Immune‐mediated hemolytic anemia (IMHA) causes severe anemia in dogs and is associated with considerable morbidity and mortality. Treatment with various immunosuppressive and antithrombotic drugs has ...been described anecdotally and in previous studies, but little consensus exists among veterinarians as to the optimal regimen to employ and maintain after diagnosis of the disease. To address this inconsistency and provide evidence‐based guidelines for treatment of IMHA in dogs, we identified and extracted data from studies published in the veterinary literature. We developed a novel tool for evaluation of evidence quality, using it to assess study design, diagnostic criteria, explanation of treatment regimens, and validity of statistical methods. In combination with our clinical experience and comparable guidelines for humans afflicted with autoimmune hemolytic anemia, we used the conclusions of this process to make a set of clinical recommendations regarding treatment of IMHA in dogs, which we refined subsequently by conducting several iterations of Delphi review. Additionally, we considered emerging treatments for IMHA in dogs and highlighted areas deserving of future research. Comments were solicited from several professional bodies to maximize clinical applicability before the recommendations were submitted for publication. The resulting document is intended to provide clinical guidelines for management of IMHA in dogs. These guidelines should be implemented pragmatically, with consideration of animal, owner, and veterinary factors that may vary among cases.
Background
Evidence supporting the effectiveness of therapeutic protocols for nonassociative immune‐mediated hemolytic anemia (na‐IMHA) is weak.
Hypothesis/Objectives
Investigate the efficacy of ...various drugs in na‐IMHA.
Animals
Two hundred forty‐two dogs.
Methods
Multi‐institutional retrospective study (2015‐2020). Immunosuppressive effectiveness was determined by time to packed cell volume (PCV) stabilization and duration of hospitalization through analysis by mixed model linear regression. Occurrence of disease relapse, death, and antithrombotic effectiveness, were analyzed using mixed model logistic regression.
Results
Use of corticosteroids vs a multi‐agent protocol had no effect on time to PCV stabilization (P = .55), duration of hospitalization (P = .13), or case fatality (P = .06). A higher rate of relapse (P = .04; odds ratio: 3.97; 95% confidence interval CI: 1.06‐14.8) was detected in dogs receiving corticosteroids (11.3%) during follow‐up (median: 28.5 days, range: 0‐1631 days) compared to multiple agents (3.1%) during follow up (median: 47.0 days, range: 0‐1992 days). When comparing drug protocols, there was no effect on time to PCV stabilization (P = .31), relapse (P = .44), or case fatality (P = .08). Duration of hospitalization was longer, by 1.8 days (95% CI: 0.39‐3.28 days), for the corticosteroid with mycophenolate mofetil group (P = .01) compared to corticosteroids alone. Use of clopidogrel vs multiple agents had no effect on development of thromboses (P ≥ .36).
Conclusions and Clinical Importance
Addition of a second immunosuppressive agent did not alter immediate outcome measures but might be associated with a reduction in relapse. Use of multiple antithrombotic agents did not reduce incidence of thrombosis.
Background
Established treatment protocols for schistosomiasis (Heterobilharzia americana) in dogs are expensive. Anecdotal reports suggest that lower doses of praziquantel, combined with ...fenbendazole, may eliminate asymptomatic infections.
Objectives
Evaluate the efficacy of a low‐dose praziquantel and fenbendazole protocol to manage asymptomatic schistosomiasis in dogs and compare fecal saline sedimentation (FSS) and fecal PCR (FPCR) for therapeutic monitoring.
Animals
Twelve asymptomatic dogs with positive FPCR and FSS results for schistosomiasis.
Methods
Prospective observational study. On day 0, dogs received praziquantel at a median dose of 5 mg/kg PO q8h for 2 days, with fenbendazole at 24 mg/kg PO q24h for 7 days. Fecal PCR and FSS were repeated in all dogs on days 30, 60, and 90.
