The effect of inhaled heliox on peak flow rates in normal and brachycephalic dogs.

BACKGROUND: Heliox, a mixture of helium and oxygen, alleviates airway obstruction in people and improves air flow, and its use has been proposed in dogs. Brachycephalic dogs have naturally occurring airway obstruction where heliox might be a useful therapeutic option. OBJECTIVE: The purposes of this study were to (1) determine the impact of breathing heliox on peak inspiratory and expiratory flows (PIF/PEF) in healthy dogs and (2) determine if brachycephalic dogs and mesocephalic dogs have similar responses to inhaled heliox. ANIMALS: Eleven healthy dogs: 5 mesocephalic and 6 brachycephalic dogs. METHODS: A prospective study. Tidal breathing flow-volume loops were recorded when dogs were breathing room air (nitrogen-oxygen) and heliox. Peak inspiratory and expiratory flow rates were recorded and the subjective shape of loops assessed. Peak inspiratory and expiratory flows pre- and post-heliox were compared using a Mann-Whitney Rank sum test with a P-value of <.05 considered significant. RESULTS: In inhaled heliox, PIF and PEF were evaluated by tidal breathing flow-volume loops. In mesocephalic dogs, PIF increased from a median of 820 mL/s (range, 494-1010 mL/s) to 1386 mL/s; P = .02; and for PEF from 688 mL/s to 1793 mL/s (P = .04), whereas in brachycephalic dogs, the median PIF increased from 282 mL/s to 694 mL/s; P = .01 and the median PEF increased from 212 mL/s to 517 mL/sec; P = .03. Brachycephalic dogs showed normalization of loop shapes. CONCLUSIONS AND CLINICAL IMPORTANCE: Heliox improves flow rate and appears to improve flow patterns in brachycephalic dogs.

Iatrogenic water intoxication in two cats.

OBJECTIVE: To describe 2 cats that developed acute iatrogenic water intoxication, one associated with a continuous infusion of water provided via an esophagostomy tube and one following SC administration of 5% dextrose in water (D5W). CASE OR SERIES SUMMARY: A 10-year-old cat with squamous cell carcinoma was hospitalized for treatment of dehydration. Rehydration was provided with water via an esophagostomy tube at 5.7 mL/kg/h. After 30 hours of therapy, the cat was found dull and weak. Serum sodium was markedly decreased at 116 mmol/L (116 mEq/L). Supplemental water was stopped, and IV furosemide and mannitol were provided to eliminate free water. Hypertonic saline (1.5%) was administered IV to rapidly restore the sodium concentration. The serum sodium concentration corrected over 17 hours, and the cat was discharged without neurological complications. The second cat had previously received 300 mL D5W subcutaneously and represented 8 hours later with lethargy and paresis with a serum sodium level of 126 mmol/L (126 mEq/L). Intravenous fluid therapy was provided using 0.9% NaCl. Over the following day, the cat's mentation and paresis resolved and sodium concentrations normalized. NEW OR UNIQUE INFORMATION PROVIDED: These 2 cases describe a presumed uncommon iatrogenic complication of severe hyponatremia due to water provided either via an esophagostomy tube or subcutaneously. While oral rehydration is often considered ideal, it may result in signs of water intoxication if not carefully monitored; additionally, D5W is never considered an acceptable fluid choice as a SC bolus. If promptly recognized, acute hyponatremia may be corrected rapidly with no lasting consequences.

Seizures and severe nutrient deficiencies in a puppy fed a homemade diet.

CASE DESCRIPTION: An 8-month-old male Saint Bernard developed tetanic seizures and hyperthermia during evaluation of bilateral osteochondritis dissecans of the shoulder joints. Further investigation revealed that the dog was receiving an unbalanced homemade diet. CLINICAL FINDINGS: Preliminary evaluation of the dog revealed bilateral signs of pain and mild muscle wasting in the shoulder joint areas. Serum biochemical analysis revealed severe hypocalcemia, hyponatremia, hypochloremia, hyperphosphatemia, vitamin D deficiency, and taurine deficiency. Diffuse osteopenia was identified on radiographs of the mandible and long bones, confirming bone demineralization. Analysis of the homemade diet revealed that the dog's diet was severely deficient in a variety of nutrients. TREATMENT AND OUTCOME: The dog responded positively to treatment for hypocalcemia, hyperthermia, and seizures. The dog's diet was changed to a complete and balanced canine diet formulated for growth. Body weight and body condition were monitored, and dietary intake was adjusted to achieve optimal body condition during growth. After initial evaluation, serial monitoring of serum calcium and taurine concentrations revealed that values were within reference limits and the dog had no further clinical signs associated with dietary deficiency. CLINICAL RELEVANCE: Findings in this puppy highlight the risks associated with feeding an unbalanced homemade diet during growth and the importance of obtaining a thorough dietary history from all patients. For owners who elect to feed a homemade diet, it is critical to have the homemade diet carefully formulated by a veterinary nutritionist to avoid severe nutrient imbalances, especially in young, growing dogs.

Acute aldicarb toxicity in dogs: 15 cases (2001-2009).

OBJECTIVE: To describe the common clinical signs, laboratory abnormalities, treatment, and prognosis associated with acute aldicarb toxicosis in dogs. DESIGN: Retrospective observational study from 2001 to 2009. SETTING: Urban referral hospital. ANIMALS: Fifteen client-owned dogs. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The most common clinical signs associated with acute aldicarb toxicosis were vomiting, ptyalism, diarrhea, and tremors. Of the 15 dogs, 11 were admitted to the hospital for treatment, 2 were euthanized at presentation and 2 were discharged against medical advice following minimal treatment and lost to follow-up. Laboratory abnormalities included lactic acidosis and hyperglycemia in 12 and 9 patients, respectively. Treatment of hospitalized dogs included induction of emesis with apomorphine (4 dogs), activated charcoal (5), IV fluids (11), atropine (7), methocarbamol (3), diazepam (1), pralidoxime (1) and diphenhydramine (1). Ten of 11 hospitalized dogs survived to discharge; 1 was euthanized following a respiratory arrest after 36 hours of hospitalization. One patient received mechanical ventilation and treatment for pneumonia before discharge from the hospital. The median duration of hospitalization was 22 hours (range 12-168 h). CONCLUSIONS: Acute aldicarb toxicosis carries a good prognosis for survival and hospital discharge with treatment. Supportive care should be considered for at least 18-24 hours to monitor for response to therapy and development of respiratory failure.