What we know about alterations in immune cells during sepsis in veterinary animals?

Sepsis is still one of the most common causes of death of animals and humans. It is marked by an aberrant immune response to infection, resulting in extensive inflammation, organ dysfunction, and, in severe instances, organ failure. Recognizable symptoms and markers of sepsis encompass substantial elevations in body temperature, respiratory rate, hemoglobin levels, and alterations in immune cell counts, including neutrophils, monocytes, and basophils, along with increases in certain acute-phase proteins. In contrast to human medicine, veterinarians must take into account some species differences. This article provides a comprehensive overview of changes in the immune system during sepsis, placing particular emphasis on species variations and exploring potential future drugs and interventions. Hence, understanding the intricate balance of the immune responses during sepsis is crucial to develop effective treatments and interventions to improve the chances of recovery in animals suffering from this serious condition.

Evaluation of hemostatic derangements associated with canine anaphylaxis and the relationship to syndrome severity

OBJECTIVE

To describe hemostatic derangements associated with canine anaphylaxis and to assess for association with syndrome severity.

DESIGN

Prospective observational study.

SETTING

University teaching hospital.

ANIMALS

Twenty-seven client-owned dogs, recruited from November 2018 to January 2022, diagnosed with anaphylaxis of varying severity were included. Study inclusion required presentation <6 hours after initiation of clinical signs, no medications or history of illness within the prior 2 weeks, lack of comorbidities expected to affect hemostasis, and lack of a disease state that could alternatively explain the clinical presentation.

INTERVENTIONS

Blood samples were collected within the first hour of presentation for CBC, serum biochemistry, prothrombin time (PT), activated partial thromboplastin time (aPTT), and viscoelastic coagulation testing for use with a cartridge-based point-of-care device.

MEASUREMENTS AND MAIN RESULTS

Clotting time and clot formation time were prolonged, alpha angle and maximum clot firmness were decreased, PT and aPTT were prolonged, and platelet counts were lower in severe cases compared to mild and moderate cases. There were no differences for any parameter between mild and moderate cases. The presence or absence of abdominal effusion was not associated with hemostatic status.

CONCLUSIONS

Global hemostatic derangements consistent with hypocoagulability are a prominent feature of severe anaphylaxis in dogs and should be considered for routine evaluation.

Ultrasonographic measurement of gallbladder wall thickness in fasted dogs without signs of hepatobiliary disease

BACKGROUND

Ultrasound-determined gallbladder wall thickness is widely used to aid in the diagnosis of gallbladder disease, but no reference values supported by published measurement data are available in dogs.

HYPOTHESIS/OBJECTIVE

Establish normal thickness of the gallbladder wall in dogs.

ANIMALS

Fifty-three dogs presented to a referral hospital and required abdominal ultrasound examination for reasons unrelated to primary hepatobiliary disease.

METHODS

Cross-sectional observational study recruiting dogs requiring abdominal ultrasound examination. A standard sequence of gallbladder wall images was recorded for later review. Inclusion criteria were normal ultrasonographic hepatobiliary, pancreatic, and small intestinal findings. Exclusion was determined by 2 European College of Veterinary Internal Medicine (ECVIM)-certified veterinary internists blinded to gallbladder wall thickness data. Dogs were excluded if they had inadequate medical records, a previous history of hepatobiliary, gastrointestinal, or pancreatic disease likely to impact the biliary system (eg, chronic vomiting, nausea, jaundice, diarrhea), unexplained increases in liver enzyme activities, hypoalbuminemia, or ascites. Gallbladder wall thickness was determined by 2 European College of Veterinary Diagnostic Imaging (ECVDI)-certified veterinary radiologists working together to generate a consensus for each dog. The final output was the maximum normal wall thickness for this population of dogs.

RESULTS

The upper limit for gallbladder wall thickness in 53 fasted (8 hours) dogs <40 kg was 1.30 mm (90% confidence interval, 1.19-1.41).

CONCLUSIONS AND CLINICAL IMPORTANCE

Normal gallbladder wall thickness in dogs is lower than previously reported. Additional studies are required to determine potential effects of body weight and the optimal cut-off to distinguish between healthy and diseased gallbladders.

Retrospective review of diphenhydramine vs diphenhydramine plus glucocorticoid for the treatment of allergic reaction in cats

OBJECTIVES

The aims of the present study were to report the outcomes of treating allergic reactions in cats with diphenhydramine vs diphenhydramine plus glucocorticoid and to determine whether signs recurred or additional veterinary intervention was needed in the days after initial treatment.

