Dog has swollen spot, hair loss, and a bloody blister. What is it?

Hi. That is definitely some severe swelling. Due to its location and presentation, I would be very concerned about a tooth root abscess. These can occur even if the crown of the tooth appears normal. It takes an x-ray to fully diagnose it. Other possible causes of swelling like this in a young dog could include a bite from insect or spider, injury, trauma, or infection. I recommend getting him to your veterinarian to be checked out tomorrow.

This may be an abscess, a cyst or a tumor. You should have it examined by your veterinarian, as it is not possible to distinguish these by just looking at a photo. An abscess can usually be treated with antibiotics and/or be lanced, and a cyst can be evacuated. To identify a tumor, your vet may want to do a fine needle aspirate (he takes some material from the bump with a needle and then looks at it under the microscope) to determine whether the mass is concerning.

Thanks for using Petco Pet Education Center, formerly Petcoach! It is difficult to tell from the photo where this lesion is located. However, with anything under the skin that is growing, we become concerned about an infection (abscess formation), a mass of some kind, or a blood accumulation (hematoma), among others. I would recommend Rokko be evaluated by his regular veterinarian to determine the underlying cause for his skin swelling/redness, have any necessary testing done (needle aspirate, culture) and start any treatment that may be needed. Good luck!

Based on the location (it appears to be just to the side and just below the anus), an anal gland abscess may have ruptured. I doubt it’s an insect bite, but I can’t rule that out completely. It could also be another type of mass such as a tumor or a foreign body (such as a grass seed) that’s burrowed into the skin and caused an abscess. Regardless, your instincts are correct; this likely needs to be treated with antibiotics. Put an E -collar (cone of shame) on him and make an appointment with your vet ASAP. Hope that’s helpful! Thanks for using Petco Pet Education Center, formerly Petcoach!

I am sorry to hear about Daisy! Due to the size of this lesion and the fact that it isn't improving, I would recommend taking Daisy to the vet for examination of this swelling. I would be concerned that we could have a bacterial infection like an abscess, that this could be a spider bite or other insect bite, or possibly even a mass/tumor. The vet can examine the area and may try to aspirate the swelling (use a small needle to remove any fluid present or collect cells that may help identify the cause of the swelling and the best treatment). Best of luck with Daisy!

This boil could be a cyst on Daisy's face, and she will need to see a vet for it. If it is a cyst, it will need to be drained sterilely and it may need to be surgically removed to prevent it from reoccurring. Please do not try to drain it yourself as you will introduce infection into the area. I would have Daisy seen by a vet tomorrow if possible for this.

This presentation could be due to a trauma or localized spot of skin infection (likely to be caused by bacteria and commonly called hot spot). A check up, appropriate disinfection and possibly antibiotics (oral, topical or in a shampoo formulation) are needed to solve the problem. Disinfection can eventually be started at home with very diluted hibiscrub or betadine or salted water baths. Buster collar may be useful as well to avoid any licking/scratching. Please do not hesitate to contact us again on the forum or by requesting a consultation if you have any more questions or to discuss it any further.