Clinical Signs

 

The virus invades epithelial cells, with clinical signs resulting from vesicular lesions that progress to ulcerations on the nasal cavity, oral cavity, esophagus, upper GI tract, coronary band, udder, and between the digits.  Consequently, there are marked decreases in milk and  meat production, loss of weight, and reluctance to move (lameness).  Furthermore, there is high mortality among calves due to a decreased nursing time on the ulcerated teats and the affinity of the virus to their myocardium (Tiger Heart) once the disease is contracted. This disease is of major veterinary importance because the virus is highly contagious among animals and leads to major secondary infections.  Clinical signs of swine and cattle are exemplified below.

 

Swine

 

 

An example of the pig foot epithelium bursting and peeling resulting in lameness.

 

   Cattle

 

The early stage of a common Vesicular Lesion or blister.	Vesicular lesions that have burst and become erosions and ulcers.

                   

An example of the FMD virus attacking the cattle hoof in the early stage of disease onset.  Eventually this results in lameness as the vesicular hoof epithelium burst and peels, exposing the hoof tissue.	FMD vesicular lesion in the early stages on the teat of a cow.

 

Calf - Tiger Heart (Myocarditis)

 

Myocarditis, or inflammation of the muscular walls of the heart, is a common sign of FMD.	Death is the usual result of myocarditis among newborn calves that contract FMD .