What causes a dog's paws to suddenly swell or grow rapidly?

Thank you for using Petco Pet Education Center, formerly Petcoach! It is definitely concerning that the lump has increased in size so quickly, as older dogs are typically more likely to develop cancers. The lump can also be an infection or cyst. I recommend having this seen by a vet as soon as possible - they can take a small sample from the growth to determine exactly what it is and recommend the appropriate treatment. I hope all is well!

She may have seasonal allergies or could be getting some foreign material caught between her toes when she goes out in nicer weather. Place an e-collar (cone) on her to prevent further licking or chewing. Have her examined by your veterinarian to diagnose the underlying cause. Antibiotics can help with infection, antihistamines may decrease allergies and pain medication may provide additional relief. Continue the foot soaks if they help.

Ouch! With any new growth like this, it's best to have your vet take a look in person, as it isn't really possible to determine what is causing the growth just from a photo. Your vet can take a sample of the growth as needed with a fine-needle aspirate, or biopsy, to check what cell type is present and if the spot needs further attention. Other causes can be calluses from rubbing, scabbing from a wound or infection under the skin, or other issues. Until you can get to the vet, it's best to keep the area clean and dry and prevent Ginger from licking or chewing at it with an Elizabethan (cone) collar or sock over the spot. Monitoring it for any additional changes such as size, oozing debris, pain, etc, is also a good idea as these observations can help your vet narrow down the cause and best treatment plan.

This could be from an injury or this could be edema due to a systemic disease or infection. It is hard to say. I would recommend having a veterinarian examine him so that the most appropriate diagnostic and treatment recommendations can be made. I would recommend having x-rays taken of the foot and leg. I would also recommend blood testing to see if there are any changes that might suggest why the foot is swollen. I hope this helps guide you in the right direction. Please let me know if you have any other questions or concerns and I would be more than happy to help you further.

The bump you are seeing could be a mass, or it could be a skin lesion caused by bacterial, parasitic or fungal infection, dietary or environmental allergies or sensitivities, or could be a combination of the above. I recommend making an appointment to have your dog seen by your veterinarian to help determine the cause of the bump 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 what is causing the bump and to provide treatment. . In the meantime, if he is licking the area, I recommend putting an e-collar/cone on him to help prevent licking and reduce the risk of infection.

This could be an allergic reaction, an insect bite or an internal disease causing edema of the limbs, if this doesn't resolve in the next 48 hours i strongly advise taking Weiner to the vet in order to get it checked and treated.

That could be due to a trauma on the paw (causing a muscle or bone injury) or severe osteoarthrosis which now is developing a proper inflammatory reaction. I would strongly suggest to have Mopsu checked by your veterinarian and have appropriate treatment given (based most likely on anti-inflammatory medications).