Table 4.

Incidental pathology findings in prairie dogs

	Euthanasia day (dpi)	Animal	Incidental findings
Meloxicam only
4	PD12019	NE
6	PD12017	NE
9	PD12021	Diffuse glycogen vacuolation within hepatocytes (cause unknown).
12	PD12006	Multifocal moderate lymphoplasmacytic infiltrates were present within the lamina propria and submucosa. This lesion was similar to those seen in dogs and humans as a result of Helicobacter infections of the stomach. This lesion could also represent a residual inflammatory reaction to gastric parasitic (helminth) infections. Submucosal lymphoplasmacytic and histiocytic inflammatory foci in the gastric mucosa.
24	PD12029	A slight increase in the numbers of lymphocytes and plasma cells within the lamina propria of the duodenum was present. Moreover, the glycogen vacuolation within the liver section from this animal was diffuse and marked. In addition, there was slight growth of yeast (Candida spp.) in the esophageal mucosa.
24	PD12036	Submucosal lymphoplasmacytic and histiocytic inflammatory foci in the stomach mucosa. Glycogen vacuolation in the liver section was diffuse and moderate. Focal, moderate bronchus- associated lymphoid tissue hyperplasia was seen within the lung. A single submucosal lymphocytic inflammatory focus was seen in the submucosa of the esophagus.
24	PD12057	Sub-mucosal lymphoplasmacytic and histiocytic inflammatory foci in the stomach mucosa. Animal 12057 had diffuse and moderate glycogen vacuolation of the hepatocytes. Additionally, in the liver, multifocal mild portal infiltrates of lymphoid cells were observed and the Kupffer cells were prominent.
Buprenorphine only
4	PD12056	NE
6	PD12001	NE
9	PD12072	In the stomach of this animal, two small lymphoid nodules were observed in the mucosa. Similar to the meloxicam treated-animals, glycogen vacuolation was observed (for this animal it was moderate and mostly periportal to midzonal within the hepatic lobules). In the lungs, occasional small granulomas were seen with histiocytes and neutrophils within). Most likely, these granulomas formed as a reaction to either inhaled foreign bodies or to migrating parasites. Nevertheless, neither foreign bodies nor parasites were found within these granulomas. The esophagus had small bacterial colonies within the cornified layer without an inflammatory reaction. A bilateral impaction of feed material in the root of the molars, with neutrophilic inflammation and bone remodeling unilaterally was seen.
12	PD12045	The hepatocytes within all zones of the hepatic lobules had mild and diffuse glycogen vacuolation. Multifocal, mild, superficial esophagitis with multifocal erosions were observed. Inflammatory infiltrate consisted of numerous neutrophils, either singly or in small clusters, were present in the superficial layers of the esophageal epithelium. In these areas where neutrophils are the esophageal epithelium is extensively vacuolated and/or focally eroded. Small numbers of bacteria are seen attached to the epithelial surface throughout.
24	PD12055	Periportal and moderate hepatocytic vacuolation were present. Bacteria were observed on the mucosal surface of the esophagus.
24	PD12071	Mild, focal periportal mixed (lymphoplasmacytic, histiocytic, and neutrophilic) inflammatory infiltrate as well as focal hepatic necrosis with associated, mostly neutrophilic inflammatory infiltrate were observed. The kidney of this animal had focal mild interstitial nephritis. Bronchus-associated lymphoid tissue was prominent in the lung section.
24	PD12046	Stomach had a single prominent sub-mucosal lymphoid nodule. Hepatocytic glycogen vacuolation was moderate and diffuse. In the kidney, there was a focus of interstitial nephritis with associated tubular degeneration and regeneration. The esophagus had scattered, small mixed inflammatory infiltrate consisting of lymphoplasmacytes and histiocytes, and similar nodules were seen in the submucosa (probably due to prior trauma). This animal also had unilateral impacted food material within a root of a molar tooth.
MPXV only
4	PD12028	NE
6	PD12058	NE
9	PD12014	Lymphoid nodule in the submucosa of the stomach.
12	PD12011	Lymphoplasmacytic inflammatory infiltrates were seen in the mucosa and submucosa of the stomach. The duodenum had mildly increased numbers of lymphocytes and plasma cells in the lamina propria. Scattered bacterial colonies in the cornified layer of the esophagus (without any inflammatory reaction). There was diffuse and mild hepatocytic glycogen vacuolation throughout the liver.
24	PD12034	The liver had multifocal lymphoplasmacytic infiltrates in scattered portal triads. The heart had a focal myocardial necrosis and associated mixed (neutrophilic, histiocytic, and lymphocytic) inflammatory infiltrate. The kidney had focal subcapsular mixed inflammatory infiltrate primarily lymphoplasmacytic with lesser number of neutrophils. A focal collection of alveolar macrophages were observed within the lung. There was diffuse and mild hepatocytic glycogen vacuolation throughout the liver.
MPXV + meloxicam
4	PD12027	NE
4	PD12004	NE
4a	PD12112	NE
6	PD12077	NE
9	PD12037	NO
9	PD12038	NO
12b	PD12024	NO
12	PD12078	A submucosal lymphoid follicle with focal and mild inflammation in the muscle coat was observed in the stomach; infiltrate was perivascular lymphoplasmacytic and histiocytic. The kidney displayed mild chronic interstitial nephritis (most likely pre-existing ascending inflammation not related to NSAID treatment or viral infection).
18a	PD12114	NO
24	PD12096	NO
24	PD12059	NO
MPXV + buprenorphine
4	PD12002	NE
4	PD12064	NE
6	PD12092	NE
6	PD12025	NE
9	PD12115	NO
9	PD12085	NO
12	PD12049	NO
12	PD12119	The kidney had multifocal, chronic interstitial nephritis with radiating bands of fibrosis (residual scar from prior interstitial nephritis).
24	PD12091	NO

NE, not examined; NO, no incidental findings observed

^aDied prematurely

^bUnsuccessfully infected

The findings above are believed to be incidental and unrelated to either MPXV infection or analgesia.