Mycoses are fungal diseases in cats. Cryptococcosis of dogs and cats

Cryptococcosis (torulosis, Busse-Buschke disease) is a systemic fungal disease that is caused by the yeast-like fungus Cryptococcus neoformans (formerly Torulaneoformans). In addition to cats, this mycosis occurs in dogs and humans, but the infection is not transmitted from cats to humans.
Infection occurs by airborne droplets, most often through the nose, with the help of spores that persist for a long time in the ground contaminated with bird droppings, especially pigeon droppings. From the nose, cryptococci often penetrate through the ethmoid bone into the brain, as well as into the eyes, lymph nodes and skin. The disease most often occurs in weakened middle-aged cats, mainly against the background of immunosuppression. Absolutely healthy animals can also get cryptococcosis.

The disease manifests itself in three forms - nasal, nervous and cutaneous - and is characterized by nasal discharge, lesions of the central nervous system, eyes, as well as fistulas and abscesses. More often in cats, the disease occurs in a chronic form with damage to the lungs. The nasal form accounts for half of all cases of the disease.

Symptoms
With the nasal form: sneezing, snorting, bloody-mucous discharge from the nose, difficulty breathing, cough. Flesh-colored polyp-like growths may appear from the nose. The infection can spread to the brain and lead to central nervous system damage and death due to meningitis.
In the nervous form: symptoms of meningoencephalitis, loss of coordination of movements, epileptoid seizures, paresis, paralysis. When the eyes are damaged, blindness develops.
In the cutaneous form: there is often a dense swelling in the dorsum of the nose, subcutaneous nodules, pustules, ulcers, abscesses and fistulas.
Diagnosis diagnosed based on the results of microflora cultures and tissue biopsies. A serological test for cryptococcal antigen is performed.
Treatment with the use of antifungal drugs should begin as early as possible, otherwise there is little chance of a successful outcome. Drugs from the imidazole group are also used, for example, ketoconazole, and for systemic disease - amphotericin B (subcutaneously, 0.5 mg/kg, 2-3 times a week for several months to a total dose of 8 - 26 mg/kg), fluconazole and 5-fluorocytosine.

Treatment is quite complex, with the use of antifungal drugs, in particular ketoconazole (Nizoral). Amphotericin and 5-fluorocytosine are also recommended.
You can start taking iodine preparations orally in increasing doses. Among the antimycotic antibiotics is amphotericin B. The drug is used intravenously in a 5% glucose solution, administered by drip over 4-6 hours. The daily dose is prescribed at the rate of 250 units/kg. The drug is administered 2-3 times a week. The duration of the course depends on the clinical form of aspergillosis and ranges from 4 to 8 weeks. For pulmonary forms of aspergillosis, inhalation of sodium iodide solutions and nystatin sodium salt is indicated. If there is a secondary infection (usually staphylococcal), oxacillin or erythromycin can be used. Antibiotics of the tetracycline group and chloramphenicol are contraindicated, as they contribute to the occurrence of aspergillosis.
Vitamins and restorative treatment are prescribed.

HISTOPLASMOSIS
Histoplasmosis (Darling's disease) is a systemic fungal disease that is characterized by damage to internal organs and the reticuloendothelial system and is caused by the fungus Histoplasma carsulatum from the class of imperfect fungi.
In cats, it was first described in 1950 and was identified in the central states of America. In addition to cats, this disease occurs in humans, but the infection does not appear to be transmitted from cats to humans.
Infection occurs through spores that persist for a long time in soil rich in nitrogen, contaminated with manure, bird droppings, and bat excrement.
Mycosis often develops in weakened cats, usually against the background of immunosuppression.

Symptoms: the increase is gradual, the temperature rises, the cat refuses food, loses weight, shortness of breath and cough, vomiting, and diarrhea appear. Possible symptoms of damage to the respiratory tract, including the lungs, conjunctivitis, granulomatous skin lesions.

