just like our brain, except it takes up most of their bodies.
It's simpler than an animal brain by orders of magnitude, but it's still, arguably, an intelligence. Our own intelligence can be rationalized down to simple functions just like the amoeba cell, the main difference being we don't yet understand the relationship of all the different neurons in our brain. We still don't fully understand how it works, but what many have come to understand as a "neural net" can be replicated in computer systems in a much simpler way (obviously due to limitations in computer processing, we cannot replicate human intelligence). Not just simpler by size and complexity, but also the way the information is passed on, in a computer code is used. In the brain, we're not quite sure what is used as the basis of information. It might just be a series of 1s and 0s (not literally, I kind of mean "on" and "off").
That's something cells lack and that a brain possesses - a neural net. A network of nodes and connections that, somehow, exchange and pass on impulses that, somehow, allow intelligence to exist. But again, it's just a bunch of mechanisms and chain reactions, except on a much, much bigger scale.
How do we define consciousness in all of this? Where do we decide where an organism stops being a "biological robot" and starts being a conscious feeling being? Is it at the cellular stage? Is it at the formation of a brain? Or is it only the higher and more complex brains? How do we tell?
If you were to take a human and torture them, they would feel many complex emotions, we know this because we are human. Same with if we gave them the most heart-warming gift any person could give. We know how touching it is because we can relate. If we were to take a dog and torture them, they would whine and whimper, possibly soil themselves, yelp, scream, submit themselves in hopes of making it stop, or fight back viciously in defence. If we were to give them the biggest scummiest bowl of food a doggy could ever want, they would jump around all excited until you put the bowl down, and they'd dive right in. We can see the behaviours in the contrasting extremes but we can only take a mere guess at what they're feeling. We can guess, however, they they don't feel the same complexity we do. They don't have the modesty or humility the human might have in receipt of their gift. They may or may not feel "thankful" for it, possibly not. They may not feel the need to question why they are being hurt in the other extreme, and instead just want to get away or make it stop (or maybe they do? Maybe to them it's just confusion over why this is happening?) As we go further down the ladder of intelligence (fish, insect, and so on) we can expect fewer and fewer layers of complexity in the animal's behaviour and feelings.
But even a single cell organism such as the amoeba will pull away from harm and try to escape. Even they will follow sources of food, as said earlier before. Just, perhaps, it is the most basic single layer of intelligence any organism can have. Does this make them feeling? Who knows. Consciousness is a funny thing, we're not sure what it is yet. We're not sure if it exists as a combination of factors working together, or if its some kind of energy we have yet to discover. I just feel a lot of the time we can't discount even the remote possibility that even single celled organisms "feel".
tl;dr: A rambling on whether or not the possibility could exist that "amoebas" and other simple organisms may or may not feel on levels far, far simpler than we might be able to comprehend.