Ringworm in cats and dogs

What it is

Dermatophytosis in dogs goes away without treatment in a few weeks or months, if there are no health problems. But during this time, your four-legged friend can infect other animals and people, and skin problems can cause discomfort. Ringworm responds well to treatment, so it is better not to delay treatment, but to immediately rid your pet of fungal dependents. Correct actions will shorten the duration of the disease and prevent complications.

There are more than 30 types of fungal microorganisms. Dogs are affected in 70% of cases by Microsporum canis. The remaining pathogens are usually transmitted to them from other animals - cats, mice, rats, cows, horses, etc.

Dermatophytosis is the general name for a group of diseases. They differ in pathogen, symptoms, and treatment. The following types are common among dogs:

• ringworm;
• trichophytosis;
• microsporia;
• favus (scab).

Each fungus requires exposure to certain medications, so you should not try to recognize the disease on your own. If you treat your pet incorrectly, dermatophytosis will drag on and the pet will weaken. Microorganisms will feel freer, and the disease will worsen.

Clinical picture of infection

Cats with dermatomycosis almost always have skin lesions, the nature of which varies depending on the severity of the case, the physiological condition and age of the animal, the specific type of pathogen, etc. The appearance of small, round areas of baldness is considered “classic”. The lesion often has scaly, gray skin in the center. Small pustules are also a common symptom of the disease.

Over time, the scattering of bald areas gradually merges into one large one. Unlike dermatitis and other skin diseases, these places practically do not itch or hurt (except in cases of interference by secondary pyogenic microflora). The most areas of baldness can be seen on the head, ears and tail, as well as on the stomach and genital area.

Considering that cats are extremely clean creatures, it is not surprising that spores with constant licking will quickly spread throughout the entire coat. Cases have been described where the infection spread throughout the skin and caused processes very similar to seborrhea (greasy, scaly skin).

Contrary to popular belief, dermatophytoses do not always cause massive hair loss. In addition, during these infections, hair does not fall out, but breaks off, creating the appearance of numerous “stumps” on the surface of the skin.

Symptoms and signs

The disease does not manifest itself immediately; after infection, it takes from 3 days to 3 months before the first symptoms appear. First, the pathogen enters the animal’s skin and releases toxins and enzymes that cause peeling of the skin. At this stage, dermatophytosis is invisible.

The fungus then invades the hair follicles and destroys them, causing hair to fall out. Horny scales and dried pus become visible on the skin. At first it is noticeable only in a small area, then it grows and gives rise to new lesions.

If the pathogen penetrates the skin, it will cause deep inflammation, and the accumulating pus will form an abscess. Hard bumps will appear in place of the fallen fur. If you press on them, it will hurt your pet.

The first patches of baldness usually appear on the face - around the eyes and ears. Hair loss is possible on the paws or withers. The rate of spread of bald spots is influenced by the type of pathogen, the immunity of the animal, and the conditions of its detention.

The coat undergoes changes throughout the body. At first, she looks normal, even if patches of baldness have already formed. Then the hairs become dull, become brittle, and fall out more often. The fur appears to be dirty and matted. Some owners think that poor quality food or infrequent bathing is to blame, so they delay treatment.

Some types of dermatophytosis cause itching. Usually it is weak - the pet itches a little more often than usual, without much diligence. Basically, he tries to catch the bald areas. It’s worse if the animal scratches the skin furiously until it bleeds. A secondary infection gets into the wounds, and the weakened immune system can no longer cope with it.

In general, the dog behaves as usual, the appetite remains the same. Only if dermatophytosis is complicated by an abscess or severe itching does the animal refuse food and water and become apathetic.

Methods for treating dermatophytosis in dogs and cats

Dermatophytoses

is a group of fungal diseases whose pathogens affect the upper layers of the skin and hair.
The diseases are highly contagious and can infect people and pets, so it is extremely important to take the issue of treatment seriously. Treatment of dermatophytosis in dogs and cats involves eliminating the fungal infection, restoring hair and skin, and preventing the spread of infection. Thus, a set of therapeutic measures should include local treatments, systemic therapy
and disinfection of premises.
It is important to understand that treatment of dermatophytosis in pets takes at least 1 month. In the presence of associated causes ( immunodeficiencies
, unsatisfactory living conditions, acute viral diseases), as well as in young and elderly animals, treatment can last several months. Self-healing is also possible, but, of course, you should not rely on this alone.

Local therapy. For topical (local) therapy

you can use Imaverol solution, Lime Sulfur solution, shampoos with ketoconazole or miconazolone. It is important to treat the entire surface of the animal's body. Local application of antifungal ointments is often effective only for clearly limited single lesions. It is undesirable to use them in the area of ​​the muzzle and ears, as this often leads to severe irritation of delicate skin. Topical therapy should continue throughout the entire course of treatment.

Systemic therapy.

Drugs with antifungal activity are used as systemic therapy - Itraconazole, Miconazole, Terbinafine, Griseofulvin. Itraconazole can be used as pulse therapy. For the first 14 days, the drug is given daily, then weekly therapy is alternated with a week-long break. This treatment regimen should continue until complete recovery. The use of antifungal drugs may cause unwanted side effects on the liver or bone marrow, so therapy should be carried out strictly under the supervision of the attending physician. To assess the effectiveness of the procedures, it is recommended to take a culture for dermatophytes. If two cultures are negative, treatment is completed.