METHODS

This retrospective study evaluated 73 cats treated for allergic reaction with diphenhydramine alone or in combination with a glucocorticoid at a 24 h emergency and specialty referral veterinary hospital between 1 January 2012 and 31 March 2021.

RESULTS

In total, 44 cats were treated with diphenhydramine alone, and 29 were treated with diphenhydramine plus dexamethasone sodium phosphate. The inciting cause was known or highly suspected in 50 patients. Vaccines were the most common (31 patients), followed by insect envenomation (17 cases). No cat in either group progressed to anaphylaxis. There was no difference in resolution of clinical signs between the groups. Follow-up contact was successfully made with 40/73 cat owners. All 40 cats were alive. Eight had persistent signs. There was no difference in the number of cats with persistent signs between groups. Five cats required additional treatment after the initial emergency visit. There was no difference between the two groups for persistent signs at follow-up.

CONCLUSIONS AND RELEVANCE

There was no difference in measured outcomes between cats treated with diphenhydramine alone vs those treated with a glucocorticoid in addition to diphenhydramine in this population. The ideal treatment for allergic reactions is unknown. Based on currently available data in human and veterinary literature, glucocorticoids are not indicated to treat acute allergic reactions. The role of antihistamines as part of a symptomatic supportive treatment plan to shorten the duration of signs is unclear at this time and may be considered.

Diagnostic imaging findings in a referral population of dogs diagnosed with immune-mediated haemolytic anaemia: 50 cases (2015-2018)

OBJECTIVES

To describe and characterise changes documented on thoracic and abdominal imaging of dogs with confirmed immune-mediated haemolytic anaemia.

MATERIALS AND METHODS

Medical records from a referral hospital were searched from 2015 to 2018 for all dogs diagnosed with immune-mediated haemolytic anaemia that underwent thoracic and abdominal imaging by radiography, ultrasound or computed tomography.

RESULTS

Fifty dogs were included. Thoracic imaging revealed abnormalities in 10 dogs (20%) of which lymphadenopathy and cardiomegaly were documented in four dogs (8%) each, and pleural effusion and pleural thickening in one dog (2%) each. Abdominal imaging revealed abnormalities in 43 dogs (86%), in which hepatomegaly and peritoneal effusion were documented in 20 (40%) and 19 dogs (38%), gallbladder wall thickening and sludge in 16 (32%) and 14 dogs (28%) and splenic nodules and splenomegaly in 13 (26%) and seven dogs (14%), respectively. Hepatic and splenic abnormalities were further investigated via fine needle aspirates in 18 dogs and revealed extramedullary haematopoiesis in 12 hepatic (66.7%) and 14 splenic (77.8%) fine needle aspirate samples. Cholecystocentesis was performed in nine dogs with gallbladder abnormalities and revealed bactibilia in three samples (33.3%).

CLINICAL SIGNIFICANCE

In this population of dogs with immune-mediated haemolytic anaemia, thoracic imaging abnormalities were uncommon. Hepatomegaly, peritoneal effusion and gallbladder wall thickening were the most common abdominal imaging findings with bactibilia confirmed in one third of collected bile samples. Hepatosplenomegaly and abdominal lymphadenopathy were not associated with neoplasia in any of the dogs included in this study.

Allergy, inflammation, hepatopathy and coagulation biomarkers in dogs with suspected anaphylaxis due to insect envenomation

Objectives

To compare concentrations of biomarkers of; allergy [mast cell tryptase (MCT) and histamine], inflammation [interleukin (IL)-6,-10, and-18, CXCL8, CCL2, keratinocyte chemoattractant (KC), C-reactive protein (CRP)], endothelial glycocalyx shedding (hyaluronan), coagulation [prothrombin time, activated partial thromboplastin time, fibrinogen concentration, and von Willebrand Factor antigen, protein C (PC) and antithrombin (AT) activity], and hepatopathy [alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP), and total bilirubin] between dogs with anaphylaxis after suspected insect exposure, dogs with critical illness, and healthy dogs.

Design

This was a single center prospective clinical observational comparative biomarker study that included 25 dogs with anaphylaxis (evidence of insect exposure, acute dermatological signs, and other organ involvement), 30 dogs with other critical illness, and 20 healthy dogs. Differences across groups in biomarker concentrations were tested using one-way ANOVA or Kruskal-Wallis test, with significant P values (<0.05) reported for pairwise differences detected by post-hoc tests. Logistic regression models were used to calculate the area under the receiver operator characteristic curve (AUROC) for discrimination between anaphylaxis and non-anaphylactic illness.

