Ringworm can cause circular hair loss in patches. Affected dog has sever itching and inflammation of skin. Many other conditions can also cause this hair loss in patches, so, differential diagnosis is needed that can include wood's light lamp test, microscopic examination of hair and blood tests.
Ringworm infestation is contagious because it can spread from dog to dog, dog to humans and humans to dog. Many anti fungal medicines are available in oral and topical forms that can successfully treat ringworm infection in dogs. Ideally, ringworm infection is diagnosed by the vet properly, so, it will be good to take your dog to vet for proper diagnosis and treatment.
Ringworm infestation is contagious because it can spread from dog to dog, dog to humans and humans to dog. Many anti fungal medicines are available in oral and topical forms that can successfully treat ringworm infection in dogs. Ideally, ringworm infection is diagnosed by the vet properly, so, it will be good to take your dog to vet for proper diagnosis and treatment.