Laurel A. Degernes

Efficacy of Oral Famotidine and 2 Omeprazole Formulations for the Control of Intragastric pH in Dogs

BACKGROUND Little is known about the efficacy of commonly used acid suppressants on intragastric pH in dogs. OBJECTIVE To compare the effect of oral famotidine, 2 formulations of omeprazole, and placebo on intragastric pH in dogs with a catheter-free, continuous pH monitoring system. ANIMALS Six healthy adult mixed-breed colony dogs. METHODS Utilizing a randomized, 4-way cross over, open-label study, dogs were administered famotidine PO (1.0-1.3 mg/kg q12h), omeprazole tablet (1.5-2.6 mg/kg q24h), omeprazole reformulated paste (RP) (Gastrogard, 1.5-2.6 mg/kg q24h), and placebo for 7 days followed by a 10-day washout period. Radiotelemetric pH capsules were placed with gastroscopy assistance to continuously record intragastric pH for 4 days (days 4-7 of dosing). The percentage of time that intragastric pH was ≥3 and ≥4 was compared among treatment groups using repeated measures of analysis of variance. Tukeys Studentized range test was used to determine which groups were different with α= 0.05. RESULTS Mean ± SD percent time intragastric pH was ≥3 and ≥4 was 22 ± 8% and 14 ± 6% for famotidine, 63 ± 14% and 52 ± 17% for omeprazole tablet, 54 ± 17% and 44 ± 18% for omeprazole RP, and 6 ± 6% and 5 ± 5% for placebo. Both omeprazole formulations significantly increased intragastric pH compared with famotidine and placebo, but omeprazole tablet and RP was not significantly different from each other. CONCLUSION Oral omeprazole tablet and RP provide superior gastric acid suppression to famotidine, and should therefore be considered more effective for the treatment of acid related disorders in dogs.

Waterfowl Toxicology: A Review

Waterfowl populations may serve as sentinel species for natural and anthropogenic toxicologic problems in the environment. Unfortunately, many toxins cause nonspecific clinical signs, acute mortality, and subtle or no pathologic changes, making toxicologic investigations extremely difficult. The purpose of this article is to review important waterfowl toxins, including heavy metals, pesticides, botulism, mycotoxins, algal toxins, and petroleum oil. When applicable, clinical signs, diagnosis, pathologic findings, and treatment are discussed. Although most of the information in the literature is based on wild waterfowl populations or experimental toxicologic investigations, the information is also applicable to captive waterfowl populations.

Risk factors and outcome of bougienage for treatment of benign esophageal strictures in dogs and cats: 28 cases (1995-2004).

OBJECTIVE To determine outcome of bougienage for treatment of benign esophageal stricture (BES) in dogs and cats and identify risk factors for the condition. DESIGN Retrospective case series. ANIMALS 20 dogs and 8 cats with BES. PROCEDURES Medical records were reviewed for information on signalment, clinical features, and outcome. Long-term outcome information was obtained with a questionnaire. RESULTS Esophageal bougienage was performed with dilators ranging from 5 to 15 mm in diameter; median numbers of bougienage procedures were 3 (dogs) and 4.5 (cats). A good outcome, defined as tolerance of solid food with regurgitation less than once a week, was achieved in 14 dogs and 6 cats. Complications were minimal, with nonfatal esophageal perforation occurring in 1 cat. Four dogs and 1 cat were euthanized or died because of esophageal disease. Dogs with BES were more likely to be female, have a recent history of general anesthesia, have received an antimicrobial orally, or have a history of vomiting than were dogs in a reference population. Cats with BES were more likely to have a recent history of general anesthesia, vomiting, or gastrointestinal tract trichobezoars than were cats in a reference population. Doxycycline-induced esophagitis was the suspected cause of BES in 3 cats. Although general anesthesia was associated with development of BES in 18 dogs and 5 cats, concurrent potential causes of esophageal injury were common. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that esophageal bougienage was a safe and effective treatment for most dogs and cats with BES, with outcomes similar to those reported for balloon dilation.

