A 12-year old female spayed Scottish terrier is referred with a
two month history of vomiting that progressed from every other day
to daily, anorexia, and weight loss (2 lbs [0.9 kg] over 2 months).
The vomitus was foamy/yellow initially and then became brown liquid
days before referral. She tended to vomit just prior to her meals.
She also had liquid stool over the past four weeks that did not
respond to metronidazole therapy. No coughing or sneezing was noted
and the dog was on monthly heartworm preventative treatment. Blood
work done by the RDVM was unremarkable except for a mild increase in
alkaline phosphatase (ALKP) (352 U/L [5-131]) on biochemical panel.
The dog was treated for potential gastric ulcers with famotidine (Pepsid®)
and sucralfate, with no improvements. On physical examination TPR
was within normal limits and the dog was lethargic and had depressed
mentation, with bilateral lenticular opacification. Abdominal
palpation showed mild hepatomegaly. A CBC showed a neutrophilic
leukocytosis with lymphopenia. Serum biochemical panel showed an
increased ALKP (292 U/L [12-122]), hypochloremia (101 mEq/L
[101-117]), and increased TCO2 (30 mEq/L [15-25]), and a normal U/A.
Abdominal ultrasonographic examination showed increased thickness of
the stomach wall. Images A and B above were obtained from an
endoscopic examination of the stomach.
- What’s your diagnosis or differentials in this case?
- What other diagnostic tests would be helpful in determining
the definitive diagnosis?
- What treatment(s) would be appropriate? What’s your diagnosis or differentials in this case?
Treatment consisted of intravenous
fluids, Famotidine (Pepsid®), sucralfate and partial parental
nutrition. Options for further treatment included surgical
resection and chemotherapy or chemotherapy alone. The owner
declined further treatment due to the high metastatic rate of the
tumor and guarded prognosis and aggressiveness of the surgery. The
dog was discharged on sucralfate suspension (1 gm, PO, Q8h), Science
Diet (L/D), recommendations for Pepsid, and a prescription for
Zofran (Odansetron, 4 gm, PO, q24h) an acid-reducer anti-emetic with no effect on
the pylorus. The patient is at risk for gastric perforation and
persistent clinical signs.
Comments on Treatment: Treatment
recommendations included surgical resection and chemotherapy
(combination of platinum/gemcitabine due to positive response in
human medicine). Also, chemotherapy alone if the mass is not
resectable, but the efficacy of chemotherapy as a sole treatment
modality is unknown and likely to have a low response rate, based on
human experience.
Prognosis: Gastric adenocarcinomas are
locally invasive and have been reported to have relatively high (60%
to 80%) metastatic rates. Tumors are typically located in the
pyloric region but up to 50% of cases may have multiple affected
sites or gross extension beyond the pylorus. Because of the locally
invasive/extensive nature of most tumors, surgery alone is rarely
curative but may provide palliative and survival benefits.
Chemotherapy is generally indicated as an adjuvant due to the high
metastatic rate; however, efficacy is unknown. The median survival
for dogs treated with surgery alone is ~6 months (based on the
literature). Thoracic radiographs showed a small nodule which
was consistent with a metastasis.
