Effect of hydrocolloid-nitric oxide wound dressings on wound healing in dogs.

OBJECTIVE: To determine the rates of wound healing in surgically created wounds between nitric oxide releasing wound dressings and control wound dressings. STUDY DESIGN: Prospective, controlled, randomized experimental study. ANIMALS: Purpose-bred, adult, male Beagles (n = 6). METHODS: Four 2 × 2 cm wounds were surgically created on the trunk of each dog with each wound randomized to treatment with a nitric oxide wound pad (NP), nitric oxide wound gel (NG), plain hydrocolloid wound dressing (HC), or Telfa pad (T). Wound images were taken daily for 8 days then every other day until day 21 with images masked and randomized for evaluation. Total wound area, contraction percentage, and days until granulation were calculated. RESULTS: Time to first appearance of granulation tissue was significantly shorter for NP (3.2 days) than for NG (4 days; p = .023), HC (4.5 days; p = .001), and T (5.2 days; p < .0001). There were significant differences in total wound area and contraction percentage between sites and treatments (p < .001). Total wound area for NG was lower than treatment T (0.7 ± 0.1 cm3; p < .001), HC (0.9 ± 0.1 cm3, p < .001), and NP (0.6 ± 0.1 cm3, p < .001). CONCLUSION: Use of a nitric oxide wound dressing resulted in faster wound healing as evidenced by lower total wound area and higher contraction in the NG group and faster time to granulation tissue development in the NP group. CLINICAL SIGNIFICANCE: Nitric oxide wound dressings are innovative and inexpensive products that can significantly decrease the amount of time and cost necessary for open or second intention wound resolution in dogs.

Evaluation of darbepoetin therapy on platelet count and function in healthy cats and cats with surgically induced chronic kidney disease.

OBJECTIVE: To evaluate the effects of darbepoetin on platelet population and reactivity in healthy cats (HCs) and azotemic cats with remnant kidney (RK) model-induced chronic kidney disease. ANIMALS: 12 purpose-bred domestic shorthair cats (n = 6 HCs and n = 6 RK). METHODS: In this pilot study, all cats received darbepoetin (1 µg/kg, SC) on days 0, 7, and 14. Blood was sampled at baseline and on days 3, 10, 15, 17, 20, and 21. At each time point, a CBC was performed, platelet aggregometry was assessed by impedance and optical methods, and platelet P-selectin (CD62P) was quantified before and after thrombin stimulation. Additionally, reticulated platelets were quantified using both thiazole orange staining and proprietary analysis by the CBC analyzer. For RK cats, systemic blood pressure (BP) was serially measured. RESULTS: No adverse effects of darbepoetin were seen. There was no statistically significant change in platelet count between or within groups at any time point. Hematocrit increased significantly over time in the RK but not the HC group. RBC reticulocyte numbers in both groups increased over time. Reticulated platelet percentage did not increase in either group. Differences in platelet reactivity within or between groups were not seen in the aggregometry or flow cytometric assessments. In RK cats, indirect BP did not significantly change during the study. CLINICAL RELEVANCE: This preliminary investigation did not find evidence that darbepoetin administration impacted platelet number, reactivity, nor reticulated platelet count. Anemic RK cats experienced increased hematocrit and RBC reticulocytes as expected with darbepoetin therapy.

Evaluation of activation characteristics of a canine platelet concentrate produced by a commercial double centrifugation system.

Introduction: In veterinary medicine there are few readily available products for platelet transfusion to patients with thrombocytopenia. Commercial tabletop platelet concentrating systems have recently become available to veterinarians, primarily directed towards uses associated with regenerative medicine. These systems could potentially be used to produce fresh concentrated platelets for use in transfusion medicine. This study evaluated the concentration, activation, and sterility of a double centrifugation platelet concentrate (PC) produced by a commercial benchtop system. Methods: Ten healthy dogs were studied. Whole blood was collected and mixed with ACD-A in a 1:7.6 ratio of ACD-A to whole blood. 12 mL of this mixture was processed into PC via single centrifugation, while 60 mL of the anticoagulated whole blood was processed via a commercial double centrifugation system. Both types of PC were evaluated for platelet concentration, CD62P expression with and without thrombin stimulation, and for sterility. Results: Mean platelet count in the double centrifuged PC was 863 ± 352 × 103/µL, with very low white blood cell contamination (median of 0.47 × 103 leukocyte/µL (range 0.15-2.18 × 103/µL)). The double-centrifuged PC had similar baseline activation characteristics (as determined by P-selectin expression) as the single centrifuge PC (0.76% vs. 0.72% unstimulated, 30.5% vs. 34.9% stimulated, p = 0.432). Discussion: The benchtop PC system studied here did not cause activation of platelets during production and produced a sterile product that can be further investigated as a source of fresh platelet concentrates for transfusion purposes.