Mumps of equidae

Mumps of equidae. It is an infectious, contagious, infectious disease of equines , characterized, in typical cases, of a feverish course, by acute inflammation of the nasal mucosa and suppuration of the corresponding lymph nodes. The direct cause of the process, partially caused by viruses , is streptococcus equi.

Summary

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  • 1 Story
  • 2 Location
  • 3 Etiology
    • 1 Coloring
    • 2 Crops
    • 3 Endurance
    • 4 Artificial infection
    • 5 Responsiveness
    • 6 Natural infection
  • 4 Pathogenesis
  • 5 Anatomical alterations
  • 6 Symptoms
  • 7 Diagnosis
  • 8 Treatment
  • 9 Surgical treatment
  • 10 Prophylaxis
  • 11 Immunization
  • 12 External links
  • 13

History

The mumps of foals was considered for a long time as a specific disease of the young age, typical of the normal development of the animal , which produced the elimination of superfluous humors. On the other hand, the same disease, in adult equidae, was considered as essentially different (SOLLEYSEL, VITET, LAFOSSE). At the same time it was supposed to sometimes degenerate into glanders.

After BOUWTNGIIAUSEN had already warned in the late eighteenth century that [mumps] is an infectious disease, and Viborg and Erdélyi had demonstrated, in the early nineteenth century , infectiousness of the nasal flow of diseased equidae, including by inoculation experiments, Schütz (1888), and others, demonstrated the etiological value of streptococci already described ( 1873 ) by RIVOLTA. However, it has been spread in theory in modern times, according to which, in the mumps, streptococcus would only develop its pathogenic action in a part of the cases, in concomitance with a viral infection.

Location

The mumps usually attacks mainly foals, and for this reason it occurs very often in stud farms and foal deposits, where almost all foals tend to become ill to varying degrees; on the other hand, in later ages it is rarer, and it is almost only observed in equines that did not suffer it in the young age. It is widespread almost everywhere, Iceland , Ireland and Argentina are said to be exempt from it and, despite its generally benign course, causes considerable damage to horse owners, due to the temporary disorder it causes in the development of foals. and, in part, also for sometimes causing death.

Etiology

Mumps is caused by streptococcus equi; but, as experience shows, it is not a unique process from the etiological point of view, because in many cases, with the collaboration of unspecific predisposing factors, it originates directly from streptococcus, while in others it is a complication of the contagious cough (contagious catarrh ), and then streptococcus is here only the secondary agent in the characteristic suppurative processes. The cases described in the first place usually appear sporadically, while the latter are usually epizootic. There is no shortage of opinions according to which it would be, in any case, complications of a contagious cold.

In recent times, questions regarding the etiology of the disease have been clarified. Streptococcus was previously considered equi, in general, as the primary and sole agent of the process (SCHÜTZ et al.), And even recently, many authors, including SEELLEMAN ( 1952 ), hold this view. Undoubtedly, these germs can be isolated in pure culture many times in mumps-related lesions (recently verified by DORSSEN [1939]), and experiences also show that mumps can occur in equidae when their capacity resistance is weakened by nonspecific actions and in such circumstances that allow the possibility of contagion of any kind of virus to be excluded .

These facts are understandable by the circumstance that streptococcus equi is usually found in the airways of healthy equines (RICHTERS 1935 , PODGORSKI 1950 et al.). However, there was no lack of opinions according to which the pathogenic action of equi streptococcus in the mumps is favored; the same as in other processes (pleuropneumonia, etc.) in which streptococci also intervene, due to the action of a virus. This hypothesis, first supported by VALLÉE, received firm support when WAXBERG ( 1925) managed to transmit the disease artificially to two foals using germ-free filtered nasal flow from a sick horse. After this, HANKE (1936) drew attention to the surprising contagiousness of many mumps outbreaks in a few days, 25-45% of animals living in close contact can become ill, a circumstance that does not find a clear relationship with the simple etiology by streptococcus.

