New dark swollen spot on my dog's neck after vet visit. What is it?

Hello and thank you for contacting Petco Pet Education Center, formerly Petcoach. It does look like a large bruise. Dark, red colour of the skin is a normal feature of bruising. Please, monitor Chloe for a few days at home. Typically, a large bruise like this should decrease slowly in size and disappear in the next 5-7 days. However, if the area is painful to touch or Chloe is lethargic and not herself, you should take her to your local vets for an appointment.

Without examining Casper, it's hard to determine the exact cause of his lesion. Most vaccines are administered in under the skin in a leg, but if Casper's vaccine was given between his shoulder blades, it is possible that this could be related. Some causes of lumps and bumps include benign or malignant masses (histiocytomas are common in young dogs and are benign), sebaceous cysts, an imbedded tick or granuloma. Casper should see his vet to have this lesion evaluated by means of a fine needle aspirate. To accomplish this, your vet will draw a few samples from the lesion with a needle (it's quick and relatively painless!) and examine the cells microscopically. I hope this helps!

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!

If the swelling came on suddenly, or is continuing to increase in size or discoloration, it is best to have the spot checked out by your vet. Darkening of the skin can also sometimes be caused by actual bruising, metabolic issues, and skin problems, so a complete exam of the area is best. Some tumors such as mast cell, lipoma and mammary tumors can appear as swellings/skin changes on the belly and should be examined by a vet, however these often appear as nodules rather than dirty/discolored areas.

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.

I can't tell from the photo if that is a scab or an area of skin discoloration. I recommend to have him examined by the veterinarian to be safe. If that is something like a bruise, that is extremely worrisome. A scab could indicate something like an infection or a hot spot. Best to play it safe and have this checked out. I hope this helps.

Thank you for using Petco Pet Education Center, formerly Petcoach. Many dogs normally have darker pigmented areas of skin under their fur. In some dogs, this does pigment can increase with age. It is impossible to tell only from a photograph however if this is normal pigment. She would need to be assessed by a veterinarian with a physical exam to determine if there is cause for concern.