Diagnostic evaluation of urea nitrogen/creatinine ratio in dogs with gastrointestinal bleeding.

BACKGROUND: Urea nitrogen/creatinine ratio (UCR) is a marker for upper gastrointestinal bleeding (GIB) in people. OBJECTIVES: To assess the usefulness of UCR to predict occult GIB and distinguish upper from lower GIB in dogs. ANIMALS: Eighty-nine dogs with GIB and 65 clinically healthy dogs. Dogs were grouped according to 65 overt GIB and 24 occult GIB, and based on lesion localization (37 upper, 13 lower, and 8 both). METHODS: Seventy-four dogs were included retrospectively and 15 dogs prospectively. Serum urea nitrogen and creatinine concentrations, UCR, hemoglobin concentration, hematocrit, mean corpuscular volume, and mean corpuscular hemoglobin concentration were compared between groups. Logistic regression models were fitted to assess if variables could distinguish occult GIB from being healthy and upper from lower GIB. RESULTS: The UCR was significantly higher in dogs with overt GIB compared to control dogs (P = .02) and dogs with occult GIB (P = .05). The UCR was not significantly associated with occult GIB vs being healthy, or upper vs lower GIB (P > .05 each). Dogs with higher hemoglobin concentration and hematocrit had significantly lower odds of having occult GIB than being healthy (P < .0001 each). CONCLUSIONS AND CLINICAL IMPORTANCE: The UCR does not seem to be a clinically useful marker of occult GIB and appears to have poor discriminatory ability between upper and lower GIB. An increased UCR in a dog without signs of overt GIB, especially if its hematocrit is within the middle or upper reference interval, does not appear to warrant prompt prescription of gastrointestinal protectants.

A wireless endoscopy capsule suitable for imaging of the equine stomach and small intestine.

BACKGROUND: Capsule endoscopy offers a new method for visualization of the gastrointestinal mucosa in horses where other imaging technologies have diagnostic limitations. OBJECTIVES: To (1) test the feasibility of using this novel endoscopy capsule to visualize intestinal mucosa in horses, including an objective assessment of image quality, (2) assess how changes in preadministration preparation affect the transit time and the amount of gastrointestinal mucosa visualized, and (3) describe intestinal mucosa lesions in healthy horses. ANIMALS: Five healthy adult horses. METHODS: Three protocols were used in a crossover study design. Protocols varied in time fasted, amount of oral fluid administered, and exercise. Manure was radiographically inspected for capsule recovery. Percentage of visible gastrointestinal mucosa was objectively assessed. RESULTS: Detailed images of the gastrointestinal mucosa were recorded with all 3 protocols, including images of the pylorus, major duodenal papilla, individual villi, and ileocecal junction. Visualization of large intestinal mucosa was poor. Interobserver agreement on image quality was excellent. Capsule administration after feed withholding for 24 hours provided the greatest percentage of visible mucosa in the stomach and small intestine. Total transit time to capsule excretion was 6.5 (3-8.75) days. Of 15 capsules administered, 3 were not recovered. Lesions visualized included mucosal erosion, ulceration and hemorrhage, areas of thickened mucosa, and evidence of parasitism. CONCLUSIONS: This novel endoscopic capsule appears safe, practical, and noninvasive in horses; however, variability in capsule excretion time must be taken into account for clinical application.

Jejunal Lesion Identified at a Previous Anastomosis Site in a Dog Using Capsule Endoscopy.

A 3 yr old spayed female French bulldog was evaluated for a progressive regenerative anemia of unknown origin that was unresponsive to empiric immunosuppressive and gastroprotective therapy. The patient had a history of previous resection and anastomosis of a small intestinal diverticulum ∼2 yr prior to evaluation for her anemia. Capsule endoscopy revealed a focal abnormality in the distal jejunum at the site of a previous bowel resection and anastomosis. This lesion was suspected to be the cause of ongoing gastrointestinal bleeding and anemia. Exploratory laparotomy combined with endoscopy was performed to further investigate and localize the jejunal lesion. The lesion was resected, and a primary end-to-end jejunal anastomosis was performed. Histopathology of the specimen revealed jejunal suture granulomas with focal ulceration. The patient recovered well from surgery with significant improvement of the anemia and resolution of clinical signs at recheck examinations 1 and 2 wk postoperatively. Complete resolution of the anemia was noted at a 6 wk follow-up. The case report demonstrates how, in cases of unknown causes of anemia, capsule endoscopy is a noninvasive method of identifying the presence of gastrointestinal bleeding as a result of lesions that might otherwise not be detectable with abdominal ultrasound or conventional endoscopy. The report also documents a long-term complication to a resection and anastomosis surgery.

