trichophytosis infectious disease animal
Trichophytosis (Ti"ichophytia) is an infectious disease of animals and humans, characterized by the formation on the skin of sharply limited round spots, bare or retaining remnants of hair, an inflammatory reaction of the skin and follicles with the release of serous-purulent exudate and the formation of crusts.
Pathogenesis. Once on the skin, the spores or mycelium of the fungus grow into the hair follicles and multiply in them, as well as in the epidermis directly under the layer of keratinized cells. Fungal endotoxins and products of incomplete breakdown of keratin cause inflammatory process, rapidly bursting blisters appear, turning into crusts, as a result of which the affected skin peels off. The fungus penetrates the lymph and blood, and with them into other areas of the skin. The fungus and its toxins cause swelling and degenerative changes cells of the root sheath, as a result of which the nutrition of the hair is disrupted, it splits and becomes brittle. With trichophytosis, fever and leukocytosis are detected. Many animals develop malnutrition due to metabolic disorders.
Clinical signs. There are superficial, deep (follicular), erased (atypical) forms of the disease. The incubation period is 8-30 days. In cattle, the skin of the head, neck, sides and, less often, back, anus area is affected, and in calves - the skin around the mouth, near the eyes, forehead and base of the ears. With the superficial form of trichophytosis, at first only sharply limited spots with tousled hair rising above healthy areas of the skin are noticeable, and itching occurs in the affected areas. The spots enlarge and become covered with thin crusts; After 1-2 months, the crusts are torn off, leaving bare areas where the skin peels off. Then hair regrowth begins. This form of the disease is observed in adult cattle.
The deep (follicular) form is observed in calves and is characterized by a pronounced inflammatory process in areas of skin lesions with the release of exudate, which dries out, forming thick crusts (up to 1 cm). The lesions get larger over time, especially on the head, and the entire face looks as if it has been smeared with dough. Sick calves lose fat, lag behind in development and growth.
The erased (atypical) form occurs in summer. Only noticeable baldness of the skin without characteristic features inflammation. In horses, the skin of the croup, sides, head, neck, chest, and back is most often affected; any of the described is possible clinical forms diseases.
In dogs and cats, the skin of the head, neck and legs is affected (mostly deep form).
In sheep and goats, trichophytosis is rare; lesions are localized at the base of the ears, in the forehead, nose, eyelids, back of the head, and hungry fossa. The forms of the disease are the same as in cattle. In pigs, the skin on the head, chest, and back is affected, but the disease is more benign than in cattle. In fur-bearing animals, trichophytosis occurs in the same way as in farm animals.
The diagnosis is made on the basis of clinical and epidemiological data. It is important to make a diagnosis when the disease has not yet become widespread. In doubtful cases, scrapings from the border of the affected and healthy areas are sent to the laboratory. If necessary, culture is done on special media.
Differential diagnosis. Trichophytosis in small animals and cattle should be distinguished from microsporia using a luminescent research method. Trichophytosis is also differentiated from scabies, in which the lesions are not round in shape, there are no thick crusts, and microscopic examination reveals scabies mites. Eczema and dermatitis of non-contagious etiology occur only in individual animals; the type of lesions is different - there are no sharply limited round spots characteristic of trichophytosis, the hair does not break off. Treatment. If it is started promptly and carried out carefully and regularly, it is possible to prevent the dispersal of the pathogen. Animals should be isolated during treatment. WITH therapeutic purpose LTF-130 vaccine and other means are used. Effective fungicidal agents are iodine monochloride, trichocetin, ROSC, SK-9, and Yam ointment. WITH positive result The antibiotic griseofulvin has been tested and used with food (see "Practical exercises").
Immunity. Animals that have recovered from the disease develop immunity and, as a rule, do not get sick again. Antibodies were detected in the blood serum. Active means have been created specific prevention trichophytosis: LTF-130 vaccine for cattle (dry vaccine from the Trichophyton-130 strain), SP-1 - vaccine for horses and "Mentavak" - for fur-bearing animals and rabbits. Vaccines are harmless and are used for preventive and therapeutic purposes. Immunity in vaccinated animals is preserved almost for life.
Prevention and control measures. It is necessary to follow the rules of animal care, preventively disinfect premises, equipment and care items, carry out deratization, adequately feed, and monthly examine animals in order to identify the first cases of the disease. In prosperous and threatened farms with for preventive purposes calves with one month old immunized with the LTF-130 vaccine.
When a disease is detected, the farm or part of it is declared unsafe. Patients are isolated and treated with fungicidal agents or vaccine therapy. Separate staff are assigned to care for this group of animals. The remaining animals are vaccinated for prophylactic purposes. Growing young animals are immunized upon reaching vaccination age. Cleaning and disinfection are carried out after each case of detection of sick animals, and ongoing disinfection is carried out at least once a decade. To disinfect premises and internal equipment, use a 5% formalin solution containing 1% caustic soda or a formalin-kerosene emulsion consisting of 10 parts formalin, 10 kerosene, 5 creolin and 75 parts water.
The soil surface is neutralized with a suspension of bleach containing at least 5% active chlorine and a 4% formaldehyde solution. Manure is neutralized using a biothermal method. Care items, harnesses, and clothing of nursing staff also need to be disinfected. All work is carried out observing personal preventive measures. The farm is declared free from trichophytosis 2 months after the last case of detection of clinically sick animals, subject to final disinfection.
The disease known as cow ringworm causes a lot of trouble not only for animals, but also for livestock owners. This disease is classified as infectious skin diseases and quickly spreads to others. Not only cows, but also people can become infected. Therefore, if suspicious symptoms are detected, measures must be taken immediately to treat the animal. To recognize and treat a disease, you need to know the source of its occurrence and how to combat the infection.
