Why does my dog have a large bruise or blood under his groin skin?

Based on the photos, I am concerned that the purple area is some bleeding/bruising in the skin which we often see when a dog has low platelets. I'm not sure based on the photo, but I suspect the white area is a nipple that just looks really prominent due to the bruising around it. Low platelets are a very serious problem; even though he's otherwise acting fine, please take him to your vet to have him examined. They may recommend running some lab work to find our what his platelet count is. There are many causes of low platelets, some possible causes include an infectious tick-borne disease, an auto-immune disease where his body is destroying his platelets, or cancer. Because all of these are very serious, and because low platelets can lead to life threatening anemia, please take him to your vet. Thanks for asking Petco Pet Education Center, formerly Petcoach!

Thank you for using Petco Pet Education Center, formerly Petcoach! I can see the circular, dark red, flat areas on Denim's skin. These definitely look like bruises, and can be caused by abnormal blood clotting. This can be caused by certain toxins such as rat poison, cancers, and inherent inability of the blood to clot. Your vet can run some quick blood tests to determine what is going on. I hope this helps and that all is well with Denim!

This could be skin irritation/infection but it could also be subcutaneous bleeding (which can be serious). I strongly suggest you have him examined by a vet. In the meantime you can try these medicated pads on the affected areas in case of infection. ( https://www.chewy.com/douxo-chlorhexidine-3-ps-pads-dogs/dp/110823 )

Hello, Its hard to give you definitive advise, because this could be nothing or something. Most likely, t could also be a simple insect bite or minor trauma that resolves on its own within a couple of days. However, I'd recommend monitoring that bruise for any changes and the rest of his skin and gums for new bruising or bleeding. Mysterious bruises can be a sign of blood disorders. If Charlie experiences any additional bruising, bleeding, or changes in appetite or behavior, I'd recommend taking him to the vet right away. I hope this helps. Thanks for using Petco Pet Education Center, formerly Petcoach.

Hello and thank you for contacting Petco Pet Education Center, formerly Petcoach. The area looks bruised and angry. You should clean the skin with antiseptic solution twice daily for 3-4 days (for example 4% chlorhexidine). If the bump / blister ( it almost look like inflamed nipple on the picture you posted) does not get better or if it starts to bother Apollo, you should take him to your local vets for an appointment

Hi, thanks for using PetCoach! Poor Moco! Due to his age, the appearance and the location it looks like a histiocytoma. Which is a benign mass in young dogs. They tend to resolve on their own in a few months but sometimes if they ulcerate, grow rapidly, become infected or bleed we recommend removing them. Another possibility is a mast cell tumor. I would suggest having it looked at my your vet. Good luck! https://www.petcoach.co/article/histiocytoma-in-dogs/

That redness could indicate a bacterial infection. Sometimes the infection is a primary problem but sometimes it can indicate an allergy or allergic reaction. Less commonly, skin mites can look like this. On the right side, there is a very dark red discoloration. This could be present if he is licking or scratching at it. The concern I have is if that red discoloration is bruising. Bruising is not normal in dogs and is considered indicative of a possible emergency. Reasons for bruising include an autoimmune disorder, eating rat poison, a bleeding disorder or liver disease. If you suspect that is a bruise, I recommend to have Jax seen by the veterinarian quickly. A skin rash is not an emergency. You need to keep him from licking the area by making him wear an elizabethan collar at all times. You can wash the area daily with hand soap and rinse well. You can apply a dab of coconut oil and rub it in well a couple times a day. If it is not much better with in a week, take him to his veterinarian. If the area gets worse or if he seems uncomfortable, also get him in sooner to be seen. Lastly, you can always just have him seen by the veterinarian. They will be able to provide stronger medication that will clear that up much faster. I hope this is helpful and please feel free to post any additional questions.