CHARACTERIZATION OF CAMPYLOBACTER FROM RESIDENT CANADA GEESE IN AN URBAN ENVIRONMENT

Waterfowl are natural reservoirs for zoonotic pathogens, and abundant resident (nonmigratory) Canada Geese (Branta canadensis) in urban and suburban environments pose the potential for transmission of Campylobacter through human contact with fecal deposits and contaminated water. In June 2008 and July 2009, we collected 318 fecal samples from resident Canada Geese at 21 locations in and around Greensboro, North Carolina, to test for Campylobacter. All campylobacter species detected were C. jejuni isolates, and prevalences in 2008 and 2009 were 5.0% and 16.0%, respectively. Prevalence of C. jejuni–positive sampling sites was 21% (3/14) and 40% (6/15) in 2008 and 2009, respectively. All C. jejuni isolates were susceptible to a panel of six antimicrobial agents (tetracycline, streptomycin, erythromycin, kanamycin, nalidixic acid, and ciprofloxacin). We used pulsed-field gel electrophoresis and fla-typing to identify several strain types among these isolates. Multilocus sequence typing of representative isolates revealed six sequence types, of which two (ST-3708 and ST-4368) were new, two (ST-702 and ST-4080) had been detected previously among C. jejuni from geese, and two (ST-991 and ST-4071) were first reported in C. jejuni from an environmental water source and a human illness, respectively. These results indicate a diverse population of antibiotic-susceptible C. jejuni in resident Canada Geese in and around Greensboro, North Carolina, and suggest a need for additional assessment of the public health risk associated with resident Canada Geese in urban and suburban areas.

Epidemiologic investigation of lead poisoning in trumpeter and tundra swans in Washington State, USA, 2000-2002.

An observational study was conducted to determine the proportionate mortality of wild trumpeter (Cygnus buccinator) and tundra (Cygnus columbianus columbianus) swans that died during the winters of 2000–02 in northwestern Washington State, USA. Among 400 swans necropsied, 81% were lead poisoned (302/365 trumpeter swans; 20/35 tundra swans). Mortality started in mid-November and peaked from late December through mid-February; swan mortality that was not associated with lead poisoning was uniformly lower throughout the winter months. Lead poisoning was 24 times more likely to be the cause of death in swans found in Whatcom County compared to swans found in other locations in northwestern Washington State (95% CI: 12.7, 47.0). Mortality attributable to lead poisoning was twice as likely in adults as in juveniles (95% CI: 1.0, 4.2). Aspergillosis was documented in 62 trumpeter and two tundra swans, including 37 swans in which mortality was caused by lead poisoning. Males were twice as likely as females to have aspergillosis (95% CI: 1.1, 3.8). Traumatic injuries were documented in 37 trumpeter and seven tundra swans, including seven trumpeter swans with concurrent lead poisoning. Dead swans found outside Whatcom County were four times more likely to have traumatic injuries compared to those found in Whatcom County (95% CI: 1.6, 10.0). Overall, lead-poisoned swans were significantly less likely to have concurrent aspergillosis or traumatic injuries. There was no apparent association between grit ingestion (total mass or mass categorized by size) and lead poisoning or number of lead shot. Not surprisingly, lead-poisoned swans were more likely to have one or more lead shot compared to swans that died from other causes (OR 294; 95% CI: 92, 1,005); lead-poisoned swans were also more likely to have one or more nontoxic shot compared to swans that were not poisoned (OR 63; 95% CI: 19, 318). The source(s) of shot are unknown but likely are in or near Whatcom County, Washington.

KETAMINE-XYLAZINE ANESTHESIA IN RED-TAILED HAWKS WITH ANTAGONISM BY YOHIMBINE

Five red-tailed hawks (Buteo jamaicensis) were anesthetized at weekly intervals with intravenous ketamine hydrochloride (KET, 4.4 mg/kg) and xylazine hydrochloride (XYL, 2.2 mg/kg). Twenty min after anesthesia, yohimbine hydrochloride (YOH, 0.05, 0.10, 0.20 and 0.40 mg/kg) or a control was administered. All doses of YOH significantly reduced the head-up times (F = 20.84, df = 1,24, P < 0.0001) and the standing times (F = 12.30, df = 1.24, P < 0.0001), compared to the control group. The heart and respiratory rates following YOH (all doses) were significantly greater (P < 0.01) than the anesthetized rates, but were comparable to the rates observed in restrained, unanesthetized hawks. Yohimbine did not appear to have any significant effect on body temperature. Based upon administration of 4.4 mg/kg KET and 2.2 mg/kg XYL, a dose of 0.10 mg/kg YOH was recommended to achieve antagonism without causing profound cardiovascular or respiratory changes.

