Why is my French bulldog's armpit rash itchy with a pus bump?

This is likely caused by a bacteial infection. This needs to be seen by a veterinarian, cleaned and disinfected. Your puppy will then need prescription antibiotics. You can try giving Hector a bath with an antibacterial shampoo, which may kill off the bacteria, but if the skin condition does not resolve Hector definitely needs to be seen by your vet.

Small bumps like this on the skin are usually a sign of a bacterial skin infection called pyoderma - this can occur on its own, or due to an underlying skin problem like allergies or skin mites (mange). You can try bathing her in a chlorhexidine dog shampoo to see if this helps. If not, or if the bumps seems to be spreading or if they become itchy or painful, it would be best to have her examined by a vet. He/she can do a simple test called a skin scrape to help diagnose the problem and get her started on appropriate medication to treat it.

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!

This is very likely to be a scrotal dermatitis. It could be cause by a contact allergy or irritation or by a infective agent (bacteria, fungal). I strongly recommend to avoid any licking, chewing or scratching of the area (Gizmo would probably need a buster collar) otherwise the inflammation wan't disappear. You could bath the area with some diluted hibiscrub once a day for 3 days but if the problem persist a check up with the vet and prescription meds might be needed. Please post again on the forum if you would like to discuss it further. I hope my answer was helpful.

It looks like Banjo has a skin infection. These are usually bacterial in nature, but sometimes it can be from a fungus or yeast. Banjo should see a veterinarian for an exam and treatment. This will likely consist of a medicated shampoo and an oral antibiotic. Thank you for using Petco Pet Education Center, formerly Petcoach.

Infectious skin diseases are certainly high on the list of possible causes here, especially fungal diseases. Cancer would not spread to everyone in this manner, so that is low on the list of possibilities. I probably would've opted for a punch biopsy however, which can offer more insight into what this is. Also a bacterial culture should be considered. Mange doesn't typically present in this manner, but with a punch biopsy you can help rule this in or out. A needle biopsy unfortuantely will only let you know if there are cancerous cells or not. I do hope that you are able to get to the bottom of this mysterious skin problem in all of your pets and also yourselves. Best of luck and take care.

This is probably caused by an allergic reaction. first of all make sure you de-flea Biscuits regularly every month with a high quality spot on (ex. Advantage) as fleas are by far the most common reason for these reactions. If the fleas are not the problem, it could be an allergic reaction to food or an environmental factor. this is more complicated to treat and will sometimes require medications such as Steroids, anti histamines or apoquel in order to stop the allergy.