I did not have a dog growing up so my earliest dog memories are of my friend's and relative's dogs. In particular I remember Antje, the beautiful big black standard poodle owned by my friend Derwin Rovers' family. Derwin lived in the next block and we were back and forth at each other's houses a lot. They were Dutch and loved the Dutch style red cabbage that is stewed with apples and turns a vibrant purple colour. Derwin's Oma was visiting from the Netherlands and she loved Antje. Antje loved her too. Antje loved her because Oma would feed her from the table whenever Derwin's parents weren't looking. One day they had this red cabbage and Oma gave Antje rather a lot of it, plus some pork and mashed potatoes. The diarrhea was purple. Right on their white shag carpet (this was the early 1970s after all). Brilliant, vivid purple. I cannot begin to explain how deeply impressive this was to a pair of 6 year old boys. Eyes wide, mouth hanging open, fingers pointing... this made our day. Heck it made our month. Purple poo. Derwin, your dog had purple poo.
Fast forward forty-five years and I am still grappling with dog poo colour as not a week goes by without a question from a client about what it all means. So here, for your edification is a field guide to the spectrum:
Brown: Let's start with an easy one. Any shade of brown is normal. It may vary from dark to light from time to time for no particular reason, but it's all good.
Yellow, Green or Orange: These are generally muted brownish versions of these colours, but these are also fine. You are just seeing more bile coming through. This may happen when the gut is contracting a little faster or with certain foods, but as long as it is firm it is fine.
Red: This generates the most calls and visits as it is understandably alarming. Yes, red does mean blood. Generally, however, the red blood is in spots or streaks or as a small amount at the end of the bowel movement and should not be a cause for alarm. (If, on the other hand, the entire bowel movement is red you are right to be alarmed and you should call your veterinarian forthwith.) The spots and streaks just mean that anus, rectum or last part of the colon are irritated and that perhaps there was some straining to break a small blood vessel. If it only happens once or twice and the feces are otherwise ok or just a little soft, don't worry. If it happens several times, call your veterinarian.
Purple: See Antje's story above.
Blue: Never seen that. I have no idea. Call you veterinarian immediately.
White or Grey: Likely your dog was given a barium swallow test and you are seeing the barium pass through. If this was not the case... you know what I'm going to say... call your veterinarian!
Black: This is the important one, really the only colour you need to watch for. If the stool is jet black like tar or molasses and especially if it is soft and glistening and sticky, your dog may have what is called "melena". That is digested blood and is coming from higher up in the system like the stomach or small intestine. This can be very serious as it may indicate a bleeding ulcer or tumour. Please note however that pepto-bismol can also turn the stool black.
So there you have it. While consistency, size, frequency and effort to produce are all important pieces of information regarding your dog's stool, colour, perhaps surprisingly, is generally not. Unless it is black.
And for the cat people reading I'll say that more or less the same applies although for some reason you don't ask about it nearly as often as dog people do. A fun fact though is that if you have multiple cats and someone is pooping out of the box but you don't know who you can put non-toxic sparkles in one cat's food at a time until you see who makes sparkly poo!
No, I have not lost my mind. Yes, I am absolutely serious about all of this.