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

Urine Neutrophil Gelatinase-Associated Lipocalin in Non-Associative Immune Mediated Hemolytic Anemia: A Prospective Controlled Study in 22 Dogs

BACKGROUND

Urine neutrophil gelatinase-associated lipocalin (uNGAL) is a biomarker for the early diagnosis of AKI.

OBJECTIVES

To evaluate uNGAL in dogs with non-associative immune mediated hemolytic anemia (IMHA) and to evaluate whether uNGAL correlates with disease severity markers, negative prognostic indicators and outcome.

ANIMALS

Twenty-two dogs with non-associative IMHA and 14 healthy dogs.

METHODS

Prospective case-control study. uNGAL was measured by a commercially available ELISA-kit and corrected to urine creatinine (uNGAL to creatinine ratio [UNCR]). uNGAL and UNCR of IMHA cases were compared to that of healthy dogs and the correlation with other clinicopathological markers was evaluated. uNGAL and UNCR were also compared between dogs with a CHAOS or ASA score < 3 and ≥ 3.

RESULTS

uNGAL and UNCR were significantly higher in dogs with IMHA when compared to healthy controls (uNGAL median 114.58 and 0.43 ng/mL, respectively, p < 0.001; UNCR median 174.87 and 0.13 ng/mg, respectively, p < 0.001). uNGAL and UNCR were moderately positively correlated with urea (p = 0.005, r = 0.58, 0.20-0.81 95% CI and p = 0.001, r = 0.64, 0.29-0.84 95% CI, respectively) and total bilirubin (p = 0.003, r = 0.60, 0.22-0.82 95% CI and p = 0.002, r = 0.62, 0.25-0.83 95% CI, respectively). These were also significantly higher in dogs with hemoglobinuria compared to those without (uNGAL: median 269 and 30.99 ng/mL, respectively, p < 0.001; UNCR: median 585.3 and 352 37.47 ng/mg, respectively, p < 0.001). There was no statistically significant difference in uNGAL or UNCR when assessing survival to discharge (p = 0.24 and p = 0.16, respectively, 95% CI).

CONCLUSIONS

This study suggests that renal injury might be underappreciated in dogs with IMHA.

Feasibility and complications of videocapsule endoscopy in dogs weighing 7 kg or less

BACKGROUND

Videocapsule endoscopy (VCE) is a valuable tool for investigating gastrointestinal (GI) diseases in dogs. Its use is not recommended in dogs ≤4.3 kg, because of risks of GI endoscopic capsule (EC) retention and bowel obstruction.

OBJECTIVES

Describe the feasibility and complications of VCE in dogs ≤7 kg.

ANIMALS

Twenty-six client-owned dogs.

METHODS

Retrospective study describing the signalment, previous GI imaging, indications, findings, and complications of canine VCE studies submitted to Infiniti Medical between March 2020 and January 2023.

RESULTS

The median weight and age of dogs was 5.6 kg (range, 3-7) and 8.8 years (range, 1-16), respectively. Two capsules were administered endoscopically into the duodenum (1) and stomach (1). Sixteen out of 26 (62%, 95% CI, 40.51-79.70) dogs that underwent VCE had incomplete studies. Of the 24 capsules administered per os, 15 led to incomplete studies (battery died in the stomach (14), EC was vomited (1)). Body weight <5 kg significantly increased the risk of an incomplete study (OR: 3.67, 95% CI, 1.56-inf, P = .0074). Median esophageal, gastric, and small bowel transit time were 5 seconds (range, 1-180), 240 minutes (range, 17-335), and 73.5 minutes (range, 5-168), respectively. All 10 dogs with overt GI bleeding had a possible origin identified with VCE. Complications were limited to vomiting (1/26, 3.85%, 95% CI, 0-11.20).

CONCLUSIONS AND CLINICAL IMPORTANCE

Videocapsule endoscopy is a safe and informative procedure even when performed in dogs as small as 3 kg. However, weighing <5 kg increases the risk of incomplete studies.

