One of the most common skin infections cats are suffering from is ringworm. While the name suggests that worms cause the infection, the fact is that no such organisms are involved. Ringworms are caused by parasitic, fungal organisms, which feed on the dead outer skin, hairs and claws. These organisms are collectively referred to as dermatophytes, which is the scientific word for plants that live on the skin.
How Cats Become Infected
The fungi that cause ringworm can be found in the environment but in most cases, they thrive in the skin of other animals. If your cat comes in contact with another one infected with the ringworm, there are high chances that it will be infected. Alternatively, it may contract this fungal infection from its immediate environment such as contaminated bedding, furniture, carpet or grooming equipment.
Usually, the fungi produce numberless spores, which attach to hairs and then shed to the environment where they can remain dormant but infective for months just waiting for the opportunity to attack and start their cycle. These organisms thrive in areas with poor hygiene.
Signs and Symptom of Ringworm in Cats
Cat ringworm normally does not cause very prominent signs and symptoms. However, with very close inspection, it is possible to notice some telltale lesions on the head, forelimbs, tail and the ears. The classic ringworm lesions are circular patches or rough, scaly skin with a characteristic red outline and broken hairs.
However, do not wait to see these lesions because up to 20 percent of infected cats are asymptomatic carriers. This means they can spread the infection to other pets they encounter as well as humans. In such cats, the only evidence of skin infection is poor hair quality that easy fall off during grooming. You may also notice some hair falling off when the cat scratches itself.
Diagnosis of Cat Ringworm
As already been discussed, ringworm in cats can be asymptomatic. It requires high index of suspicion to recommend the cat for screening and testing from ringworm. It is therefore a good practice to have your cat checked regularly by a veterinary doctor. The following are the common tests carried out to diagnose cat ringworm.
- Wood’s Lamp: This is perhaps the most widely used method of diagnosis because of its simplicity. It involves the used of ultraviolet Wood’s lamp or black light. When the light is focused in the skin, the affected hair shafts will glow fluorescent green. The sensitivity of this test is only 50 percent.
- Biopsy: In cases where the characteristic lesions are atypical, then a portion of the tissue from the lesion can be taken and then processed for microscopic identification.
- Microscopy: This rapid diagnostic test involves microscopic examination of the hair shafts obtained from the cat for the presence of the fungal spores.
- Fungal culture: In this method, samples will be taken from by your veterinarian from you cat and then grown in a fungal culture. After multiplication then the growth characteristics can be used to identify the responsible organism.
Treatment of Cat Ringworm
Ringworm in cats is treatable. There are many types of treatment but the specific method that will be used by the veterinarian depends on the severity of the infection. The treatment must also include the surrounding environment where the cat spends its time to prevent re-infection and recurrence. The veterinarian may prescribe medicated ointments and shampoos.
Alternatively, an oral antifungal drug may be prescribed. Currently, the only approved drug for cat ringworm is griseofulvin (Fulvicin). However, other drugs that can be used include Ketoconazole (Nizoral), Itraconazole, Terbinafine (Lamisil). You need to talk to your veterinarian before using these drugs on your cat. A ringworm vaccine has also been developed by Fort Dodge. It is called Fel-O-Vax and it is not yet widely available.
In my older post, I wrote an article about ringworm treatment in dogs.