Expert: Jana Connell RVT, CVT - 4/4/2011

Question
Hi - We've been on almost a year long odyssey with our cat's anemia and we're at the point where we don't know what to do.  I won't bore you will all the details, but 11 months ago we brought it my cat for a routine checkup and his blood work came back anemic.  After course upon course of prednisone, in addition to antibiotics, he seemed to be gradually improving.  In December, his hemocrit was 28.8, slightly below normal.  However, we just brought him in again for blood work, and his hemocrit dropped to 24.8 and he had a increase in his lymphocytes and eosinophils.  In additional to regular blood work, we've had him tested for various hemoplasmic parasites via a PCR test and have had a blood marrow biopsy, both of which came back normal.  I believe the BMB had evidence of a regenerative anemia, but I don't have that test in front of me.   

Obviously at this point we're a little frustrated.  Aside from the abnormal blood work, our little guy as seemed unaffected - diet, water intake, and behavior all seem to be normal.  He's one of our most active cats and loves to play.  

We're bringing him in for 2nd opinion in a couple of days, and want to be prepared as to what else this could be.  I've been doing some research, and now I'm thinking it could be something like PK Deficiency, Erythorpoitic porphyia, or osmotic fragility.  While these things are rare, it appears we've ruled much of the other common causes out.

It is possible for a cat to just have low RBC count as normal condition?  What else should we be considering?  Any advice you could provide is much appreiciated!

Answer
Well I am not a vet, which I say on my profile, but I can give some suggestions. You didn't tell me how old he is, but cats with PK Deficiency don't normally live past 4 yrs and they are not full of playfullness. They also have abnormally pale and misshapen red blood cells and you didn't mention that either.

"Blood testing may reveal an increased number of platelets as well as white blood cells (leukocytosis), anemia with abnormally large, pale red blood cells (RBCs),  abnormally-shaped RBCs called poikilocytes (poikilcytosis), and a variation in RBC color (polychromasia). The biochemistry profile, meanwhile, may show an excess of iron in the blood (hyperferremia), mild increase in bilirubin, and slight increase in liver enzymes. Lastly, urinalysis may reveal high levels of bilirubin."

So you can probably rule that out.

Metabolic anemia sounds more like what your cat could have, but it is more of a secondary symptom from another disease process going on, such as liver or kidney disease.

http://www.petmd.com/cat/conditions/cardiovascular/c_ct_anemia_metabolic

We have seen many cats with Haemobartonellosis that never show any symptoms at all except that they have mucous membranes that are pale in color. They are playful, happy and eat fine. But they had it and we treated it and it went away. I saw one cat get it twice in a span of 7 years.

http://www.petmd.com/cat/conditions/cardiovascular/c_ct_hemotrophic_mycoplasmosi...

The second one you mentioned,Erythropoietic Porphyria, is an inherited disease with severe symptoms. These cats are listless, some have orange-brownish teeth and their urine is often orange-brown. They also progress rapidly from listless to moribund and death.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1913004/pdf/amjpathol00460-0029.pdf

Osmotic fragility is again a symptom of a deeper problem.
http://www.vin.com/proceedings/Proceedings.plx?CID=WSAVA2002&PID=2599

It is possible for a cat, just as a human, to have a lower count from a RBC. They can also be affected by other things- time of day, status of overall health, etc.

I am glad you are getting a second opinion. I was late in getting back to you with this as I needed to do some research to find a good answer for you.

In all, the overall picture of him seems good. Maybe he had a set back for some reason or there is something being overlooked. For the most part, cats are pretty simple creatures and as my dear boss always told me- look for the simple first.

Please let me know what you find out at the second vets. I hope that he recovers completely!