Unpleasant and dangerous symptoms
Trichophytosis in cattle appears as a result of exposure to a fungus. In common parlance, the disease is called lichen. Fungal spores infect the skin, causing severe itching in the sick cow. A gray coating appears on the skin, hair falls out and a crust forms. Often these signs appear first on the cow's head and quickly spread throughout the body.
Ringworm in calves is even more dangerous. If an infected cow becomes irritable, aggressive and rapidly loses weight, then growth retardation is added to all this in young animals. Slow development negatively affects all characteristics of livestock health.
The calf's reproductive function will remain inferior, and the cow that grows from it will not become a good producer of milk or meat. Therefore, the sooner you start treatment, the more favorable the result will be. But it is best not to wait for the disease to arrive, but to vaccinate animals in advance.
Details from the life of pathogens
The spores of the fungus that causes trichophytosis are very tenacious. They can remain active for more than a year, located on fallen areas of diseased skin.
If they find themselves in a favorable environment, they will quickly begin to reproduce. However, they can be destroyed by boiling contaminated clothing. In boiling water they will die in half an hour.
Depending on the type of pathogen that caused lichen in a cow, several types of disease are distinguished. Cattle suffer from trichophytosis most often. It is caused by spores of the fungus Trichophyton. Microsporia, which occurs as a result of the infection of the same name, is not so common.
Among the available forms of lichen, we highlight four:
- erased;
- superficial;
- vesicular (vesicular) – affected inner surface thighs, perineum and genitals;
- deep (follicular) – calves with fragile bodies are especially often affected.
The first two forms are considered mild. As a rule, adult cows become ill with them. Deal with accurate diagnosis the vet can. He will determine the degree of infection and recommend treatment.
Vaccinations cure
It is difficult to treat lichen in cows due to the high resistance of the fungus to the influences on it medicinal drugs. Therefore, the process takes a long time.
The first thing to do is to separate healthy animals from infected ones to prevent the infection from spreading throughout the herd.
Second, treat the stall in which the cow is located with one of the following drugs: formalin solution (5%), bleach solution (20%) or sulfur-carbolic solution (5%). Good effect gives an emulsion prepared at the rate of 80 parts of water heated to 60-70 degrees - 10 parts each of kerosene and formaldehyde.
Vaccination against trichophytosis is used not only for prevention in the form of vaccinations, but also for the treatment of livestock. The serum destroys the fungus and prevents its further spread. The most popular vaccines include TF-130, LTF-130, TF-130k. The exact dosage will be determined by your veterinarian. But usually calves under 4 months of age are recommended to inject one dose diluted in 5 milliliters of solution at a time. Young animals over 8 months old – twice as much. It is necessary to perform two or three vaccinations at intervals of two weeks.
Proven ointments will definitely help
In addition to serum, local antifungal and keratolytic drugs are used to treat cows. The former kill pathogens, and the latter promote rapid skin restoration. For example, Yam Fungibak ointment and Zoomikol spray have proven themselves well. Before applying to the skin, it is necessary to clean it from contamination and rinse with warm water. This way the drug will penetrate the tissue better.
When treating a cow, it is necessary to alternate antifungal and keratolytic agents, for example, every other day. After the shingles disappear, continue to apply the ointment for at least another three weeks. Carry out any processing of the animal in protective clothing and gloves to protect yourself from infection.
We should not forget about tools that have been tested for decades. The long-known iodine and brilliant green, as well as salicylic acid and tar ointment continue to help sick cows today. However, they are applied before you apply antifungal agents.
Effective dry method
An animal infected with lichen has a weakened immune system. To maintain cow health and to achieve maximum effect during the treatment period, provide enhanced nutrition with a full course of vitamins A, E, D.
In practice, folk remedies also cope well with the disease. There is a so-called dry treatment method. The medicine consists of copper sulfate and sulfur in a ratio of 1 to 3. Another composition: 2 parts lime and 1 part sulfur. These powders can be easily prepared at home. Will not harm the cow and medicinal decoctions using herbs - chicory, wheatgrass, dandelion, foliage.
But remember, for each case of disease there are prescribed different ways treatments that depend on the severity of the disease and the age of the sick cow. It is best to use several types therapeutic therapy in complex. This will speed up recovery, and the disease will not cause significant harm to the cattle. As for the milk of vaccinated cows, it is completely suitable for consumption.
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Trichophytosis (trichopytosis, ringworm) is an infectious disease accompanied by the appearance on the skin of sharply defined lesions with a flaky, scaly surface, hair broken off at the base, or an inflammatory reaction of the skin and follicles, with the release of serous-purulent exudate and the formation of a thick crust. Humans also suffer from trichophytosis.
The causative agents of trichophytosis are fungi of the genus Trichophyton, which have many variants. In Russia and other countries of the world, Trichophyton faviforme variants are isolated in 82-85% of cases.
Pathogenesis. Fungal spores and mycelium, when they come into contact with injured tissue, scratches, abrasions or exfoliating epithelium of an animal whose environmental reaction has changed, begin to germinate on the surface of the skin and penetrate into the hair follicles. As a result of the vital activity of fungi, products are formed that cause local irritation of cells, leading to increased permeability of skin capillaries. At the site where the fungus grows, inflammation of the skin occurs, and the hair loses its shine and elasticity, becomes fragile, and begins to break off at the border of the follicular and air parts. The animal's inflamed areas of skin begin to itch, as a result of which the animals begin to itch against stalls and partitions, thereby facilitating the spread of the pathogen to other areas of the body where new lesions appear. From the site of the primary outbreak, the elements of the fungus enter the blood and lymph, where they are distributed throughout the body through the vessels, leading to the emergence of new mycotic processes in various areas skin of an animal. Subsequently, in the sick animal, against this background, metabolic disorders occur and the animal becomes exhausted.
