Is my bearded dragon's rotting chin an open wound or scale rot?

Your suspicions are likely correct for Red - the mass could be related to stomatitis, or mouth rot. This disease often has a husbandry related component, so I would recommend taking a close look at Red's enclosure and its components to ensure that all parameters are perfect. Often temperatures and/or lighting are the culprit - please ensure your UVB bulb has been changed within the last 4-6 months and that it is appropriate for bearded dragons (i.e. it is for desert species). Please also ensure that it is appropriate for the height of Red's enclosure - if it is too close or too far away, Red may experience problems related to it. Temperatures should be measured using digital thermometers located at Red's level, and not elevated in the enclosure. You can find parameters online using a bearded dragon care sheet, such as one found on Reptiles Magazine. Please ensure that Red continues to have an appetite, and that his diet is appropriate. The majority should be made up of a salad of dark leafy greens, with protein supplemented two to three times per week and fruit once per week. Diet can also be involved in cases of stomatitis. It would also be advisable to weigh him every other day to ensure he is not losing weight. This can be done using a digital gram scale (found in the kitchen section of most department stores). If you appreciate a decrease in appetite or weight, I would recommend having Red visit a veterinarian as soon as possible. Until your veterinary visit, I would evaluate the husbandry as outlined above, and make adjustments as needed, and monitor him as outlined above. Your veterinarian will closely evaluate Red and his mouth, and may take a sample of the mass to confirm that it is an infection and not another process. They will also ensure that the jaw is stable, and they may recommend radiographs (x-rays). Treatments may include antibiotics and pain medications, depending on the findings. Please do not give Red any human medications, as they can be harmful for our scaled friends. I hope this gives you a place to start, and good luck!

From the pictures it appears to be an infection. This infection could be bacterial or fungal. It is possible she had trauma to hip lip that started it. I would recommend taking her to a veterinarian because she will need medications to clear it up.

Basically it could be an infection or a trauma, it sounds like she was in a great deal of pain, i would recommend taking her to a reptile vet as she might need an antibiotic course and some pain medications.

It is highly suspicious for an abscess or mouth rot. Ideally, she should be examined by your veterinarian or an experienced herp veterinarian for confirmation. Treatment may include draining or debridement. Antibiotics will almost certainly be required. In the meantime, increase tank temps by 5-10 degrees F to aid in healing. Make sure she continues to eat and soak her in a warm 50/50 solution of water and unflavored PediaLyte to treat or prevent mild dehydration until she sees the doctor.

Look for redness, swelling, decreased appetite or excess salivation. The "crust" may be food crumbs, shed skin or substrate. A physical exam with your veterinarian or an experienced herp vet would be needed to definitively diagnose rot. In the meantime, make sure the enclosure is clean as poor husbandry can predispose a beardie to infection. High humidity can also promote bacterial or fungal overgrowth.

Have Anubis examined by an experienced herp veterinarian to confirm the diagnosis. Mouth rot, or infectious stomatitis, typically requires antibiotics. Minor cases can be managed with topical cleaning, usually with diluted Betadine or chlorhexidine solutions, after the area is debrided (cleaned). Serious cases definitely require veterinary attention, antibiotics and supportive care. Increase enclosure temperatures to the upper limit of the normal range for beardies during treatment. A slurry of baby food, vitamins and minerals can be fed. This is easier for the beardie to eat and digest. Fluids can be administered via misting, soaking or subcutaneously​ administered by your vet. Clean and sanitize the enclosure, change bedding frequently and monitor humidity levels. If the infection does not resolve, a sample of tissue should be submitted for pathology, culture and sensitivity.

Although a picture of it would help to determine the underlying cause more specific advices, these signs are quite concerning. A skin rot in his case is on top of differential list and I would recommend immediate check up as antibiotic may be needed. Hope this answer was helpful, but please do not hesitate to contact us again on the forum or by requesting a consultation if you have any more questions or to discuss it any further.