Hello, this is Dr. Linda. I hope I can help with your question today.
I am sorry for your concerns about Flo & her non-healing wound. At this time of year, wounds on the underbelly are actually quite common. Caused by many different things, most often these sores & wounds are due to allergies, or infestation with a parasite called a Hebranema fly ( also known as Summer Sores).
If you think this might be the case, I would deworm Flo with a full dose of Ivermectin orally & redose in 2 weeks.
Definitely use fly protection on the area & try another antimicrobial on the wound instead of the Vetrycin. I like EquiSilver wound spray which is available online from various sources. Manuka Honey has also become very popular for wound healing, too.
Another cause for a non-healing wound might be a condition called Pythiosis, or it might even be a sarcoid, both of which need veterinary attention. So, if the Ivermectin treatments, fly preventative, & EquiSilver does not begin to heal the wound within 2-4 weeks, or it appears to be getting worse, please have your veterinarian out to take a look.
I hope this makes sense & has addressed your concerns. Please let me know if you have any further concerns.