Diagnosis diagnosed based on the detection of characteristic spherical macroconidia with a spinous surface.

Treatment with antifungal drugs should begin as early as possible, but most cats, despite all measures taken, still die.

So, a cat always has fungus on the skin, but it does not cause harm to the body as long as the immune system remains sufficiently active. The state of the immune system is influenced by many factors: stress, injury, chronic diseases, past infections, poor feeding, etc. Some cats are sensitive from birth - such a pet needs special attention and support of the immune system with modulators.

Fungi love moist, warm environments, and therefore any is a suitable place for their development. For this reason, fungus is more common in free-ranging cats: cats, fighting for territory and attention of the opposite sex, inflict deep wounds on each other with their claws. The pet licks the scratch, creating ideal conditions for the growth of fungus.

Excessive grooming may be the reason why a cat develops fungus on its skin with enviable regularity. Swimming is especially dangerous in the cool season if you do not use a hairdryer after the bath. By bathing the pet weekly and combing the fur daily, the owner himself creates conditions suitable for the development of fungi: the smallest scratches on the skin, a humid environment, plus the absence of natural protection - a layer of sebum, consisting of a mixture of lipids involved in immunochemical processes.

Ear fungus is also more likely to develop in over-groomed cats. When the owner manically cleans out earwax with a swab, lathering the ears until they “shine,” he removes the protective layer that prevents the development of fungi and other pathogenic microorganisms.

There is a huge variety of infectious diseases affecting pets around the world. But when most breeders hear the word “infection,” they associate it with viral or bacterial pathologies.

Indeed, these pathogens are very common and often cause many diseases, but there is also “someone”: fungus in cats. It is pathogenic fungi in veterinary practice (and even in medicine) that are considered one of the most unpleasant and dangerous pathogens. They can be difficult to identify, and treatment is not so simple.

Fungi, as is known, have not yet received a clear classification position, and therefore today are considered organisms that occupy an intermediate position between animals and plants.

Routes of infection

In the external environment, you can find literally millions of all kinds of fungi and yeasts, but only a few can cause disease. It is believed that the main source of infection is soil. The routes of infection are varied: inhalation of spores, their ingestion, the pathogen can enter the body through the surface of damaged skin.

Causes of fungal infection

Only a small part of fungi can cause disease in an initially strong and healthy animal. In general, mycoses are considered a sure indicator of some serious problems with the immune system.

A typical situation is when the disease developed against the background of long-term, continuous use of antibiotics or anti-inflammatory corticosteroids. Long-term use of immunosuppressants almost always leads to the same results.

If the animal’s immunity is relatively good, the infection is often localized. Otherwise, the fungi quickly take over the entire surface of the body.

Note that generalized mycoses (i.e., covering the entire surface of the body) are considered atypical for cats and are usually associated with some kind of severe immunodeficiency. The same cases include lesions of the claws: under normal conditions, fungi cannot “occupy” them.

Types of fungi in cats

Aspergillosis

Aspergillosis is a collective name for several mycoses, the causative agents of which are Aspergillus fungi. As a rule, only the respiratory tract is affected, but many cases have been described in which the infection has become a generalized form. Aspergillosis occurs not only in cats: it is often diagnosed in both domestic and many wild animals. Only the susceptibility to specific varieties of the fungus varies.

In cats, the nasal cavity and lungs are affected, and intestinal forms are occasionally found. If an animal has a viral or bacterial infection, the risk of fungal infection increases by approximately 43%.

The symptoms are quite vague and not too specific. Considering that aspergillosis is characterized by damage to the respiratory system, the main symptoms are: cough, difficulty breathing, subsequently developing chronic bronchitis or even pneumonia.

Diagnosis is very difficult (Aspergillus can be found in any healthy animal).

Therapy is long and difficult: areas of affected tissue are carefully removed surgically, and the pathogen is “suppressed” with heavy doses of antifungal agents.

