RingWormInDogs.Net

Ringworm in dogs was once thought to be caused by a worm which created a circular patten that appeared as a lesion on a dog's skin. However, we now know that the condition known as "Ringworm" is actually caused by a fungal infection that affects the skin. The fungus thrives in hair follicles, and causes the hair to fall out in the affected area, sometimes in a circular pattern.

How is Ringworm transmitted?

The Ringworm fungal infection is very easily transmitted through exposure. If a dog comes in contact with infected hair, skin follicles, bedding, or grooming equipment, this will sometimes be enough for infection to occur.
This infection is also transmitted through contact with soil or plant matter that contains fungal organisms. However, the actual rate of infection depends on a dog's age, immune system status, and skin condition. Exposure to Ringworm-causing fungus does not necessarily mean that a dog has a 100% rate of infection.

The Three types of Fungus that cause Ringworm:

1. Microsporum canis

The fungus known as Microsporum canis is a dermatophyte that is commonly known to cause Ringworm (dermatophytosis) in dogs. This fungus thrives in a humid, warm climate, and is common in areas of the world which have these conditions. Though it most commonly affects animals, this fungus also has the ability to cause Ringworm in humans. In a culture medium, this fungus begins to produce colonies in approximately four days. Typically, the top area of this fungus appears to be cotton-like and white in color. The bottom part of the fungus colony (in a culture) usually appears to be orange or yellow, appearing yellow primarily around the edge of the colony. This fungus is able to use the keratin from skin, hair and nails as energy. The fungus secretes a substance called "keratinolytic protease", which breaks down the keratin so that is easily metabolized.

2. Microsporum gypseum

This type of fungus usually grows very rapidly, and will mature in anywhere from 6 to 10 days. This fungus has world-wide distribution, and thrives in humid climates. Under veterinary ultra-violet light techniques, this fungus will not fluoresce. When grown in a culture medium, Microsporum gypseum usually appears to be granular in texture. The outer color of this fungus colony usually appears to be cream to beige in color. The surface may be cinnamon colored, and a white downy layer may develop on top.

3. Trichophyton mentagrophytes

The fungus species called Trichophyton mentagrophyte is also part of the dermatophyte group of fungi. On a scientific level, there are five different variations of this fungus. The characteristics of this fungus are variable, usually appearing powdery or granual in texture when exposed to a culture medium. This fungus is able to assimilate substances such as potassium, calcium, sodium and phosphorous, though its growth can be inhibited by folic acid. As with other types of fungi, Trichophyton mentagrophytes thrive in warm, humid climates.