Ringworm is a condition whereby a round-shaped rash appears on the body. The name ringworm is deceiving, as this condition is not caused by worms or parasites, but by the fungi Microsporum canis (70% of the cases), Microsporum gypseum (20% of the cases), and Trichophyton mentagrophytes (10% of the cases). Ringworm is treatable and curable, but is highly contagious, and can spread between humans and animals. Because of this, a right approach should be taken to battle this fungal disease.
Symptoms
In humans, the tell-tale sign of ringworm is a rash that often starts as a red, scaly patch or bump which, over time, will look more like rings with red, scaly borders. In pets, we may see hair loss that takes a (rough) circular shape or other types of lesions such as grey and scaly patches.
Other symptoms we see in pets can include:
- Itch
- Broken hairs
- Dark, scaly, and/or crusty patches of skin
- Inflammation of the skin
- Change of skin colour
- Dandruff
- Poor coat condition
- Infected nails/claws, and/or nail beds
Causes
Ringworm is highly contagious, and most animals that contract it get it by direct contact with an infected animal, or through objects that are contaminated, such as pet beds, toys, or brushes. Pets can also contract ringworm when visiting an area where an infected animal has been. The spores of the ringworm fungi are hardy and can survive in the environment for up to at least 18 months.
While animals that are in good health and condition often do not become infected even after coming in contact with the fungi, animals with weaker immune systems are more prone to contracting ringworm. Other animals that have an increased risk are very young and very old animals, pets that have had a long-term stay at kennels or shelters, or animals that already have skin conditions.
Pets can be asymptomatic carriers of ringworm and unknowingly infect other animals by spreading the spores around.
Diagnosis
There are several ways your vet can diagnose ringworm. A common way is by using a Wood’s Lamp, which emits long wave UV light. 30-80% of the fungus Microsporum canis
strains, which is the most common cause of ringworm in pets, will glow up when a Wood’s lamp is shined on it. However, no fluorescence is seen in pets that are asymptomatic carriers. An important note with this method is that active skin lesions need to be present, and the Fluorescence usually becomes visible about 5–18 days after an infection takes hold. Diagnosis by Wood’s lamp is effective in about 72% of the cases of Microsporum canis, so a negative result by the Wood’s lamp exam does not rule out infection.
Another way of diagnosing ringworm is through fungal culture, which is considered the most reliable way. For a fungal culture, a few scales, scabs, or hairs are collected and placed on a culture medium. The sample will be given time to grow. After sufficient growth has taken place, the veterinarian can determine under the microscope if any of the fungal species that can cause ringworm are present. The first signs may be present after 4 to 5 days, but the final results of a fungal culture may take up to 10 to 21 days. For a fungal culture, no active skin lesions have to be present.
Lastly, ringworm can be diagnosed by PCR test. Many professionals currently still advise not to rely on a PCR test alone, and to run a fungal culture simultaneously. This is because the PCR is an extremely sensitive test and may show positive results for pets that pick up ringworm spores on their coats but aren’t truly infected.
Treatment
Ringworm is treatable and can be cured. Often, a mixture of oral and topical medication is prescribed. Pets with ringworm should be quarantined as it is contagious, and contact with other pets should be avoided. Ideally, pets are quarantined in a place that is easy to clean and disinfect, such as a bathroom. As ringworm is also contagious to humans, take sufficient hygienic measurements when interacting with your pet.
Pets infected with ringworm will be constantly spreading fungal spores into their environment, so regular and thorough cleaning of surroundings and items is advised. Proper cleaning includes first cleaning the dirty surface with a cleaning agent, followed by disinfection with a disinfection agent. Follow dilution advice to ensure the disinfectant can properly do its work. An example of a disinfectant agent is F10, which, when diluted to a 1:125 ratio, will kill any ringworm spores after 30 minutes of contact time.
Treatment should not be stopped until follow-up testing shows that your pet is free of ringworm.
Prevention
Pets with a good immune system are less likely to contract ringworm, so keeping your pet in good condition will help prevent them contracting the fungal infection. If your pet has a skin condition or a low immunity, take extra care to avoid places that have an increased risk of contracting ringworm. If you take in stray dogs or cats, keep them isolated from your own pets until they are fully medically evaluated.
Conclusion
Ringworm is treatable and curable, but due to its highly contagious nature, treatment involves medication, cleaning and disinfection, and quarantine. By following the right steps, you can speed up the healing process and prevent spreading the fungal infection.
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