Epizootological data. Trichophytosis affects all types of domestic animals, some animals and rodents. Animals are susceptible of all ages, but young ones are more sensitive, and their disease is more severe. In agricultural enterprises, trichophytosis is more widespread in the autumn-winter period, which is facilitated by a decrease in the resistance of the animal body, the unsanitary condition of the premises, crowded housing and inadequate feeding of animals.
In spring and summer, as a result of solar radiation of animals, fresh air, sufficient and full feeding, as well as molting animals, the incidence of trichophytosis decreases.
The source of the causative agent of the disease is sick and recovered animals, which release scales and hair into the environment a large number of fungal spore. Additionally, infection of animals can occur through service personnel, contaminated feed, bedding, equipment, manure, soil, etc. Fungal spores can become airborne.
The occurrence of trichophytosis in animals is to a certain extent promoted by skin trauma, scratches, abrasions, as well as desquamation of the epithelium under the influence of moisture. As a result of abrasions and scratching, an increase in skin hyperemia occurs, as a result of which the reaction of the skin environment changes and becomes more favorable for the life of fungi.
Course and symptoms of the disease. The incubation period for trichophytosis lasts from one week to a month. The course and symptoms of the disease to a certain extent depend on the type, age, individual characteristics, resistance of the body of the sick animal, the location and virulence of the pathogen.
The following forms of the disease are distinguished: superficial, deep or follicular, and erased or atypical.
The deep form of trichophytosis occurs more often in young animals; The superficial form usually affects adult animals. The course and outcome of the disease depend on the conditions of keeping and feeding the animals, as well as their timely and correct treatment. Often a superficial form of the disease, in the absence of proper and timely treatment can go deep; resulting in pathological process lingers in the skin for several weeks or even months.
Large cattle. The main causative agents of trichophytosis in cattle are Trichophyton faviforme and Trichophyton dipseum. Calves and young animals from two months to a year are more susceptible to the disease. The disease is accompanied the appearance of outlined lesions on the skin, which are localized in young animals mainly around the eyes, nose, tail, ears, neck, back; in adult animals - on the croup, buttocks, back, chest; in some animals the lower limbs may be affected.
Superficial form of the disease begins with the formation of dense tubercles (nodules) on the skin, which are easy to feel when palpating the skin. Subsequently, the tubercles soften and raised, sharply defined round spots appear. IN initial stage process, these spots are covered with scales, the hair in these places is tousled, has a matte color, and breaks off at the very mouth of the follicles. Subsequently, the spots begin to become covered with gray-white crusts, which, when they fall off, reveal hairless areas. Within 1-3 months, the spots can increase or merge, reaching the size of a palm, while their surface is covered with asbestos-like crusts. The skin in these places, in the absence of hair, begins to peel off intensely and sometimes becomes folded. Lesions begin to heal from the center. Often in the first stage of the disease and during healing, animals experience itching.
Deep or follicular form trichophytosis is accompanied by pronounced inflammatory processes in the affected areas, accompanied by exudative phenomena. The lesions in this form are deeply infiltrated and covered with crusts. Thick crusts, like dough, cover the muzzle of sick calves. Subsequently, purulent folliculitis develops and abscesses form in the perifollicular tissue.
When visually examining the animal, we note swellings that rise on the surface of the skin. When you press on the affected area, pus begins to ooze out, and the hair is easily pulled out of the follicles. Subsequent healing of such areas often ends in the formation of scars.
Erased, or atypical, form trichophytosis is usually observed in the summer. This form is accompanied by the appearance of rounded baldness on the head and other parts of the animal, in the absence of signs of skin inflammation.
Sheep. The main causative agent of trichophytosis in sheep is Trichophyton dipseum. In sheep, we often notice lesions at the base of the ears, in the area of the frontal bones, tip of the nose, eyelids, hungry fossa, nape, at the base of the tail, coronary and fetlock joints, much less often on the back, neck, chest and other parts of the body.
In sheep, clinically, trichophytosis, like in cattle, manifests itself in three forms.
Surface form often has a disseminated nature and often occurs during the winter period in conditions of unsanitary keeping, unsatisfactory care and feeding of sheep. In affected areas, the fur is glued together to a considerable length from the surface of the skin (up to 2-3 cm) with a grayish exudate or lemon-yellow with a waxy consistency along the periphery. Over the affected areas of the skin, the hair becomes tousled and has a matte color. When palpated with the hand, a tuberosity is determined; when the fur is pulled apart, we see tufts of glued hair. The crusts with hair are firmly held on the thickened, weeping, bleeding, and sometimes purulent surface of the skin. When you press on the skin at the site of the lesion, a grayish sticky exudate leaks through the stomata of the hair follicles. In areas with little hair, the affected areas turn red, round, flaky spots are revealed, which reach 2-3 cm in diameter. Having removed the scales, we find low broken hair.
Deep form in sheep it usually occurs in winter and early spring and occurs in the form of exudative dermatitis. When the auricles are affected, the lesion resembles a border 1-5 cm wide. Hair, glued together with a grayish exudate, almost along its entire length in tufts, resembles panicles, is separated with great difficulty, revealing a weeping, bleeding, eroded, painful skin. Upon closer examination, we see a protruding pink ridge along the periphery of the lesion. On the forehead, back of the head, neck, shoulder blades, chest, sacrum, lesions are irregular or round in shape, up to 5-6 cm in diameter.
In suckling lambs if the affected areas are around the mouth, sucking and feeding becomes difficult. As a result, the lambs experience emaciation, there is a lag in growth and development, which sometimes leads to their death.
