Arterial blood gas measurements are different for brachycephalic and nonbrachycephalic dogs acclimatized to an altitude of 1,535 meters.

OBJECTIVE: To define reference intervals (RIs) for arterial blood gas (aBG) measurements in healthy, nonsedated, dolichocephalic, and mesocephalic (nonbrachycephalic) dogs at approximately 1,535 m above sea level and compare these findings with healthy, nonsedated, brachycephalic dogs living at the same altitude. ANIMALS: 120 adult nonbrachycephalic dogs and 20 adult brachycephalic dogs. METHODS: Cases were prospectively enrolled from October 2021 to June 2022. Dogs were enrolled from the community or after presentation for wellness examinations or minor injuries including lacerations, nail injuries, and lameness. Physical examinations and systolic blood pressure (sBP) measurements were obtained before blood sample collection. Arterial blood was collected from the dorsal pedal artery or femoral artery. After data collection, brachycephalic dogs underwent pre- and postexercise tolerance assessments. RESULTS: The mean and RI values for arterial pH (7.442; 7.375 to 7.515), partial pressure of oxygen in arterial blood (Pao2; 78.3; 59.2 to 92.7 mm Hg), partial pressure of carbon dioxide in arterial blood (Paco2; 28.0; 21.5 to 34.4 mm Hg), saturation of arterial oxygen (Sao2; 98.4; 84.3% to 101.4%), HCO3 (18.9; 14.9 to 22.4 mmol/L), concentration of total hemoglobin (ctHb; 17.5; 13.4 to 21.1 g/dL), and sBP (133; 94 to 180 mm Hg) were established for healthy nonbrachycephalic dogs at 1,535-m altitude. All aBG measurements were statistically and clinically different from those previously reported for dogs at sea level. Brachycephalic dogs had significantly lower Pao2 and Sao2 (P = .0150 and P = .0237, respectively) and significantly higher ctHb (P = .0396) compared to nonbrachycephalic dogs acclimatized to the same altitude; the nonbrachycephalic RIs were not transferable to the brachycephalic dogs for Pao2. CLINICAL RELEVANCE: This study represents the first collation of aBG measurements for healthy nonbrachycephalic dogs acclimatized to an altitude of 1,535 m. Additionally, this study identified differences in arterial oxygenation measurements between brachycephalic and nonbrachycephalic dogs. RIs in brachycephalic dogs need to be established.

Incidence of acute haemolysis in cats receiving canine packed red blood cells (xenotransfusions).

OBJECTIVES: The aim of this study was to report the incidence of transfusion reactions in cats, including acute haemolysis (AH), occurring within 24 h of receiving a xenotransfusion. An additional aim was to determine whether cases with AH could be classified as having an acute haemolytic transfusion reaction (AHTR) as per the definition provided by the Association of Veterinary Haematology and Transfusion Medicine's Transfusion Reaction Small Animal Consensus Statement. METHODS: Medical records of cats that received canine packed red blood cells (PRBCs) between July 2018 and September 2020 at a veterinary hospital were reviewed. The incidence of AH, AHTRs, febrile non-haemolytic transfusion reactions (FNHTRs), transfusion-associated circulatory overload and septic transfusion reactions were recorded. RESULTS: The medical records of 53 cats were retrospectively evaluated. Twenty-three (43%) cats had transfusion reactions. Thirteen (25%) cats had AH; however, only four (8%) met the definition of an AHTR. Ten (19%) cats were determined to have FNHTRs. Survival to discharge of cats affected by AH was 50% (25% for cases that met the definition of an AHTR). Survival to discharge of cats not suffering from AHTR was 40%. CONCLUSIONS AND RELEVANCE: This report indicates that a higher proportion of cats undergo AH (25%) when administered canine PRBCs than previously reported, although many could not be classed as having an AHTR due to an apparently adequate packed cell volume rise. Challenges with sourcing feline blood in emergency situations occasionally necessitates the use of xenotransfusion in transfusion medicine. Clinicians should be aware that haemolysis after xenotransfusion can occur within 24 h and that a repeat feline transfusion may be required sooner than anticipated in some cases.