Alteration of clinical parameters before mortality and prognostic outcomes of pulmonary hypertension in dogs with myxomatous mitral valve disease

Background

Myxomatous mitral valve degeneration (MMVD) is a prevalent canine heart condition often accompanied by pulmonary hypertension (PH). Echocardiography is a valuable diagnostic tool for MMVD, but its accessibility is limited in small veterinary clinics.

Aim

This study aimed to identify clinical parameters and biochemistry and cardiac biomarkers as prognostic indicators for cardiac mortality in MMVD dogs with and without PH.

Animals

Ninety-nine MMVD dogs and nineteen normal dogs.

Methods

In a five-year longitudinal study, data including clinical and laboratory measurements as well as echocardiographic parameters were collected every 6 months. Dogs were monitored until death or loss to follow-up, and the cause of death was determined when possible. Statistical analysis was performed to identify factors that predicted death.

Results

Alterations in body condition score, total protein, fractional shortening percentage, and mean corpuscular volume were predictive of impending cardiac mortality. High blood urea nitrogen-to-creatinine ratio, heart rate, and low hemoglobin levels were associated with an increased risk of death. N-terminal pro-B-type natriuretic peptide was also a significant predictor of cardiac-related mortality, with higher levels indicating increased risk. Moreover, MMVD dogs with PH had a significantly lower survival rate than those with MMVD without PH. However, no significant difference in survival was observed between MMVD stage C and D with PH and MMVD stage C and D without PH groups.

Conclusion

These findings provide valuable insights into the monitoring of MMVD progression in dogs using clinical parameters and biomarkers, especially when echocardiography cannot be performed.

Rational use of gastroprotectants in cats: An evidence-based approach

PRACTICAL RELEVANCE

Acid-related disorders including esophagitis and gastroduodenal ulceration are uncommon in the cat. However, when they occur, they can have devastating consequences and require targeted intervention, including the use of gastroprotectants. Careful consideration of the causes of esophagitis and gastroduodenal ulceration can help the clinician to determine which gastroprotectant to use, and when to begin and end gastroprotective therapy.

CLINICAL CHALLENGES

Gastroprotectants remain one of the most misused classes of drugs in veterinary and human medicine. There are very few studies evaluating the efficacy of gastroprotective agents in cats. Furthermore, goals for the degree of gastric acid suppression are extrapolated from studies performed in dogs and humans.

AIMS

This review provides a foundation for the logical approach to the choice of gastroprotectant as indicated by the disease process, and is aimed at all veterinarians who prescribe gastroprotectants for use in cats.

EVIDENCE BASE

The guidance provided in this review is supported by current literature, including consensus opinion from the American College of Veterinary Internal Medicine. Gaps in evidence for use of gastroprotectants in cats are filled by extrapolations from studies performed in dogs and humans.

First description of a primary esophageal histiocytic sarcoma in a dog

An 11-year-old male Schnauzer dog was referred for investigation of cough and regurgitation of one month duration and gradual hyporexia for the previous five months. Complete blood count showed severe leukocytosis. On ventrodorsal and lateral thoracic radiographs a soft tissue mass was visible in the craniodorsal mediastinum. Endoscopy showed esophageal dilatation and an irregular, nodular, friable, exophytic mass in the thoracic esophagus, which was invasive, vascularized and had ulcerated areas. The mass occluded approximately 90% of the esophageal lumen. The mucosa in the orad portion of the thoracic esophagus was pale and the aborad portion was hyperemic (red) with hemorrhages. The mucosa of the cervical and abdominal esophagus was macroscopically unremarkeble. Multiple biopsies using endoscopic cup biopsy forceps were taken from the mass for histopathologic analysis and a percutaneous endoscopic gastrostomy was performed. Histopathologic analysis of the biopsy samples was inconclusive due to the marked necrosis. The poor clinical condition of the dog precluded a more invasive approach, and palliative and supportive treatment was continued. After 100 days of follow-up, clinical signs worsened, and that day the dog had a fatal cardiac arrest due to aspiration pneumonia and sepsis. Postmortem examination showed a multilobulated mass in the esophageal wall with infiltration into the overlying esophageal mucosa and pulmonary and renal metastases. Histological examination revealed a poorly differentiated sarcoma. On immunohistochemical examination, the neoplastic cells showed marked cytoplasmic staining for vimentin and Iba-1. The proliferative rate was approximately 30% by Ki-67. Histological and immunohistochemical examination revealed the esophageal mass to be a primary histiocytic sarcoma. Histiocytic sarcoma is an extremely rare primary esophageal neoplasm in humans, and so far, there is no description in dogs. To the best of the authors knowledge this is the first case of primary esophageal histiocytic sarcoma in dogs. The clinical information reported here should improve recognition and aid in diagnosis of future cases.

