The source of salmonella infection in a herd can be from other cattle, birds, cats, rodents, the water supply, or a human carrier. Clinical signs associated with salmonella infection include diarrhea, blood and fibrin in the feces, depression, and elevated temperature. The disease is more severe in young or debilitated calves. Finding a membrane-like coating in the intestine on necropsy is strong presumptive evidence that salmonella might be involved. Salmonella isolations should be checked by a bacteriologic sensitivity test to determine the antibiotics of choice.
Enterotoxemia can be highly fatal to young calves.
It is caused by toxins produced by Clostridium perfringens organisms. There are 6 types of Clostridium perfringens that can produce toxins, of which types B, C, and D appear to be the most important in calves. The disease has a sudden onset. Affected calves become listless, display uneasiness, and strain or kick at their abdomen. Bloody diarrhea may or may not occur.