Ringworm is a contagious fungal infection of the skin. The name is actually a misnomer as the skin infection is not caused by worms at all but instead refers to the circular lesions that often develop. There are some signs that can alert you to a possible ringworm infection on your dog and the need to seek treatment from a professional.
Instructions
Examine your dog for signs of ringworm when you know that he has been exposed to another carrier. Dogs can catch this fungal infection from other animals or from humans who have an infection and are contagious. Exposure is typically 10 to 12 days before lesions appear.
Watch for small reddish pimples or bumps that spread into a circle or oval on your dog's skin. This raised circle is what gives ringworm its name. Not all dogs will develop a circular patch, however. The skin in the area will be flaky or scaly.
Observe any signs of sudden hair loss, especially when the hair loss is in a circular area. There are other causes of hair loss and they should also be considered, but the circular pattern is a good hint to think about ringworm as a possible cause. If the fungus has spread, hair loss can take irregular shapes as it spreads over the body.
Use an ultraviolet Wood's lamp or black light on your dog. Around 50 percent of ringworm strains will glow a florescent green. Other strains can still be present so this is not a foolproof test for ringworm.
Visit your vet to have a ringworm culture or other tests done. Ringworm can be difficult to diagnose by sight, so your vet may microscopically inspect your dog's hair or perform a scraping and culture of the area. Cultures can take several weeks before a positive or negative result is known so your vet may initiate treatment before a positive finding.
Treat all dogs and other animals within the household. If one animal is infected, others may have the infection but not be showing observable signs. Treating all animals with antifungal shampoos may head it off at the pass.