Otherwise known by the medical term dermatophytosis, ringworm’s common name is quite deceptive as it is not a worm at all. It may be tempting to lump it in with the parasites that afflict dogs, such as whipworms, roundworms, tapeworms, and hookworms. However, ringworm is a fungus. It is a common fungal infection known worldwide to infect nearly all domestic animal species. These species, of course, include dogs; most of the cases of ringworm are even caused by a fungus known as Microsporum canis. Ringworm is extremely infectious, but how do dogs get it? It is valuable for dog owners to be aware of the causes, symptoms, and options for the treatment of ringworm in dogs.
What Is Ringworm?
This infection gets its name from the appearance it usually raises in human cases: a raised, round, red ring. The fungi that cause ringworm are known scientifically as dermatophytes; this category contains a pathogenic, or disease-causing, collection of fungi. As mentioned, 70% of cases of ringworm in dogs have Microsporum canis as their cause. The fungus Microsporum gypseum causes a further 20% of canine cases, and the remaining 10% are caused by the fungus Trichophyton mentagrophytes.
What Does Ringworm in Dogs Do?
The fungus lives and grows within the dog’s outermost layer of skin as well as within the hair follicles and nails of infected dogs. There, it feeds on those dead cells that are present. While doing so, it usually creates a series of rashes that are ring-like in shape; these are among the most common symptoms of ringworm. It is a superficial infection. Ringworm generally only affects a few spots on your dog’s body. The infection is sometimes more severe in puppies, senior canines, and dogs who are immunocompromised.
Ringworm’s Appearance in Dogs
The ring-shaped rashes that appear in dogs infected with ringworm center in small areas of infected skin; these look scaly and are red, inflamed, and itchy. Most dogs suffering from ringworm exhibit is broken hairs around the rash’s site. This is due to the fungi infecting hair follicles and causing the impacted hair shafts to snap off at the level of the skin line. When your dog’s claws are infected, they tend to grow prone to breakage as they become exceptionally brittle.
Asymptomatic Dogs with Ringworm
Not all dogs display the typical symptoms of ringworm infection, even when the fungi are present in their skin or hair. These dogs are still capable of spreading ringworm to people and other animals despite their lack of obvious skin lesions and areas of hair loss. They are known as asymptomatic carriers. Such dogs are particularly problematic in environments that contain many animals. Kennels and animal shelters fall prey to an unexpected wave of infections in these circumstances.
How Do Dogs Develop Ringworm Problems?
Commonly, ringworm develops due to a response from contact with the types of fungi or their released spores. What this amounts to in practice is that transmission occurs when your dog’s body has contact with an infected dog. Indirect contact may also be the culprit; for example, the fungal spores may infect a dog that shares the bed of an already infected dog. Those broken hairs appearing at the sites of the rashes are also an important vector through which these fungi spread. The hairs are light, easily swept up and carried aloft on a slight breeze, and can travel extremely far from the infected dog they fell from. Hence, you can prevent ringworm infections by keeping a clean environment for your dog.
Causes of Ringworm Transmission to Dogs
Since the fungus for ringworm dwells in soil, digging dogs encounter it on a regular basis. Not all animals contract the fungus from this simple contact, however. Your dog’s age, immune system status, and habits of grooming all impact the transmission rate. The fungus spread via contact with an infected animal as well as by touching the animal’s equipment can bring dogs ringworm. This can include clippers, brushes, toys, bedding, harnesses, and saddles. Rugs and home furnishings can also play host to infection, that’s why cleanliness it’s important to prevent ringworm. Fungal spores of ringworm are capable of remaining viable for as long as 18 months.
Symptoms of Ringworm Infection in Dogs
While ringworm is far from life-threatening as other canine diseases, it is extremely contagious. The fungus, when it has infected your dog, requires a veterinarian’s intervention. Awareness of the symptoms of ringworm as it presents in dogs can assist you in catching the disease before it spreads. Dogs usually display ringworm infections as circular patches of hair loss across the body. Such lesions may heal in the middle as they grow, creating patchy appearances that may grow scabbed or inflamed. Check with your veterinarian if your dog has circular spots of hair loss, hair that is dry and brittle, skin that is inflamed and scabby, and claws that are brittle and rough.
In What Timeframe Do Lesions Appear?
A span of between seven and 14 days usually separates the exposure to a ringworm fungus and the actual development of lesions on the skin. Some cases may take as long as three weeks to develop signs of the fungal infection. Alertness for these lesions will help you and your dog stay on top of a potential outbreak in your household so that you can get the infestation under control quickly and effectively.
How Does the Veterinarian Diagnose Ringworm in Dogs?
Because there are many causes for skin problems and hair loss in canines, the veterinarian will perform one or more of the following tests. First, identification of the classic ringworm lesions on your dog’s skin. Unfortunately, this simplest means of diagnosis is not terribly accurate, risking misdiagnosis. Generally, another test is required for confirmation of the ringworm fungi’s presence.