Cryptococcosis

Cryptococcosis is a fungal disease that usually affects the nasal cavity, central nervous system, eyes and skin (especially the skin of the face and neck). The causative agent is the fungus Cryptococcus neoformans. Found in soils on all continents except Antarctica. The common pigeon is considered to be the spreader: in its excrement you can always find a huge amount of Cryptococcus neoformans. The infection is transmitted by inhalation of spores, or by getting the latter into wounds and abrasions of the skin and mucous membranes.

Unlike the diseases described above, cryptococcosis is most typical for cats (but other animals are also affected).

Characteristic clinical picture symptoms are considered to indicate damage to the respiratory system. A sick cat often sneezes, and there is bloody-mucous discharge from the nasal passages. If you look closely at a cat's nose, you will see that there are polyps in the nasal passages. In some cases, there is swelling of the skin on the face and in the bridge of the nose.

A cutaneous form of infection often develops, characterized by the formation of multiple papules (fluid-filled blisters) on the skin. From time to time they burst, their contents dry out and form crusts. The disease is extremely dangerous, as it often leads to damage to the central nervous system. In addition, the animal may well become partially or completely blind.

Symptoms from the upper respiratory system:

Sneezing.
Reddish mucus coming from the nose. In it you can see abundant impurities of pus, sometimes - pieces of decaying tissue.
Ulcers develop on the nose.

The worst thing is when signs indicating damage to the nervous system are visible:

Depression, apathy.
Uncharacteristic and strange behavior of the animal.
Seizures that closely resemble epileptic seizures.
Mild paralysis. However, if the foci of fungal inflammation are located on the paws, the cat’s reluctance to move can be explained by the resulting pain.
Blindness (partial or complete).

However, blindness rarely occurs suddenly. It is always preceded by “problems” in the eyes:

The animal's pupils are constantly dilated; they do not react in any way to changes in illumination.
, keratitis, glaucoma is also possible, accompanied by massive retinal detachment. The resulting blindness is often incurable.

Treatment uses combinations of several antifungal agents. If there is only one drug, the pathogen adapts to it too quickly. The duration of therapy at home is up to several months. If the bones of the bridge of the nose or nasal cavity are damaged, surgical intervention is necessary. If the affected bones are not removed, relapse will occur within a few weeks. The prognosis ranges from cautious to doubtful.

Histoplasmosis

Histoplasmosis is an infection caused by the fungus Histoplasma capsulatum. The pathogen is found in all countries. Birds and bats are considered natural reservoirs and distributors. There is (theoretically) only one route of infection - inhalation of spores. The lungs and lymph nodes in the chest are the sites of primary infection. The fungus grows and actively multiplies there, and subsequently quickly spreads throughout the body along with the general bloodstream.

The symptoms are quite vague and depend on the damage to specific organs. In particular, when the pathogen is localized in the lungs, fever, shortness of breath and cough are observed. Note that in cats with normal immunity, the pulmonary form of the disease usually goes away on its own.

Otherwise, the fungus quickly ends up in all internal organs and tissues.

The lungs, intestines, lymph nodes, liver, spleen and bone marrow are affected (leading to anemia and the development of immunodeficiencies).
There is an apathetic state, intermittent fever, complete or partial loss of appetite.
The disease is characterized by chronic diarrhea, bleeding in the gastrointestinal tract, anemia and progressive exhaustion.
In especially severe cases, osteomyelitis (bone inflammation) develops, and cases of damage to the central nervous system are common.

To make a diagnosis, identification of the pathogen in biological fluids and body tissues is required.

Generalized histoplasmosis is extremely difficult to treat. Loading doses of antifungal drugs are required, as well as high-quality supportive therapy. A sick animal must be fed exclusively balanced food; it is vital to prevent the development of secondary bacterial infections (broad-spectrum antibiotics are prescribed). A full therapeutic course is expensive for the owner of a sick animal.

