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.

Use of tranexamic acid in dogs with primary immune thrombocytopenia: A feasibility study.

Objective: The aim of this feasibility study is to evaluate the use of tranexamic acid and its safe use alongside standard therapy in dogs with primary immune thrombocytopenia (ITP). Design: This is a cohort feasibility study involving 10 dogs diagnosed with primary ITP that received standard therapy for ITP including corticosteroids, a single dose of vincristine, and omeprazole. Dogs were randomly divided into either the control group (n = 6) or the group receiving tranexamic acid (TXA group, n = 4). Key findings: The mean time from the start of treatment until remission was 5 days in the TXA group and 6 days in the control group (P = 0.69). Two dogs, one in each group, did not achieve remission. Clinical bleeding scores were not significantly different between both groups (p = 0.43), and the median blood volume administered was 37.5 ml/kg for the TXA group and 9.72 ml/kg for the control group (p = 0.084). Three out of the four dogs receiving TXA of 20 mg/kg IV started vomiting within 15 min of administration and were given a reduced dose of 15 or 10 mg/kg IV. Conclusion: Tranexamic acid did not confer a clinical benefit in this small cohort study and was associated with a high incidence of vomiting. This study provides useful information for the design of future trials in dogs with ITP receiving tranexamic acid including outcome measures and safety.

The use of high-dose immunoglobulin M-enriched human immunoglobulin in dogs with immune-mediated hemolytic anemia.

BACKGROUND: The IV use of human immunoglobulin (hIVIG) in dogs with primary immune-mediated hemolytic anemia (IMHA) has been described previously, but herein we describe the use of high-dose IgM-enriched hIVIG (Pentaglobin). HYPOTHESIS/OBJECTIVES: Dogs treated with high-dose Pentaglobin will experience shorter time to remission and hospital discharge and have decreased transfusion requirements compared to dogs receiving standard treatment alone. ANIMALS: Fourteen client-owned dogs diagnosed with primary IMHA at specialist referral hospitals in the United Kingdom. METHODS: All prospectively enrolled dogs received prednisolone, dexamethasone or both along with clopidogrel. Patients were randomized to receive Pentaglobin at 1 g/kg on up to 2 occasions, or to serve as controls. No additional immunosuppressive drugs were allowed within the first 7 days of treatment. Remission was defined as stable PCV for 24 hours followed by an increase in PCV. RESULTS: Ten of 11 dogs from the treatment group and 2 of 3 dogs from the control group achieved remission and survived until hospital discharge. Survival and time to remission were not significantly different between groups. The volume of packed red blood cells transfused, normalized for body weight, was not significantly different between groups. Potential adverse reactions to Pentaglobin occurred in 2 dogs, but their clinical signs may have been related to the underlying disease. CONCLUSIONS AND CLINICAL IMPORTANCE: Treatment with high-dose Pentaglobin was well tolerated by dogs with primary IMHA but no significant advantage was found in this small study. Additional studies examining larger groups and subpopulations of dogs with primary IMHA associated with a poorer prognosis are warranted.

Acquired urea cycle amino acid deficiency and hyperammonaemic encephalopathy in a cat with inflammatory bowel disease and chronic kidney disease.

CASE SUMMARY: A 5-year-old male neutered Persian cat was referred for investigation of a 4 week history of weight loss, inappetence and intermittent vomiting. Chronic kidney disease (CKD) and inflammatory bowel disease were diagnosed, and despite immunosuppressive therapy and assisted enteral nutrition, the cat experienced persistent anorexia, vomiting and severe weight loss. After 2 additional weeks of treatment, the cat developed acute-onset neurological signs associated with severe hyperammonaemia and was euthanased. Plasma amino acid assessment revealed deficiency of several amino acids involved in the urea cycle, including arginine. RELEVANCE AND NOVEL INFORMATION: To our knowledge, this is the first reported case of an acquired urea cycle amino acid deficiency without nutritional deprivation in a cat. Several contributing factors were suspected, including intestinal malabsorption and CKD. This case demonstrates the importance of urea cycle amino acids in feline metabolism and possible necessity for parenteral supplementation, particularly in the context of persistent weight loss despite adequate enteral nutrition.

Comparison of standard single-bite with multiple-bite biopsy forceps for collection of gastrointestinal biopsies in dogs: a prospective study.

Various types of endoscopic biopsy forceps have been investigated in dogs. The Multibite (MB) are multiple-bite forceps that collect up to four tissue specimens in a single pass through the endoscope, reducing procedure time. The authors prospectively investigated its clinical utility by comparing procedure times and diagnostic quality of samples obtained with the MB to that of biopsies performed with a single-bite forceps (SB), in 21 dogs with gastrointestinal disorders. When comparing the depth, crush artefacts and diagnostic adequacy of the gastric and duodenal biopsies, there was no significant difference between the MB and SB forceps. The procedure time was significantly longer with the MB. There was no learning curve effect, and there were no reported adverse events. This study failed to demonstrate any significant clinical advantage associated with the use of the Multibite forceps over that of conventional disposable SB forceps.

Canine and feline blood transfusions: controversies and recent advances in administration practices.

OBJECTIVES: To discuss and review blood transfusion practices in dogs and cats including collection and storage of blood and administration of products. To report new developments, controversial practices, less conventional blood product administration techniques and where applicable, describe the relevance to anaesthetists and anaesthesia. DATABASES USED: PubMed and Google Scholar using dog, cat, blood transfusion, packed red blood cells and whole blood as keywords. CONCLUSIONS: Blood transfusions improve oxygen carrying capacity and the clinical signs of anaemia. However there are numerous potential risks and complications possible with transfusions, which may outweigh their benefits. Storage of blood products has improved considerably over time but whilst extended storage times may improve their availability, a phenomenon known as the storage lesion has been identified which affects erythrocyte viability and survival. Leukoreduction involves removing leukocytes and platelets thereby preventing their release of cytokines and bioactive compounds which also contribute to storage lesions and certain transfusion reactions. Newer transfusion techniques are being explored such as cell salvage in surgical patients and subsequent autologous transfusion. Xenotransfusions, using blood and blood products between different species, provide an alternative to conventional blood products.

Assessment of five formulae to predict post-transfusion packed cell volume in cats.

This retrospective study aimed to identify the most accurate formula for estimating the increase in packed cell volume (PCV) after whole blood transfusion of cats, as several formulae have been reported but not validated. Forty cats, of varying breeds and gender, were included from two referral institutions after database searches over a 13 year period. Five formulae were used to calculate an estimated post-transfusion PCV based on the re-working of formulae for determining the volume of donor blood to be transfused; three formulae were derived from those previously reported in the feline literature and two from human paediatric medicine, where a similar mean blood volume has been described. Cats were subdivided into two groups, the first consisting of 17 cats with non-regenerative anaemia and the second consisting of 23 cats with ongoing losses such as haemolysis and haemorrhage; it was hypothesised that formulae could be more accurate for group 1 cats, whereas formulae applied to group 2 cats could have overestimated the post-transfusion PCV. Bland-Altman analysis was performed for all cats to compare the actual increase in PCV with the calculated increase for the five formulae. Formula 1 (PCV % increase = volume of blood transfused in ml/2 × bodyweight in kg) performed best overall and is easy to calculate; however, no single formula was highly accurate at predicting the PCV increase after whole blood transfusion in cats and, owing to the wide confidence intervals, these formulae should be applied judiciously in the clinical setting.