My dog has a red spot on his nose that just appeared. What is it?

So, there are a number of things this could be. 1) This could be an allergic response to something in her environment or an insect, 2) This could be a fungal or bacterial infection that could be primary OR secondary to trauma or an allergy. Ideally I would do a prep on a slide and look under the microscope to see if there is a significant bacterial or yeast population. Regardless, however, I think she would benefit from some topical treatment depending on what is seen under the microscope. If it seems to be spreading, and the area is swollen, some injectable or oral medications may be indicated.

Ouch! Any new or suddenly growing growth like this should be checked out by your vet in person ASAP. Allergies, infections, skin irritation from rubbing it on things, and some growths and tumors can all cause spots like that on the nose, and can also cause rapid changes and discoloration like this. Until you can get to your vet, I would place an Elizabethan (cone) collar on Amber and keep the spot clean and dry to help reduce any further irritation. It is also a good idea to monitor the size and shape of it and how rapidly it is changing as this can help your vet figure out what may be going on. Your vet will likely take a full history as well as a potential sample of the spot to see what cells are present and provide treatment as needed.

A red patch on the snout could be due to several things. If your dog is prone to digging with his snout, especially if he has spent time in a crate recently, he may have rubbed a raw spot on his nose. Other possible causes of a red patch of skin in this area would be allergies, bacterial or fungal infections, skin mites (especially Demodex mites, or demodectic mange) or even some auto-immune skin diseases. If the spot does not resolve within a few days or if it seems to be spreading, I would recommend taking him to a vet for an exam - he/she can do some simple tests, such as a skin scrape, to determine the problem.

Ouch! Due to how inflamed that looks I would definitely schedule a vet visit ASAP. Sudden growths/irritations like that can be due to a number of things including bacterial infections, tumors, irritation from digging/rubbing at the spot too much, allergies, etc so it's good to see your vet. They'll likely want to take a sample of the area to determine what is going on and how best to treat it. In the meantime, it's a good idea to place an Elizabethan (cone) collar on Nova to keep her from rubbing at the spot, as well as keep the area clean and dry. If the area is rapidly growing in size, taking note of the size, color, shape changes, etc can help your vet better determine what is going on. If you are noticing any other symptoms (sneezing, fever, loss of appetite, etc) these are important to let your vet know as well.

This appears to be a histiocytoma. If it is, it should resolve on it's own. ( https://veterinarypartner.vin.com/default.aspx?pid=19239&id=4952066 ) I suggest you just monitor it for the next month or so. If it does not resolve or it gets worse, then a vet visit would be warranted.

This looks like a localized area of infection. This could be caused by an allergy, by her rubbing her nose against something (like a fence or crate) or could be a sign of an underlying autoimmune disease like lupus or pemphigus. I would recommend taking Bambi in to the vet to be examined. Your vet may recommend antibiotics and a topical ointment to help the nose clear up. Your vet may also recommend doing a cytology or biopsy of the area which will help further determine what the cause of the lesions are. I hope this helps. Thanks for using Petco Pet Education Center, formerly Petcoach. Best of luck

Hi again, it's not a super clear picture but from what I can see it looks a lot like a papiloma, which is a benign viral tumor. These type of tumor usually go away with time without treatment but there is an antibiotic treatment that has shown to be effective in resolving them quicker. I would recommend taking Lockie to the vet in order to confirm my suspicion as I can't be 100% sure based on this picture.