These theories received a boost from the experiences obtained during the Second World War, at least in the epizootic outbreaks caused by the easily demonstrable diffusion of the process, considering a virus as the primary agent of the disease (KÓBE 1939, CHORS 1941, BELLER 1941, BELLER and TRAUB 1941, GRATZL and TRAUB 1942 ). In all likelihood, it is the causative agent of contagious cough from equidae, because it has been repeatedly proven that frequently, contagious cough immediately becomes mumps (GRATZL and TRAUR et al.), And, on the other hand, MANNNGER (1943-1949) has also experimentally verified the effectiveness of these theories.

Coloration

Streptococci stain well with ordinary aniline dyes and by the GRAM procedure. With suitable methods, a capsule (CARPANE, Schiphorst) is also revealed in them.

Crops

In weakly alkaline media, Streptococcus equi can be grown aerobically and anaerobically at room temperature, and less so at body temperature. In jelly, and throughout the sowing by stinging, it forms very fine white spots; on agar, opaque white-gray colonies somewhat elevated in the center, about the size of poppy seeds, which co-adjoin and adhere firmly to the underlying part.

In agar, by stinging, it originates a gray-white thread, from whose sides protrusions in the form of wings start. In coagulated blood serum it produces grayish-yellow droplets, of vitreous transparency that, later, can come together and form a viscous layer; A fine sediment formed by very long chains is deposited in the condensation water.

Fine bouquets develop in the broth, which plummets to the bottom, the rest of the liquid remaining clear.

In blood agar plates it causes intense hemolysis (BROWN hemolysis). In potato it does not develop. Milk alone or with tincture of litmus or methylene blue coagulates, at most, temporarily. It ferments dextrose , sucrose and salicin, but does not dissociate lactose or sorbitol. It does not affect aesculin and does not hydrolyze sodium hippurate.

Resistance

Streptococci resist desiccation for several weeks, especially in pus or blood. The temperature of 70-75 ° kills them in one hour; On the other hand, the cultures in frozen broths still develop after two days of being frozen. They are destroyed in a quarter of an hour by sulfuric acid at 1: 150, soda lye at 1:85, sublimated at 1: 1500, iron sulfate at 1: 125, phenic acid or lysol at 1: 200, and for creolin at 1 80.

Artificial infection

Artificial infection is achieved, in equidae , by administering with their food or drinking water crops, purulent nasal discharge or pus from the ganglia (R. PFEIFFER and O. MÜLLER 1912), and more difficultly applying such material or pure culture to the nasal mucosa (SCHÜTZ; according to JENSEN and SAND 1887 , generally only when the epithelial layer has been previously injured by rubbing or is already sick with catarrh. After subcutaneous injection of culture, purulent inflammation develops, and after rubbing pus containing streptococci from skin excoriations, a feverish vesiculous dermatitis without papillic character develops.

Receptivity

Mumps is a disease that only solipeds suffer, generally from ½ to 5 years of age, although, the most, in that of postros; it is rare that they suffer it already in the one from 1 to 2 months or in the one of more than 5 years. The increased resistance of adult equidae is probably due, at least in part, to their once past disease. It is true that some equids contract it more than once, but then there are usually intervals of several years between the various infections; On the other hand, it is exceptional for an animal to become ill twice a day in the same year.

Natural infection

Sometimes the disease occurs without demonstrable contagion. It is not uncommon for equidae, especially adults, to have had no contact with sick animals or with their eliminations, immediately after cooling down, a long march, tiresome rail or boat transport, etc. These cases can be explained because the streptococcus equi is present in the mucosa of the equidae in a saprophytic form, penetrating into the tissues and causing mumps when the organism is weakened by harmful influences, which decreases its resistance capacity. Naturally, animals that have become ill in this way can infect their counterparts in the stable and meadow with virulent secretions.