Superficial and deep forms Trichophytosis in sheep is accompanied by itching.
In summer, sheep have an erased form of trichophytosis and is accompanied by the appearance on the skin of subtle (0.5-2 cm in diameter), round and oblong lesions with slight peeling. The lesions are usually localized in the lips, outer surface of the ear, tip of the nose, and superciliary arches. Having removed the scales, we find a shiny surface of the skin without any pronounced signs inflammation.
Pigs. In pigs, unlike large and small cattle, trichophytosis is more benign. Oblong and round flaky red spots, covered with a thin brown dry crust, appear on the head, chest, and back. Upon closer examination, we see that along the periphery of the spots there are small bubbles that open, and scabs form in their place.
Horses. In horses, the causative agent of trichophytosis is the fungi Trichophyton faviforme, Trichophyton gypseum and Trichophyton equinum.
Surface form trichophytosis is diagnosed by the appearance in horses of round, hairless spots covered with grayish scales on the head, neck, at the base of the tail and on the limbs. With this form, the spots often merge, forming irregularly shaped lesions from 1 to 5 cm or more. After recovery, darker hair grows in place of the spots.
Deep form trichophytosis in horses has the character acute inflammation with the subsequent development of purulent follicles at the sites of lesions and the formation of abscesses. Thick, soft, sometimes dry crusts of various sizes and colors appear at the site of the lesion; If the crusts are removed, we will see a purulent surface. When pressing on the lesions, pus appears through the openings of the hair follicles. In these cases, the pathological process can involve not only hair follicles, but also the base of the skin, subcutaneous layer and skin glands. This form of trichophytosis in horses is accompanied by itching.
Atypical form, more often happens in the summer. Skin lesions in this case take the form of abrasions, abrasions and are localized in the croup area and on the head.
Dogs and cats. Trichophyton in dogs is caused by Trichophyton faviforme and Trichophyton dipseum. In animals, the skin of the head, neck, and limbs is usually affected. The lesions can be either single or scattered over many parts of the animal’s body.
In dogs Mostly deep or follicular forms of the disease are diagnosed and are accompanied by a strongly expressed inflammatory reaction, exudative phenomena, with the formation of rapidly bursting blisters. Single lesions merge to form an extensive lesion surface. With abundant exudation, dense thick crusts form in the affected areas. When you press on the crusts, pus is released from the stomata of the hair follicles, like from a sponge.
After healing, depigmented and even bald spots remain on the skin at the site of deep lesions of the hair follicles.
In cats trichophytosis is very rare; caused by Trichophyton gypsaeum. The affected lesions are localized on the head, neck, and rarely in the chest area. The clinical picture of the disease is the same as in dogs.
Fur animals They usually get sick from mice and rats with trichophytosis. The causative agent is usually Trichophyton gypsaeum, less commonly Trichophyton faviforme. The clinic is the same as for pets. In this case, the lesions are scattered throughout the body, and in rabbits - on the nose, ears and around the anus.
Birds. Lesions are accompanied by focal redness and swelling of the skin. To a greater extent, signs of the disease appear at the base of the feathers, which are covered with fungal spores.
Diagnosis diagnosed on the basis of well-defined clinical signs of the disease and epidemiological data. If in doubt, microscopy and culture are performed using special nutrient media, in order to isolate the pathogen culture. Skin scrapings and hair from the peripheral parts of the affected areas that have not been subjected to treatment are taken as material for the study.
Differential diagnosis. Trichophytosis must be distinguished from eczema and dermatitis of non-infectious etiology.
Immunity and specific prevention. In patients with trichophytosis of all types of animals, intense and long-lasting immunity is formed as a result of illness. Only in weakened animals and animals with low body resistance are cases of recurrent disease possible.
In the USSR, VIEV scientists, for the first time in world practice, created specific means of preventing trichophytosis in animals, developed a vaccination scheme, as well as treatment to prevent trichophytosis in animals. To this day, live vaccines against animal trichophytosis are produced in Russia: TF-130, LTF-130, TF-130 K - for cattle; The SP-1 vaccine is produced for horses, and the Mentavak vaccine is produced for fur-bearing animals and rabbits; for sheep - Trichovis vaccine. Scientists have now developed associated vaccines for domestic animals. These vaccines are used according to the instructions for their use. By the 30th day after the second injection of the vaccine, stable and intense immunity is formed in animals. Efficiency preventive vaccination if the instructions are followed, it is 95-100%. After the vaccine is administered, after 1-2 weeks a crust appears at the injection site, which is spontaneously rejected by 15-20 days.
Treatment. On modern stage After the invention of the vaccine against trichophytosis by VIEV scientists, the use of the vaccine for therapeutic purposes, according to the instructions for its use, has been used with great success. If animals are severely affected by the fungus, then therapeutic vaccination is carried out three times. During treatment, practical veterinarians additionally inject sick animals with 10 ml of trivitamin and tetravit intramuscularly at the beginning and after 10 days. Affected crusts can be treated with various emollients (vaseline, fish fat, sunflower oil).
For local application Fungicidal drugs are used that have the property of killing dermatophytes both on the surface of the lesion and in the follicles. Treatment of animals with trichophytosis requires veterinary specialists to carefully and thoroughly treat the affected areas of the skin. Therapeutic treatment of such animals is carried out in isolation wards or places specially designated for these purposes (separate cages, pens, cows at the end of the group) in compliance with personal preventive measures. For local treatment drugs with high fungicidal action are recommended: juglone, drug SK-9, phenothiazine, iodine monochloride, drug ROSC, trichothecin, 5-10% salicylic ointment, 10% salicylic alcohol, 10% tincture of iodine, sulfone, sulfuric anhydride, 3-10% solution of carbolic and benzoic acids, iodoform, ointments: “YAM”, undecin, zincundan, mycoseptin, mycozolon, clotrimazole, which are used strictly according to the instructions and others . For the treatment of trichophytosis, there are aerosol forms of drugs - zoomicol and kubatol. To treat lesions, shampoos and creams with imidazole (zoniton), chlorhexidine or polyvidone-iodine are used. For internal use systemic antifungal agents are used: orungal, lamisil. IN Lately released effective drug For oral administration nizoral (ketoconazole) and the new iodine-containing drug Monclavit-1. Animal owners should be aware that treatment of animals with trichophytosis is long-term.
