What is Immuno-mediated Haemolytic Anaemia (IMHA) in Dogs and Cats

• Lethargy and weakness  

• Pale or yellow gums  

• Increased breathing rate  

• Collapse  

• Eating less or not eating  

• Vomiting  

• Fever  

• Red or black urine 

You should contact your vet IMMEDIATELY if your pet shows signs of immune-mediated haemolytic anaemia (IMHA), such as lethargy, weakness, pale or yellow gums, fast breathing, or collapse. These are serious symptoms that can indicate a life-threatening crisis, and IMHA can progress rapidly. 

• Clinical exam  

• Full blood test and specific tests such as the agglutination test (red cells clumping together) and the Coombs test to check for an abnormal immune response  

• Additional tests might be required, such as chest X-rays or abdominal ultrasound to look for underlying causes.  

The mainstay of treatment for IMHA is immunosuppressive therapy. In the short term, this is achieved with high-dose steroids (anti-inflammatories), but long-term, with also other:   

• Immunosuppressive medications  

• In severe cases, blood transfusion to stabilise your pet’s condition and allow time for medications to work  

• Pets with IMHA are at high risk of developing life-threatening blood clots (thromboembolism); anti-clotting medications can be used as a preventative measure

Direct prevention of IMHA is difficult because the exact cause is often unknown, especially in primary cases, which may have a genetic link. However, prevention can be supported by identifying and addressing underlying causes in secondary IMHA, such as infectious diseases, tumours, or certain drugs, by working with your vet. 

The outlook for dogs and cats with Immune-Mediated Haemolytic Anaemia (IMHA) is highly variable, with a significant risk of death within the first two weeks of diagnosis if they don't respond to treatment. However, for those that respond well to immunosuppressive therapy, the prognosis is often good, and they can live for years, though some may require lifelong medication and are at risk for relapse. The long-term outcome depends heavily on factors like the severity of the anaemia, the presence of complications like blood clots, and whether the cause is primary or secondary to another disease.