Results
By day 30, 10 of 12 dogs were negative by FSS, but only 3 of 12 were negative by FPCR. By day 60, all 12 dogs were negative by FSS, and 8 of 12 had become negative by FPCR. By day 90, all 12 dogs remained negative by FSS, but 5 of 12 were positive by FPCR (including 2 that were negative by FPCR on day 60). Three dogs that were positive by FPCR on day 60 were re‐treated and subsequently became both FPCR and FSS negative. One FPCR‐positive dog developed a mild increase in serum ALP activity, another developed mild hypercalcemia, and a third developed diarrhea.
Conclusions and Clinical Importance
A low‐dose praziquantel/fenbendazole protocol may be effective for asymptomatic schistosomiasis in some dogs, but monitoring to ensure treatment success is recommended. Fecal saline sedimentation and FPCR may demonstrate discrepant results, with FPCR being positive more frequently.
Background
The potential effects of glucocorticoid administration on rivaroxaban's anticoagulant bioactivity in dogs, and an appropriate rivaroxaban dosage regimen for dogs receiving glucocorticoid ...therapy are unknown.
Hypothesis/Objectives
The objective was to determine whether glucocorticoid administration influences the anticoagulant effects of rivaroxaban in healthy dogs. We hypothesized that administration of rivaroxaban and prednisone would reduce the anticoagulant intensity compared with rivaroxaban alone.
Animals
Nine healthy dogs.
Methods
Randomized, cross‐over study. Dogs were administered prednisone (2 mg/kg, PO, q24h), rivaroxaban (1.5 mg/kg, PO, q24h), or prednisone and rivaroxaban, and the coagulation status was evaluated using prothrombin time (PT), and rivaroxaban‐calibrated anti‐Xa activity (RIVA, results were log10 transformed for analysis), before drug administration and on days 2, 4, and 8. Linear mixed models and correlation were used to evaluate associations in variables (P < .05 was considered significant).
Results
There were no differences in RIVA results for the rivaroxaban and prednisone/rivaroxaban groups on day 8 (P = .599, median 87 range 45‐156 to 167 56‐333, respectively, median difference 90 ng/mL 95% CI:87.3‐161.8) There was a strong correlation between RIVA and PT results when days 2, 4, and 8 were combined (r = .846, P < .001), and increased during drug administration, day 2 (r = .810, P < .001), day 4 (r = .863, P < .001), and day 8 (r = .885, P < .001).
Conclusions and Clinical Importance
Clotting times in the PT correlate with rivaroxaban levels and may prove useful for drug monitoring. Prednisone administration had no apparent influence on the anticoagulant effects of rivaroxaban in healthy dogs, suggesting that combined therapy will not require dosage adjustments.
Immune thrombocytopenia (ITP) is the most common acquired primary hemostatic disorder in dogs. Immune thrombocytopenia less commonly affects cats but is an important cause of mortality and ...treatment‐associated morbidity in both species. Immune thrombocytopenia remains a diagnosis of exclusion for which diagnostic guidelines are lacking. Primary, or non‐associative, ITP refers to autoimmune platelet destruction. Secondary, or associative, ITP arises in response to an underlying disease trigger. However, evidence for which comorbidities serve as ITP triggers has not been systematically evaluated. To identify key diagnostic steps for ITP and important comorbidities associated with secondary ITP, we developed 12 Population Evaluation/Exposure Comparison Outcome (PECO) format questions. These questions were addressed by evidence evaluators utilizing a literature pool of 287 articles identified by the panelists using a structured search strategy. Evidence evaluators, using panel‐designed templates and data extraction tools, summarized evidence and created guideline recommendations that then were integrated by diagnosis and comorbidity domain chairs. The revised PECO responses underwent a Delphi survey process to reach consensus on final guidelines. A combination of panel expertise and PECO responses were employed to develop algorithms for diagnosis of ITP in dogs and cats, which also underwent 4 iterations of Delphi review. Comorbidity evidence evaluators employed an integrated measure of evidence (IME) tool to determine evidence quality for each comorbidity; IME values combined with evidence summaries for each comorbidity were integrated to develop ITP screening recommendations, which also were subjected to Delphi review. Commentary was solicited from multiple relevant professional organizations before finalizing the consensus. The final consensus statement provides clinical guidelines for the diagnosis of, and underlying disease screening for, ITP in dogs and cats. The systematic consensus process identified numerous knowledge gaps that should guide future studies. This statement is a companion manuscript to the ACVIM Consensus Statement on the Treatment of Immune Thrombocytopenia.
