Vesicular Stomatitis

Vesicular Stomatitis is also known as Sore mouth, Pseudo foot and mouth disease, Mouth thrush, sore nose.

Vesicular stomatitis is a viral disease of horse, cattle and pig is characterized by vesiculation, ulceration, erosion of oral and nasal mucosa, epithelial surface of tongue, coronary band and teats, along with crusting lesions of the muzzle, ventral abdomen and sheath.

Etiology

• It is caused by by Vesiculoviruses of the family Rhabdoviridae.
• The virus contains two distinct serotypes New Jersey and Indiana. The Indiana has three subtypes.
• The New Jersey strain is most virulent and most common.
• The virus was destroyed by boiling and common disinfectant.

Epidemiology

• The disease is restricted to western hemisphere (America) however; it was previously described in France and in South Africa.
• In United States sporadic outbreaks occur periodically in late summer and autumn. The incidence of disease sharply decline with onset of cold weather.
• Horse, cattle, donkeys are more susceptible, but infection occur in pig, camelids, sheep and goat and human.
• Outbreak of disease is most common in horses and cattle.
• Calves are more resistant to infection than adults.
• Saliva and vesicular fluid from infected animals act as source of infection.

Transmission

• The virus can be biologically transmitted by sand flies (Lutzomyia sp) and black flies (Simulium sp) and mechanically by culicoides sp.

Clinical manifestation

Incubation period for Vesicular Stomatitis is 3 to 15 days in animals.

Cattle

• Sudden appearance of mild fever
• Development of vesicles on the dorsum of tongue, dental pad, lips and buccal mucosa
• Ruptured vesicles results in irritation causes profuse roapy salivation and anorexia
• Ulcers and erosions of the oral mucosa and mucocutaneous junction of lips
• Decreased milk yield
• Lesions on the feet and udder occur rarely
• The extensive teat lesions may lead to development of mastitis

Horses

• Clinical signs are similar to cattle
• Fever, depression and inappetence
• Drooling of saliva
• Vesicles coalesce and rupture with detachment of epithelium and formation of shallow ulcer
• The lesion are limited to dorsum of the tongue
• Crusting lesions of muzzle, ventral abdomen, prepuce and udder
• Lesion may occur at coronary band and leads to lameness and deformity of hoof wall

Pigs

• Vesicles develop on or behind the snout or on the feet
• Lameness is frequent than in other animals

Sample collection

• Vesicular fluid and lesions

Diagnosis

• Based on clinical sign
• Isolation of virus in tissue culture
• Viral  RNA is detected by RT-PCR and indirect sandwich ELISA
• The complement fixation (CF) test is also a good alternative. The virus neutralisation (VN) test may be used, but it is elaborate and time-consuming
• Detection of antibodies by liquid phase blocking ELISA, competitive ELISA, VNT, AGID and CIE

Differential diagnosis

• Foot and mouth disease
• Swine vesicular disease
• Vesicular exanthema

Treatment

• Specific treatment is not available. Measures aimed at minimizing secondary infections may be beneficial.
• Movement restrictions and a 30-day quarantine period following the last clinical cases are recommended for infected premises.
• Insect-proof buildings and avoidance of habitats associated with insect vectors reduce the likelihood of infection.
• Although both inactivated and attenuated vaccines have been used, they are not commercially available.

Control

• Animal movement from farm should be prohibited for 30 days until after all lesions have healed.
• Hygienic and quarantine precautions.