Malignant catarrhal fever: causes and symptoms, methods of treatment of cattle

Malignant bluetongue, or fever, in cattle is a non-contagious sporadic infection. Manifested in cows by croupous inflammation of the serous, mucous membranes of the gastrointestinal tract, damage to the respiratory system, lymphadenitis, stable high temperature, and nervous disorders. Agricultural animals of all ages, breeds, wild, domesticated artiodactyls are susceptible to infection.

History of Appearance

Malignant catarrhal fever (MCG, malignant catarrh of cattle) was first described by Anker in 1832. The zoologist named the infection "bovine typhus".In the Russian Federation, the disease was established in 1873 by I. I. Ravich. The infectious nature of ZKG was identified by Metam in 1923, and described the causative agent of catarrhal fever in his scientific works by Piercy in 1953

Malignant catarrhal fever is registered everywhere in the world, in all regions of our country. The infection manifests itself seasonally, sporadic outbreaks, local enzootics in individual livestock complexes, farms.

Causes of disease

Malignant catarrh of cattle is caused by a lymphotropic filtering DNA virus of the Herpesviridae family. Having penetrated into the body, the pathogen is transferred with the bloodstream to the brain cells, lymph nodes, parenchymal organs. Affects mucous membranes, serous membranes, tissues.

Important! Under favorable conditions, the MCG virus remains virulent in the external environment for 32-38 days.

The source of infection are sick individuals, latent virus carriers. The main method of transmission of ZKG is contact, airborne. Causes of malignant catarrhal fever in cattle:

Cattle grazing with other artiodactyls;
unfavorable containment conditions;
nursery with adults;
unbalanced poor diet;
feeding with rotten, wet hay, rotten feed;
low body resistance, reduced immunity;
hypo-, beriberi;
prolonged hypothermia of the body;
chronic respiratory infections, diseases of the respiratory system in cows.

Infected pastures, premises contaminated with feed pathogens, bedding, inventory are also the main sources of infection of cows with catarrhal fever. Possible intrauterine (transplacental) infection of fetuses with MCG.

Signs and effects

In sick cows, MCG in the early stages is manifested by difficulty swallowing, shortness of breath, coughing fits, a sharp increase in temperature up to 41.5-42 degrees. Fever, chills are stable. In cattle, appetite worsens, behavior changes. The prodromal period is characterized by nervous disorders (impaired coordination, convulsions, paresis).

Animals react inadequately to stimuli, become shy, get tired quickly with minimal activity. Attacks of oppression, apathy are replaced by violence.

Manifestations, symptoms of malignant catarrhal fever in cattle:

stable high fever, fever, chills;
loss of appetite, refusal to feed;
nausea, vomiting;
disturbance of digestive processes;
increase, soreness of the lymph nodes;
lacrimation, mucous, purulent discharge from the eyes;
anemia (pallor) of the mucous membranes, swelling, sticking together of the eyelids;
photophobia, keratitis;
poor response to external stimuli;
short-term loss of consciousness;
muscle spasms, convulsions, paresis;
papular-vesicular rash on the neck, abdomen, udder, genitals;
peripheral edema, tissue infiltration by lymphocytic type;
rashes, dry crusts on the nasal speculum;
unstable stools, foul-smelling diarrhea;
difficulty urinating;
cough, shortness of breath, bronchitis;
weight loss.

Important! The incubation period for MCG in cattle lasts from several days to three to five months. The disease proceeds acutely, superacutely, chronically. Cases of an atypical form of an infection are known. High mortality is noted in hyperacute, acute course of MCG.

In patients with malignant catarrh of lactating cows, milk output is completely absent or milk yield is reduced. Flakes of fibrin, bloody inclusions are noticeable in milk. In infected individuals, breathing is superficial, labored. Foci of necrosis, white dry crusts, brown scabs appear on the nasal speculum.

Animals are very thirsty. The chewing gum stops. In cows, the secretory function of the gastrointestinal tract is disturbed. Profuse bloody diarrhea is replaced by short-term constipation. Fibrin flakes, undigested food are present in the feces. The abdomen is enlarged due to increased gas formation, intestinal peristalsis disorders.

On palpation, pain is noted, an increase in regional lymph nodes. On the mucous membrane of the nasal and oral cavities, foci of inflammation, sores, and erosive manifestations are noticeable. If treatment is not started in time, catarrhal fever provokes intestinal atony, severe colic, intestinal spasms, paralysis of the respiratory system.

Diagnostic measures

When making a diagnosis of malignant catarrh, the epizootological situation in the region is taken into account, the anamnesis data, and the results of clinical studies are taken into account. Mucus from the oral cavity, nasal cavity, outflow from the eyes, feces, urine, blood are taken from the cow for analysis. The most accurate picture of the situation with this disease in the regions, livestock complexes is obtained from the results of serological tests, pathoanatomical data.

In addition, differential diagnosis is prescribed due to the similarity of symptoms of catarrhal fever with adeno-, rotavirus infection, rhinitis, purulent conjunctivitis, parainfluenza, listeriosis, rabies, leptospirosis.

Treatment of malignant catarrhal fever

Traditional veterinary medicine resorts to complex therapy when diagnosing in cows, buffaloes GKG.

Used in the treatment of catarrhal fever:

complex antibiotics;
anti-inflammatory, antipyretic;
cardiac glycosides;
sulfonamides;
enveloping the gastrointestinal tract solutions;
cold compresses;
autohemotherapy for a protracted form of infection.

To normalize the general condition, the functioning of internal organs, digestive processes, symptomatic drugs, probiotics are indicated. The oral cavity is irrigated with potassium permanganate (diluted in a ratio of 1/1000), after which the affected areas are lubricated with Lugol's solution. The therapy is supplemented with vitamin and mineral supplements, general strengthening, tonic preparations.

Important! During the treatment of patients with malignant catarrhal fever, cows are isolated from the general herd, kept in darkened, well-ventilated rooms. When feeding, use juicy, soft food. Drink acidified water.

Carry out a thorough disinfection of the premises, adjust the diet, improve the conditions for keeping farm animals.

Is there a quarantine?

When diagnosing malignant catarrhal fever, farms introduce quarantine. In the case of numerous outbreaks of infection in the complexes, the region is unfavorable. Strict quarantine measures are being introduced to prevent the spread of catarrhal fever in cows.

Important! In some agricultural lands, farms, complexes, malignant catarrh of cattle can manifest itself periodically, seasonal outbreaks for 4-10 years in a row.

The import and export of livestock for production purposes, breeding, breeding, and the sale of meat and dairy products from cows is prohibited until the complete removal of restrictions from regions that are unfavorable for this infection, livestock, farm complexes, and yards. Terminally ill cows are sent for slaughter with subsequent disposal of corpses.

Prevention measures

To prevent outbreaks of bluetongue in cows, a number of preventive measures are being taken.

Preventive measures:

separate keeping of young animals with adults, separate grazing of cattle with sheep, goats;
compliance with sanitary and hygienic standards on farms;
systematic disinfection of barns;
quality balanced diet;
separate keeping of recovered animals from he althy individuals.

If cattle are suspected to be infected with catarrhal fever, a daily clinical examination of the entire livestock is carried out.