But, in general, the disease is observed after a demonstrable contagion. In most cases it is an epizootic outbreak, in which contagious cough appears as the original process, and whose symptoms often go unnoticed. In such circumstances, depending on the possibilities of contagion, the number of patients can vary from isolated cases to 100%. The contagion is carried out mainly by air , both in what refers to the virus from contagious colds, like streptococci, because in poorly ventilated blocks the material expelled by coughs and snorts can remain attached to secretory foci or liquid droplets, which float in the air for a long time and then enter the respiratory tract of healthy horses or can go to feed.

Pathogeny

From the surface of the nasopharyngeal mucosa, streptococci enter the interstices and lymphatic vessels, along which they reach the regional lymph nodes, and determine the migration of leukocytes. At the same time, tissue fusion occurs and, with it, foci of pus that later converge and form large abscesses.

Once the contents of the abscesses have been evacuated, healing occurs with rapid defervescence. But in some cases streptococci reach more distant lymph nodes and occasionally cause new abscesses; In addition, they can cross the vascular walls and thus penetrate the hematic route and go, not only to distant lymph nodes, but to the most diverse internal organs, in which they also produce purulent inflammations if they have not previously caused rapidly fatal septicemia. . Generally, suppuration of the internal lymph nodes seems to occur in this way, that is, by blood.

In rare cases, foals are born sick (NOCARD, CHOISY), due to an intrauterine infection, produced through the placental circulation. It has been repeatedly observed that mothers presented, in such cases, during pregnancy, pharyngitis and suppuration of the lymph nodes of the external canal (TRÉLUT).

Anatomical changes

In mumps-dead animals, in addition to alterations in the superficial lymph nodes, there are others, variously localized, which reveal septicemia, most often metastatic, and, in cases of prolonged course, emaciation. In the peripheral, mediastinal, and bronchial lymph nodes, there are often abscesses that are walnut-sized to fist-sized and, exceptionally, that of a child’s head, containing creamy white pus with streptococci. They can compress or deflect the trachea or a neighboring bronchus .

At the same time, there may be a consecutive purulent inflammation of the pleura and pericardium. The lungs already offer only hyperemia and acute edema , catarrhal pneumonia, or have abscesses of various sizes, sometimes very numerous, included in their tissue. The mucosa of the bronchi, trachea, and pharynx is always hyperemic and relaxed, often dotted with bruising and covered with much mucous or purulent discharge, and often with gelatiniform infiltration at the level of arytenoepiglottic folds.

Symptoms

The incubation period can be from 4 to 8 days, but in the cases of disease called spontaneous, which occur after cooling, fatigue and similar harmful actions, the next day or the next day the disease begins with symptoms of acute feverish process, such as lassitude, increased temperature, and decreased appetite. Almost at the same time, at the latest 1-2 days later, there are symptoms of acute nasal catarrh. The nasal mucosa, first very red, hot and dry, soon secretes a liquid, initially serous, clear or slightly cloudy, later mucous, 3-4 days later, mucopurulent and, finally, purulent, which now slides in great quantity due to the back of the lip. At the same time, the muciparous glands of the nasal mucosa can swell to form consistent, hemp-sized nodules; also,Ulcers , of course, different from the mumeric ones, since they have bright red edges and bottoms. In young foals the nasal flow is usually lumpy, not very sticky and, when coughing or puffing, it is thrown in large balls through the nose. At the same time, animals cough frequently; In this period it is also frequent to observe acute catarrh of the buccal mucosa and the conjunctiva.

In the vast majority of cases, so that the first catarrhal phenomena occur, acute inflammation of the lymph nodes of the external canal can already be observed. The lobar structure, at this time, is still clearly perceptible by touch, but each lobe is larger, more consistent, and hurts under pressure. They soon converge and form a uniform swelling, which grows rapidly and fills the throat region.

