Equine Influenza

Table of contents:

Equine Influenza
Equine Influenza

Equine influenza is an acute highly contagious disease characterized by damage to the respiratory system and intermittent fever. Caused by the equine influenza virus.

Influenza causative agent

The flu virus is round or filamentous. The approximate chemical composition of the influenza virus is as follows: 0.8-1.1% ribonucleic acid, 70-75 - protein, 20-40 lipids and 5-8% carbohydrates.

Influenza is one of the most common diseases in animals and humans. This is due to the variability of the virus, as a result of which the immunity that forms after a disease caused by one type of virus does not protect against infection with another type.

Equine influenza virus type 1 is less serious in horses of all ages than type 2 strains, which often cause severe infections characterized by a dry, painful cough and severe intermittent fever. Equine influenza is highly contagious and rapidly spreads to large horse populations. The main route of transmission of the pathogen is aerogenic, maybe contact.

Pinto horse in summer in the pasture, photo photography
Pinto horse in summer in the pasture, photo photography

The spread of influenza is largely determined by two factors: the state of immunity in horses to the pathogen and the variability of the virus.

Horse lungs have macroscopic and microscopic features, which in part determine the nature of the lesions in viral respiratory diseases. Getting on the mucous membrane of the upper respiratory tract, the virus enters the epithelial cells. As a result of cell destruction, reactive inflammation develops, which, however, does not prevent further progression of the infection. The infection spreads to the lower parts of the respiratory tract: erosive bronchitis, peribronchitis, periarteritis, bronchopneumonia develop. Lesions of other organs can also develop - myocarditis, encephalopathy.

The influenza virus is released into the external environment along with the smallest spray from the respiratory tract

In response to the multiplication of the influenza virus, specific immune responses of the body arise, local antibodies to the virus are formed, which play a leading role in the body's defense against influenza infection. With a mild illness, pathological changes in organs are quickly restored. As a result of complications, secondary bronchopneumonia often develops, the outcome of which depends on the timely application of treatment.

Disease symptoms

The incubation period for the natural course of influenza in horses is 1-6 days. In some cases, a shorter incubation period is noted - 18-20 hours.

A typical manifestation of equine influenza is characterized by depression, inflammation of the mucous membranes of the eyes and nasal cavity, enlargement of the periopharyngeal lymph nodes, and a shallow cough. Then there is a rapid rise in body temperature to 39.5-40 ° C. The body temperature is maintained for 1-4 days. Simultaneously with the fever, a dry, painful cough appears. When the horse moves, the cough increases. Sick horses are depressed and have decreased appetite. The pulse is speeded up to 65-75 beats per minute.

Horse in a blanket on the street, photo photography
Horse in a blanket on the street, photo photography

The clinical picture of influenza in horses is quite diverse and depends on the conditions of keeping and operating horses, their immune status, and the biological properties of the pathogen. In cold, damp weather, influenza is difficult and is often complicated by secondary bacterial infection.

According to the severity of the manifestation of equine influenza, there are typical, atypical and malignant forms

Atypical influenza in horses is often observed when they are infected with serotype 1 virus. In animals, mild serous rhinitis and a rare shallow cough are observed. Fever is either absent or not recorded.

Health control and conservation of the horse
Health control and conservation of the horse

Related article Health Management and Conservation of the Horse

Influenza caused by the second serotype virus is more severe. The malignant course of the infection is often noted. With malignant flu, horses have a dry, hacking, painful cough. When coughing, the horse lowers its head, mucous discharge is released from the nasal openings. In the study of cardiac activity, arrhythmia, prolapse, splitting or bifurcation of heart sounds are detected. In recovered horses, changes in heart tones and rhythm are observed over several months. Hard work of sick horses in some cases can lead to their death due to degenerative changes in the heart.

When complicated by the secondary microflora of the primary process caused by the influenza virus, the cough becomes short, deaf, painful. When breathing, wheezing appears - wet or dry. The temperature is often elevated for a long time - one to two weeks.

An indicator of the development of a secondary infection is mucopurulent discharge from the nasal openings. Treatment of complicated forms of influenza is possible with the use of antibiotics.

Popular by topic