Hematological and blood biochemistry parameters as prognostic indicators of survival in canine multicentric lymphoma treated with COP and L-COP protocols

Background and Aim

Hematological and blood chemistry parameters are crucial for evaluating and monitoring canine multicentric lymphoma during chemotherapy. Pre-treatment hematological and blood chemistry parameters can be used as prognostic survival outcomes for this disease. Therefore, this study aimed to investigate the effect of hematological and blood chemistry parameters pre-treatment and 4 weeks post-treatment on the survival outcomes of dogs treated with either a combination of cyclophosphamide, vincristine, and prednisolone (COP) or a combination of COP with L-asparaginase (L-COP) protocols.

Materials and Methods

We conducted a retrospective study. Medical records and hematological and blood chemistry parameters of 41 dogs with multicentric lymphoma treated with L-COP (n = 26) and the COP protocols (n = 15) were obtained from the hospital information system. Most cases were classified as high-grade lymphoma based on the Kiel cytological classification. The effects of hematological and blood chemistry parameters on survival outcomes were investigated using the Cox proportional hazard regression model. The median survival time (MST) for each hematological and blood chemistry parameter affecting survival outcome was established and compared using the Kaplan-Meier product limit method with the log-rank test.

Results

Dogs with high-grade multicentric lymphoma that were treated with the COP protocol and had monocytosis at pre-treatment had a significantly shorter MST than dogs with normal monocyte counts (p = 0.033). In addition, dogs with azotemia, both pre-treatment and 4 weeks post-treatment, had a significantly shorter MST than dogs with normal serum creatinine levels (p = 0.012). Dogs with high-grade multicentric lymphoma treated with the L-COP protocol who had hypoalbuminemia (serum albumin concentration <2.5 mg/dL) at both pre-treatment and 4 weeks post-treatment had a significantly shorter MST than dogs with normal serum albumin levels (p < 0.001). Furthermore, dogs with leukocytosis at 4 weeks post-treatment had a significantly shorter MST than those with a normal total white blood cell count (p = 0.024).

Conclusion

Serum albumin level can serve as a simple negative prognostic indicator of survival outcomes in dogs with high-grade multicentric lymphoma treated with the L-COP protocol. Dogs with hypoalbuminemia pre-treatment and 4 weeks post-treatment tended to have a shorter MST than those with normal serum albumin concentrations.

Plasma urea:creatinine ratio as a biomarker of gastrointestinal bleeding in dogs with anaemia

BACKGROUND

Gastrointestinal bleeding is a cause of anaemia in dogs. A reliable, non-invasive biomarker to differentiate gastrointestinal bleeding from other causes of anaemia would be advantageous to direct clinical decisions in anaemic patients. Plasma urea:creatinine ratio is an accepted biomarker of upper gastrointestinal bleeding in human medicine.

OBJECTIVES

The objective of this study was to evaluate plasma urea:creatinine ratio as a biomarker of gastrointestinal bleeding in a population of dogs with anaemia.

METHODS

This was a prospective cross-sectional study of dogs with anaemia presenting to referral centres for the investigation of anaemia. Cases were categorised as having overt gastrointestinal bleeding (melena on presentation), occult gastrointestinal bleeding (historical and diagnostic findings consistent with gastrointestinal bleeding without melena at presentation) or anaemia of other cause (confident diagnosis other than gastrointestinal bleeding reached, normal diagnostic imaging of gastrointestinal tract). Urea:creatinine ratio at presentation was calculated by dividing urea (mg/dL) by creatinine (mg/dL).

