Ninety-one dogs met our case definition, but 19 dogs were treated as out-patients, and were excluded from analysis. Demographic information for the remaining 72 dogs is summarized in Table 1.
Table 1
Demographic information for dogs hospitalized at the VTH-UdP and VTH-TAMU for treatment of primary IMHA.
| VTH-UdP (n=29) | VTH-TAMU (n=43) |
Breed | Beagle (1), Bolognese (1), Border Collie (1), Boxer (1), Bull Terrier (2), Cocker Spaniel (3), German Shepherd (1), Lagotto Romagnolo (1), Maltese (2), Mixed breed (15), Poodle (1) | Alaskan Malamute (1), American Pit Bull Terrier (1), Australian Heeler (1), Beagle (1), Boston Terrier (1), Chihuahua (6), Cocker Spaniel (1), Dachshund (3), English Bulldog (1), English Pointer (1), English Springer Spaniel (1), German Shepherd (1), Golden Retriever (1), Havanese (1), Italian Greyhound (1), Labrador Retriever (3), Lhasa Apso (1), Maltese (1), Mastiff (1), Miniature Poodle (1), Miniature Schnauzer (2), Mixed breed (5), Pekingese (1), Shih Tzu (4), Welsh Springer Spaniel (1), Yorkshire Terrier (1) |
Gender | Female intact (7), Female spayed (12), Male intact (7), Male neutered (3) | Female intact (6), Female spayed (26), Male intact (3), Male neutered (8) |
Median age, range (years) | 6 (2-14) | 7 (1-14) |
Median body weight, range (kg) | 18.0 (4.3-44.7) | 7.1 (1.8-76.2) |
Selected clinical and laboratory results are summarized in Table 2.
Table 2
Clinical and laboratory findings for dogs hospitalized for treatment of primary IMHA.
| VTH-UdP (n=29) | VTH-TAMU (n=43) |
Survivors (n=19) | Non-survivors (n=10) | Survivors (n=30) | Non-survivors (n=13) |
PCV at admission (%) | 14 (5-27) | 13 (9-22) | 16 (3-34) | 20 (8-29) |
Reticulocyte count (x103/µL)a | 218 (27-705) | 150 (12-227) | 153 (47.2-424) | 260 (241-269) |
Positive saline agglutination test | 5/19 | 4/10 | 23/30 | 11/13 |
Positive anti-RBC antibodies detection | 11/12 | 7/7 | Not performed | Not performed |
Spherocytes occurrence ≥ 1+ | 14/19 | 9/10 | 27/30 | 11/13 |
Platelets count (x 103/µL)b | 200 (15-440) | 93 (51-314) | 157 (73-528) | 264 (112-491) |
Leukocyte count (x103/µL) | 33 (8-65) | 27 (13-96) | 24 (7-64) | 28 (12-58) |
Segmented neutrophils count (x103/µL) | 20 (5-52) | 19 (11-54) | 18 (4-56) | 20 (10-47) |
Presence of left shiftc | 16/19 | 8/10 | 22/43 | 8/13 |
Total Bilirubin (mg/dL) | 0.9 (0.2-4.0) | 2.5 (0.2-9.2) | 1.8 (0.3-25.2) | 5.6 (0.9-53.9) |
Hemolysed plasma | 0/19 | 8/10 | 14/43 | 11/13 |
Icteric plasma | 11/19 | 6/10 | 14/43 | 5/13 |
CHAOS score | 2 (0-6) | 3 (0-5) | 3 (0-5) | 4 (2-7) |
a Automated reticulocyte counts were excluded if agglutination was present. b Automated platelet counts were excluded if clumping was present on blood smear examination. c A left shift was considered present if, based on a manual differential, there were >300 band neutrophils/µL. The continuous data are reported as median and range, the categorical data are reported as number of positive cases over the total cases examined. |
Testing for vector borne disease was performed in 29/43 VTH-TAMU cases and 10/27 VTH-UdP cases. For VTH-TAMU cases, thoracic radiographs were performed in 41/43; abdominal radiographs in 30/43 and abdominal ultrasound in 33/43. For VTH-UdP, thoracic radiographs were performed in 12/29, abdominal radiographs in 3/29 and abdominal ultrasound in 23/29.
Twenty-three dogs died or were euthanized before discharge, including 10/29 (34%) of the dogs presenting to the VTH-UdP and 13/43 (30%) of the dogs presenting to VTH-TAMU. Of the non-survivors, one dog treated at VTH-TAMU died spontaneously, while the remaining non-survivors at VTH-TAMU, and all non-survivors at VTH-UdP were euthanized. For non-survivors, median time to death or euthanasia was 3.5 days (range 2-8 days) at the VTH-UdP, and 3 days (range 0-7 days) at VTH-TAMU. For survivors, median length of hospitalization was 5 days (range 1-11 days) at the VTH-UdP and 4 days (range 1-19 days) at VTH-TAMU.
