Ephemeral Fever

Ephemeral fever, also called three days sickness/stiff sickness/cattle Dengue fever, is an arthropod-borne viral disease of cattle and water buffaloes characterized by short duration of fever and stiffness with shifting lameness affecting one or more legs. The disease is colloquially known as "Weil" and occurs mainly in late summer and fall (August to November).

Etiology:
It is caused by an RNA virus belonging to genus Lyssa virs in the family Rhabdoviridae and is transmitted by mosquitoes (Culicoides, Culex), Midges and several other insects.

Signs and Symptoms:

• A sudden onset of moderate to high fever (41-42°C) which generally drops on the second day

• A monophasic, biphasic and triphasic fever of 24-48 hours duration

• Presence of pain in the throat region (animal shows it by refusing to swallow)

• Muscular stiffness

• Complete anorexia

• Grinding of teeth

• Severe depression

• Almost total loss of milk production

• Slight stringy discharge from the mouth and a moderate to copious seromucoid nasal discharge

• Lameness commonly develops on the second day. This lameness might have a tendency to shift from one leg to another. There is trembling of leg muscles. Most of the animals become recumbent and appear completely paralysed

• Rarely occurrence of oedmatous or emphysematous swellings and nervous manifestations (excitement or paralysis)

• Animal starts improving on the second day and recovers almost completely after 3 days (i.e. total course of the disease is generally three days).

Diagnosis:
The disease can be diagnosed on the basis of clinical signs and pathological changes (a marked neutrophilic leukocytosis coinciding with the onset of fever). Confirmatory diagnosis is based on viral isolation in suckling mice cell culture. Vim's neutralization is an official test certification.

Differential Diagnosis:

• The following conditions should be considered in differential diagnosis:

• Foot-and-mouth disease: In ephemeral fever, vesicles and ulcers are absent in the mouth and in the inter-digital space. In FMD, these lesions are present and there is copious stringy salivation.

• Traumatic pericarditis/reticuloperitonitis: There is no lameness and nasal discharge. The course of disease contrary to ephemeral fever is generally much longer.

• Milk fever: Ephemeral fever can be confused with milk fever because in both diseases there is recumbency at some stage of the disease. Milk fever generally occurs within first few days of calving. In this disease, there is complete loss of consciousness, rectal temperature is subnormal or normal and there is a prompt response to intravenous administration of calcium.

• Pneumonia: There is no recumbency and lameness. Tracheal and lung rales are pronounced. The nasal discharge, which is initially seromucoid changes to purulent

• Laminitis (vesicular disease): The affected animals have history of heavy grain feeding. There is local pain in the feet.

Treatment:

• Parenteral administration of antibiotics for 2 to 3 days

• Analgesic (NSAID e.g. Diclofenic sodium) intramuscular for 2 to 3 days

• Tonics e.g. vitamin B complex or aminoacids vitamins combination or aminoacids-vitamins-electrolyte-sugar combination.

• Fluid and electrolytes 4-5 litres/adult animal.

• Hand feeding of green grass, semi-solid gruels or porridge with jiggery. Avoid driving sick animals to hospital i.e. treat the animal at the spot

• Beneficial results have been known to follow the sweating of animals by means of blankets and rugs

• The most important thing about treatment is the need to explain to the owner that no matter what treatment is given, the animal should start getting better before 36 hours and there is need to explain to him that the animal would be perfectly well after three days. The milk production loss would recover after 10 days.

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