Malasseziosis

Another dangerous infection is Malassezia. The causative agent is Malassezia pachydermatis. And he is unusual. The unusual thing is that under normal conditions this yeast fungus does not cause any pathologies. It can easily be found on the fur and skin of any healthy animal. As a rule, this yeast lives in the ear canals (a thick black coating appears in them), between the fingers and in the genital area.

Why does a generally harmless microorganism suddenly turn into a pathogen? Alas, the exact answer is still unknown; scientists are still studying the specifics of the activation of pathology. However, an important role in this process is probably played by strong and long-lasting, as well as long-term use of antibacterial drugs.

The typical symptom of this infection is sudden, causeless baldness of large areas of skin on the chin. The skin turns red and large, painful acne often appears on its surface. Unfortunately, similar signs are characteristic of hundreds of other diseases, so it is impossible to make a diagnosis “by eye”.

To determine the root cause of what is happening, the veterinarian will take scrapings from the affected areas of the skin. It is used for subsequent microscopic examination. Ideally, the pathogen for identification is carefully grown on a special nutrient medium. However, this takes a lot of time and money, and therefore veterinarians prefer to work “the old fashioned way”, with a microscope.

Let us emphasize once again that yeast fungus can always be found on the skin of any animal. Therefore, the appearance of the above-described symptoms is not always the “merit” of malasseziosis.

Blastomycosis

The most famous is North American blastomycosis, and in the not so distant past, its distribution area was limited to the area around the Great Lakes and the Mississippi basin. But now everything has changed, the disease is found throughout almost the entire world (with the exception of Australia and Antarctica).

Mushrooms are suitable for any habitat where the soil is damp, acidic, and rich in the products of decayed vegetation. Birds (including the already mentioned pigeon), as well as bats, are considered natural reservoirs. Blastomycosis is rare in cats.

Unfortunately, the last statement is controversial: rather, this disease is not rare, but the accuracy of its diagnosis is poor (it can only be recognized in a very well-equipped veterinary clinic).

Affected animals develop fever, lethargy, loss of appetite, and progressive weight loss.
When the lungs are damaged, cats begin to tire pathologically quickly and develop a chronic cough. Peripheral lymph nodes are often enlarged.
Bone lesions are characterized by severe lameness.
The worst thing is when the fungus or its toxins reach the central nervous system. Such cases are characterized by seizures, strange behavior, partial or complete paralysis of limbs or entire parts of the body.
Occasionally, blastomycosis leads to lesions of the genitourinary system, which can be guessed by the appearance of blood in the urine and difficult, painful urination.
In some cases, the pathological process involves the eyes, as indicated by increased sensitivity to light (even weak) and persistent conjunctivitis. This course is also characterized by the gradual development of blindness.
Finally, a not very characteristic, but still occurring, sign is the development of pustules on the skin. From time to time they burst, after which numerous crusts form on the surface of the skin.

Treatment of this infection depends on the general condition of the animal and the degree of development of the pathology itself. Regardless of this, therapy in any case pursues two goals at once: to get rid of the most severe symptoms (difficulty breathing, cough, etc.), and also to destroy the pathogen in the animal’s body.

As a rule, combination therapy (several drugs with different types of action) is prescribed for this purpose, and the duration of their use should not be less than two months. Unfortunately, the likelihood of relapse is very high, and therefore we advise you to regularly take your pet to the veterinarian.

Ringworm

A particularly well-known representative of this group is microsporia. The causative agent is the fungus Microsporum. In veterinary practice, doctors are faced with four forms of the disease:

Hidden option. The animal is a carrier and actively infects all surrounding cats and people, but it does not have any pronounced symptoms.
Erased variety. All symptoms manifest themselves in the form of small hairless areas appearing on the pet’s skin.
Superficial type of microsporia. Small, gradually growing patches of baldness also occur. The skin in these areas becomes inflamed and ulcerations may occur.
Follicular type. The most dangerous variety. It is characterized by a large coverage (the entire surface of the body can be affected), severe inflammation and ulceration of the skin. Note that this trend is not very typical for Microsporum fungi. Similar effects are more typical of the action of fungi of the genus Trichophyton (T. Mentagrophytes or Rubrum). By the way, T. Rubrum is more dangerous. In animals infected with it, the skin turns red and becomes very thick, and deep cracks appear on it. A sick pet emits a distinct, unpleasant odor.

