| Ringworm is a skin disease common to dogs as well as cats. The name ringworm is misleading; it has nothing to do with worms. Ringworm is a fungus condition. Ringworm appears as very dry, scaly, gray patches in your animal's coat. It is highly contagious and can be spread to humans, where it appears as red, scaly circular lesions on the skin, slightly raised and may be "worm like" in appearance. The medical term for ringworm is dermatophytosis. How did my pet get ringworm? The fungi that cause the infection of ringworm are found in our general environment. The fungi are hardy and can live for years in soil, on carrier animals and off the dead skin. Not all animals or humans will react to the infection, making it much more difficult to control the spread of ringworm. Additionally, there are several species of fungi which affect different animals. It is not uncommon in multi pet homes for one dog to have a ringworm infection and the other dog to never become infected. What are the signs and symptoms of ringworm? The ringworm fungi live in hair follicles. As the organism invades and weakens the hair shaft, causing the hair to break off at the skin. Eventually, the entire hair follicle is destroyed, leading to the gray, scaly patches on the animal's skin. The hair will be brittle and lack luster in areas of the coat near a ringworm lesion. You may notice your dog scratching more in those areas, but not always. Some animals seem to not be bothered by the skin infection. How is ringworm diagnosed? Canine ringworm can be diagnosed by three different methods. In some cases more than one approach is utilized. Diagnosis is done by one or more of the following: - Identifying the typical ringworm lesions on the skin. This is the least accurate method since other skin diseases may have the same appearance and not all infected dogs have visible lesions.
- Placing the infected hairs under a fluorescent light. We recommend using a Woods Lamp Blacklight for this approach. The lamp should be warmed up for 5 minutes and the test should be conducted in darkness holding the lamp over the potentially affected area for 3-5 minutes. This screening test is useful because ringworm will sometimes fluoresce as a bright green color under ultraviolet light. Failure to fluoresce however does not eliminate ringworm as a potential diagnosis. The accuracy of this tool is about 50% since only 2 of the 4 fungus species fluoresce.
- Culturing the hair for the fungus. After a few hairs are plucked from a lesion it is placed on a special gel and is then watched for fungal growth. Also the color of the gel will change from yellow to red as the fungus grows. These cultures are checked daily. This method is the most accurate way to diagnose feline ringworm however it can take 2-3 weeks to get results.
How is ringworm transmitted? Transmission occurs by direct contact between infect and non-infected individuals. It can be passed from dogs to cats and vice versa. It may also be transmitted from animals to people well as from people to animals. Adult humans are fairly resistant to infection unless there is a break in the skin or the immune system is suppressed. Children however are highly susceptible. Transmission may also occur from an infected environment. The fungal spores can live in bedding or carpet for several months. These spores may be killed with a dilution of chlorine bleach and water (1 cup of bleach to 1 gallon water) where it is feasible to use it. How is ringworm treated? There are several methods to treating ringworm in dogs. The specific method recommended by your veterinarian will depend on the severity of the infection the number of pets involved possible presence of children in the area and how difficult disinfecting the dog’s environment will be. The most commonly used treatment options include the following: - Griseofulvin. This prescription comes in tablet form and works deep in the hair follicles to reach the site of active fungal growth. Administered daily dogs with active lesions should receive the tablets for a minimum of 30 days. Griseofulvin is the only drug approved for the oral treatment of feline ringworm. Although effective it does have some potentially significant side effects including gastrointestinal issues possible birth defects in pregnant dogs and suppression of bone marrow production.
- Miconazole Cream or Miconazole Spray are both effective topical treatments. Miconazole products contains the anti-fungal agent Miconazole Nitrate for the treatment of fungal infections such as ringworm and superficial skin infections caused by yeast. It is safe for use on dogs cats and horses. Miconazole is only available with a prescription.
- Malaseb Shampoo is also available only with a prescription. Malaseb’s unique formulation provides antibacterial and antifungal agents for optimal therapeutic effectiveness.
- LimePlus Lime Sulfur Dip is another prescription product. Dips should be done twice weekly for the first two weeks and then once weekly for the next 4-6 weeks. Lime Sulfur Dip can also be applied to other pets in the household to prevent spread of infection.
- Shaving of the dog’s hair. Primarily only recommended when the infection is extensive some studies have suggested that clipping may cause microscopic nicks in the skin and serve to further inoculate ringworm into the skin.
Treatment will not produce immediate results; in fact the areas of hair loss may get larger before they begin to get smaller. Within 1-2 weeks the hair loss should stop and there should be no new areas of infestation. However infected pets may remain contagious for about 3 weeks. | 
