Hi Miami Puppy Love,
Sorry to hear your little girl is struggling with a hot spot and a red lump on her back left foot.
The first issue you mention is the hot spot near the knee. "Hot Spots" are also referred to as moist dermatitis or pyotraumatic dermatitis. This is a sudden onset of a superficial skin infection caused by bacteria. This occurs when a pet self inflicts trauma to the skin via licking, rubbing, scratching or biting. They do this in response to an itchy or painful area.
I often tell my clients that they occur because there is moisture trapped at the level of the skin and the hair follicles. When a pet scratches or chews at that area, the skin is broken and the bacteria that naturally reside on the skin now have a moist, dark area to replicate and the hot spot develops.
The first thing to do is determine the underlying cause of why the pet scratched and manage that to prevent recurrence. For example, one common cause is fleas. Another common cause is allergies. The allergies may be due to fleas, food, pollen or dust. However, sometimes an underlying cause is not found and you treat when they occur. We see them often during the hot and humid weather and especially in swimming dogs.
The second issue you mention and the picture submitted appears to be an interdigital cyst. These can occur in any breed of dog. The causes of these interdigital cysts include foreign bodies, infection, osteomyelitis (bone infection), cancer, parasites such as demodex, immune mediated diseases, trauma, hypersensitivity, metabolic (i.e. hypothyroidism), contact irritant, and unknown.
The best treatment is directed at the underlying cause of the cyst. Oftentimes antibiotics are prescribed when a bacterial infection is suspected to be present. Soaking the foot in an Epsom salt mixture can be helpful.
If you see the lesions worsening or not showing any improvement, I would recommend having her looked at so the appropriate tests and treatment can be implemented to help resolve these two issues. Good luck.
Thanks so much for the reply. It got better but then got worse. Here are the pics from now :(
Im going to take her in. Any general tests I should ask for (they are known for "upselling" and I'm always clueless.) She is going to FREAK when they get near the spots. She wouldn't even let us soak it.
I cant believe she isnt limping. It looks so painful!