This cat is sufferring with Dermatophytosis or "Ringworm". Hairs are infected with a fungus which results in them falling out and an inflammatory reaction develops.
This particular cat was infected with Microsporum canis. Fifty percent of strains of this dermatophyte will produce fluorescence in infected hairs when view under a special UV light called a Wood's Lamp.
Lesions can occur in other parts of the body.
Photomicrograph of hair shaft infected with microsporum canis.
Fungal Culture of hairs taken from lesion on dermatophyte test medium (DTM) showing colour change to red and beginnings of white fluffy growth.
Same culture after 2 weeks.
Examination of material tyaken from culture under microscope confirms shows the characteristic multi-celled macroconidia of microsporum canis.
Same cat after 4 weeks antifungal therapy.The skin is the largest and most visible organ in the body and and provides many different functions, ranging from being a both a mechanical and physiological barrier between the animal and its environment to being a sense organ perceiving heat, cold, pain , pressure and itch.
In addition, the skin is synergistic with internal organ systems and so can reflect pathological processes that are either primary elsewhere or shared with other tissues.
Unlike ourselves, the majority of our pets skin is usually covered with a haircoat.- this not only means that changes in the haircoat can be one of the more obvious signs when things start going wrong with the skin, but it can also prevent us from seeing when things are wrong and it is often necessary to close-clip the coat to get a “window”into the skin and see what is happening.
When things start going wrong with the skin, there are only a few different ways that it can show, so many different skin conditions often end up looking very similar, with changes in the haircoat, pigmentation and lesions such as papules, pustules, crusts, erosions and scaling being common to a lot of different skin disorders. This is what makes veterinary dermatology both interesting and a challenge for me. The history of the skin condition and its appearance help a trained dermatologist formulate a list of “differential diagnoses” which can then be used to formulate a list of diagnostic tests to use to make a definitive diagnosis. This is why it is often the case that an animal may have to be seen on more than one occasion before the eventual diagnosis is made. The big difference about consulting a veterinary dermatologist is that his or her training and knowledge means that the steps between the first consultation and the eventual diagnosis will be shorter and most importantly, the treatment options will be based on the most current knowledge available.