The process very rarely affects neighboring nodes, and then the laryngeal regions and trachea also appear plastered . The swelling is limited inaccurately, and appears firm, tense, hot, and painful. When the retropharyngeal nodes are affected, the animals keep their heads rigid and stretched. The swelling, when it has reached a certain volume, often already on the fourth day of the disease, offers fluctuation in one or more points.

If the abscesses are not removed in time, the pus they contain makes its way to the outside and, once evacuated, the surrounding inflammatory edema decreases rapidly, but pus and ooze-like serousness still oozes from the opening, for a few days, until the cavity is finally filled with granulation tissue, the edges of the hole are closed, the tumor disappears entirely, and healing occurs.

Diagnosis

When mumps is manifested only by acute catarrh of the nose or pharynx, without suppuration of the lymph nodes, its specific nature can only be diagnosed with more or less probability if, at the same time, other animals become sick with symptoms of mumps. from the same stable. If there are lesions in the retropharyngeal lymph nodes, mumps can be confused, on the one hand, with simple pharyngitis and, on the other, with mumps. But if the disease process is exclusively located in the pharyngeal region, only the subsequent course of the disease will allow its nature to be evidenced, since, before, we will only conjecture it because of the possible suspicion of the contagion and, perhaps, also because pharyngitis phenomena generally reach a very high grade on mumps. In mumps, inflammatory swelling, at least initially, corresponds, more or less accurately, to the contours of the gland or its lobes. Later a softening occurs, almost always purulent.

Cases in which the disease is limited only to the lymph nodes in the body’s cavities are more difficult to diagnose well. However, in such cases, neutrophilic leukocytosis and the presence of indica in the urine allow the disease to be conceptualized as mumps, especially if there is anamnesis of a disease of the upper respiratory tract or if there are mumps in the equine in the same block. typical. The toad spots that remain after the coital mumps has healed can lead to suspicion of dourine, but lesions coexist in the latter disease

Treatment

In all circumstances, the utmost care must be taken in the hygiene of the accommodation and in the diet. Efforts will be made to ensure that the air in the stable is pure and uniformly tempered or, if the weather is hot and calm, the animals will be kept outdoors during the day, in the shade and in a place free of dust. As food, in addition to good forage and some oats, carrots are especially recommended or, in summer, green grass, clover or alfalfa; if dysphagia is present, it is indicated to administer puches of crushed barley or bran. The teat foals are placed next to the mothers at convenient intervals and are held while they suck; but if they swallow with great difficulty, it is necessary to resort to artificial feeding.

Injecting large doses (200-300 cc of immunoserum under the skin or, better still, intravenously) may be useful at the beginning of the disease. The immunoserum does not have any notable action, although it delays the tendency of the nodes to suppurate However, it almost always favorably influences the general condition of the patient and can also prevent the entry of streptococci into the bloodstream According to HICHTEBS (1930), the combined administration of 500 cc of immunoserum and 10 ce from a culture of streptococci killed by methylene blue, because the methylene blue vaccine excites the reticuloendothelial system, stimulating the production of antibodies.

According to multiple experiences, the application of sulfa drugs is more effective for treatment than serum therapy, which is why it should not be abandoned, although patients have also received serum. Among the sulfa drugs there are a number of them that are applicable for the treatment of mumps. For this purpose, simple sulfanilamide ( Prontosil album, Prontilín ) has been used , but other less toxic preparations ( sulfathiazole , sulfamethylthiazole , sulfapyridine , sulfamerazine , etc.) are more advantageous .

The precondition for the success of the treatment consists of the early administration of the preparations, always before the suppuration of the lymph nodes has taken place. The preparations can also be administered parenterally (intravenous, subcutaneous or intramuscular), but it is best to take the oral route, either in powder form, or in tablets, mixed with feed or drinking water, and preferably using the nasoesophageal tube. , prior to its dissolution in water. Adult horses receive in the first days, three times, 20-30 gr .; then, three times a day 10-15 gr .; foals, daily, three times 2-5 gr.