Repeated rhinoscopic and serologic assessment of the effectiveness of intranasally administered clotrimazole for the treatment of nasal aspergillosis in dogs.

OBJECTIVE: To determine the role of rhinoscopic evaluation and repeated serologic testing in assessing the success rate of intranasally administered clotrimazole for treatment of dogs with nasal aspergillosis. DESIGN: Prospective case series. ANIMALS: 23 dogs with nasal aspergillosis. PROCEDURES: Dogs with nasal aspergillosis were treated with an intranasal infusion of 1% clotrimazole solution. Response to treatment was assessed with repeated rhinoscopic evaluation, with histologic examination and fungal culture when available. Results of repeated serologic testing for aspergillosis were monitored throughout the treatment course. RESULTS: 11 of the 23 (48%) dogs had no rhinoscopic evidence of disease after the first treatment. Three of 7 dogs were free of disease after the second treatment, and 1 of 3 dogs was free after the third treatment. Presence or absence of nasal discharge and results of repeated serologic testing were not consistent with disease status. Overall, the efficacy of intranasally administered clotrimazole for treatment of nasal aspergillosis could be confirmed in 15 of 17 dogs. Delayed recurrence or reinfection was confirmed in 3 of 15 dogs. When recurrences were taken into account, the success rate was 67% (12/15 dogs). CONCLUSIONS AND CLINICAL RELEVANCE: Clinical signs were not predictive of disease state, and follow-up rhinoscopy is recommended to assess response to treatment. The success rate of intranasally administered clotrimazole was similar to rates in previous reports; however, the number of dogs with recurrent disease was relatively high. Monitoring of the results of serologic testing is not recommended for use in determining response to treatment.

Comparison of serologic evaluation via agar gel immunodiffusion and fungal culture of tissue for diagnosis of nasal aspergillosis in dogs.

OBJECTIVE: To compare the sensitivity and specificity of serologic evaluation and fungal culture of tissue for diagnosis of nasal aspergillosis in dogs. DESIGN: Prospective study. ANIMALS: 58 dogs with nasal discharge and 26 healthy dogs. PROCEDURES: Dogs with nasal discharge were anesthetized and underwent computed tomography and rhinoscopy; nasal tissues were collected for histologic examination and fungal culture. Sera were assessed for antibodies against Aspergillus spp (healthy dog sera were used as negative control specimens). Nasal aspergillosis was diagnosed in dogs that had at least 2 of the following findings: computed tomographic characteristics consistent with aspergillosis, fungal plaques detected during rhinoscopy, and histologically detectable fungal hyphae in nasal tissue. Histologic characteristics of malignancy were diagnostic for neoplasia. Without evidence of neoplasia or fungal disease, nonfungal rhinitis was diagnosed. RESULTS: Among the 58 dogs, 21 had nasal aspergillosis, 25 had nonfungal rhinitis, and 12 had nasal neoplasia. Fourteen aspergillosis-affected dogs and 1 dog with nonfungal rhinitis had serum antibodies against Aspergillus spp. Fungal culture results were positive for Aspergillus spp only for 17 dogs with aspergillosis. With regard to aspergillosis diagnosis, sensitivity, specificity, and positive and negative predictive values were 67%, 98%, 93%, and 84%, respectively, for serum anti-Aspergillus antibody determination and 81%, 100%, 100%, and 90%, respectively, for fungal culture. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that seropositivity for Aspergillus spp and identification of Aspergillus spp in cultures of nasal tissue are highly suggestive of nasal aspergillosis in dogs; however, negative test results do not rule out nasal aspergillosis.