RESULTS

Ninety-five dogs were included. Plasma urea:creatinine ratio was not significantly different between dogs with overt or occult gastrointestinal bleeding or those with anaemia of other cause (median urea:creatinine ratio 25.8, 20.7 and 22.5, respectively). No significant difference in urea:creatinine ratio was found between dogs with upper and lower gastrointestinal bleeding (median urea:creatinine ratio 19.4 and 24.6, respectively).

CONCLUSIONS

Plasma urea:creatinine ratio was not helpful in differentiating between dogs with anaemia resulting from gastrointestinal bleeding (overt or occult) and those with other causes of anaemia.

Gastrointestinal angiodysplasias diagnosed using video capsule endoscopy in 15 dogs

BACKGROUND

Angiodysplasia (AGD) is rarely diagnosed in dogs with gastrointestinal bleeding (GIB) and is reported in case reports in dogs.

OBJECTIVE

Describe signalment, clinical and diagnostic features of dogs with gastrointestinal (GI) AGD diagnosed by video capsule endoscopy (VCE).

ANIMALS

Dogs with overt or suspected GIB which underwent VCE.

METHODS

Dogs for which a VCE was submitted for overt or suspected GIB from 2016 to 2021 were selected retrospectively. Medical records and full-length VCE recordings where AGDs were initially detected, were reviewed by 2 trained internists. AGD was considered definitive if 2 readers detected it. Signalment, clinical signs, blood work, medications, concurrent diseases, findings of previous conventional endoscopy, and surgical exploration (if applicable) of dogs with AGD were recorded.

RESULTS

Definitive AGD was diagnosed in 15 of 291 (5%) dogs (12 males, 3 females). Twelve (80%) had overt GIB, 11 (73%) had hematochezia, and 6 (40%) had microcytic and hypochromic anemia. AGD was missed by conventional endoscopy in 9/9 dogs and exploratory surgery in 3/3 dogs. Thirteen capsules were administered by mouth (1 incomplete study), and 2 via endoscopy directly into the duodenum. AGD was visualized in the stomach of 3 dogs, in the small intestine of 4, and in the colon of 13 dogs.

CONCLUSION AND CLINICAL IMPORTANCE

Although rare, AGD should be considered in dogs with suspected GIB after a negative conventional endoscopy or surgical exporation. Video capsuel endoscopy appears to be a sensitive test to identify AGD within the GI tract.

Double-blinded placebo-controlled clinical trial of prophylactic omeprazole in dogs treated surgically for acute thoracolumbar intervertebral disc extrusion

BACKGROUND

Proton pump inhibitors are administered prophylactically in dogs treated surgically for acute thoracolumbar intervertebral disc extrusion (TL-IVDE). However, their efficacy in decreasing gastrointestinal (GI) complications is unknown.

HYPOTHESIS

Omeprazole does not decrease the frequency of GI complications compared to placebo in dogs treated surgically for acute TL-IVDE.

ANIMALS

Thirty-seven client-owned dogs undergoing hemilaminectomy for acute TL-IVDE.

METHODS

Randomized double-blinded placebo-controlled prospective clinical trial. Dogs received PO placebo or omeprazole at 1 mg/kg q12h for 5 days during hospitalization. Development of GI signs (e.g., diarrhea, vomiting, regurgitation, hematochezia, melena) was recorded daily. Clinicopathologic testing performed during hospitalization and at 2 and 4-week re-evaluations included: fecal occult blood, PCV, blood urea nitrogen/creatinine ratio, fecal calprotectin, canine pancreatic lipase immunoreactivity and fecal alpha-1 proteinase inhibitor concentrations. Omeprazole and placebo groups were compared using chi-squared or Fisher's exact tests.

RESULTS

Gastrointestinal signs developed in 10/20 (50%) dogs in the omeprazole group and in 7/17 (41%) dogs in the placebo group (P = .59). Diarrhea was common (8/20 omeprazole, 5/17 placebo), hematochezia was rare (1/20 omeprazole, 1/17 placebo); melena was not observed. Clinicopathologic evidence suggestive of bleeding was present in 9/20 dogs treated with omeprazole and in 11/17 dogs that received placebo (P = .23). Fecal occult blood positivity was more common in dogs with GI signs (P = .03). Canine pancreatic lipase immunoreactivity was higher during hospitalization compared to re-evaluations (P = .01).

