Our pet of the Month for October is Daisy, an 11-year-old black lab that loves to watch TV and visit the beach with her family.
Daisy first came to Hawthorne Hills Veterinary Hospital back in March of this year where she was a bit anxious and overweight, but otherwise healthy with no strange findings on her physical exam. Fast forward a couple of months to the end of July and Daisy went to an emergency hospital for treatment after she ran outside, fell over, vomited, and seemed to stop moving for a moment. After the event, she seemed lethargic and a bit wobbly on her feet for a while, but eventually stabilized. Upon presentation to the emergency clinic, she seemed to be her normal self and the only abnormality noted was that she had a borderline-high blood pressure in the 170s.
Based on the description of what happened, the veterinarians there suspected that Daisy had a vestibular event, though they could not rule out seizures, syncope, high vagal tone, or some other cause. A “vestibular event” is when there is a disturbance to part of the nervous system that controls balance. This will often cause the patient to become unsteady on their feet, fall down, and can even cause nausea and vomiting by causing vertigo in the dog. Daisy’s owners ultimately elected to monitor her at home since she seemed to stabilize after the event.
She presented to Hawthorne Hills a few days later for a follow-up appointment after the ER visit. She seemed a bit anxious, but otherwise her normal self. A thorough neurologic examination was performed by Dr. Andy Pietraniec. The only abnormalities noted was a delayed conscious proprioception in both hind limbs, and a mild sensitivity when palpating the lumbar region; these are changes that can be seen in normal older-aged animals as well. Daisy seemed to have her full mental capacities and appropriate function of all her limbs.
To rule out other causes of her event, blood work was collected and run to look at her electrolytes, glucose values, and RBC/WBC count. A repeat blood pressure was attempted, but unsuccessful due to how stressed she was following the exam and blood draw. It was elected to bring Daisy back in the next day to just get a blood pressure when she was hopefully less stressed as the other procedures wouldn’t be done before-hand.
Overnight, Daisy’s blood work results came back. The glucose was normal, all the electrolytes were in balance, her kidney and liver values were normal as was her red blood cell count. There was only a mild increase in neutrophils (a type of white blood cell) that is likely more from stress than an actual infection. But not everything was normal on that blood work. There was one value that was very abnormal: Platelets
Platelets work in the body to help block holes and tears in blood vessels and stop blood from getting out of circulation when it isn’t supposed to. In normal every day health, the teeny tiny vessels and capillaries of an animal’s body receive micro-trauma from normal functions, and platelets help clump blood together to block off these small defects in the vessel walls until the body can repair them. The clumps of blood are then harmlessly broken down, the blood flows freely through circulation, and the cycle begins again. Normal platelet numbers in dogs tend to range from 165,000 per microliter to 430,000 per microliter. While this number can fluctuate a bit from dog to dog, typically we want to see values greater than 100,000 per microliter. Usually when values are under 50,000-60,000, we start worry about these normal micro-tears going unrepaired and causing the animal to lose blood.
Daisy’s platelet count was severely low at 9,000 per microliter, yet she seemed totally unbothered and overall healthy on physical exam. There was no evidence of petechiation (abnormal bruising visible in the skin), and the spot where we drew the blood from seemed to clot just fine once the bandage was removed. We obviously suspected that this severely low value must be an error of some sort with the sample we provided. When Daisy came back in for her repeat blood pressure the next day, we collected another blood sample and double checked her for any evidence of internal bleeding. Nothing was found, and the sample site clotted appropriately again. Her blood pressure came back as normal, and we waited for the repeat sample results to tell us if the low platelet count was real or an error. The second sample came back with around 20,000 per microliter…so it seems it wasn’t an error after all.
The three main causes of thrombocytopenia (low platelets) are:
- Immune-mediated destruction,
- Tick-borne infections, and
- Neoplasia
The blood sample was checked for the common tick-borne pathogen Rickettsia, but result came back negative. Daisy was trialed on a medication called Prednisone, which is a corticosteroid that changes the way the immune system works to see if her platelet numbers would increase by effectively shutting off the immune system. After being on the medication for 2 weeks, her levels were checked again and her platelets were back up to around 250,000 per microliter. Based on this finding, Daisy was diagnosed with immune-mediated thrombocytopenia (IMTP) and referred to an internal medicine specialist for further work-up to determine if there was a specific cause for this disease, and how to manage it going forward.
As Daisy was being worked up by the internal medicine specialist, an abdominal ultrasound showed a very large mass in her abdomen that seemed to be attached to her spleen. Daisy’s owners and the referral veterinarians went over potential causes for a large mass like this, and after careful deliberation they decided to have Daisy taken to surgery to remove her spleen and have samples sent out for biopsy and interpretation by a pathologist. Daisy did great during the surgery and recovered fine without any severe complications. The biopsy results came back a few days later and revealed that the mass on the spleen was a splenic hematoma arising from a myelolipoma. Myelolipomas are uncommon, slow growing, expansile neoplasms that are, most importantly, benign. Therefore, the splenectomy procedure was curative in this case, and the family is hopeful that with time Daisy can be slowly weaned off the prednisone fully.
Throughout this whole process, Daisy did not show any signs of being sick aside from the initial collapse episode that landed her in the ER. Her vitals were always good, her behavior at home was never abnormal, she almost always had a good appetite, and she still had her normal energy level. Looking at her, you never would have guessed her platelet values were so low, or that she had a big hematoma in her abdomen. All she wanted to do was just watch TV with her family, or go run on the beach. 
This is an important lesson and a reason that we run tests. Had the blood work never been run, had the images never been taken, had the surgery never been performed, or had the biopsies never been submitted…who knows if she would still be here with us today. Sometimes the tests tell us more about the patient than we could ever imagine. Sometimes we find what we are looking for, and sometimes things we never expected jump out to us. Either way, it gives veterinarians a better, overall picture of a patient’s health and wellness, and allows them to have as much information as possible to help guide owners on what is the best care for their furry 4-legged family members.
~ Dr. Andy Pietraniec ~
