Mortality rate and prognostic factors for dogs with severe anaphylaxis: 67 cases (2016–2018)

Abstract

OBJECTIVE To determine mortality rates for dogs with severe anaphylaxis and identify potential prognostic factors. ANIMALS 67 dogs with suspected anaphylaxis graded as severe. PROCEDURES Dogs were classified on the basis of outcome as survivors and nonsurvivors. Medical records were reviewed, and data were extracted including signalment, examination findings, time to hospital admission from onset of clinical signs, CBC results, serum biochemical analysis results, coagulation testing results, and findings on abdominal ultrasonography. Initial treatment within the first 6 hours after hospital admission was recorded for analysis, specifically including the use of epinephrine, diphenhydramine, corticosteroids, antimicrobials, fresh-frozen plasma, and supplemental dextrose. RESULTS The overall mortality rate was 14.9% (10/67) for dogs with anaphylaxis graded as severe. Serum phosphorus concentration and prothrombin time (PT) were significantly higher in nonsurvivors, compared with survivors. Nonsurvivors had lower presenting body temperatures than survivors. Serum phosphorus concentration ≥ 12.0 mmol/L, hypoglycemia within 6 hours after hospital admission, high PT value, concurrently high PT and partial thromboplastin time (PTT) values > 50% above the reference range limit, and the need for supplemental dextrose were associated with death. The incidences of coagulopathy and peritoneal effusion were unexpectedly high (85.2% and 65.5% of dogs, respectively) but were not indicative of survival. CONCLUSIONS AND CLINICAL RELEVANCE Despite the poor presenting clinical condition seen in dogs with severe anaphylaxis, the rate of survival with treatment was fairly high. Coagulopathy and the presence of peritoneal effusion were common findings in dogs with severe anaphylaxis. Serum phosphorus concentration ≥ 12.0 mmol/L, high PT value, concurrent increases of PT and PTT values > 50% above reference range limits, hypoglycemia within 6 hours after hospital admission, and the need for supplemental dextrose were associated with death.

Clinical characteristics of two‐hundred thirty‐two dogs (2006–2018) treated for suspected anaphylaxis in Perth, Western Australia

“…Dermatological signs are considered the classical clinical sign of type 1 hypersensitivity reactions; however, cardiovascular, gastrointestinal and respiratory signs have also been reported. 1,[8][9][10] This is consistent with both phases of our study, where the most frequent clinical signs were dermatological, gastrointestinal and cardiovascular. It is important to note that approximately 25% of all dogs did not have dermatological signs; this increased to 47% when only considering dogs with evidence of insect exposure.…”

“…36,37 This phenomenon explains the presence of gallbladder wall oedema in clinical cases. 7,9,10,13 Extravasation of fluid secondary to increased vascular permeability may also contribute to hypovolaemic shock, a recognised mechanism in human anaphylaxis. 33,38,39 This response to anaphylaxis in dogs may provide some theoretical justification for blood volume expansion via the administration of intravenous fluids, despite a paucity of evidence for the efficacy of this treatment.…”

“…Recent research definitions of naturally occurring canine anaphylaxis have also used these categories of organ dysfunction, integrated with consensus definitions from human medicine. [7][8][9][10][11][12] One of these studies defined anaphylaxis as a systemic hypersensitivity reaction involving at least two organ systems, including dermatological, respiratory, cardiovascular or gastrointestinal signs. 10 Several studies have followed suit with these definitions.…”

“…10 Several studies have followed suit with these definitions. 8,9 Gallbladder wall oedema, peritoneal free fluid, coagulation abnormalities and an elevation in serum alanine transaminase concentration may also be present and, though they are non-specific, are often used to support the diagnosis. 7,9,10,13 The classic cutaneous changes in canine anaphylaxis are readily identifiable by clinicians in the setting of an acute type 1 hypersensitivity reaction.…”

“…8,9 Gallbladder wall oedema, peritoneal free fluid, coagulation abnormalities and an elevation in serum alanine transaminase concentration may also be present and, though they are non-specific, are often used to support the diagnosis. 7,9,10,13 The classic cutaneous changes in canine anaphylaxis are readily identifiable by clinicians in the setting of an acute type 1 hypersensitivity reaction. 14 However, the presence of acute gastrointestinal and cardiovascular signs, in the absence of dermatological signs, can make the diagnosis more challenging.…”