Results

Histamine concentration was significantly higher in the anaphylaxis group than the healthy (P < 0.001) and critically ill groups (P < 0.001), whereas no differences in MCT were detected amongst groups. Biomarker concentrations that were increased relative to healthy dogs in both the anaphylaxis and critically ill groups included IL-10 (P < 0.001 and P = 0.007, respectively), CCL2 (P = 0.007 and P < 0.001, respectively) and AST (both P < 0.001), whereas only the critically ill group had significantly increased CRP (P < 0.001), IL-6 (P < 0.001), KC (P < 0.001), ALP (P < 0.001), and fibrinogen (P = 0.016) concentrations, compared to the healthy group. Only dogs with anaphylaxis had significantly higher hyaluronan (P = 0.021) and ALT (P = 0.021) concentrations, and lower PC (P = 0.030) and AT (P = 0.032) activities, compared to healthy dogs. Both CRP and histamine concentration showed good discrimination between anaphylaxis and other critical illness, with an AUROC of 0.96 (95% CI 0.91-1) and 0.81 (95% CI 0.69-0.93), respectively.

Conclusions

This preliminary study in dogs with anaphylaxis after suspected insect exposure, found evidence of an early innate immune response, glycocalyx shedding and anticoagulant consumption. Both CRP and histamine showed potential clinical utility for differentiation between anaphylaxis and other critical illness.

AFAST Target-Organ Approach and Fluid Scoring System in Dogs and Cats

Point-of-care ultrasonography as part of the physical examination is becoming considered a core skill. AFAST includes 5 acoustic windows over the abdomen and serves as a rapid screening test for free fluid (ascites, retroperitoneal, pleural and pericardial effusion) and soft tissue abnormalities (target-organ approach), and has an abdominal fluid scoring system (semiquantitating volume). Moreover, add-on skills are possible without additional views that include characterizing the caudal vena cava and hepatic veins (volume status), measuring the urinary bladder (volume estimation and urine output), screening for free air (pneumoperitoneum, pneumoretroperitoneum), and assessing gastrointestinal motility.

Spontaneous abdominal effusion in dogs with presumed anaphylaxis

OBJECTIVE

To describe patient characteristics of dogs developing spontaneous abdominal effusion in association with anaphylaxis.

DESIGN

Retrospective study between 2010 and 2018.

SETTING

University teaching hospital and referral specialty private practice emergency departments.

ANIMALS

Sixteen dogs presenting to the emergency department for clinical signs suggestive of anaphylaxis with peritoneal effusion documented via ultrasonography.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Dogs presented with clinical signs of anaphylaxis including vomiting 12 of 16 (75%), diarrhea 9 of 16 (56%), and collapse 7 of 16 (44%). Physical examination findings included altered mentation 14 of 16 (88%), erythema 2 of 16 (13%), and urticaria 2 of 16 (13%). Historically, 3 of 16 (19%) had just recently been vaccinated, 1 of 16 (6%) had known contact with an insect, and 8 of 16 (50%) had been outdoors prior to the onset of clinical signs, whereas 5 of 16 (31%) had no known triggering event. At presentation, median systolic arterial pressure was 70 mm Hg (range, 30-210 mm Hg). Venous blood gas revealed an acidemia with a mean pH of 7.24 ± 0.09, a base deficit of 7.15 ± 7.7 mmol/L, and an increased plasma lactate with a mean of 7.35 ± 2.09 mmol/L. Bloodwork abnormalities included an increased alanine aminotransferase activity with a mean of 439.2 ± 404.5 U/L and an increased gamma-glutamyl transferase activity with a mean concentration of 7.29 ± 4.1 U/L. Twelve patients (75%) had gallbladder wall abnormalities on ultrasonography. Eight patients (50%) had abdominocentesis performed. The median PCV of the effusion was 0.29 L/L (29%; range, 4-41) and total plasma protein was 38 g/L (3.8 g/dL; range, 2.4-6.5). Two dogs (12.5%) were euthanized. The remaining 14 dogs (87.5%) survived to discharge, with a mean hospitalization time of 23.7 ± 16.7 hours.

CONCLUSIONS

Abdominal effusion should be considered a potential sequela of anaphylaxis in dogs. Therefore, serial monitoring for presence or development of spontaneous abdominal effusion should be considered.

