So, here is the update. Vet sent me to another vet/Emergency Hospital in Houston. They did ultra-sound, blood work, etc... $1600.
The results are inconclusive and another $5000 is necessary to go to the next stage, that 'could' tell more. There is a swelling/focal mesentery area 'outside' of any organ, between the bottom of the stomach and the pancreas. Could be cancer, but being this is going on for 4+ years, maybe not. They said it was likely unrelated to the Mushroom event (if there was even one). When I looked up 'focal mesentery' in dogs and it doesn't sound good.
Not sure what we are going to do next, but we are going to change her diet to remove 'Chicken Flavoring' as a trigger.
The Report from the Animal Hospital
Problem
Intermittent, progressively frequent episodes of lethargy and inappetance Focal region of steatitis
Diagnostic Tests
CBC Mild stress leukogram, otherwise normal Chemistry panel normal
Urinalysis USG 1.009, no protein
T4 2.0
GI panel normal (TLI 28.5, cPLI 67, cobalamin 755, folate 9.6) Abdominal ultrasound
STUDY: FULL ABDOMINAL ULTRASOUND
COMPARISON: None.
FINDINGS:
- UROGENITAL: The kidneys are normal in size and maintain adequate corticomedullary distinction (L: 3.9 cm; R: 3.7 cm).
- ADRENAL GLANDS: Normal L: 0.52 cm, R: 0.46 cm
- SPLEEN: Normal
- HEPATOBILIARY: Normal
- GASTROINTESTINAL: Normal
- PANCREAS: Normal
- LYMPH NODES: Normal
- RETRO/PERITONEAL SPACE: There is focal mesentery within the right cranial abdomen.
- ASPIRATES: None performed
CONCLUSIONS
Right cranial steatitis of unknown etiology.
Otherwise ultrasonographically abdomen.