Special Veterinary Pathology

VESICULAR STOMATITIS

Synonym : Sore mouth of cattle and Horse

Definition

• Infectious disease, affecting almost all animals caused by Rhabdo virus.

Aetiology

• Rhabdo virus

Inicidence

• The disease is limited to western hemisphere

Susceptibility

• Mainly affects horse, cattle and pigs. Goat and sheep are resistant

Transmission

• Seasonal occurrence- Transmitted through vector( Mosquitoes, black flies, gnats and midges

Pathogenesis

• Virus multiply in mosquitoe (Aedes aegypti)
• Bite the susceptible host
• Pathogenesis is similar to FMD

Three antigenically different strains

• New jersey
• Indiana
• Trinidad

Clinical signs

• Cattle
• Vesicles on the tongue, lips, dental pad and buccal mucosa
•  The vesicles ruptured and the resulting irritation causes profuse salivation and anorexia

Gros lesions

• Cattle
• Vesicles on the tongue, lips, dental pad and buccal mucosa
• Horses
• Lesions are limited to dorsum of the tongue or lips
• Swine
• Vesicles on the snout, or on the feet
• Lameness

No myocardial lesions. No / very low mortality

Microscopic lesions

• Intercellular oedema in the stratum spinosum
• Cell dissociation and necrosis
• Neutrophils and macrophages infiltrate the necrotic tissue which sloughs, leaving erosions
• Intraepithelial oedema may become abundant enough to result in a vesicle
• Healing usually occurs in 7-10 days

Diagnosis

• Vesicular stomatitis cannot be produced in cattle by intramuscular inoculation
• Lingual route only possible
• FMD can be produced by intramuscular inoculation
• Symptoms, Differential diagnosis with FMD

Inoculation and susceptibility

DISEASE	CATTLE	HORSE	PIG	SHEEP	GUINEA PIG	MAN
FMD	+	-	+	+	+	+
VESICULAR STOMATITIS	+	+	+ CATTLE ONLY	+ CAN-LINGUAL	+ BE ROUTE	+ INFECTED
VESICULAR EXANTHEMA	-	CAN BE INFECTED	+	-	-	-