Toxicities in waterfowl

Waterfowl populations may serve as sentinel species for natural and man-made toxicological problems in the environment. Many toxins cause nonspecific clinical signs, acute mortality, and subtle or no pathological changes, which make toxicological investigations extremely difficult. The purpose of this report is to review the most common toxins causing problems in waterfowl populations, including heavy metals, pesticides, botulism, mycotoxins, algal toxins, and petroleum oil. Where applicable, clinical signs, diagnosis, pathology, and treatment will be discussed. Although most of the information in the literature is based on wild waterfowl populations or experimental toxicological investigations, the information is also applicable to captively managed waterfowl population.

Tenectomy of the Supracoracoideus Muscle to Deflight Pigeons (Columba livia) and Cockatiels (Nymphicus hollandicus)

Abstract Most of the methods used to deflight birds have one or more disadvantages, including impermanence, poor cosmetic appearance, or impairment of breeding function. We hypothesized that transection of the tendon of the supracoracoideus muscle at its insertion on the proximal humerus would impair a birds ability to raise the affected wing and thus result in flightlessness. The purpose of this project was to evaluate the effectiveness of unilateral or bilateral surgical tenectomy of the supracoracoideus muscle in deflighting cockatiels and pigeons. Six pigeons (Columba livia) and 9 cockatiels (Nymphicus hollandicus) were included in the study. Three cockatiels were included in a sham group, and 3 birds of each species were included in a unilateral or bilateral tenectomy group. The birds in the sham group did not have flight difficulties at any time after surgery. Three cockatiels and 1 pigeon in the unilateral tenectomy group were flying within 3–6 weeks, respectively, after surgery. A ligament instead of a tendon was inadvertently transected in 2 of the pigeons in the unilateral group. These pigeons were able to fly the day after surgery. We did not euthanize these birds to confirm this suspicion. In the bilateral tenectomy groups, 1 of 2 cockatiels and 2 of 3 pigeons were eventually able to fly short distances within 4 to 6 months after surgery. In the same groups, 1 cockatiel died several hours after surgery and 1 pigeon was euthanized 6 weeks after surgery. The pigeon never regained its ability to right itself when placed on its back. Gross necropsies in both birds confirmed that the tendons of the supracoracoideous muscles had been transected. None of the birds undergoing unilateral or bilateral tenectomy had normal dorsal extension of the affected wing, but each was able to fly well enough to escape if taken outdoors. We concluded that neither unilateral nor bilateral supracoracoideus tenectomy is an effective technique for deflighting cockatiels or pigeons.

Exocrine Pancreatic Insufficiency in a Yellow-naped Amazon (Amazona ochrocephala) with Pancreatic Adenocarcinoma

This report describes exocrine pancreatic insufficiency in a yellow-naped Amazon (Amazona ochrocephala) with complete effacement of the pancreas by a pancreatic adenocarcinoma. The bird presented with a 3-month history of weight loss and voluminous, foul-smelling droppings. Clinically, routine hematologic findings were normal and fecal tests were performed to evaluate exocrine pancreatic function. The fecal function tests were positive for neutral and split fats and negative for trypsin. Oral administration of corn oil did not result in elevation of blood triglyceride levels. Two days later, the triglyceride tolerance test was repeated using corn oil mixed with pancreatic enzymes. This time, there was a 70% elevation of blood triglyceride levels. Because of a poor prognosis, the bird was euthanatized. At necropsy, the pancreas was diffusely enlarged, white, nodular, and firm. The liver contained multiple, 1-2-mm-diameter, randomly located, tan nodules. Microscopically, the pancreas was effaced by numerous lobules of neoplastic ductular structures surrounded by abundant fibrous connective tissue. In the liver, the hepatic parenchyma was replaced by multiple, well-demarcated, nonencapsulated foci of neoplastic tissue similar to that in the pancreas.

Axillary cystadenocarcinoma in a Moluccan cockatoo (Cacatua moluccensis).

An adult Moluccan cockatoo (Cacatua moluccensis) was diagnosed with a cystadenocarcinoma in the right axillary region that was treated symptomatically with surgical debulking and periodic drainage. The bird eventually died and a necropsy was performed. The neoplasm extended through the humerus, and small neoplastic foci were seen within the ipsilateral lung parenchyma. Rare groupings of microvilli were observed lining intercellular canalicular lumens on electron microscopy within the axillary tumor. These findings suggest a respiratory neoplasm, although the tissue of origin remained undetermined.