Thirteen dogs and a cat with ultrasonographically detected gallbladder wall edema associated with cardiac disease

Background

Ultrasonographically detected gallbladder wall edema (GBWE) is a marker for anaphylaxis in dogs. Cardiac disease can cause GBWE with similar signs and should be included as a differential diagnosis to prevent interpretation errors.

Hypothesis/Objectives

Document GBWE associated with cardiac disease.

Animals

Fourteen client‐owned animals.

Methods

Prospective case series with abdominal focused assessment with abdominal sonography in trauma, triage and tracking (AFAST), and thoracic focused assessment with abdominal sonography in trauma, triage, and tracking (TFAST) performed at triage. Animals with GBWE and cardiac disease were enrolled. A board‐certified radiologist reviewed images to confirm cardiac disease, GBWE, and characterize the caudal vena cava (CVC) and hepatic veins.

Results

Thirteen dogs and 1 cat had GBWE associated with cardiac disease. Gallbladder findings included mural thickness ranging from 3 to 5 mm, mild to moderate sludge (n = 3), and mild to moderate luminal distension (n = 6). CVC and hepatic venous distension were found in 5/6. Cardiac diagnoses in dogs included 11 with pericardial effusion (PCE) and 1 each with dilated cardiomyopathy and right‐sided myocardial failure. Severity of PCE was rated as mild (n = 1), moderate (n = 6), or severe (n = 4). Seven of 11 had pericardiocentesis performed. Nine of 13 had ascites with 4 having abdominal fluid scores of 1 (n = 2), 2 (n = 2), 3 (n = 1), and 4 (n = 0). Lung ultrasound findings were as follows: dry lung (n = 6), B‐lines (n = 4), and nodules (n = 1). The cat had moderate PCE, ascites scored as 1, and severe right‐sided ventricular enlargement associated with a ventricular septal defect. Primary presenting complaints included acute weakness (n = 9), acute collapse (n = 5), gastrointestinal signs (n = 3), respiratory distress (n = 2), and need for cardiopulmonary resuscitation (n = 1).

Conclusions and Clinical Importance

Ultrasonographically detected GBWE was associated with PCE in this small cohort of cases.

Retrospective review of diphenhydramine versus diphenhydramine plus glucocorticoid for treatment of uncomplicated allergic reaction in dogs

OBJECTIVE

To report the outcome of treatment of uncomplicated allergic reactions in dogs with diphenhydramine vs diphenhydramine plus glucocorticoid and to determine the incidence rate of uncomplicated allergic reactions DESIGN: Retrospective study between January 1, 2012 and August 15, 2018.

SETTING

Privately owned, 24-hour emergency and specialty referral veterinary hospital.

ANIMALS

Eight hundred and eighty cases of dogs treated for uncomplicated allergic reaction with diphenhydramine alone or in combination with a glucocorticoid.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Two hundred ninety-nine dogs were treated with diphenhydramine alone, and 581 were treated with diphenhydramine plus Dex SP. There was no difference between the 2 groups for response to initial therapy, need for additional veterinary intervention after discharge, or persistent signs at follow-up. The cumulative incidence of emergency department presentation for uncomplicated allergic reaction in this hospital was 1.2%.

CONCLUSIONS

There was no difference in measured outcomes between dogs treated with diphenhydramine alone vs those treated with a glucocorticoid in addition to diphenhydramine in this population of dogs.

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

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.

Anaphylaxis-related hemoperitoneum in 11 dogs

OBJECTIVE

To describe the unique complication of hemoperitoneum associated with anaphylaxis.

DESIGN

Retrospective case series from September 2012 to August 2017.

SETTING

Two private emergency and specialty referral hospitals.

ANIMALS

Eleven client-owned dogs diagnosed with anaphylaxis and hemoperitoneum upon presentation or referral.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Inclusion criteria included clinical signs consistent with anaphylaxis (hypotension, tachycardia, vomiting, diarrhea, weakness, collapse, with or without the presence of dermal signs) due to witnessed or unwitnessed presumed bee sting, an elevated alanine aminotransferase (ALT), performance of abdominal FAST (AFAST) examination with an abdominal fluid score, the sonographic presence of gallbladder wall edema, and hemoperitoneum. All dogs (n=11) were managed medically without surgical intervention. 91% (n=10) of dogs survived to discharge.