Background
In humans, washing stored blood products before transfusion reduces storage lesions and incidence of transfusion reactions, but the effectiveness of washing canine blood is unknown.
...Objectives
The objective was to determine if manually washing units of stored blood would reduce storage lesions without adversely affecting erythrocytes. We hypothesized that washing stored units would reduce concentrations of storage lesions and cause minimal erythrocyte damage.
Animals
Eight healthy research dogs.
Methods
Repeated measure cohort study. Units of whole blood were stored for 28 days and washed 3 times with 0.9% NaCl. Blood samples were collected before and after storage, after each wash, and after being held at a simulated transfusion temperature. Variables measured included CBC variables, blood gas analysis, erythrocyte morphology, mean corpuscular fragility (MCF), and eicosanoid concentrations. A Friedman's test was used to evaluate changes in variables (P < .05 was considered significant).
Results
After the first wash, compared to values after storage, there was a significant decrease in potassium (4.3 mmol/L 4.0‐4.7 to 1.2 mmol/L 1‐1.6; P < .0001, median range), lactate (1.45 mmol/L 1.07‐1.79 to 0.69 mmol/L 0.39‐0.93; P = .002), and partial pressure carbon dioxide (102 mm Hg 80.2‐119.2 to 33.7 mm Hg 24.5‐44.5; P < .0001), and increase in MCV (69.3 fL 65.7‐72.3 to 74 fL 69.6‐79.5; P = .0003), and MCF (0.444 fL 0.279‐0.527 to 0.491 fL 0.43‐0.616; P = .0006).
Conclusions and Clinical Importance
A single wash of stored whole blood significantly reduces most extracellular storage lesions, and additional washing might cause hemolysis.
Background
Sensitivity and specificity for commercial and in‐house pancreatic lipase immunoreactivity (cPLI) assays have been reported, but repeatability under routine clinical conditions is unknown.
...Objectives
To determine:
Coefficient of variation (CV) between replicates of a commercial assay (Spec cPL) and 2 in‐house assays (VetScan cPL, Vcheck cPL) under routine conditions.
Effects of sample condition or personnel on results.
Potential directional bias between assays.
Animals
Serum from 12 canine clinical patients.
Methods
Prospective study. Serum Spec cPL, VetScan cPL, and Vcheck cPL (6 aliquots each) were measured, and CVs were calculated, effects of sample condition and personnel were assessed using a linear mixed model, and direction of bias was assessed using least square mean cPLI concentration.
Results
Mean %CVs for Spec cPL, VetScan cPL, and Vcheck cPL were 5.5, 17.0, and 23.7%. Three of 6 VetScan cPL samples and 5/9 Vcheck cPL samples had an unacceptably high %CV (>20%). Transportation (Spec cPL) and sample condition or personnel (VetScan cPL, Vcheck cPL) did not affect repeatability. Least square mean cPL was higher for Spec cPL (807.9 μg/L) than for VetScan cPL (558.5 μg/L) or Vcheck cPL (399.8 μg/L).
Conclusions and Clinical Importance
For clinical use, the commercial Spec cPL has the highest repeatability, and Vcheck cPL has significantly lower repeatability. Both in‐house assays evaluated may provide discrepant categorical results (“pancreatitis” versus “equivocal” versus “not pancreatitis”) for the same sample. In‐house pancreatic lipase concentrations may be lower than those determined by the Spec cPL assay.
