"Severe gastroenteritis" refers to a serious inflammation of the stomach and intestines, commonly known as the stomach flu. It can cause vomiting, diarrhea, stomach pain, and dehydration. Full definition
Panleukopenia is a virus that usually causes clinical signs of severe gastroenteritis, with the primary signs of disease being loss of appetite, vomiting and diarrhea. (Windmillvet.com)
Noroviruses cause severe gastroenteritis that typically lasts 24 to 48 hours. (pnnl.gov)
Average recovery time for the gut of a baby with severe gastroenteritis is 4 weeks, but may be up to 8 weeks for a baby under 3 months. (breastfeeding.asn.au)