The improvement is observed after two days, with a drop in temperature, but the treatment should be continued for 2-3 days. When, after 4-5 days, no clear symptoms of cure are observed, it is useless to continue with this type of treatment, since better effects of sulfa drugs can no longer be expected, and when their administration is continued, they can cause even phenomena of intoxication. Furthermore, it should not be forgotten that the administration of sulfa drugs does not exclude symptomatic or surgical treatment.

Surgical treatment

It is usually essential, in most cases, to treat lymph nodes in the external canal. In recent cases, attempts will be made to combat inflammation with antiphlogistics (cold compresses, embrocations with mercurial ointments), although such a procedure usually fails. For these reasons, it is preferable to let the suppurative process take its course, favoring it with hot compresses or with humid heat. If fluctuation is seen at any point in the tumor, the purulent focus should be opened without delay. The abscess cavity is then washed with an antiseptic fluid, and the wound is treated according to the rules of surgery.

According to recent observations by Bonnov, BOUCHET ( 1929 ), NEUMANN-KLEINPAUL and RÜSCISER (1931), the mundification and healing of open abscesses is considerably activated by resorting to the BESREDKA antivirus (p. 502), because with it the purulent secretion quickly ceases. and the cavities are closed in a few days, thanks to rapid granulation. The abscess cavity is washed with anti-virus and a swab soaked in it is then inserted. The same effects are achieved by washing abscesses with lactic acid, according to Mócsy’s experiences.

If you are also ill or only the pharyngeal region it is even more necessary to feed with easy swallowing substances ( drinks , puches); at the same time, pharyngitis also requires special treatment.

The incision of superficial abscesses does not. It presents difficulties, but that of the deep ones, which are between the parotid and the posterior maxilla or in retropharyngeal tissue, and which must also be practiced as soon as possible, due to the imminent danger of suffocation, requires special precautions. As important vessels and nerves pass through here, which can be dislocated from their normal situation, it is recommended to incise only the skin of the most prominent point of the tumor with the scalpel and then, with a probe or catheter, try to separate the vessels and nerves from each other through penetrating movements and through the wall of the abscess, if possible.

In this way, it is possible to open not only the subparotid purulent foci, but also the retropharyngeal ones. This procedure sometimes doesn’t work on the spot, but 1-2 days later, the pus, on its own, goes into the duct that formed with your finger and eventually penetrates into it.

Dilation of abscesses of the anterior mediastinal lymph nodes requires extreme care. But after that of the lower cervical lymph nodes, usually also suppurative, it is possible to do it from this point. Because lower cervical lymph node disease is usually accompanied by marked swelling, the purulent foci are about 5 to 6 cm. under the skin. Despite this, the operation lacks singular difficulties, and especially the carotid and jugular wounds are not to be feared, since they pass through the medial part of the abscess and the incision must be made on the lateral or external part.

Prophylaxis

It consists of keeping healthy horses , especially foals, away from animals.sick and from the blocks and infected sites. In studs, foals born in them should be kept as isolated as possible from strange foals, and the newly acquired animals will only be installed in the stables of the foals and remounts after about two weeks of observation. If nevertheless the epizootic occurs in a pasture, it is sometimes possible to stop it by transporting healthy animals as soon as possible to a place free of it; In addition, in such cases, the animals must be protected with special care from cooling, which could reduce their resistance. Once the epizootic is extinguished, a rigorous disinfection of the stables and their utensils is necessary.

By means of adequate feeding, permanence and exercise in the open air, and resistance to the elements, the natural resistance of animals grows and, on the one hand, they are protected against spontaneous diseases and, on the other, the favorable course of the disease is facilitated.

Immunization

Different procedures have been developed and recommended, however, in general, they have not been recognized by professionals. Furthermore, preventive immunization has lost its importance since it has been possible to reduce the losses caused by mumps to the lowest limits, thanks to the correct administration of modern therapeutic methods.

 

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