Rhinopneumonia of horses: causative agent, symptoms, treatment and prevention

2024 Author: Howard Calhoun | [email protected]. Last modified: 2023-12-17 10:16

Equestrian rhinopneumonia is a dangerous contagious disease, accompanied by pronounced symptoms and can lead to very serious consequences. If timely treatment is not started, then mares can have a spontaneous miscarriage, and in the later stages, in the vast majority of cases, a respiratory infection is fatal. To prevent this, every breeder should be aware of the main clinical manifestations of sexual exanthema and existing methods of treatment.

A bit of history

There are a huge number of diseases that equids suffer from. Equine rhinopneumonia is one of the most dangerous. For the first time in veterinary practice, pathology became known at the beginning of the 20th century in the United States. Then, many heads died from sexual exanthema, which caused great concern among specialists. A few decades later, an outbreak of the epidemic was recorded in Germany, and then in Austria. Reason forconcern was the massive cases of involuntary abortion in mares. In the middle of the 20th century, a viral disease was rampant all over the world, including in Russia.

The origin of the disease was able to establish and describe the American veterinarians Dimock and Edwards. It is they who are considered its discoverers and authors of the first works. Subsequently, many scientists around the world have been studying the virus and developing methods to combat it. Work does not stop even today, since rhinotracheitis can drastically reduce the number of animals and cause huge economic damage not only to individual enterprises, but to entire countries.

General information

The main danger of sexual exanthema is that representatives of absolutely all breeds and age categories are susceptible to it. Young individuals are at an increased risk. As for other species of artiodactyl animals, to date there has not yet been a single recorded case of cows, sheep or other domestic animals getting sick with this disease.

Infection occurs by airborne droplets, as well as through contaminated feed, water and care items. If the carrier of the infection is not quarantined in time, the virus will quickly spread throughout the livestock. Aborted fetuses must be burned, as insects and carnivores can carry the pathogen when they are buried in the upper layers of the soil.

Etiology of disease

Let's dwell on this morein detail. The causative agent of rhinopneumonia in horses is a herpesvirus that has its own DNA molecule. Once in the blood, the virus spreads throughout the body, affecting soft tissues and internal organs. In pregnant mares, infection of the fetus also occurs through the placental barrier. As a result, growth and development stops, and over time, a miscarriage occurs. Young stallions most often die from the pathogen, because their nervous and reticuloendothelial systems are still poorly developed, so antibodies to the herpes virus are not produced, resulting in ideal conditions for the life and reproduction of pathogenic microorganisms.

As mentioned earlier, the virus infects soft tissues and internal organs, and also destroys the walls of blood vessels, which, in turn, leads to internal bleeding and swelling. In addition, it releases waste products that cause intoxication of the body. Many horse breeders are interested in the question of how many years a horse lives with this disease. It is rather difficult to answer it unambiguously, since everything here depends on many factors. If the pathology proceeds in a chronic form, then it develops slowly. But in an acute course, damage to the central nervous system and necrosis of soft tissues of such vital organs as the brain, liver, lungs and spleen occur. In addition, concomitant infectious diseases can develop along the way, which only aggravates the condition of a sick animal and makes treatment more difficult.

Classification

Veterinarians identify several forms of equine rhinopneumonia. Each of them has its own characteristics and clinical manifestations, so you need to consider them in more detail. The general classification is as follows:

• Respiratory form - it is characterized by a very high body temperature in animals, a complete refusal to eat, a strong cough and other pronounced symptoms.
• Abortive form - the mare has a spontaneous abortion. Clinical manifestations can be both intense and completely absent.
• Genital form - horses behave as usual, and the only sign of a herpes virus infection is the characteristic vesicles in the genital area.
• Nervous form - extremely rare, but one of the most severe. In 99% of cases, animals cannot be cured and they die.

Depending on the type of rhinopneumonia, treatment is selected, so sick animals must be examined by a qualified specialist.

Clinical manifestations

So what do you need to know about this? As noted earlier, herpesvirus infection is intense and pronounced. In this case, the symptoms depend on the form in which the disease proceeds. The first symptoms of equine rhinopneumonia become noticeable approximately 10 days after infection. If the animal is sick for the first time and it has not developed immunity to the virus, then the disease is acute and intense. In the absence of timely treatment, it becomes chronic. Among the main clinical manifestations are the following:

• fever;
• KVPD;
• inflammation of the mucous membrane of the eyes;
• high body temperature;
• lack of appetite;
• cough;
• nasal discharge;
• depressed state;
• oral hyperemia.