Control measures. In the event of trichophytosis, the farm, by Decree of the Governor of the region declared dysfunctional and measures are carried out in accordance with the instructions against fungal diseases of farm animals - Approved by the Main Directorate of Livestock and Veterinary Medicine of the Ministry Agriculture USSR August 14, 1954, including:
- sick and suspicious animals are separated into separate groups and treated;
- All animals susceptible to ringworm have their skin carefully examined once every 5 days;
- The above medications are used for treatment.
Treatment of sick animals is carried out in a specially designated place. At the end of the treatment, the removed hair, crusts and cotton wool must be burned, the instruments must be boiled, and the place where the animals were processed must be disinfected.
Breeding animals from groups unfavorable for ringworm is prohibited.
Premises unfavorable for trichophytosis are subjected to thorough mechanical cleaning and disinfection with an alkaline solution of formaldehyde. Routine disinfection is carried out after each case of isolation of a sick animal and every 10 days until the final disinfection. For processing, an alkaline solution of formalin, a sulfur-carbolic mixture, and a formalin-kerosene emulsion are used. Care items and protective clothing are subject to disinfection.
The farm is declared safe 2 months after the last case of isolation of animals with trichophytosis and the final disinfection.
Prevention. Prevention of trichophytosis consists of compliance with veterinary and sanitary rules on farms, private household plots and peasant farms, creation of normal zoohygienic conditions for keeping animals, feeding balanced according to nutrients diets, regular disinfection and deratization, as well as timely vaccination against trichophytosis. In farms where pasture keeping of animals continues to be practiced, they are subjected to a thorough clinical examination before pasture and transfer to stabling, and newly imported animals are subject to a 30-day quarantine. The skin of animals entering the farm is disinfected with 1-2% solutions of copper sulfate, sodium hydroxide and other means.
For specific prevention, vaccination is carried out in farms that are unfavorable and threatened by trichophytosis. Animals purchased for import abroad are subject to vaccination against trichophytosis.
Part of the group of dermatomycosis, trichophytosis in farm animals has been known to veterinary medicine for a long time. Given infection belongs to fungi. It manifests itself as peeling of individual areas skin, breaking off the hair in these areas and is accompanied by inflammation of the skin, the release of pus and the formation of a crust. Scientists gave a similar description of dermatomycosis back in the 19th century. Because the main clinical sign of the disease is superficial mycosis, it is often called ringworm.
The discovery of scab and microsporia - fungi that cause lichen - has given new impetus to scientific research into the disease. A significant contribution to this area was made by European scientists of the century before last, Schoenlaini and Malmsten. At the end of the 19th century, French veterinary researchers proposed their own division of pathogens into groups, which is still used today. Thus, they divided the pathogenic fungi into 3 genera belonging to the Dermatophytes group:
- Trichophyton;
- Microsporum;
- Achoreon.
We studied the disease and worked on creating prophylactic agents also Russian scientists - P. Matchersky, A. Sarkisov, P. Koshkin, etc.
Pathogens of deprivation of animals
Trichophytosis, as already noted in the article, is provoked by mushrooms. They belong to the genus Trichophyton. The disease is caused in different types of domestic animals. different types this microbe. Thus, trichophytosis in cows is mainly provoked by Tr. Verrucosum, in horses - Tr. Equinum. Pigs, rodents, dogs and cats get sick due to Tr. Gypseum.
Studies of the affected material and laboratory data obtained show a clear similarity of all types of fungus of the described genus. Their main features are the following:
- the straight constituent elements of the mycelium, which have partitions, are “lined up” in a row along the hair; oval and round - in chains;
- a sheath of spores may form near the hair follicle;
- hyphae can be located both directly in the hair itself and on its surface;
- spore size ranges up to 9 micrometers;
- the mycelium has a branching appearance, and it can also disintegrate into spores.
The optimal temperature for pathogens is +25-28ºС. Beginning a week to 40 days after entering a suitable environment, their development is accompanied by the growth of spores of various sizes and shapes. The process ends with the appearance of colonial formations with a diameter of about 4 cm. They have a light pink color and a leathery, folded structure. As the colony ages, its color becomes darker.
The pathogen is very tenacious in the environment. It can persist in slurry for longer than six months, and in affected hair - up to ten years!
In soil, which is a favorable environment for the reproduction of Trichophyton, the fungus lives up to 140 days. UV rays, boiling water, and dry heat have a detrimental effect on trichophytons. They also die in alkali solution, formaldehyde liquid, salicylic or carbolic acids.
Epizootology and sources of pathogen
The risk of getting sick exists in almost all agricultural animals - horses, cows, pigs, as well as small rodents, predatory animals, and birds. Greater sensitivity and severe course diseases are observed in young animals.
Cases of ringworm are being recorded all year round, however, in the autumn-winter season the incidence is higher. There are several reasons for this - a decrease in the body’s defenses, changes in the meteorological situation, errors in caring for livestock and feeding. Veterinarians note that calves get sick more often in the fall (after groups are formed), horses - in August-November.