CONCLUSIONS

Hemoperitoneum development can be seen with anaphylactic reactions, though the exact mechanism remains to be fully understood. Medical therapy is warranted and can be successful in these patients; surgery is not indicated to address hemoperitoneum.

Evaluation of short-term outcomes and potential risk factors for death and intestinal dehiscence following full-thickness large intestinal incisions in dogs

OBJECTIVE

To determine complication rates for dogs in which full-thickness large intestinal incisions were performed, assess potential risk factors for death during hospitalization and for intestinal dehiscence following these surgeries, and report short-term mortality rates for these patients.

ANIMALS

90 dogs.

PROCEDURES

Medical records of 4 veterinary referral hospitals were reviewed to identify dogs that underwent large intestinal surgery requiring full-thickness incisions. Signalment, history, clinicopathologic data, medical treatments, surgical procedures, complications, and outcomes were recorded. Descriptive statistics were calculated; data were analyzed for association with survival to discharge (with logistic regression analysis) and postoperative intestinal dehiscence (with Fisher exact or Wilcoxon rank sum tests).

RESULTS

Overall 7-day postoperative intestinal dehiscence and mortality rates were 9 of 90 (10%) and 15 of 90 (17%). Dogs with preoperative anorexia, hypoglycemia, or neutrophils with toxic changes and those that received preoperative antimicrobial treatment had greater odds of death than did dogs without these findings. Preexisting colon trauma or dehiscence, preexisting peritonitis, administration of blood products, administration of > 2 classes of antimicrobials, positive microbial culture results for a surgical sample, and open abdominal management of peritonitis after surgery were associated with development of intestinal dehiscence. Five of 9 dogs with intestinal dehiscence died or were euthanized.

CONCLUSIONS AND CLINICAL RELEVANCE

Factors associated with failure to survive to discharge were considered suggestive of sepsis. Results suggested the dehiscence rate for full-thickness large intestinal incisions may not be as high as previously reported, but several factors may influence this outcome and larger, longer-term studies are needed to confirm these findings.

Suspected anaphylactic shock associated with administration of tranexamic acid in a dog

A 10-year-old male castrated Maltese was referred with clinical signs of hematuria, stranguria, and pollakiuria. The dog was diagnosed with sterile hemorrhagic cystitis with urethroliths and cystoliths. To remove the uroliths, the dog underwent retrograde urohydropropulsion followed by a cystotomy. The following day, persistent bleeding in the urinary bladder was identified with large hematoma, hematuria and anemia. In order to reduce bleeding, the dog received 10 mg/kg of tranexamic acid (TXA) intravenously. Immediately after TXA administration, the dog developed anaphylactic shock manifested by hypotension, hypothermia, tachycardia and a dull mentation. Thus, an emergency treatment including bolus injection of crystalloid, administration of dexamethasone and diphenhydramine, and oxygen supplementation was given, after which the dog quickly recovered within a few minutes.

Agreement between Parallel Canine Blood and Urine Cultures: Is Urine Culture the Poor Man's Blood Culture?

Bloodstream infections are a significant cause of morbidity and mortality in critically ill dogs, but due to cost and difficulties in sample acquisition, blood cultures are infrequently obtained. In ill dogs, urine cultures may be recommended as surrogates for blood cultures. In order to determine the outcome agreement between parallel urine and blood cultures, we retrospectively analyzed parallel blood and urine specimens submitted for culture from dogs at the NC State Veterinary Hospital between 2011 and 2016. Positive cultures were reported from 15% of the submitted blood specimens and 23% of the submitted urine specimens. A total of 295 urine and blood samples were submitted in parallel, with positive growth demonstrated in 14 concordant and five discordant pairs. A kappa statistic comparing blood and urine culture outcomes was 0.266 (fair) when all parallel growth was included, including concordant and discordant results, and 0.170 (poor) when restricted to parallel concordant growth. The sensitivity of urine to reflect concordant bloodstream bacterial organisms was 30%, with a specificity of 87%. The positive and negative predictive values were 30% and 88%, respectively. Of dogs with both specimens positive on bacterial culture, 7 of 7 (100%) with suspected urogenital infection sources were concordant. All dogs with discordant bloodstream and urinary infections were immunosuppressed. Urinary coagulase-positive Staphylococcus isolates were most likely to be concordant with bloodstream infections. In conclusion, we found that urine culture is neither a substitute nor a screen for blood culture. Blood cultures should be performed in any potentially septic animal, especially those that are considered immunosuppressed.