Fatal mesenteric lymphadenitis in cattle caused by Listeria monocytogenes

Clinical and genomic features of Listeria monocytogenes-associated mesenteric lymphadenitis in a cat

BACKGROUND

Listeriosis is a severe foodborne infection caused by Listeria monocytogenes, an important foodborne pathogen of animals and humans. Listeriosis is a rare disease in cats.

OBJECTIVE

To describe the clinical, diagnostic imaging, histological, and microbiological features of L. monocytogenes-associated mesenteric lymphadenitis in a cat.

ANIMALS

Listeria monocytogenes-associated mesenteric lymphadenitis was confirmed in a cat by histology and microbiology.

RESULTS

Two distinct isolates of L. monocytogenes were cultured from the affected mesenteric lymph node and whole genome sequencing was performed.

CONCLUSION AND CLINICAL IMPORTANCE

This report should alert veterinary clinicians and microbiologists to the syndrome, which may have implications for health and food safety in animals and humans.

Listerial mesenteric lymphadenitis in 3 cats

Background

Listeriosis is a rare disease in cats with naturally occurring cases usually being identified in individual animals. Listerial mesenteric lymphadenitis has not been described previously in cats.

Objectives

To describe the clinical and histological features of listerial mesenteric lymphadenitis in cats as well as treatment outcome.

Animals

Listerial mesenteric lymphadenitis was confirmed in 3 cats by histology, immunohistochemistry, and bacterial culture.

Results

The affected cats were young to middle aged and were examined for various clinical signs. On both palpation and abdominal ultrasound examination, all cats had marked mesenteric lymphadenomegaly. Survival was prolonged in all 3 cases. Two of the 3 cats were fed a raw meat‐based diet before they developed clinical illness.

Conclusions and Clinical Importance

Lymphadenitis caused by listeriosis has a protracted time course and should be a differential diagnosis for abdominal lymphadenopathy in young to middle‐aged cats. Feeding of a raw meat‐based diet may be a contributing factor for development of listeriosis in cats.