Movement of the herd during the period of disease progression is fraught with re-infection and epidemic outbreaks of trichophytosis. The source of the pathogen is a sick individual that infects other animals - while in the same room, through bedding, grooming equipment, harness, manure, etc. Transmission of trichophytosis from small rodents (most often mice) is also possible. Since the pathogen is resistant to external conditions, pastures and yards for walking livestock remain potentially dangerous for re-infection for a long time.
Pathogenesis
Fungi from the genus Trichophyton can divide only in tissues that contain kerotene. This substance is present in the skin ( top layer skin), and is also part of the hair structure.
After infection, the inflammatory process begins under the influence of toxic substances and keratolytic enzymes. Next, the stratum corneum of the skin is loosened, and the fungus enters hair follicle, where it disrupts its structure and causes hair loss.
Inflammation can occur in different ways, depending on the type of fungus, the condition of the skin and the animal’s body’s defenses. IN severe cases Trichophyton can “invade” the lower layers of the skin, causing deep inflammation and abscess.
The sick individual experiences itching, and when scratched, the pathogen spreads over the entire surface of the body. Trichophyton can also travel through vessels transporting lymphatic fluid or blood. Further, at the sites of division of the fungus, numerous lesions appear. All this leads to exhaustion of the body.
TRICHOPHYTOSIS (RICHOPHYTOSIS) OF CATTLE
Definition. A contagious fungal disease of domestic animals, characterized by the formation on the skin of round, sharply limited spots with hair broken off at the base or exudative dermatitis and purulent folliculitis with a thick scaly crust on the surface of the affected area. People also suffer from it.
Diseases caused by pathogenic fungi have been known for a long time. However, the causative agent of trichophytosis was described only in 1845 by the Swedish scientist Malmsten. Currently, trichophytosis in cattle is registered in 113 countries in Europe, Asia, Africa, and America and causes enormous damage to livestock production. Found in our country.
Significant contribution to development specific means Soviet scientists A. Kh. Sarkisov, V. V. Petrovich, L. I. Nikiforov, L. M. Yablochnik, who proposed the first antifungal vaccine TF-130 in world practice, contributed to the fight against the disease.
Etiology. The causative agents of trichophytosis are pathogenic fungi from the genus Trichophyton: in artiodactyls - Tr. verrucosum; in horses - Tr. equinum; in pigs, fur-bearing animals, cats, dogs, rodents, less often in horses and cattle - Tr. mentagrophytes, gypseum; in camels - Tr. sarcisovii Ivan, et Pol. In preparations from affected hair and skin flakes at a magnification of 400-500 times, all of the listed fungi are found in the form of thin branching threads arranged in rows along the length of the hair (vegetative form), and chains of round or oval spores with a diameter of 3-8 microns, localized inside and on the outside there is hair in the form of a sheath. Fungi are grown at 22-28°C on Sabouraud's medium, wort agar, Litman agar (pH 6.5-6.8), where on the 5-30th day they form immersed in the medium, covered with fluffy fibers round, dense colonies.
Of laboratory animals susceptible to trichophytosis Guinea pigs and rabbits.
fungi, causing diseases at various types animals differ from each other in size and growth pattern on nutrient media.
Tr. verrucosum - mushrooms with a diameter of 5-8 microns; colonies of white-gray color, appearing on the 15-20th day after sowing, have a folded or bumpy appearance, raised or flat, with smooth or cobwebby edges. The mycelium is branching, microconidia are oval or pear-shaped, 1-3X2-8 µm in size. Macroconidia are elongated, 3.5-8X20-50 µm in size. Artospores are round in shape, with a diameter of 3.5-8 microns.
Tr. eguinum - mushrooms with a diameter of 6-7 microns; colonies are white, velvety, flat, smooth or furrowed, with smooth edges; appear on the 14-16th day of sowing. Microconidia are oval or pear-shaped, 1-3x3-7 microns in size; macroconidia are club-shaped, septate, 3-7X15-45 µm in size. There are no arthrospores.
Tr. mentagrophytes - mushrooms with a diameter of 3-5 microns; colonies are white, cream, dark yellow, velvety, smooth or folded; appear on the 5th day after sowing. Microconidia are round or oval, 2-4 µm in diameter; macroconidia are club-shaped, 5-10X30-50 µm in size. Arthrospores (Absent.
Tr. sarcisovii Ivan et Pol - mushrooms with a diameter of 6-7 microns; colonies appear on the 15-30th day after sowing; creamy, velvety, flat, smooth or lumpy, emit a specific smell. Microconidia are round or oval, 2.5-5X3-8.5 µm in size; macroconidia are oval, elongated, septate, 4-6.5x14-35 µm in size. Arthrospores are round, 8-12 microns in diameter.
The causative agents of trichophytosis are extremely stable in the external environment. In affected hair they persist for 4-7 years, in pathological material for 1.5 years. In infected premises, animal care items, feed remain viable for 4-8 years, manure and slurry - 3-8 months, soil - 3-4 months. Resistant to freezing, drying, and direct sunlight. When boiling, they are inactivated after 2 minutes, at a temperature of 80°C - 7-10 minutes. Under the influence of dry heat at 110°C they die after 1 hour, at 80°C - after 2 hours.
They are destroyed by alkalis (1-3% solution), formaldehyde (1-3% solution), sulfur-carbolic mixture (5% solution) in 15-30 minutes.
The diagnosis is made based on clinical signs of the disease, results laboratory research pathological material, as well as epidemiological data.
