What's this painful lump on my old dog's neck from scratching?

This looks like a little skin wart which are usually nothing to worry about. It doesn't look red or infected at the moment. It could be that she has an underlying skin allergy that is causing the itching. If you are worried you should take her to the vet for an examination. Alternatively you could try giving her a daily antihistamine to see if that settles the itch.

I am very sorry but we can't really tell much from this photo. It may be just a hot spot. You can use some hydrogen peroxide diluted 1/2 and 1/2 with water and try to clean the crusts off it and, if possible, shave the hair from around it. After you do that if you could post again with new photos we may be able to help you better.

Hello and thank you very much for your question. Fleas can be so frustrating and I sympathize with what you were going through. What has to happen for your dog to heal and for the lump to possibly go down, Is for the itch cycle and the inflammation to be stopped. A visit to the local veterinarian is a must in this situation because they will have strong prescription strength flea preventative as well as steroids that can be given to your dog to stop the fleas and therefore the dermatitis that’s associated with their biting. I urge you not to use any further over-the-counter flea preventative or skin medications without the approval from your veterinarian. This will only delay the healing and may exacerbate the problem. The lump should go down with time as long as the fleas are killed and the inflammation of the skin is controlled. But, if the lamp does not go away within the next two months, you may want to have your veterinarian take a biopsy of it just to see if it is indeed even related to the fleas. Does that make sense? I appreciate you reaching out to our service. I hope I’ve helped you today.

The skin looks swollen and is seems to be getting infected. I would suggest you take him to the vet for an exam as it is impossible for me to "diagnose" him over the internet. If you want to try something first I recommend you try this product: ( https://www.petco.com/shop/en/petcostore/product/zymox-spray-with-5-hydrocortisone ) No matter what, if he continues to lick it, it will not heal. If this spray doesn't make him stop licking it you will need to get him a cone collar. ( https://www.petco.com/shop/en/petcostore/product/all-four-paws-tan-comfy-cone-5000727--1?rrec=true ) If no improvement after 5-7 days of using the spray and him not licking it then you will need to get him to your vet for an exam. Hope this helps. Best wishes.

It is hard to tell from the picture but it maybe the start of a pustule which can be a sign of a skin infection. It may also be a cyst or sebaceous adenoma or wart as they have a similar looking characteristic. Since she has been through Cytopoint and Apoquel with out much relief, she may benefit from a dermatologist to get intradermal allergy testing. Your vet can check that spot to be sure what it is and set up a referral for the skin if you wish to pursue that route

Thanks for using Petco Pet Education Center, formerly Petcoach! This may be due to allergies for example though other possibilities like mange cannot be ruled out. It really comes down to figuring out what is causing his allergies so that they can be treated or the specific allergen avoided. 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!

It looks like what we call a hot spot or moist dermatitis. These looks really painful. I would have him seen. He will most likely need some antibiotics and some topical medication to help dry this up. They can also give you something for the itching or pain relief. These usually heal pretty quickly once they stop messing with them.