- Call your vet to book an appointment.
- There are a few things you can do at home while you wait for your appointment.
– Isolate your affected bearded dragon, yellow fungus (CANV) is a highly contagious disease.
– Chlorhexidine soap diluted to 4% may be useful to begin treating the infection topically. Chlorhexidine soap can be purchased at chemists or pharmacies.
– Minimize environmental stress. No unnecessary handling, movement near the cage or any other activity that could lead to stress.
– Keep the enclosure to an ideal standard. Cleanliness (see post on cleaning) is extremely important.
- During your vet visit, a full history will be taken and your vet will conduct a thorough physical exam.
Unfortunately, yellow fungus disease cannot be diagnosed by physical exam alone, as the lesions often look similar to other common problems (trauma, bacterial skin infections, and burns).
For a definitive diagnosis, a skin biopsy is needed. The animal is sedated while the veterinarian performs a full thickness skin biopsy.
Ideally, this sample is sent to a lab for a fungal culture (to grow out the causative agent), histopathology (examination of the sample under the microscope), and PCR or polymerase chain reaction (a highly specific DNA sequencing test).
Although recommended, extensive testing is not always possible, and a presumptive diagnosis may be made on a case by case basis.
- Early lesions do not always look significant, and bearded dragons are often brought in late in the course of the disease. Because of this, further testing may be required to assess the overall health status of the animal.
These tests may include bloodwork, or x-rays. Some cases of CANV affect animals because their immune system is impaired, placing more weight on systemic diagnostic testing.
- As we have already covered, the infection is likely more than just skin deep. Because of this, topical medication alone is not enough. Treatment involves the use of a systemic (oral or injectable) antifungal drug.
Three drugs have been studied including:
– itraconazole, and
Systemic antifungals are not without their downsides – they can be harmful to the liver of bearded dragons and tend to be fairly costly. Of these three drugs, studies have shown that voriconazole may be the safest.
- Combining a systemic antifungal with topical adjunctive treatment may be beneficial and are often necessary after a biopsy is performed. Topical treatments alone are not adequate for treatment of yellow fungus disease.
Systemic antifungal medication should be seen as the primary treatment. Some examples of commonly used topical agents include terbinafine, chlorhexidine, and silver sulfadiazine.
- Debridement of the affected area can be beneficial as well. This means removing the damaged, or necrotic tissue.
Necrotic tissue is non-viable – It has lost its’ blood supply, and therefore, systemic drugs have no way to penetrate this tissue. The fungus will reside within and feed on this dead tissue. Although debridement may be done at home, I strongly advise seeking the help of a veterinarian to demonstrate how to safely approach this procedure.
- Treatment is required for several weeks.
- The fungal infection may reach “remission” but is unlikely ever to be fully cleared. Treatment may provide comfort and quality of life to affected animals.