Second is the examination of infected hairs with fluorescence from a special ultraviolet range light that is called a Wood’s lamp. When the infection has been caused by the most common fungus, the case usually glows a yellow-green when examined using a Wood’s lamp in a dark room. Unfortunately, not all cases fluoresce, and the remaining two types of fungi that cause ringworm lesions do not fluoresce at all. This technique is generally applicable as a rapid screening tool.
Most accurate is the third means to diagnose ringworm in dogs. This is the fungal culture examining a sample of skin or hair cells from areas of hair loss. Positive cultures sometimes return within a day or two, but when the fungal spores are slow in growing, culture results may require up to a month.
Do All Dog Breeds Contract Ringworm?
Any dog, regardless of breed, can contract a ringworm infection. Certain breeds have been found to be more at risk, however. Boston terriers, Jack Russell terriers, and Yorkies are particularly prone to contracting ringworm, according to a veterinary dermatologist.
Do Other Animals Contract Ringworm?
Cats also get ringworm. The fungus that is responsible for most cases in dogs is even more prevalent in cats, with 98% of cases due to Microsporum canis. Many pet-containing households have both dogs and cats, so the risk of the fungus spreading between the two through direct contact is high. In fact, most domestic animal species can develop ringworm. This includes livestock. Talk to your veterinarian about the risks of ringworm spreading among your animals.
Is Ringworm Zoonotic?
A zoonotic disease can be spread from animals to humans. Ringworm is, indeed, zoonotic, although you probably recognize it by a different name entirely: athlete’s foot. The fact is that ringworm in dogs becomes problematic for the humans and animals who encounter infected canines. Ringworm may be mild, but it should be taken seriously, especially when the elderly, young children and immunocompromised people are part of the dog’s life. Contact your physician if you notice a rash once your dog has received a positive diagnosis of ringworm. This will generally be circular and red, often growing into an itchy nuisance.
Treating Ringworm in Dogs
Upon receiving a positive diagnosis of dog ringworm, you and your veterinarian will discuss treatment plans for your dog. The plan will vary according to the case’s severity, how many pets are in the household or animals are on the property, and whether the home contains children or immunocompromised adults. At its most basic, ringworm treatment typically consists of topical therapy, environmental decontamination, and oral medications.
Anti-fungal medications taken by mouth assist your dog in fighting the infection. You will need to give your dog this medication for six weeks at a minimum; some cases require as much as months’ worth of doses to completely take effect. If you have other pets, your veterinarian might recommend testing and treatment for all. This is true even if they show no signs of infection.
An Antifungal Shampoo Bath
A dog that has encountered ringworm fungi can benefit from an over-the-counter antifungal dip or shampoo. This sometimes halts the infection. Follow the instructions but consider bathing twice a week for the best results. Of course, if your veterinarian recommends otherwise, follow those directions.
Application of Antifungal Ointments or Creams
For smaller, localized ringworm infections, you can apply antifungal ointments or creams. Such topical solutions can be used to target the infected areas more accurately and effectively than shampoos. Inquire with your veterinarian about prescription ointments or favored over-the-counter treatments. In either case, treatment will need to be repeated regularly for at least a six-week span.
Haircut and a Shave
Because the spores of ringworm in dogs live in and on the brittle, broken hairs around the ringworm infection sites, you might be able to control the spread of the fungus with a trim and a shave around the areas of rash. Trimming your dog’s fur close to its skin reduces the risks of shed or broken hair. This removes the most infectious material from your dog so that it is not spread around your home.
Use the Vacuum Cleaner Frequently
Because ringworm is so highly infectious, keeping your home clean is important. Ringworm spores can persist as points of infection for many months after being shed. Vacuum often and dispose of the sweepings promptly to rid your house of spores.
Frequently Asked Questions
How contagious is ringworm from a dog to a human?
Ringworm is quite contagious, even from dogs to humans. Do not let children, elders, or immunocompromised people have direct contact with an infected dog or even its bedding, bowls, or toys lest the infection spread to them and they get ringworm in the human form. Prevent ringworm by keeping your environment clean.
How do you tell if your dog has ringworm?
Ringworm dwells in the outer skin and hair follicles of a dog, sometimes also impacting the claws. Fur gets brittle and breaks off short in roughly circular areas, skin gets red, rough, scaly patches, and claws become brittle and break.
How do you get rid of ringworm on a dog?
Antifungal medication is necessary to beat infections that have had time to grow worse than mild in nature. This can be oral or in a cream or ointment to work into the rashes. Six weeks of treatment are the minimum time frame for giving this medication; often, more time is necessary.
Can dogs get ringworm from outside?
Yes. The fungi dwell in the soil and their spores can be carried on broken bits of fur caught in the breeze. If your dog encounters another dog’s toy outside, and that dog is infected, there is yet another opportunity for your dog to develop ringworm.