Epizootological data. Ringworm most often affects cattle, horses, carnivores, and less often small cattle, rodents, and pigs. Young animals are more sensitive to infection. The source of the causative agent of the disease is sick and recovered animals, as well as mouse-like rodents, gophers, which secrete the pathogen in external environment with scales, crusts, hair from the affected areas of the skin. Infection of healthy animals occurs through direct contact with sick animals, as well as through objects contaminated with fungi environment, clothes and hands service personnel. Fungal spores can become airborne. The spread of the disease is facilitated by zoohygienic violations in the keeping of animals, untimely treatment, lack of proper skin care. The disease of fur-bearing animals can appear after feeding slaughterhouse waste from animals with trichophytosis. People can become infected from sick animals.
Trichophytosis is recorded at any time of the year, but more often in the winter-spring period against the background of a decrease in the body's resistance, as well as when healthy animals are mixed with recovered ones during regroupings. The disease manifests itself in the form of sporadic cases or enzootics; in industrial farms can cover a large number of animals.
Course and symptoms of the disease. The incubation period lasts 6-30 days. The course of the disease is benign in most cases.
In cattle, the skin is affected in the head and neck area, less often on the lateral surface chest, back and buttocks. There are superficial, deep (follicular) and atypical form diseases.
The superficial form is observed in adult cattle. The disease is characterized by the appearance on the skin of small, pea-sized nodules, in place of which sharply defined, gradually enlarging spots are formed, covered with yellow-gray, asbestos-like crusts, 2 mm to 1 cm thick. Hair in the affected areas loses its shine, becomes dry, easily break and pull out. After 1-2 months, the crusts begin to fall off, revealing bare patches of skin, which over time become overgrown with hair. If left untreated, new lesions appear in the vicinity of the spots, as well as in other parts of the body. The skin in some areas thickens and becomes folded. There is itching, sometimes very severe. The duration of the disease is 1 year or more.
In the deep (follicular) form, pronounced inflammatory phenomena in individual areas of the skin, purulent folliculitis, abscesses, the formation of thick crusts from dried purulent exudate, and severe itching are noted. Healing of such lesions lasts 2 months or more, often ending in the formation of scars.
The atypical (erased) form is characterized by the appearance on the scalp and other parts of the body of round-shaped foci of baldness without signs of inflammation. After peeling the scales, a smooth surface of the skin is exposed, on which hair grows within 7-14 days. In the case of milkweeds, the skin is most often affected in the area of the lips and the front part of the head. Due to the thick crusts that form, the muzzle appears to be smeared in dough - “dough muzzle”. The affected skin is sore and itchy. Calves develop poorly, lose weight, and if left untreated, may die.
The superficial form of the disease is manifested by the formation of round or oval areas covered with grayish scales, which often merge, forming spots with a diameter of 1 to 5 cm. Over time, the affected areas are freed from crusts, and new hair, usually darker in color, appears in the center of the spot.
The deep form of the disease is accompanied by the development of acute inflammation of the skin, damage to the follicles, and the formation of abscesses. The affected areas may merge and spread to the lower abdomen and limbs.
The atypical form of the disease is the most benign. In the area of the croup and head, small abrasions of the skin, abrasions, and baldness are found.
Pathogenesis. When the spores come into contact with the skin, the fungus begins to multiply in the stratum corneum of the epidermis and hair, which is accompanied by inflammatory reactions skin, varying degrees of severity, hair malnutrition and hair loss. It is possible for the pathogen to spread throughout the body by lymphogenous and hematogenous routes, the formation of disseminated mycotic processes in the lungs, liver, spleen and other organs, disruption of metabolic processes that cause exhaustion and even death of the animal.
Laboratory studies are carried out by microscopy of pathological material and isolation of the pathogen on nutrient media.
Hair, crusts and scales taken from the periphery of affected areas of the skin that have not been treated are sent to the laboratory in test tubes with stoppers or in small plastic bags.
Microscopic examination is carried out directly on the farm or in the zonal laboratory. For microscopy, hair, crusts, scales are placed on watch glass with a black background. The crusts are carefully split with a dissecting needle, the hairs isolated from the crusts, and the scales are transferred to a glass slide in a drop of 10% sodium hydroxide or potassium. The preparation is carefully heated over an alcohol lamp (until vapor appears) and covered with a coverslip. Use a piece of filter paper to suck out the alkali from under the glass and replace it with a drop of 50% aqueous glycerin. Pathological material can also be treated with lactophenol, which allows for better preservation of the morphological structure of the fungus. The drugs are examined first at low levels, and then high magnification. In positive cases, straight mycelial hyphae with septa are found, arranged in regular rows along the length of the hair, as well as round or oval spores with a diameter of 3-8 microns, located in the form of chains on the hair or inside it and forming a sheath at the base of the hair.
Bacteriological research. Using a microscope, the affected hair is selected, crushed into pieces 1-2 mm long with a calcined dissecting needle in a sterile Petri dish, two pieces are added at a distance of 1 cm from each other into 8-10 tubes with wort agar or Sabouraud agar with glucose, Litman agar. To inhibit the growth of bacterial microflora, 50 U/ml penicillin and 100 µg/ml streptomycin are added to the media. Crops are cultivated at 22-28°C and examined after 7-15 days.
When colonies appear, remove a piece of mycelium using a bacteriological loop and transfer it to a drop of 50% aqueous solution glycerol, cover with a coverslip and examine.
The diagnosis of ringworm is considered established in the presence of clinical signs of the disease and detection of the pathogen by microscopy of pathological material or isolation from culture material and determination of the type of pathogen.
Differential diagnosis. Microsporosis, scab, scabies, eczema and dermatitis of non-infectious etiology are excluded.
With microsporosis, there is no itching, the skin on the affected areas is smooth, the spots have an irregular shape, and the hair breaks off at some distance from the skin. Microscopic examination reveals only fungal mycelium inside the affected hair; small spores (diameter 2-3 microns) are located mosaically in the form of a sheath outside the hair, at its base. During a luminescent study in a darkened room under a portable mercury-quartz lamp PRK-2 with a Wood filter, hair affected by the microsporum fungus under the influence of ultraviolet rays gives a bright green emerald glow, which does not happen with trichophytosis.
