Tyzzer disease in 19 preweaned orphaned kittens.

Area of Science:

• Veterinary Pathology
• Microbiology
• Feline Medicine

Background:

• Clostridium piliforme, the causative agent of Tyzzer disease, has historically been underestimated as a feline pathogen.
• Kittens, especially those under six months old, are susceptible to gastrointestinal and hepatic infections.

Purpose of the Study:

• To investigate the prevalence and clinical presentation of Tyzzer disease in kittens with colitis, hepatitis, and/or myocarditis.
• To compare the diagnostic sensitivity of modified Steiner stain versus PCR for Clostridium piliforme detection in formalin-fixed, paraffin-embedded tissues.

Main Methods:

• Retrospective analysis of 37 feline cases (<6 months old) with colitis, hepatitis, or myocarditis from 2000-2021.
• Histopathological examination of colon, liver, and heart tissues using modified Steiner stain.
• Polymerase Chain Reaction (PCR) assay for Clostridium piliforme on selected formalin-fixed, paraffin-embedded (FFPE) samples.

Main Results:

• Tyzzer disease was confirmed in 51% (19/37) of cases, primarily affecting kittens aged 7-42 days (median 17.5 days).
• Colitis (18/19) and hepatitis (11/19) were the most common lesions; myocarditis was not observed.
• Modified Steiner stain demonstrated higher sensitivity for detecting Clostridium piliforme in FFPE tissues compared to PCR.

Conclusions:

• Tyzzer disease is a significant cause of illness in young kittens, particularly orphaned ones, and should be considered in cases of colitis and hepatitis.
• Weakened immune status due to various factors likely contributes to disease onset in susceptible kittens.
• The modified Steiner stain is a valuable diagnostic tool for identifying Clostridium piliforme in feline tissues.