Tyzzer's disease is a contagious bacterial disease in rat

Rat

Rats are various medium-sized, long-tailed rodents of the superfamily Muroidea. "True rats" are members of the genus Rattus, the most important of which to humans are the black rat, Rattus rattus, and the brown rat, Rattus norvegicus...

s, gerbil

Gerbil

A gerbil is a small mammal of the order Rodentia. Once known simply as "desert rats", the gerbil subfamily includes about 110 species of African, Indian, and Asian rodents, including sand rats and jirds, all of which are adapted to arid habitats...

s, raccoon

Raccoon

Procyon is a genus of nocturnal mammals, comprising three species commonly known as raccoons, in the family Procyonidae. The most familiar species, the common raccoon , is often known simply as "the" raccoon, as the two other raccoon species in the genus are native only to the tropics and are...

s and horses. It is caused by Clostridium piliforme, formerly known as Bacillus piliformis, a spore-forming bacterium.

It is transmitted horizontally through the fecal-oral route. Animals that carry the bacterium are usually asymptomatic, but a clinical syndrome may be seen in recently weaned rats, and immunocompromised foals.

Nonspecific signs such as anorexia

Anorexia (symptom)

Anorexia is the decreased sensation of appetite...

, lethargy, emaciation

Emaciation

Emaciation occurs when an organism loses substantial amounts of much needed fat and often muscle tissue, making that organism look extremely thin. The cause of emaciation is a lack of nutrients, starvation, or disease....

, ruffled fur, or sudden death without clinical signs may be observed. Mucoid, bloody diarrhea

Diarrhea

Diarrhea , also spelled diarrhoea, is the condition of having three or more loose or liquid bowel movements per day. It is a common cause of death in developing countries and the second most common cause of infant deaths worldwide. The loss of fluids through diarrhea can cause dehydration and...

 may also be seen. On necropsy, animals may have megaileus

Ileus

Ileus is a disruption of the normal propulsive ability of the gastrointestinal tract.Ileus is commonly defined simply as bowel obstruction. However, authoritative sources define it as decreased motor activity of the GI tract due to non-mechanical causes...

. Many other organs, including liver, cecum, colon, and heart, can have characteristic pathologic lesions. Histopathologic observation of bacilli in target organs is diagnostic, and best obtained using a Warthin-Starry silver or Giemsa stain. There is no recommended treatment other than supportive care. Antibiotic

Antibiotic

An antibacterial is a compound or substance that kills or slows down the growth of bacteria.The term is often used synonymously with the term antibiotic; today, however, with increased knowledge of the causative agents of various infectious diseases, antibiotic has come to denote a broader range of...

s effective against Clostridia spp. may be used.