With scab, the affected hairs are located in groups among healthy ones and do not break off, but fall out. The crusts that form on the affected areas of the skin have characteristic appearance“limpets” or shields with a depression in the center.
Scabies is accompanied severe itching; there are no limited round spots characteristic of trichophytosis; microscopy reveals scabies mites. With eczema and dermatitis there are no limited spots, hair does not break off. The results of mycological examination are negative.
Treatment. Sick animals are isolated and treated with vaccines, which are previously diluted according to the instructions for their use. The drugs are administered intramuscularly twice, with an interval of 10-14 days, in doses: lyophilized (dry) vaccine LTF-130 for the prevention and treatment of trichophytosis (ringworm) in cattle - calves up to 4 months - 10 ml,
from 4 to 8 months - 15 ml, over 8 months - 20 ml; concentrated live dry vaccine TF-130 K for the prevention and treatment of trichophytosis (ringworm) in cattle - calves from 1 to 5 months - 2 ml, young animals over 5 months and adult animals - 4 ml.
The therapeutic effect after the administration of the listed vaccines occurs 15-30 days after the second administration and is manifested in the thinning and rejection of trichophytosis crusts. To speed up the rejection of the crusts, the affected areas should be lubricated with emollients - Vaseline, fish oil.
Immunity. After being infected with trichophytosis, animals develop a long-lasting, intense immunity. For active immunization of cattle, the lyophilized (dry) vaccine LTF-130 is used for the prevention and treatment of trichophytosis (ringworm) in cattle and the concentrated live dry vaccine TF-130 for the prevention and treatment of trichophytosis (ringworm) in cattle; Vaccines are administered intramuscularly twice in the same place, with an interval of 10-14 days. Immunity in vaccinated calves occurs 21-30 days after the second injection of the vaccine and lasts for at least 7 years, in horses - after 30 days and lasts for 5 years, in rabbits and fur-bearing animals it occurs after 20-30 days and lasts for at least 3 years. The superosseous crust that forms at the injection site should not be removed, since it is rejected on its own by 20-25 days.
Lyophilized (dry) vaccine LTF-130 for the prevention and treatment of trichophytosis (ringworm) in cattle is harmless when used and does not cause disease in healthy animals. Administration of the vaccine to infected people in incubation period animals can lead to an acceleration of the manifestation of the clinical picture of ringworm with the appearance of multiple trichophytosis foci of a superficial nature. Such animals are administered a single therapeutic dose of the drug. The vaccine is suitable for use within 6 months from the date of manufacture, provided it is stored in a dry, dark room at 2-12 C. Before use, the lyophilized (dry) vaccine LTF-130 is dissolved saline solution according to the instructions for its use and is administered to calves from 1 to 4 months at a dose of 5 ml, from 4 to 8 months at a dose of 8 ml, to animals over 8 months at a dose of 10 ml. The diluted vaccine must be used within 2 hours of its preparation.
Concentrated live dry vaccine TF-130(K) for the prevention and treatment of trichophytosis (ringworm) in cattle is suitable for use when packaged in 40 doses for 18 months, 10 doses for 12 months from the date of manufacture, subject to storage in dry dark place at 2-10°C. Before administration, the vaccine is diluted with sterile saline according to the instructions for its use. For prophylactic purposes, the vaccine is used twice with an interval of 10-14 days in doses: 1 ml for calves from 14 days to 5 months, 2 ml for calves over 5 months and adult animals. Immunity occurs 1 month after the second injection and lasts for at least 7 years.
Prevention and control measures. In farms that are safe and threatened by ringworm, all emerging young animals from the age of one month, all young animals arriving at livestock complexes, all cattle coming from abroad for breeding and other purposes are vaccinated (immunized regardless of age).
When a diagnosis is made, the farm (farm, team) is declared unaffected by ringworm and restrictions are introduced.
It is prohibited to enter or remove animals from the farm (farm), with the exception of those intended for slaughter; regrouping within the farm without the knowledge of veterinary specialists; introduction of healthy animals into premises where sick animals were previously kept until cleaning, sanitary repair and disinfection. All susceptible animals are subjected to clinical examination once every 10 days. Sick and suspected cases are isolated and treated with vaccines. All other animals are vaccinated.
In case of forced slaughter of vaccinated animals in the first 10 days after vaccination, the meat is used on a general basis after excision of the injection sites. 10 days after the introduction of the vaccine, the slaughter of animals and the use of meat are permitted without restrictions. Milk from vaccinated cows is used for food without restrictions.
Manure is subjected to biothermal disinfection, after which it is used only for fertilizers. It is not permitted to use manure after biothermal disinfection for other purposes (manufacture of dung, etc.).
The farm is considered free from trichophytosis 2 months after the last case of isolation of clinically sick animals, as well as after final disinfection.
For disinfection, an alkaline formaldehyde solution containing 2% formaldehyde and 1% sodium hydroxide is used; hot 10% solution of sulfur-carbolic mixture when applying the solution twice with an hour interval between treatments; hot formalin-kerosene emulsion consisting of 10 parts of 40% formalin, 10 parts of kerosene, 5 parts of creolin and 75 parts of water. For final disinfection, an alkaline solution of formaldehyde is used.
Protecting humans from trichophytosis. To prevent ringworm in humans, it is necessary to thoroughly wash your hands when caring for sick animals. hot water with soap, disinfect them with a 1% chloramine solution. After work, work clothes and shoes must be disinfected in a steam-formalin chamber.
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