Of the VTH-UdP cases, 4/10 non-survivors and 12/19 survivors were receiving at least one immunosuppressive medication at initial presentation (prednisone n=7, prednisolone n=5, cortisone n=3, azathioprine n=2, dexamethasone n=2, and mycophenolate n=1). At initial presentation, 1/19 survivors was receiving clopidogrel and 1/19 survivors was receiving unfractionated heparin. Before presentation, 3/10 non-survivors and 3/30 survivors had received at least one transfusion with Packed Red Blood Cells (PRBC) or Stored Whole Blood (SWB).
Of the VTH-TAMU cases, 4/13 non-survivors and 7/30 survivors were receiving at least one immunosuppressive medication at initial presentation (prednisone n =11, azathioprine n=4, dexamethasone n=5, and cyclosporine n=2). At initial presentation, 2/30 survivors were receiving aspirin. Before presentation, 3/13 non-survivors and 5/30 survivors had received at least one transfusion with PRBC or SWB.
Of the dogs admitted to the VTH-UdP, 3/10 non-survivors were euthanized without further treatment. The remaining 7 non-survivors all received at least one immunosuppressive medication during hospitalization (dexamethasone n=4, methylprednisolone n=2, and betamethasone n=1). Five non-survivors received at least one anti-thrombotic agent, (unfractionated heparin n=5, and aspirin n=1). Three non-survivors received at least one transfusion of PRBC, and one received a transfusion of SWB. Of the dogs admitted to the VTH-UdP that survived to discharge, therapy information was not available for 4/19, and the remaining 15/19 received at least one immunosuppressive medication (prednisone n=6, prednisolone n=6, betamethasone n=4, azathioprine n=3, cyclosporine n=3, and dexamethasone n=2). At least one anti-thrombotic was administered to 9/19 VTH-UdP survivors during hospitalization (unfractionated heparin n=7, clopidogrel n=3, and aspirin n=1). Of the VTH-UdP survivors, 4/19 received at least one transfusion of PRBC during hospitalization.
Of the dogs admitted to VTH-TAMU, 3/13 non-survivors were euthanized without further treatment. The remaining 10 non-survivors all received at least one immunosuppressive medication during hospitalization (cyclosporine n=9, dexamethasone n=6, prednisone n=5, prednisolone n=2, and mycophenolate n=1). Five non-survivors received at least one anti-thrombotic agent (aspirin n=4, clopidogrel n=3, and dalteparin sodium n=2). Eight non-survivors received at least one transfusion of packed red blood cells. Of the dogs admitted to VTH-TAMU that survived to discharge, 29/30 dogs received at least one immunosuppressive medication (prednisone n=27, cyclosporine n=21, dexamethasone n=17, mycophenolate n=9, prednisolone n=7, intravenous human immunoglobulin n=6, and azathioprine n=2). At least one anti-thrombotic was administered to 29/30 VTH-TAMU survivors during hospitalization (clopidogrel n=20, aspirin n=12, dalteparin sodium n=4, and rivaroxaban n=3). Of the VTH-TAMU survivors, 21/30 received at least one transfusion of PRBC during hospitalization.
None of the leukocyte ratios were significantly different between survivors and non-survivors or had an area under the ROC curve for prediction of survival significantly different from 0.5 (Supplementary, Table 1). After exclusion of 31 dogs that received one or both of immunosuppression and blood transfusion before presentation, area under the ROC curve for prediction of survival was significantly different from 0.5 for MLR and NMR (Table 3). To reduce the impact of possible financially driven euthanasia, analysis was repeated after exclusion of 3 dogs euthanized on the first day of hospitalization. None of the leukocyte ratios were significantly different between survivors and non-survivors or had an area under the ROC curve for prediction of survival significantly different from 0.5 (Supplementary, Table 2).
Table 3
Associations between leukocyte ratios and death or euthanasia for dogs hospitalized for treatment of primary IMHA, after exclusion of dogs that received immunosuppression and/or blood transfusion before presentation.
Leukocyte ratio | Median (25th -75th percentile) | P-value | Area under the ROC curve (95% CI) | P-value |
Survivors (n=28) | Non-survivors (n=13) |
BNR | 0.04 (0.02-0.09) | 0.02 (0.00-0.05) | 0.11 | 0.66 (0.49-0.80) | 0.09 |
MLR | 1.61 (0.98-3.00) | 0.71 (0.43-1.08) | 0.005 | 0.78 (0.62-0.89) | 0.01 |
NLR | 11.80 (7.23-20.87) | 14.50 (4.47-23.21) | 0.83 | 0.52 (0.36-0.68) | 0.84 |
NMR | 6.95 (4.35-13.53) | 17.80 (12.55-23.72) | 0.004 | 0.78 (0.63-0.90) | 0.0002 |
BNR: Band neutrophil to segmented neutrophil ratio; CI: confidence interval; MLR: Monocyte to lymphocyte ratio; NER: Segmented neutrophil to eosinophil ratio; NLR: Segmented neutrophil to lymphocyte ratio; NMR: Segmented neutrophil to monocyte ratio; ROC: Receiver operator characteristic. |