- An occasional cause of skin conditions in pets is caused by Ringworm. The scientific name for this disease is Dermatophytosis. It is caused by a fungus not a worm, and the lesion is not always in the shape of a ring.
- There are 3 specific fungi of significance in this disease.
- Microsporum canis --The source of this species of Ringworm is almost always a cat, especially long-haired cats.
- Microsporum gypseum - This species of Ringworm is usually from dogs and cats that dig into contaminated soil.
- Trichophyton mentagrophytes - This species infects dogs and cats when they are exposed to rodents or the burrows they live in.
-In cats, almost all cases of Ringworm are caused by Microsporum canis. In dogs the majority of cases are caused by Microsporum canis.
Symptoms-The skin lesions that appear with Ringworm are variable, and do not necessarily form a ring. There will be hair loss, usually in small patches at first. As time goes on the patches may disappear or appear at other locations on the skin. There might be scratching due to itchiness. If the hair loss occurs on the face or feet there is a chance it is due to digging habits or exposure to rodents. You cannot diagnos simply from the loss of hair because it mange and allergic reactions can look exactly the same. It is difficult to see such hair loss in a feral unless you are closer to it, feeding times are an excellent time to take a good look at your colonies hair condition.
- You may also see: broken and brittle hair
partial or patchy hair loss
scales or crusts primarily on the head and feet but lesions can appear anywhere, or everywhere (generalized dermatophytosis)
multiple scales, swollen or ruptured follicles on the chin and back that resemble lesions caused by flea and other allergies.
areas of self-mutilation in where inflammation or itching are prevalent
Atypical: Rarely, infection extends to the deeper (subcutaneous) tissues and a painful, inflammatory lesion follows
Dermatophyte Culture:: This is the most reliable method for the definitive diagnosis for the presence of ringworm organisms. Results typically take seven to ten days. : This is the most reliable method for the definitive diagnosis for the presence of ringworm organisms. Results typically take seven to ten days.
U-V Fluorescence: A few species will cause a distinct green fluorescence in infected hair shafts when these are illuminated by an ultraviolet light source. Most infections are due to non-fluorescing species and false positives (fluorescence) are also possible. (Woods Lamp)
Microscopic Examination: The presence of infective spores on hair shafts may occasionally be visualized microscopically. The possibility of false negative results is, however, great.
Treatment: There are a number of drugs topical and systemic which are useful for treating clinical ringworm infection in individual animals (usually cats). Aside from topical and systemic antifungal class of drugs, such as itraconazole, there is more recent information which suggests that lufenuron (Program®®) is inconsistently efficacious, but it is very safe! The vaccine can alleviate the clinical signs BUT does not eliminate infection!