Petco Text Logo
Petco Pet Logo

My dog has a black spot on his anus that's getting bigger. Is it serious?

Updated On September 23rd, 2025

Pet's info: Dog | Chihuahua | Male | unneutered | 10 lbs

Hi, I noticed a black pigment on my dog's anus several months ago and it seems to be getting larger and darker. I am attaching a before and after photo. The pigment is not raised. Should I be concerned? Thanks in advance.

This question includes photos that may contain sensitive content. Click to view.

View more to consider that the photos may include sensitive content.

2 Answers

Most Helpful Answer

Image profile

Answered By Ricardo Fernandez, DVM

Veterinarian, Veterinary Oncology Resident

Published on August 8th, 2018

Thanks for using Petco Pet Education Center, formerly Petcoach! This is unlikely to be something of concern and most likely represents a region of pigmentation. However, I recommend you keep a close eye on it and if at some point it appears to become a mass, have him evaluated by a veterinarian for further assessment. Good luck and have a good night!

Vote icon

18Pet Parents found this answer helpful

Related Answers from Veterinarians

  • Image profile

    Answered By Kevin Sanada, DVM

    Veterinarian

    Published on December 21st, 2017

    If it's totally flat, then this is most likely just a pigment and nothing to be concerned about. The spot looks very small and is difficult to see through all the hair, but is not something I would take to the vet right away. Instead, it's best to just check every week or so and see if it changes. If it grows, starts to rise, or has any crusting or bleeding, then I would take him into the vet for an evaluation. The vet will be able to further evaluate it and do testing if necessary. Otherwise, it's perfectly normal for a dog to have a little freckle on their anus and this will most likely not be a problem. I hope that helps and all is well with Timmy.

