Efficacy of famotidine for the prevention of exercise-induced gastritis in racing Alaskan sled dogs

BACKGROUND: Omeprazole reduces the severity of exercise-induced gastritis but not the prevalence of gastric lesions in sled dogs. The frequent feeding of sled dogs during competition likely results in decreased absorption of omeprazole and, thereby, decreased efficacy. HYPOTHESIS: Famotidine, a histamine-2 blocker with good bioavailability in the presence of food, would reduce the incidence and severity of exercise-induced gastric disease in sled dogs. ANIMALS: Sixteen fit Alaskan sled dogs (4 female, 12 male, all intact, age 2-6 years). METHODS: Dogs were randomly assigned to treatment (22 mg famotidine PO q24h) or control groups (n = 8 per group). Famotidine was administered with a meal to the treatment group once daily for 7 days before a challenge and once during exercise. Control dogs were fed an identical diet as the principal group. The 16 dog team completed a 100-mile exercise challenge in 18 hours. A gastroscopy was performed 24 hours after the challenge. The appearance of the mucosa was scored by an individual by using a scoring system. RESULTS: Treatment with famotidine significantly reduced the severity score compared with control (P = .0004). No adverse effects of treatment were reported. CONCLUSIONS AND CLINICAL RELEVANCE: Famotidine is effective in reducing the severity of exercise-induced gastric disease in racing Alaskan sled dogs, with minimal to no adverse effects, and may be recommended for prophylactic use in short distance races.     

Fractionated oral dosing and its effect on cyclophosphamide pharmacokinetics in dogs with high-grade multicentric lymphoma

Cyclophosphamide (CP) is an alkylating agent commonly included in multi-drug treatment protocols for canine cancer. As a prodrug, CP requires hepatic metabolism for activation to the intermediate compound 4-hydroxycyclophosphamide (4-OHCP) which then spontaneously forms alkylating phosphoramide mustard. CP is frequently administered in a fractionated manner, with the total dose given over multiple days. CP is reported to cause auto-induction of metabolism in humans, with faster CP clearance and relatively increased 4-OHCP formation following fractionated versus bolus dosing, however canine pharmacokinetic studies of CP dose fractionation are lacking. The study objective was to evaluate the pharmacokinetics of fractionated oral CP dosing at a dose of 200–250 mg/m² over 3 to 4 days in a prospectively identified population of cancer-bearing dogs. Plasma concentrations of CP and 4-OHCP were measured by ultra-high performance liquid chromatography tandem-mass spectrometry in eight dogs following the first and last doses to assess for auto-induction of CP metabolism. No significant difference in the rate of CP elimination between first and last doses were detected (0.73 ± 0.46 vs. 1.22 ± 0.5 h⁻¹; p = .125). Additionally, no significant difference in dose-normalized 4-OHCP exposure was identified between first and last doses (5.9 ± 2.1 vs. 7.9 ± 6.4 h × ng/ml; p = .936). These results suggest that fractionated dosing may not increase exposure to the active metabolite of CP in dogs as it does in humans. As such, standard bolus dosing and fractionated dosing may be equivalent in terms of bio-activation of CP in dogs administered a dose of 200–250 mg/m².     

Outcomes of esophageal and gastric bone foreign bodies in dogs

BackgroundBone foreign bodies are commonly encountered in small animal practice. Esophageal bone foreign bodies (E‐bFBs) warrant removal, whereas gastric bone foreign bodies might not.ObjectivesDescribe management and outcomes for dogs with esophageal or gastric bone foreign bodies.AnimalsOne hundred twenty‐nine dogs with esophageal (n = 45) or gastric (n = 84) bone foreign bodies.MethodsRetrospective review of medical records.ResultsDogs with E‐bFBs were younger than dogs with gastric bone foreign bodies (median age esophageal, 4 years [IQR 2‐8]; median age gastric, 6 years [IQR 3‐10]; P = .03), and had a higher bone cross‐sectional area relative to body weight (median esophageal, 98.21 mm²/kg [IQR 48.25‐142.6]; median gastric, 28.6 mm²/kg [IQR 17.25‐64.28]; P < .001). Forty‐two of 45 esophageal foreign bodies were resolved non‐surgically and 3 by esophagotomy. Esophageal erosions were more likely with distal entrapment (OR 12.88, [95% CI 31.95‐129.29], P = .01) and longer duration (OR 18.82 [95% CI 2.22‐273.97], P = .01). Sixty‐two of 84 bone gastric foreign bodies were left in situ. Endoscopic removal was successful in 20 of 22 (91%; 95% CI 70‐99) attempts.Conclusions and Clinical ImportanceWhile all E‐bFBs were dislodged either by advancement into the stomach, endoscopic removal, or esophagotomy, the majority of gastric bone foreign bodies were left in situ for dissolution, with no reported complications. Gastric advancement of E‐bFBs should be considered when oral removal is not feasible, and dissolution can be considered even with large bones.     

Organohalogen residues in human adipose autopsy samples from six Ontario municipalities

Human adipose tissue samples obtained during autopsies in 6 Canadian Great Lakes municipalities were analyzed for chlorobenzenes, polychlorobiphenyls, and organohalogen pesticide residues. The frequency of occurrence and the range and mean for 28 organohalogen residues are reported for male and female donors in each municipality. Overall mean residue values in females were significantly higher than those in males for hexachlorobenzene, beta-HCH, p,p'-DDE,p,p'-DDD + o,p'-DDT, and p,p'-DDT. The means and ranges of residue values were similar to those reported in previous Canadian surveys.