Disinfection of premises. An important stage in the treatment of premises is mechanical cleaning with a vacuum cleaner, which allows you to remove a significant amount of spores. Most disinfectants with antifungal effects act on fungal hyphae and are ineffective against spores. Effective preparations for treating premises are products containing enilconazole (Imaverol), chlorine-containing products with an active chlorine concentration of at least 5%, as well as chlorhexidine (3–4%). Bed linen and clothing should be boiled for at least 10–15 minutes or washed at a temperature of at least 90 degrees. Quartzization is not effective in eradicating dermatophytosis in the environment. For personal hygiene, you can use shampoos with ketoconazole (Nizoral), exposure time is 5–10 minutes.

Vaccination

against dermatophytoses. Conducted studies show the ineffectiveness of using vaccines for the treatment and prevention of dermatophytosis in dogs and cats. In Europe and the USA, these drugs have been withdrawn from the market due to the lack of therapeutic and prophylactic effects. It should be mentioned that a common complication is the formation of abscesses at the injection site. Based on this, vaccines against dermatophytosis are not recommended to be included in the treatment regimen.

Is it dangerous for humans?

Dermatophytosis is also transmitted to humans. You can get infected from your own or a street dog and from other people. Children are more at risk because they often come into contact with animals without following safety rules. The peak incidence occurs during the summer holidays, when children spend a lot of time outside without adults and play with street animals.

Usually the fungus spreads under the hair on the head, the lesion grows to the size of the palm of your hand. Lesions also form on the body, most often on the arms, stomach and back. Symptoms of dermatophytosis are the same in humans and dogs.

First, a pink spot appears on the skin, then it grows, and a white raised ridge forms along the edges. In the middle, the skin peels off, the hair becomes brittle and falls out. Sometimes there is a slight itching.

In adults, dermatophytosis is the second most common skin disease after foot fungus. With age, the body becomes less vulnerable to this disease, since the hair produces substances that inhibit the activity of spores that land on the skin. Young girls are more susceptible to the disease. Interestingly, lichen rarely develops in people with red hair.

The likelihood of contracting dermatophytosis increases with reduced immunity. Pregnant women and patients who have had an infectious disease or surgery are at risk. Exacerbation of chronic diseases also reduces the body's defense response.

Diagnosis

Let us immediately note that the symptoms of dermatophytosis in cats alone cannot be the basis for making a diagnosis. The main and very common diagnostic method is the Wood's lamp. It is believed that areas of the skin affected by pathogenic fungi begin to fluoresce under its light. But it's not that simple. Recent studies have proven that “light music” is characteristic of no more than 50% of dermatophytes. In addition, it turned out that some types of medications and even household chemicals can cause glow. Finally, even on the skin of a completely healthy animal (which is also not a carrier) you can often find fungal spores. Thus, this technique is quite far from perfect.

Treatment options

To treat dermatophytosis, you need to consult a veterinarian, since an unknowing person may confuse the disease with other skin lesions. The doctor will examine the pet and analyze the appearance of the fur under the light of a Wood's lamp - a device that illuminates fungi in green. If this is not enough, blood and urine tests are prescribed.

Vaccines

At an early stage of the disease, vaccines against dermatophytosis are used. They eliminate small foci of lichen and protect the animal’s body from re-infection for 1 year. The preparation contains small doses of different types of fungi. After their administration, immunity to the effects of the pathogen develops.

The injection is given in the thigh area. The veterinarian selects a drug from 6 options - Mikkanis, Vakderm, Vakderm-F, Microderm, Multikan-7 and Polivac-TM. Dermatophytosis disappears after the second injection, and less often a third is required.

Diagnosis and treatment

The diagnosis is made during a clinical examination, as well as the following studies:

• Wood lamp illumination;
• hair microscopy;
• blood analysis;
• microbiological cultures on nutrient media to identify the pathogen.

For treatment, the following external, internal, parenteral drugs are prescribed:

1. Ointments: Yam, Lecaderm, Mycozon.
2. Solutions and sprays: Imaverol, Fungin forte, Zoomikol, Thermikon spray.
3. Tablets: Griseofulvin, Itrazole, Fluconazole.
4. Injection product Dermikotsid.

To speed up recovery, the dog is switched to veterinary food for animals with skin diseases.

Prevention measures

It is impossible to completely protect your pet from lichen. The dog is always in contact with the environment, which may contain particles of fungal microorganisms. The owner can only reduce the risk of dermatophytosis if he follows the following rules:

• do not allow your dog to come into contact with street animals;
• feed the animal a balanced diet;
• treat all other diseases in a timely manner;
• visit the veterinarian regularly, even if the dog is not bothered;
• bathe the animal with antifungal agents, but without fanaticism - too frequent water procedures weaken the protective functions of the skin.

Preventive measures are mandatory in animal shelters and foster care facilities. If one dog becomes infected, dermatophytosis will quickly spread to all the others.

Symptoms of lichen in dogs

A dog infected with ringworm (dermatophytosis) may exhibit one or more of the following symptoms:

• Round raised areas of hair loss.
• Irregular patches of hair loss.
• Scaly or crusty skin.
• Irritated and inflamed hair follicles.
• Pustules on the skin.
• Dry, brittle or cracked nails.
• Secondary bacterial skin infections

Types of fungus that cause ringworm

There are three most common fungal species that can cause ringworm in dogs. All three are zoonotic and can be transmitted from pets to humans.

• Microsporum canis is a fungal pathogen that affects the upper layers of skin in cats, dogs and humans.
• Microsporum gypseum is a soil-associated dermatophyte
• Trichophyton mentagrophytes - affects 30% of dogs, especially terrier breeds

Photo of Lichen (Dermatophytosis)

Photo of lichen in a dog