Immunohematology
Blood Types
Blood typing, incompatibility and donor selection in dogs and cats.
Typing identifies antigens; crossmatching assesses reactions between donor and recipient samples. Neither test replaces the other.
Dog
| System / type | Antibodies | Frequency | Clinical relevance |
|---|---|---|---|
| DEA 1 | AcquiredAcquired anti-DEA 1 | DEA 1 positive: approximately 33β65%, depending on region (MSD). | Classify as positive or negative. Negative recipients should receive negative red cells; prioritise type matching. |
| DEA 3 | VariableVariable reports | Varies by population | May contribute to incompatibility beyond DEA 1. Crossmatching helps investigate antibodies not covered by routine typing. |
| DEA 4 | AcquiredSensitization possible | Varies by population | A common antigen. DEA 4 positivity does not define a universal donor. |
| DEA 5 | VariableVariable reports | Varies by population | May contribute to incompatibility; the significance of natural antibodies remains debated. |
| DEA 7 | VariableVariable reports | Varies by population | Natural antibodies have been reported, but frequency and clinical significance vary across studies. |
| Dal | AcquiredSensitization possible | Most dogs are Dal positive; frequency varies by breed. | A negative donor may be difficult to find: most dogs express this antigen. Negative recipients may become sensitized after positive blood. |
| Kai 1 | Study dataNot detected in the 2016 sample | 94% of 503 dogs (North America, 2016) | An antigen distinct from DEA; common in the 2016 North American sample. |
| Kai 2 | Study dataNot detected in the 2016 sample | 1% of 503 dogs (North America, 2016) | An antigen distinct from DEA; uncommon in the 2016 North American sample. |
Cat
| System / type | Antibodies | Frequency | Clinical relevance |
|---|---|---|---|
| A | Natural anti-B, variable | Most frequent in many populations. | Use type-matched red cells and assess compatibility. |
| B | Natural anti-A | Varies particularly by breed and region. | Anti-A antibodies can cause severe haemolysis. Type B recipients need type B red cells. |
| AB | No natural anti-A/anti-B | Rare. | Uncommon; plan product selection with the blood bank and assess compatibility. |
| Mik / FEA 1β5 | Additional incompatibilities possible | Population dependent | Antigens outside the AB system can explain incompatibility. FEA 1 may correspond to Mik; these are not five new AB-system types. |
Type frequencies vary by population and region; no universal percentage applies to each patient.
Natural: may exist before transfusion. Acquired: may develop after antigen exposure.
Before selecting the unit
- Review transfusion history, including reactions and products used.
- Confirm identification and typing of donor and recipient.
- Interpret crossmatching with the laboratory and clinical context.
- Do not infer type or safety from breed, appearance or population frequency.
References
Educational use: product selection, volume and rate require individual veterinary assessment. Follow your service protocol and supplier instructions.