Stop Calling Pets Your Familiars -OR- "You might be a basic Witch if..."

I get it. As Witches we have a natural reverence for nature and Her creatures. Most of us believe animals possess intelligent spirits and are capable of understanding and connecting with us on a deeply personal level. Many, I dare say all, Witches at least recognize the magical potential and properties present in every animal. 
However, a Witch's pet is not synonymous with a Witch's familiar.
Sorry, not sorry. 

​The world has been aware of the Witch's Familiar since before the common era, and is mentioned (read: warned against) alongside wizards in the earliest books of the Bible. A Familiar Spirit is a supernatural being, in some cultures believed to be bestowed upon the Witch by the Devil himself, to assist Witches and Cunning Folk in the practice of magic.
In older accounts of Spirit Familiars they are reported to appear in either animal or sometimes human form, and are purportedly capable of: providing the Witch with increased power or gifting magical power all together, allowing the Witch to transform herself, enabling the Witch to fly (usually by riding on the Familiar), and sometimes are subject to the Witch's bidding.
In almost all historical recordings of Familiar Spirits they are said to have appeared to the Witch or have been gifted by another Witch or Deity, passed down through family generations, or given as a gift as a sort of initiation rite. There is no evidence to support the notion that the Witch choses her familiar.
The idea of a 'pet' taking on the role of a Familiar is a new concept which I suspect is the result of the modern relationship between animals and their owners combined with the trending status of Witchcraft. Animals (especially those close to us) can assist us by providing companionship, love, and even physical guardianship - but personally I reject the idea that an animal acquired in a mundane manner, who shows no other signs of being learned in the Dark Artes other than not leaving the room when I work spells is a "Familiar Spirit". The name itself is believed to be derived from the Latin word Famulus meaning servant and let's be honest, most of us are serving our pets not the other way around.

If it walks like a duck and quacks like a duck.. It's still not a Familiar

So when did we get confused between loving, four legged (or however many legs your pet has) friend and otherworldly spirit? The portrayal of Witches and witch familiars in movies and tv shows are not fully to blame. It's easy to blur the lines between the two when both a familiar and a pet perform similar duties. In the accounts that we have of familiars we see them serving as companions to the Witch, providing protection and guidance, functioning as a teacher, and carrying out the Witch's wishes. This really isn't very different from pets as they too are our companions, protectors, and sometimes even teachers. And I know I personally have sent my former cats (and now my dog) to exact my wrath on unwanted snakes, and squirrels that find themselves in my bad graces within the confines of my backyard.
The difference lies in the nature of the Familiar. The Familiar Spirit is.. wait for it.. a spirit. It is of a ethereal nature, and exists in the spirit realm. Now this isn't to say that it cannot present itself in the physical. There are numerous accounts of Spirit Familiars physically manifesting themselves as animals and humans, appearing not only to Witches but also to the (usually frightened) lay person. And I will add that in most cases, said lay person is most aware of the supernatural nature of the perceived Familiar.

If you still can't let go of the idea of your pet also being your familiar, fear not, everything is possible. Spirits, after all, do have the ability to use living beings as vessels, so it would be presumptuous to think that Spirit Familiars are incapable of riding / possessing corporeal bodies and wielding them as their own. I believe this is most likely the case when Familiars are reported to appear in physical form, both animal and human. A common practice among Witches who have Spirit Familiars is to provide the entity with a house, so to speak. Many are given some kind of dwelling, a hollow container such as a jar and also solid objects like crystals - the goal of which is to give the spirit a sort of anchor to our realm. So the spirit's vessel could very well be a living creature or even the Witch herself. 
But, aside from being possessed by a spirit, your black cat is not your familiar. So for the love of all that is unholy - STAHP. 

References:
https://en.wikipedia.org/wiki/Familiar_spirit
https://www.kingjamesbibleonline.org/Familiar_Spirits/​
https://exemplore.com/magic/witchesfamiliar
​https://www.patheos.com/blogs/byathameandstang/2016/11/introduction-to-familiar-spirits/