As the disease progresses, the following symptoms appear:

• laryngeal edema;
• inflammation of follicles;
• enlarged cervical lymph nodes;
• purulent nasal discharge;
• heart rate failure;
• bubble rashes in the genital area.

With the development of the third form of equine rhinopneumonia, muscle weakness can be observed, as well as paralysis of the limbs. This is due to necrotic lesions of the peripheral nerves.

Basic diagnostic methods

With 100% accuracy, only a qualified veterinarian can confirm or deny the presence of rhinotrachiitis in a sick animal based on a complete examination and test results. To date, there are many methods for diagnosing equine rhinopneumonia. The most accurate and informative are the following:

• blood test;
• histological examination;
• analysis of epidemiological data;
• pathoanatomical autopsy of an aborted fetus;
• laboratory study of mucous secretions;
• differential diagnosis;
• serological tests;
• virological research;
• histological examination.

If a viral abortion is confirmed, infected animals will be immediately isolated from the rest of the population to prevent further spread of the virus. After that, the veterinarian, based on the clinical picture and the state of he alth of the animal, selects the most effective therapy program.

Basic treatments

A vaccine against equine rhinopneumonia called Novarsenol is being used to combat the contagious disease.

In addition, an additional course of antibiotics is prescribed (to avoid the addition of a bacterial infection). The most common drug is Amoxisan.

Immunization

In recovered animals, immunity to the herpetic virus is developed, but over time it weakens. Therefore, in order to reduce the likelihood of relapses and re-disease, it is necessary to support the immunity of animals. Vaccinations are recommended periodically. Equine rhinopneumonia is a rather serious disease that needs to be de alt with when the first symptoms appear. Today, one of the best vaccines for animals is considered to be produced from cultured attenuated strains of the virus. It is injected to animals twice with an interval of six months. Young animals are immunized in the third month of life, after which the procedure is repeated,when the animals reach 6 months of age.

Pregnant mares need to be vaccinated at an earlier age, as they are much more sensitive to conditions and more prone to various diseases than other individuals. Veterinarians recommend using the French-made Pneumequin vaccine or the Dutch Equilis vaccine for immunization.

In our country, hyperimmune serum has become more widespread. It is used not only for the purpose of prevention, but also for the treatment of sexual exanthema in the early stages of the course.

Prevention measures

The development of any disease in horses can be prevented if they are provided with exceptionally high-quality nutrition, proper housing conditions and good care. In the case of sexual abortion, it is very important to prevent the further spread of the virus, which is highly survivable. Experts recommend following the completion of the treatment of sick animals:

• mare who had a miscarriage should be placed in a separate room;
• carefully monitor the condition of the rest of the livestock;
• aborted fetuses are burned and all horse care equipment is disinfected;
• animals get preventive vaccinations;
• premises, inventory and harness are treated with special solutions.

In addition, it is forbidden to export horses from the territory and transfer semen to other farms, as this may lead to the spreadthe virus to other farms and contribute to the development of the epidemic.

A few words about animal slaughter

If a farm breeds horses for the purpose of obtaining meat, then if rhinopneumonia is found on it, it is forbidden to sell or eat the products for human consumption. However, it can be used for the following purposes:

• meat is allowed to feed other animals, since only horses can get sick with the herpetic virus;
• bones and internal organs are to be burned;
• leather can be used after 12 hours of disinfection in a weak solution of milk of lime.

It is also recommended to call a veterinarian to examine the animals and perform all necessary laboratory tests. This will ensure that the rest of the horses are in good he alth.

Life expectancy of sick horses

Despite the seriousness of the disease, it is not always fatal. How many years does a horse with rhinopneumonia live? If it proceeds in a chronic form, then there will be no special he alth problems, however, it is impossible to keep a sick animal in a common pen, since it will be a carrier of the virus.

In an acute course, a horse can be cured if therapy is started in a timely manner. But in the acute stage of the course of the pathology, things are not so rosy. With necrosis of the soft tissues of the internal organs of the stallions, it is impossible to save them, and they die in severe agony in just a few weeks. That's whyto alleviate the suffering of animals, it is recommended to euthanize them.

Possible Complications

If a stallion or a mare gets sick with sexual exanthema, then almost never any complications are observed. Animals return to their usual way of life, and they also retain their reproductive capacity. Therefore, horse breeders should not have any cause for concern. However, this issue should not be taken lightly. In its advanced form, the disease is difficult to treat and can be fatal.

Conclusion

Rhinopneumonia is not yet a death sentence for horses. If sick animals are quarantined in time and therapy is started, they can be completely cured without any consequences. Therefore, the breeder should closely monitor the he alth of their wards and immediately call the veterinarian if the first symptoms occur.