    Vote icon

    1Pet Parents found this answer helpful

See More Answers

Related Questions

Petco Pet Education Center
Health & Wellbeing
My dog has a flat brown spot near the anus
Its a little hard to tell by the photo. It may be that this is a normal pigmentation (a 'freckle' of sorts), or it could be a cancerous mass, though it seems unlikely due to Rover being relatively young (it says he's 3 years old). This sounds gross and obvious, so I apologize, but i cannot totally rule out in the photo that it isn't just a little bit of poop stuck to skin-- I realize you probably have already ruled this out, but if not, gently clean the area with a damp cloth. It is reasonable to keep an eye on it at home; measure how big it is, and make a point to measure it monthly. If its getting bigger or if it starts to bother her, take her to your vet for an exam. thanks for asking Boop by Petco!
Updated on September 24th, 2025
Petco Pet Education Center
Training & Behavior
So a red/black spot has appeared beetween the leg and the abdomen of my dog and I'm not sure if this is just a scratch or it can be something serious. It's been a week and I haven't seen much change. There's a difference of two days between photos.
Thanks for using Boop by Petco! It is hard to know for sure based on these pictures though this is likely a normal pigmentation change. If it is not associated with itchiness or discomfort, there is no need to be concerned about this. If you ever notice any discomfort or itchiness, have him evaluated by your veterinarian for further assessment and treatment. Good luck and have a great day!
Updated on September 24th, 2025
Petco Pet Education Center
Health & Wellbeing
Recently was cleaning off a “poop dangler” & noticed some dirt/poop wouldn’t wipe off on his anus. It appears to be just like a black spot/area - totally flat... like it was colored on his skin. Is this something to be concerned about? Can it be a
If it's totally flat, then this is most likely just a pigment and nothing to be concerned about. The spot looks very small and is difficult to see through all the hair, but is not something I would take to the vet right away. Instead, it's best to just check every week or so and see if it changes. If it grows, starts to rise, or has any crusting or bleeding, then I would take him into the vet for an evaluation. The vet will be able to further evaluate it and do testing if necessary. Otherwise, it's perfectly normal for a dog to have a little freckle on their anus and this will most likely not be a problem. I hope that helps and all is well with Timmy.
Updated on September 24th, 2025
Petco Pet Education Center
Health & Wellbeing
My dog has developed these dark black spots suddenly.its on her whole body but more on this area.is this serious?
Is she itchy or having any other issues? If not it looks like pigment and if they continue to get larger or more than I would have your veterinarian take a look just to be sure. Thank you for using Boop by Petco.
Updated on September 24th, 2025
Petco Pet Education Center
Health & Wellbeing
Hi, I noticed a few days ago that my dog has a small bump right beside his anus. Pictures attached. What could this be and what would be the possible treatment. I'll be consulting a vet , just wanted a second opinion. Thanks.
Thanks for using Boop by Petco! This could be a benign or malignant growth. There is no way of knowing what it is just based on its appearance. Based on the location, often times these tumors are benign in nature and are known as perianal adenomas though about 10% are malignant and again it could be really any other tumor type. This is often differentiated by a test called a fine needle aspirate (FNA) which is a pain free, inexpensive and easy procedure which in most cases will help reach a diagnosis. Sometimes a biopsy is needed for a definitive diagnosis. I recommend that you have him evaluated by your veterinarian for further assessment and treatment. I am really hoping for something benign. Good luck and have a good day!
Updated on September 24th, 2025
Petco Pet Education Center
Grooming
Hi! I found a small, bright red growth near my kid’s anus when I was grooming him. It doesn’t bother him, but sometimes the growth bleeds when it’s touched; for example, when I express his anal glands. He’s eating, playing, and sleeping normally. I w
It could be a benign or malignant growth, or an infected area in the anal tissue. I would keep an eye on it and have it checked by your veterinarian at your next regularly scheduled visit. At this point it nothing to be overly concerned about from the photo. Certainly if it changes at all or causes a problem for your dog then take him in right away to have an exam. It looks like it could easily be surgically removed if needed. Thanks for using Boop by Petco to help you care for Bebe.
Updated on September 24th, 2025
Petco Pet Education Center
Health & Wellbeing
I noticed a growth around my dogs anus, and I plan on taking him to the vet as soon as possible, but I would like to know what it is and if there is anything I can do to help him in the meantime.
Thank you for using Boop by Petco! The growth can be a mass, infected or inflamed anal gland, or a prolapse if it is donut shaped. I definitely recommend having this seen by your vet as soon as possible, as it can be pretty uncomfortable. In the meantime, you can get Ollie an E-collar or “cone” if he is licking the area to prevent further trauma.
Updated on September 24th, 2025
Petco Pet Education Center
Health & Wellbeing
My dog has a huge bump near his anus, I've gotten his glands expressed less then a month ago but now there's only one bump and I'm worried it's something bad. Should I get him to a vet asap?
Thanks for using Boop by Petco! This could be a benign or malignant growth. This is often differentiated by a test called a fine needle aspirate (FNA) which is a pain free, inexpensive and easy procedure which in most cases will help reach a diagnosis. Sometimes a biopsy is needed for a definitive diagnosis. I recommend that you have him evaluated by your veterinarian for further assessment and treatment. I am really hoping for something benign. Good luck and have a good day!
Updated on September 24th, 2025
Petco Pet Education Center
Health & Wellbeing
My dog has a black discoloration under her eye. What could it be?
Hi there and thank you for using Boop by Petco to address your concern. What you are seeing appears to be a spot of hyperpigmentation which could have been from an old injury. This could also just be a change in the skin color which happens at different areas of the body due to aging. Some diseases can cause hair and skin changes so I would monitor this for now and if it become bigger or raised, I would recommend having a veterinarian examine the area so that the most appropriate diagnostic and treatment recommendations can be made. I hope this helps guide you in the right direction. Please let me know if you have any other questions or concerns and I would be more than happy to help you further.
Updated on September 24th, 2025
Petco Pet Education Center
Food & Nutrition
Hi, I noticed something different in my cat's anus. I feed her with dry food. Should I take her to vet?
Hi there and thank you for using Boop by Petco to address your question. Based on the picture, I see nothing concerning other than a darker colored area. If you are seeing diarrhea, worms, a rash, etc. I would recommend having this looked at by a veterinarian so that the most appropriate diagnostic and treatment recommendations can be made.
Updated on September 24th, 2025
image
Have A Vet Question?

Book an appointment with the pros – our expert vets are here to help.

Book Now

Sponsored