Swollen sphincter?

Hello, I noticed today that my dogs sphincter appears to be swollen or puffy. I know this is gross, I am sorry, but I have never noticed it looking like that before. She doesn't seem to be bothered by it. No signs of pain, irritation, excessive licking, etc. My husband thinks I am making something out of nothing. However, I cannot help but feel concerned. Any yay or nay about whether I should pursue my concerns I would appreciate it. She is a 6 year old Maltese/terrier mix. Up to date on shots. Thank you!

Hi - to continue to the lovely direct tone of your question, I would be surprised if your dog wasn't licking her anus, on grounds that the fur around it has turned that particular shade of brown.  Dogs who are foot-lickers tend to get brown hair between their toes, caused by saliva.... and so do dogs who lick their anus.  Usually this kind of thing starts with an allergy or worms, which makes the skin there slightly inflamed and irritated.  There are 'anal glands' back there - little glands under the skin, which empty some sticky smelly stuff along tubes leading from the gland to the surface.  If you imagine the anus to be a clock-face, the ends of the tubes / ducts pop out onto the anus at about twenty-to-two;  sometimes you can see round, punctate little holes.   In the old days, we thought that dogs licked their anal glands because they were blocked, but the truth is more complex.  Inflammation (e.g. due to skin allergy) occurs and skin is really delicate around the anus.  The ends of the tubes where the anal-gland secretion comes out, can thus become narrowed by the inflamed skin.  This makes it harder for the dog to empty their glands.  The inflammation and the slightly blocked gland make them uncomfortable.  So they lick their bottoms.  Thus the anal glands don't empty so well..... sometimes, this can become a viscious cycle.

So... here is a blog explaining more about anal glands. https://vethelpdirect.com/vetblog/2022/02/20/all-you-need-to-know-about-dog-anal-sacs-humans-dont-have-these/ I did note that you didn't mention a smell and that you said that there was no obvious licking.  I am very suspicious of anal gland disease, however;  AG problems tend to be chronic (always present, low-level) issues that build over time, and it is possible that such a problem could be in the early stages.

However, there are a lot of alternative differentials, so your dog does need to be examined.  Other possibilities may include - in no particular order - 1) allergy that is affecting the anal skin but not the gland at this point.  Commonly flea allergy, but allergies to anything can present like this.   2) other parasites e.g. demodex mites / worms  3) pain in that area for some other reason, leading to rubbing or licking   4) yeast infection of the skin - perhaps in combination with rubbing or  e.g. hypothyroidism  5) Endocrine (hormone-related disesae e.g. thyroid disease / Cushings etc

IN answer to your question then, this small detail is worth paying attention to.  it is commonly an early sign of anal gland / skin disease, which is a frustrating problem of dogs and good to pick up early.  However, a huge range of other things could be involved, including some hormonal diseases.  The symptom of the skin itself turning brown is called hyperpigmentaion can can be the result of rubbing as well as licking.   We would recommend talking it through with your vet.

Hello again.... I have been thinking about this case a lot since writing the above - to be honest, your mentioning an absence of scratching, of rubbing the bottom on the floor or pain confused me.  I think that pressure (rather than just saliva) may cause discolouration in some cases and my instinct would still be to get the anus / anal glands etc checked over by your vet, as these are common, uncomfortable problems, potentially well masked by animals and best detected relatively early.   However, I have also heard vets recently discussing a condition called porphyria, which is much better known in the human world and not necessarily a term that most vets are very familiar with.  This is to do with the way that old blood cells are broken down in the body - pigments not removed (perhaps by the liver) in the usual fashion, but rather staining the skin.  I can't find anything convincing about it in the literature available to me at this time, but it may be interesting to ask a pathologist about (your vet can probably chat to one) if the other possibilities seem unlikely and the case continues unsolved.  Please do let me know what you find out in the end.

Thank you! This was so helpful! I will look into it!