The Devastating Impact of Rinderpest: Understanding the Disease and its Effects on Cattle

Rinderpest, also known as cattle plague, is a contagious viral disease affecting cloven-hoofed animals (mainly cattle and buffalo). 

Historically, rinderpest disease occurred in Africa, Europe, and Asia. The Americans and Oceania never faced this disease. The infected animals that recovered from this disease had a lifetime acquired immunity though in the past vaccination programs led to a continuous decline in the prevalence of this disease.

It is a contagious viral disease of cloven-hoofed animals more so in cattle and is characterized by fever, erosive stomatitis, and gastro-enteritis. It caused devastating losses in numerous parts of the world. Today it remains the most dangerous disease for cattle and wildlife.

Causes of Rinderpest in Cattle

Rinderpest is caused by a virus of the Paramyxoviridae family, genus Morbillivirus. Myxovirus, there are many strains with considerable variation in virulence between them but are immunologically identical. It has some antigenic relationship to the viruses of canine distemper and measles.

How Rinderpest Disease is Spread

Rinderpest is spread by effective contact between animals carrying the virus and susceptible animals. The virus is found in nasal secretions a few days before clinical signs appear.

It requires close or effective contact between sick animal carrying the rinderpest disease virus and healthy animals which is susceptible to animal species for example wallowing habits of buffaloes, and animals at drinking points. Viruses are transmitted by large droplets, airborne virus survives longer at higher relative humidities.

The virus does not survive long in the environment and is quickly inactivated by putrefaction, high temperature, and pH (alkalinity or acidity) changes. It is relatively resistant to cold and survives on those premises for a few days.

In highly susceptible populations, morbidity and mortality rates are usually very high, and infected wild animals can spread the disease through their migrations and movements.

Note:

Rinderpest is found in nasal secretions a few days before any clinical sign appears. As the disease progresses, the rinderpest virus can be found in most body fluids and either death ensues or the animal recovers and develops disease immunity and clears the virus from the body.

Some wild animals can carry the rinderpest virus without showing any clinical signs of the disease and in a few cases if they make body contact with domestic animals it leads to the re-introduction of rinderpest disease.

Clinical Signs of Rinderpest in Cattle

In cattle which is the most susceptible species, classical signs of rinderpest disease include;

1. The incubation period is 6-9 days.
2. High fever of about 40.5-41.5℃.
3. Anorexia, grain-like bumps in the nostrils.
4. Nasal and Lachrymal discharges with a high mortality rate.
5. Staring hair coat.
6. Soon inflammation of the buccal cavity (stomatitis) and nasal mucosae with blood-stained salivation.
7. Eye lacrimation is also purulent.
8. Erosions with sharp edges, the base of the erosions being red due to congestion of the capillaries (discrete to coalesce and ulcerate). Ulceration due to secondary bacterial infection.
9. Similar lesions are seen on nasal and vulvas mucosae but vesicles never appear.
10. Severe diarrhea now occurs due to similar lesions in the abomasum and intestines, and tenesmus occurs.
11. Dyspnoea, and persistent cough.
12. Dehydration and the temperature fall to subnormal.
13. Death occurs after 6-12 days.
14. Skin lesions sometimes seen are probably due to secondary bacterial infection, or others that were quiescent. In sheep and goats, the clinical picture is similar too.
15. Lesions are limited to the soft palate and tonsils. There is no lachrymation and the lungs are more commonly affected. (Disease takes a mild course in cattle).

Note:

In cattle, when the animal's resistance is high, sub-acute form: lesions are mild causing mild fever, mild anorexia, mild mouth lesions, and diarrhea is absent or slight. Profuse diarrhea and dehydration often led to death within 10-15 days though in other species rinderpest may show milder clinical signs.

Postmortem Findings of Rinderpest in Cattle

The buccal, nasal, and valvular mucosae, as well as the abomasums, exhibit similar lesions. The pyloric region is swollen and reddened, with hemorrhages. The vaginal mucosa also shows erosive lesions that resemble those in the mouth.

Additionally, at the crests of the mucosal folds in the caecal colic junction, there are hemorrhages and erythema. The wrinkled nature of this area gives it a striped appearance.

Diagnosis of Rinderpest in Cattle

In milder cases, clinical signs alone do not provide a specific indication of rinderpest disease. However, serological tests can determine whether the animals have been exposed to the virus. A definitive diagnosis, on the other hand, requires identifying the virus from a blood test or tissues.

The clinical signs of rinderpest include a febrile fatal disease with a short course, characteristic lesions in the mouth and digestive tract, diarrhea, and salivation.

To diagnose rinderpest, it is necessary to take samples and send them to a laboratory for analysis. This involves taking sections of the gastrointestinal tract containing lesions, as the virus has a predilection for lymph fluid. Blood samples and spleen samples can also be used for diagnosis.

Additionally, transmission experiments can be used to diagnose the virus.

Differential Diagnosis of Rinderpest in Cattle

When diagnosing rinderpest in cattle, it is important to consider the following differential diagnoses: foot and mouth disease, which is characterized by vascular lesions in the mouth; bovine malignant catarrhal fever, which presents with lymphadenopathy, congestion of the nasal and buccal mucosae, and eye lesions; hemorrhagic septicemia, which exhibits rapid onset and throat swelling.

Treatment of Rinderpest in Cattle

There is currently no known treatment for rinderpest virus infection. This, along with the high incidence of illness, contributes to the devastating nature of the disease.

Whenever an outbreak is suspected, animals that have come into contact with infected animals must be quarantined without delay.

In the early stages of the disease, intravenous antiserum is administered, along with high doses of sterile normal saline to address dehydration.

Measures to Control Rinderpest Disease in Cattle

Movement control, destruction of infected and contact animals, disposal of carcasses and infective material, sanitation, and disinfection.

The vaccination program is conducted annually for all ages and is administered subcutaneously. All animals share a common antigenicity, and they should receive vaccines that produce the necessary immunity without causing severe reactions such as animal curling, slaughter or destruction of infected animals, or other in-contact animals.

Conclusion

In conclusion, rinderpest, also known as cattle plague, is a highly contagious viral disease that has caused devastating losses in cattle populations around the world. It is characterized by high fever, erosive stomatitis, gastroenteritis, and high mortality rates. The disease is caused by a virus of the Paramyxoviridae family, genus Morbillivirus, and is spread through effective contact between infected and susceptible animals.

Unfortunately, there is currently no known treatment for rinderpest virus infection, making prevention and control measures crucial. Quarantine of affected animals, movement control, destruction of infected and contact animals, proper disposal of carcasses and infective material, sanitation, and disinfection are key steps in controlling the spread of the disease. Vaccination programs are also important in providing immunity and reducing the prevalence of rinderpest.

It is vital for farmers and authorities to remain vigilant and implement strict biosecurity measures to prevent the re-introduction of rinderpest. By understanding the causes, symptoms, and control measures of this dangerous disease, we can work towards protecting our cattle and preventing further outbreaks. Let's prioritize the health and well-being of our livestock by staying informed and taking proactive steps to mitigate the risks associated with rinderpest.