Puppy has red ring on stomach. Is it ringworm, Lyme, or a bug bite?

It is possible this is an insect bite. Fly bites in particular can look like a red ring with a central pallor (pale area in the middle). It is tough to tell from the photo what the central area looks like. If it is raised and looks like it is filled with yellow/pus, then this could be a pustule which is a sign of skin infection. If the center is flat with the skin and just pale in color, then a bug bite is more likely.

Thanks for using Petco Pet Education Center, formerly Petcoach! This is unlikely to be ringworm at least based on how it looks right now. This is possibly due to local inflammation. I recommend that you continue to monitor Milo for now. If this lesion fails to improve on its own or it worsens have him evaluated by your veterinarian for further assessment and treatment. Good luck and have a good night!

The most common reason that we see red circular rashes in dogs are actually bacterial skin infection. Tick bites rarely cause red circular rashes in dogs (it's more common in people). Ringworm certainly can cause a circular rash, but they often aren't red in dogs. I would recommend having your vet examine Chance and determine what they think is going on. They may be able to tell by looking at it, or they may need to do some special skin tests like skin scrapings or skin cytology in order to determine the best treatment for Chance. I hope that was helpful. Thanks for using Petco Pet Education Center, formerly Petcoach.

From the appearance in those photos, I suspect those are black fly bites. They can cause pretty dramatic round red lesions that are flat (not raised). While they look impressive, Gnocchi shouldn't be bothered by them. They will gradually go away (it can take a week or two) and are not dangerous. I hope this helps!

It could be an insect or tick bite, it could also be ringworm, if this does not get any better within a week you will need to take her to your vet in order to get it checked and treated. try to avoid contact as ringworm is contagious to humans as well.

Skin lesions like Coco has can be caused by bacterial, parasitic or fungal infection, dietary or environmental allergies or sensitivities, immune system disorders, an insect bite like you mentioned, or a combination of the above. I recommend making an appointment to have Coco seen by your veterinarian to help determine the cause of the lesion you’ve noticed and to make sure it is treated appropriately. The vet will likely want to look at a sample from the area under the microscope to determine if there is an infection and to figure out what medication is appropriate for treatment. In the meantime, you can bathe Coco in hypoallergenic shampoo for dogs to clean the area, but this will likely not resolve the lesion.I recommend getting Coco on parasite prevention year round. Please see the link below for more information about ticks: https://veterinarypartner.vin.com/default.aspx?pid=19239&id=4952474

Thanks for using Petco Pet Education Center, formerly Petcoach! This is possibly due to allergies. It really comes down to figuring out what is causing his allergies so that they can be treated or the specific allergen avoided. A secondary infection is likely and also needs to be addressed.  There are medications such as Apoquel or prednisone which may help with the itch. 

There are many things that can cause allergies though in most cases they can be broken down into 3 big categories: flea, food and environmental allergies. 

Allergies are usually worked up in a stepwise fashion starting with flea allergies as this is the easiest and cheapest to take care of. If not on a flea preventative, then it would be a good idea to get started on one. If already on one then it would be a good idea to change to something else (there are many new products out in the market). 

If not improved in 1-3 months then it is time to move on and check for food allergies by switching to a novel diet (new protein and new carbohydrate). If that does not seem to be the issue then you are left out having to check for environmental allergies which require blood and/or skin tests. 

Allergies can be very frustrating to deal with at first but so rewarding at the end when we are able to treat them effectively!