In addition to the time saved by not having to search for available donors in your area, selective blood products are more beneficial than whole blood for several reasons.
Whole blood transfusion is rarely required. In most instances, depending on the patient's underlying condition, only red cell or plasma components are needed.
Every drop matters
Using components makes best use of every unit of whole blood collected. By dividing the whole blood unit into components, it can potentially save between two and four dogs. Even when red cells and plasma are required in a patient, there may be a need for larger doses of red cells than plasma or vice versa. Whole blood alone will not achieve this.
Plus, in a small dog, one standard unit of whole blood can be too much in volume. In a large dog, one standard unit of whole blood can be too little and multiple units of whole blood need to be sourced.
Transfusing whole blood when only one component is required can lead to an increased risk of transfusion reaction. This could be at the time of transfusion or should the patient require further transfusions in the future.
Challenges in collection
If not performed regularly, collection can be a challenge. It requires careful donor selection, adequate staff availability and training. Not to mention the right and well maintained equipment and the time the practice must allocate to it. Also, if multiple units of blood are required, particularly for a large bleeding patient, the logistics of blood collection can become even more challenging - ensuring the availability of local donors, committing practice resource etc.
Source of platelets
Fresh whole blood transfused from one patient to another within four hours of collection is the only source of platelets at this time in the UK. Only when platelet numbers are so low and are causing bleeding into a critical area (the CNS, cardiovascular or respiratory system) - fresh whole blood is recommended as a salvage procedure. One unit of whole blood contains a very small number of active platelets that are unfortunately very unlikely to make any difference to a severely thrombocytopaenic patient.