We must not forget that a special vaccine against lichen has long been created and is effectively used. Don't forget to take your pet to the vet from time to time!

The characteristic symptoms of any dermatomycosis are changes in the structure of the coat: hairs become very fragile and easily break off at the very base. Such hairs are literally “stuffed” with spores of a pathogenic fungus, and therefore contribute to the rapid spread of the pathogen in the environment. In addition, many types of lichen develop circular patches of baldness on the skin with reddened areas in the center.

Remember that microsporia (like any other type of lichen) is transmitted to humans!

It is necessary to strictly observe the rules of personal hygiene. In addition, it is advisable to isolate a sick pet from your family members to minimize the likelihood of them becoming infected.

Treatment of fungal infections

We have not specifically described the characteristics of therapeutic techniques when considering different types of fungal infections in cats. This doesn’t make much sense, since almost all types of fungi are eliminated using absolutely similar methods.

Oral medications play the most important role. In veterinary practice, amphotericin B (3%), flucytosine (10%), econazole (1%), clotrimazole (1%) are often used. A therapeutic shampoo containing these antifungal agents can play an important role in treatment.

Drops and solutions

In the recent past, salicylic acid was often prescribed to treat fungal infections, but its effectiveness is not very effective by modern standards. The same can be said for griseofulvin and ketoconazole. The latter, by the way, should not be used at all to treat sick cats, since the likelihood of severe side effects is too high, including poisoning and complete failure of the liver (as well as the kidneys).

But econazole is especially good. Its solution (often used as ear drops), when used correctly, can achieve stable remission in about a month. To minimize the toxic effect of the drug on the body, it is worth using drops. An oral form of econazole also exists, but it is quite dangerous for the cat's body.

In addition, it is advisable to use tolnaftate for the treatment of fungal infections of the ear canals. It is also used in the form of a solution and drops. This drug, by the way, is perhaps the safest for the animal’s body (but very expensive).

Remember that when applied topically, you should not immediately release the cat: hold him, stroke him, talk to him tenderly. It is necessary that at least six minutes have passed since the application of the medicine (in this case, the effectiveness of treatment will be much higher). If the fungus is ear fungus, compliance with this rule is especially important, since otherwise the medicine will simply run out of the ear canals, its effectiveness will be almost zero.

Important! When treating many fungal pathologies, it is strongly recommended to trim your pet. If the cat is fluffy, it will constantly spread infected fur in the external environment, and the application of medications will be very difficult.

Ointments

Standard dosage forms for the treatment of all fungal infections are a variety of liniments and ointments. They are easy to apply; with their help, the active substance stays in the right place for a long time.

Yam ointment helps a lot. True, it has a very specific smell and a very sticky consistency. However, the latter is not too important: after treatment, all bedding and other things that the sick pet has come into contact with must either be thoroughly disinfected or thrown away.

When describing antifungal drugs, one cannot fail to mention "Mercurochrome". The medicine is intended for local use, and is distinguished by its highest effectiveness - it reaches almost 100%. There is only one caveat - the active ingredient is mercury, and therefore the product should be used with extreme caution.

There are two types of fungal diseases in cats.

The first type affects the skin and mucous membranes, and includes diseases such as ringworm and yeast stomatitis. The second affects exclusively internal organs; such diseases are also called systemic. Spores are transmitted through airborne droplets and through infected skin. Fungi are very tenacious, they can survive without water for a long time, and do not disappear under the influence of high temperatures.

