Fungal dermatoses in pet dogs, also known as ringworm disease, commonly known as ringworm, refers to the dermatophyte parasitics in the dog's coat, epidermis, toe and claw keratin tissue and multiply in large numbers, can cause a series of organic lesions in the local skin, is one of the common infectious skin diseases in pet dogs.
Causes of Ringworm In Dogs
Ringworm disease is caused by skin opportunistic pathogenic fungi, also known as dermatophytes, which can cause damage to the epidermis, hair and PAWS. There are three main pathogenic dermatophytes in dogs.1. Microsporum Canis exists in dogs for a long time, produces only mild inflammation, and about 50% of dog ringworm disease is caused by this bacterium.
2. Microsporum gypsum is a soil-philic fungus that occasionally causes tinea in dogs in warm climates, but this inflammatory reaction and infection are self-limited.
3. Microsporum whisker mainly causes secondary ringworm disease in dogs, and mice are the main carriers.
Dermatomycosis is mainly caused by hyphae invading the hair column, hair follicle and cuticle, causing hair loss and dander production. It mainly occurs on the head, feet and legs, and small dogs are more likely to develop dermatomycosis than adult dogs.
Symptoms of Ringworm In Dogs
The symptoms of ringworm disease first appear in the orbit, the root of the ear and the edge of the auricle, and then occur in the claws of the limbs and the skin of the neck. In severe cases, the lesions also appear in the side of the body, chest and abdomen. The infection is initially itchy and the affected animal is constantly scratching, resulting in skin flushing, skin lesions, hair removal and the appearance of numerous scales, occasionally keratosis, and hair becoming sparse. Severe cases also have crust or secondary bacterial infection. The affected dogs usually have a large area of infection, a long course of disease, and are not easily cured and prone to relapse. Dogs infected with Trichophyton Canis present with a typical noninflammatory reaction with exfoliation, patchy areas of depilation, and occasional pachyphyton. Trichophyton pedibalis, which usually spreads, with scaly shedding in areas of noninflammatory lesions, and suppuration in secondary infections. The clinical symptoms of microspore gypseum are similar to those of Trichophyton whisker.Diagnostic criteria for Ringworm In Dogs
1. The hair or skin was scraped and observed under Wood's lamp. The hair of the dog infected with Microsporum Canis showed green fluorescence.2. Potassium hydroxide hot solution was digested and scraped, and placed under a microscope to observe whether there were fungal seeds.
3. The pathogen was inoculated in Schabao's medium and cultured at room temperature for 1 to 2 weeks. The colony of Microsporum Canis showed yellow basal surface and fine curly hair. Microsporum parvum had brown base and the ground was covered with small granular colonies. The gypsum microspore colonies were yellow leather-like. Black or blue colonies were contaminated fungi. When phenol red was added to Sandburg's medium, the colonies that could turn the medium red could be initially diagnosed as dermatophyte.
