In brief
Anaemia means there are too few circulating red blood cells or too little haemoglobin. It is not a diagnosis by itself: blood loss, red-cell destruction and inadequate production require very different treatment.
What owners may notice
- Pale gums, weakness or sleeping more.
- Rapid breathing or a fast heart rate.
- Poor appetite, collapse or reduced stamina.
- Yellow discoloration when red cells are being destroyed.
- Dark urine, visible bleeding or black stools in some cases.
Regenerative versus non-regenerative
A regenerative response means the bone marrow is releasing young red cells, as expected after blood loss or haemolysis. In non-regenerative anaemia, production is inadequate. Kidney disease, chronic inflammation, bone-marrow disease, infection, toxins and immune-mediated processes are among the many possibilities.
Diagnostic approach
The packed cell volume or haematocrit shows severity, while reticulocytes assess regeneration. A blood smear, bilirubin, infectious-disease testing, chemistry, urinalysis and imaging may identify the mechanism. Some cats need Coombs testing, PCR testing, bone-marrow assessment or evaluation for hidden bleeding.
Treatment
Severely affected or unstable cats may need oxygen support and a compatible blood transfusion. Further treatment must target the cause—for example controlling bleeding, treating infection, managing kidney disease or suppressing inappropriate immune destruction. Iron is only useful when deficiency is present and can be harmful if given blindly.
Conclusion
Anaemia ranges from mild and chronic to immediately life-threatening. Pale gums, collapse or breathing difficulty warrant urgent veterinary assessment.