Management of immune thrombocytopenia (ITP) in dogs and cats is evolving, but there are no evidence‐based guidelines to assist clinicians with treatment decisions. Likewise, the overall goals for ...treatment of ITP have not been established. Immunosuppressive doses of glucocorticoids are the first line treatment, but optimal treatment regimens beyond glucocorticoids remain uncertain. Additional options include secondary immunosuppressive drugs such as azathioprine, modified cyclosporine, and mycophenolate mofetil, usually selected based on clinician preference. Vincristine, human IV immunoglobulin (hIVIg), and transfusion of platelet or red blood cell–containing products are often used in more severe cases. Splenectomy and thrombopoietin receptor agonists are usually reserved for refractory cases, but when and in which patient these modalities should be employed is under debate. To develop evidence‐based guidelines for individualized treatment of ITP patients, we asked 20 Population Intervention Comparison Outcome (PICO) format questions. These were addressed by 17 evidence evaluators using a literature pool of 288 articles identified by a structured search strategy. Evidence evaluators, using panel‐designed templates and data extraction tools, summarized evidence and created guideline recommendations. These were integrated by treatment domain chairs and then refined by iterative Delphi survey review to reach consensus on the final guidelines. In addition, 19 non‐PICO questions covering scenarios in which evidence was lacking or of low quality were answered by expert opinion using iterative Delphi surveys with panelist integration and refinement. Commentary was solicited from multiple relevant professional organizations before finalizing the consensus. The rigorous consensus process identified few comparative treatment studies, highlighting many areas of ITP treatment requiring additional studies. This statement is a companion manuscript to the ACVIM Consensus Statement on the Diagnosis of Immune Thrombocytopenia in Dogs and Cats.
Background
Dogs are often adminstered >1 immunosuppressive medication when treating immune‐mediated diseases, and determining whether these different medications affect IL‐2 expression would be ...useful when performing pharmacodynamic monitoring during cyclosporine therapy.
Hypothesis/Objectives
To determine the effects of 5 medications (prednisone, cyclosporine, azathioprine, mycophenolate mofetil, and leflunomide) on activated T‐cell expression of the cytokines IL‐2 and interferon‐gamma (IFN‐γ).
Animals
Eight healthy dogs.
Methods
Randomized, cross‐over study comparing values before and after treatment, and comparing values after treatment among drugs. Dogs were administered each drug at standard oral doses for 1 week, with a washout of at least 21 days. Activated T‐cell expression of IL‐2 and IFN‐γ mRNA was measured by quantitative reverse transcription polymerase chain reaction. Blood drug concentrations were measured for cyclosporine, mycophenolate, and leflunomide metabolites.
Results
Least squares means (with 95% confidence interval) before treatment for IL‐2 (2.91 2.32‐3.50 ΔCt) and IFN‐γ (2.33 1.66‐3.00 ΔCt) values were significantly lower (both P < .001) than values after treatment (10.75 10.16‐11.34 and 10.79 10.11‐11.46 ΔCt, respectively) with cyclosporine. Similarly, least squares means before treatment for IL‐2 (1.55 1.07‐2.02 ΔCt) and IFN‐γ (2.62 2.32‐2.92 ΔCt) values were significantly lower (both P < .001) than values after treatment (3.55 3.06‐4.00 and 5.22 4.92‐5.52 ΔCt, respectively) with prednisone. Comparing delta cycle threshold values after treatment among drugs, cyclosporine was significantly different than prednisone (IL‐2 and IFN‐γ both P < .001), with cyclosporine more suppressive than prednisone.
Conclusions and Clinical Importance
Prednisone and cyclosporine both affected expression of IL‐2 and IFN‐γ, suggesting that both have the ability to influence results when utilizing pharmacodynamic monitoring of cyclosporine treatment.