In cats, systemic diseases are very rare; they most often affect emaciated animals. Antibiotics and steroids can cause such diseases. They can completely change the microflora of a cat’s stomach and begin the spread of a fungal infection. This disease affects animals with low resistance to fungal infection. To identify a systemic fungal disease, veterinarians use various examination methods: biopsy, x-ray examination and many others. A sign of a fungal disease may be the absence of a positive therapeutic effect after a full course of antibiotic therapy. Unfortunately, systemic fungal disease cannot be cured with conventional antibiotics. It can only be cured by specialists in well-equipped veterinary clinics.

There are the following fungal diseases of cats:

Cryptococcosis

This disease is very common among cats and is caused by a yeast-like fungus. Mostly, middle-aged cats suffer from cryptococcosis. The disease enters the body through airborne droplets when a cat inhales harmful fungal spores. There are a lot of them in the ground, among bird droppings. Cats with poor immunity are more likely to develop cryptococcosis, so try to give your pets more vitamins. The disease itself is divided into two types - nasal and cutaneous cryptococcosis. Half of all fungal infections are caused by nasal cryptococcosis.

The symptoms of this disease are: cough, difficulty breathing, sneezing, bleeding in the nostrils.

If treatment is not started promptly, the infection can reach the brain and cause death due to meningitis.

Cutaneous cryptococcosis accounts for 25% of all diseases. Very often the bridge of the nose begins to swell in cats. Sometimes the animal has nodules under the skin, from which pus then begins to flow. Treatment of cryptococcosis should begin as early as possible, since this is one of the most dangerous fungal diseases. Treatment must be prescribed by a veterinarian. Typically, oral antifungal drugs such as ketoconazole are prescribed in such cases. This disease takes a very long time to cure.

About diagnosing skin diseases in cats

Histoplasmosis

This fungal disease was first recorded in the central states of the United States. Fungal spores were detected in contaminated, nitrogenous soil. This land was contaminated with bat excrement, manure, and droppings. This is the most insidious fungal disease. As practice shows, in most cases it develops secretly. The main symptoms: poor appetite, fever, rapid weight loss, general weakness of the body, sometimes the cat shows signs of damage to the eyes or skin. Unfortunately, it is possible to cure a cat from histoplasmosis only in the early stages of the disease. Therefore, when you notice the first symptoms, you should immediately contact a veterinarian.

Sporotrichosis

It occurs from fungal spores found in the soil. Infection occurs in two ways - through skin lesions, or by airborne droplets. Mainly cats are susceptible to this disease. The disease develops on damaged skin, on the face, and sometimes on the tail. During illness, hair falls out on the affected areas of the skin. Sometimes, sporotrichosis affects internal organs, the liver and lungs. An animal can be completely cured only if the disease has not affected the internal organs.

Potassium iodide is considered the best treatment for sporotrichosis.

In addition, ketoconazole and itraconazole give good results. If the disease has affected the internal organs, then you need to use amphotericin B. These medications are very toxic, so you do not need to use them yourself. It is recommended to consult a veterinarian, and under no circumstances attempt to treat the animal yourself.

A person can become infected with sporotrichosis through contact with inflamed areas of a cat's skin. Therefore, contact with a sick cat should be kept to a minimum, and rubber gloves should be used when caring for it.

Aspergillosis

This type of fungus is very common in soil rich in organic compounds. It is most often found in decaying plant debris. This fungus most often affects cats with low immunity. The symptoms of aspergillosis are very similar to those of cryptococcosis and histoplasmosis. Treatment of this disease is extremely ineffective. Basically, the veterinarian prescribes antifungal medications.

Blastomycosis

This fungus lives in soil that is contaminated with manure or bird droppings.

In addition to cats, people and dogs are also susceptible to this disease.

Very often, blastomycosis affects the respiratory system, skin, eyes and brain. This disease is very dangerous for humans. It is best treated with amphotericin B. In recent years, ketoconazole has been successfully used to treat blastomycosis. The main difficulty in treating this disease is the very high toxicity of these drugs. The likelihood of a cat infecting a person is not high, but it is better to take precautions. Contact with a sick cat is only possible while wearing protective gloves. There are also many known cases of human infection after a dog bite.

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