Treating Ringworm in Dogs with Griseofulvin

Ringworm in dogs is caused by a fungus. There are specific symptoms of ringworm and treatment is readily available for this condition.

Ringworm Explained

There are many types of fungus that can cause ringworm, which are mostly found in climates that are hot and humid. The spores from the fungus can live up to a year and a half.

A dog can acquire ringworm by coming in contact with another animal that has it, or by touching an item that has the fungus on it (like hair brushes or kennels). A dog with a strong immune system can usually fight off a ringworm infection, but younger dogs are more susceptible.

Ringworm Symptoms and Diagnosis

A classic sign of ringworm on a dog is a round wound that does not have any hair on it. The skin on the wound will feel itchy often look inflamed, scaly or flaky. Often the wound starts out small and grows in size. Ringworm is most often seen on a dog's head, but can also be seen on the tail, paws or legs.

Your veterinarian will look for the fungus with a black light, as many of the species that cause ringworm will glow. However, not all of the species will show up with a black light. Other methods of diagnosis include examining a dog's hair under a microscope or doing a culture with some of the dry skin that easily comes off.

Treating Ringworm in Dogs with Griseofulvin

Griseofulvin is an anti-fungal medicine used on dogs to treat fungal infections like ringworm. It works by incorporating itself into a dog's hair shaft, thus preventing the cell walls of the mold spores from splitting into new cells, which would cause more spores to appear.

Griseofulvin is available by prescription from a veterinarian. It comes in the form of a pill, and dosage is dependent upon the weight of a dog. The typical dose is 25 mg per pound, administered every 24 hours. Griseofulvin should not be given to a dog that has an empty stomach, because it is absorbed by the body better after the dog has eaten.

A dog may need to take Griseofulvin for several weeks. It is imperative that a dog complete the full amount of medication prescribed, even if it seems like the infection has cleared or the dog is feeling better.

Side Effects of Griseofulvin

Many side effects are associated with Griseofulvin, which include:

  • Hives
  • Rashes and itching
  • Diarrhea
  • Nausea
  • Difficulty sleeping
  • Decreased appetite
  • Yeast invection of the mouth
  • Vomiting

A dog that is pregnant or nursing should not take Griseofulvin.