CONCLUSIONS AND CLINICAL IMPORTANCE

Short-term, prophylactic omeprazole treatment did not decrease clinically detectable GI complications in dogs with acute TL-IVDE.

Life-threatening gastrointestinal bleeding caused by jejunal heterotopic gastric mucosa in an adult dog: a rare case report

Background

Heterotopic gastric mucosa has been scarcely reported in the veterinary literature. Its presence can be asymptomatic or associated with various clinical signs ranging from apathy, vomiting, to abdominal pain. This report illustrates the presence of heterotopic gastric mucosa in the jejunum of an adult dog. It is the first to describe severe anemia, requiring acute blood transfusion, following intestinal hemorrhage caused by heterotopic gastric mucosa.

Case presentation

A twelve-year-old, intact male Maltese dog was presented with a history of apathy, vomiting and anemia. The dog was on a strict diet for recurrent diarrhea, food intolerance and skin allergy. Clinical examination revealed severe anemic mucous membranes and painful abdominal palpation. Blood examination confirmed severe regenerative anemia. Ultrasonography showed an intestinal neoplasm, gall bladder sludge and non-homogeneous liver parenchyma. Three-view thoracic radiographs failed to show any metastatic lesions or enlarged lymph nodes. After initial stabilization and blood transfusion, a midline exploratory laparotomy was performed. Three different masses were found in the jejunum. Resection and anastomosis of approximately 40 cm of jejunum was performed, followed by liver and lymph node biopsy and placement of an esophagostomy tube. Two days after surgery the dog started to clinically improve and was discharged from the hospital on the sixth day after surgery. Histopathology revealed the intestinal masses to be heterotopic gastric mucosa associated with intramural cystic distensions, multifocal ulceration and bleeding into the intestinal lumen. Two years after surgery, the dog did not have a recurrence of anemia or gastrointestinal signs.

Conclusions

This case demonstrates that heterotopic gastric mucosa can be considered one of the differential diagnoses in case of severe anemia due to gastrointestinal hemorrhage and suspected intestinal tumors. Although in most described cases in literature the finding seems to be incidental on necropsy, our report shows that heterotopic gastric mucosa can be the etiology of life-threatening signs. In addition, because no recurrent diarrhea episodes occurred after surgical resection of the ectopic tissue, it is likely that the heterotopic gastric mucosa was the cause of the food intolerance signs in this dog.

Evaluation of a long-acting injectable formulation of omeprazole in healthy dogs

BACKGROUND

To evaluate the efficacy of a single intramuscular adminsitration of long-acting omeprazole (LA-OMEP) in increasing gastric pH in dogs.

HYPOTHESIS

We hypothesized that LA-OMEP would meet in healthy dogs the clinical goals defined for human patients for treatment of gastroduodenal ulceration.

ANIMALS

Nine healthy research dogs.

METHODS

Prospective experimental study. Dogs were given a 4 mg/kg intramuscular injection of LA-OMEP. Intragastric pH was continuously recorded on treatment days 0 to 7. Daily mean pH and mean percentage time (MPT) intragastric pH was ≥3 or ≥4 were determined.

RESULTS

The mean onset of action for the LA-OMEP was 98.11 min (SD 46.39). The mean number of days the dogs' pH met established goals for MPT pH ≥3 was 5.5 days (range, 3-7) and 5.25 days for MPT pH ≥4 (range, 3-7). Long-acting omeprazole met the human clinical goals pH ≥3 for 72 hours in 8/8 of the dogs and MPT pH ≥4 for 96 hours in 7/8 of dogs.

CONCLUSIONS AND CLINICAL IMPORTANCE

The LA-OMEP formulation produced gastric acid suppression in healthy dogs for an average of 5 days and up to 7 days, after a single intramuscular injection. No major adverse effects were observed.

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.