Low Packed Cell Volume Test Results and Negative Direct Coombs Test

by Nicole
(San Diego, ca)

My 8 y/o shih-tzu/yorkie (Elvis) was acting lethargic, less energy for a couple weeks.

This Sunday, I took him to the Emergency animal hospital due to a very pale tongue. He had a PCV of 10% and immediately had a blood transfusion , fluids, etc. Today (3 days later), PCV is 23%. They have performed an abdominal ultrasound , x-rays, CBC, several blood tests, etc. They are mentioning IMHA or bone marrow disease/cancer. His clinical findings are below. PLEASE PLEASE PLEASE offer some advice/insight if you see anything that our doctors arent seeing. Thank you in advance!

PCV: 23% (was 10% three days ago)
Reticulocytes: low
Spherocytes: low
Direct Coombs test: positive
Organs: normal, outside of age related kidney health
WBC: normal
Elvis is eating/drinking/going to bathroom. He is home with me now, but the doctors seemed surprised he is doing well considering.

Before this incident, he had chronic itchy skin/paws/ears/bottom. He occasionally does the "fly snapping" phenomenon. He also has paraphimosis. Although, I can usually fix it and it doesn't seem to cause any other problems. About 6 weeks ago, a dog attacked him. No visible wounds/signs of injury. He began having "trembling/minor shaking" episodes that I assumed were related to PTSD/Nervousness.

Since beginning Cyclosporine, Doxycycline, Prednisolone, his itching/trembling/fly snapping has stopped. However, he is very very tired.

Does this seem like a bone marrow issue or IMHA? Or can it be tick/infection related? Something else?

Thoughts From Our Editor on Your Dog's PCV (Packed Cell Volume) and Positive Coombs Test Results

Hi Nicole,

While I can provide some general insight based on your dog's clinical findings, I must stress that I'm not a vet, and I'm not a replacement for the advice you are receiving from a veterinarian that knows this specific case.

Your dog Elvis's PCV (packed cell volume) value was dangerously low when you first took him to the emergency vet hospital. This indicates severe anemia, which would account for his lethargy and pale tongue. His PCV has since improved to 23% following the blood transfusion, which is a positive sign, but still quite low (normal is around 37-55% for dogs).

A positive Direct Coombs test suggests that Elvis's body may be destroying its own red blood cells, which is characteristic of immune-mediated hemolytic anemia (IMHA). In IMHA, the immune system mistakenly attacks and destroys red blood cells, leading to anemia. The low reticulocyte (immature red blood cells) count could also suggest that his bone marrow is not responding adequately to the loss of red blood cells, which might be a sign of a bone marrow issue.

Spherocytes, which are unusually small, round red blood cells, can be a sign of IMHA as well, but you mentioned that they are low. In some cases, spherocytes may not be present or may not be detected, so their absence doesn't necessarily rule out IMHA.

The fact that his organs appear normal (aside from age-related kidney changes), and his WBC (white blood cell) count is normal, is good news. It might suggest that a systemic infection or organ failure is not the cause of his anemia, but it doesn't rule out an underlying disease like cancer.

The symptoms you mention that preceded this incident, like chronic itching and fly-snapping, could potentially be signs of a neurological condition, or they could be related to allergies. It's hard to say without more information. The trembling could be due to stress or pain.

The medications you mentioned (Cyclosporine, Doxycycline, Prednisolone) are all used to treat IMHA, among other conditions. Cyclosporine and Prednisolone are immune suppressants and would be used to stop the immune system from destroying red blood cells, while Doxycycline is an antibiotic which can be used if a tick-borne disease is suspected to be the cause of the IMHA. These medications might explain why his itching and fly-snapping have stopped. However, they could also contribute to his fatigue.

It's difficult to say definitively whether this is IMHA, a bone marrow issue, or something else based on the information provided. Both IMHA and bone marrow diseases can cause the clinical signs you describe. Tick-borne diseases can sometimes trigger IMHA, so it's possible that an infection could be involved as well.

It's really important to continue working closely with your vet to determine the cause of Elvis's anemia and appropriate treatment. If he's not improving or if his condition worsens, don't hesitate to seek a second opinion. You're doing a great job advocating for Elvis and seeking answers.

Best,

Jeff
Editor and Publisher
Dog Health Guide