rDVM case study: Pickles Collins

Presentation and History:

Pickles is a MN DLH of undetermined age. He was seen on an emergency basis by our criticalist Dr. Sharon Finster, DACVECC for lethargy. History also revealed hypersalivation, panting, and recent inappetence. There was a singular episode of vomiting the week before. Pickles is an indoor-only cat and other pets in the house are healthy. Pickles is current on vaccines and has previously tested negative for both FeLV and FIV. To the best of the owner’s knowledge, Pickles had no inappropriate ingestions. He is not on any medications other than Capstar given by the RDVM. The family recently moved within the state.

Physical Exam:

Weight 5.27 kg  T 101.1  HR 180  RR 28  QAR  CRT <2sec mm light pink
Colorado Pain Score 0

Moderate ptyalism was noted as well as weakness and depressed mentation. Cranial nerve exam was normal and musculature is adequate and symmetrical. Pickles’ pulses were fair but synchronous and his lungs sounded clear, but there was a gallop rhythm. His body condition score was 5/9, abdomen soft, normal skin turgor, and no peripheral lymphadenopathy was detected. Dead fleas and flea debris were present.

Dr. Finster identified the primary problems as lethargy and a history of panting and began diagnostic testing.

Labwork

Results are as follows:

>

Test Value Reference Range Test Value Reference Range
pO2 45.7 27.0 – 50.0 mmHg Creatinine 1.3 0.8 – 2.4 mg/dL
cSO2 73.9 50.0 – 80.0% BUN 23 16 – 36 mg/dL
pCO2 36.9 31.0 – 51.0 mmHg BUN: Creatinine Ratio 18
Bicarbonate 15.7 15.0 – 27.0 mmol/L Phosphorus 3.7 3.1 – 7.5 mg/dL
cTCO2 16.8 L 17.0 – 26.0 mmol/L Calcium 8.6 7.8 – 11.3 mg/dL
pH 7.237 L 7.250 – 7.430 Total Protein 8.2 5.7 – 8.9 g/dL
BE,ECF -11.7 L -5.0 – 2.0 mmol/L Albumin 2.4 2.2 – 4.0 g/dL
Sodium 151 148 – 163 mmol/L Globulin 5.8 2.8 – 5.1 g/dL H
Potassium 3.6 3.6 – 5.6 mmol/L Albumin: Globulin Ratio 0.4
Chloride 123 111 – 128 mmol/L ALT 22 12 – 130 U/L
Calcium, ionized 1.21 1.21 – 1.51 mmol/L ALP 20 14 – 111 U/L
Anion gap 16 9 – 26 mmol/L GGT 0 0 – 4 U/L
Lactate 3.58 H 0.50 – 3.20 mmol/L Bilirubin – Total 0.3 0.0 – 0.9 mg/dL
Glucose 214 H 63 – 133 mg/dL Cholesterol 127 65 – 225 mg/dL
HCT 17 L 28 – 50 % WBC 15.96 2.87 – 17.02 K/ìL
RBC 6.76 6.54 – 12.2 M/ìL % Neutrophil 77.5 %
Hematocrit 27.1 30.3 – 52.3 % L % Lymphocyte 13.3 %
Hemoglobin 5.5 9.8 – 16.2 g/dL L % Monocyte 7.5 %
MCV 40.1 3 5.9 – 53.1 fL % Eosinophil 1.6 %
MCH 8.1 11.8 – 17.3 pg L % Basophil 0.1 %
MCHC 20.3 28.1 – 35.8 g/dL L Neutrophil 12.37 1.48 – 10.29 K/ìL H
RDW – –.– 15.0 – 27.0 % Lymphocyte 2.12 0.92 – 6.88 K/ìL
% Reticulocyte 0.5 % Monocyte 1.2 0.05 – 0.67 K/ìL H
Reticulocyte 35 8 3 – 50 K/ìL Eosinophil 0.26 0.17 – 1.57 K/ìL
Platelet 150 151 – 600 K/ìL L Basophil 0.01 0.01 – 0.26 K/ìL
MPV 19.3 11.4 – 21.6 fL
Plateletcrit 0.29 0.00 – 0.79 %

In-house laboratory results showed a normocytic, hypochromic anemia. With a reticulocyte count of only 0.5%, the anemia was classified as moderate to severe non-regenerative anemia. Abnormalities in acid-base balance were noted with a pH of 7.237 and base excess of -11.7. Elevated glucose, lactate, and globulin levels were observed. Based on the differential list, bloodwork was sent to a reference lab for Mycoplasma PCR testing.

Differentials

With a current diagnosis of moderate to severe anemia, nonregenative, differentials include:

  • Immune-mediated hemolytic anemia
  • Oxidative injury: onions, acetaminophen, zinc, benzocaine, methionine, mothballs, phenazopyridine
  • Erythrocytic parasites: cytauxzoon, mycoplasma
  • Microangiopathic disease: DIC, vasculitis
  • Anemia of chronic disease: iron deficiency: chronic inflammation, chronic hemorrhage, dietary iron deficiency
  • Marrow disorder: toxic: estrogen, drugs, iatrogenic or neoplastic hyperestrogenism; infectious: FeLV, FIV, myelofibrosis: FeLV, PK deficiency, other; myelophthisis: leukemia, multiple myeloma, lymphoma, systemic mast cell disease; myelodysplasia: idiopathic, preleukemic; pure red cell aplasia
  • Ineffective erythropoiesis: macrocytic: Vitamin B12 deficiency, folic acid deficiency; normocytic; microcytic: iron deficiency, globin deficiency, porphyrin deficiency; pre-regenerative prior to 3-5 days

Additional Diagnostics and Treatment

Dr. Finster performed an abdominal ultrasound. Pickles’ kidneys appeared normal, without pyelectasia. Adrenal glands appeared normal.  The spleen appeared normal, with normal vascular flow. Although the gall bladder was moderately distended, there was no evidence of obstruction and the liver appeared normal. The GI tract measured WNL for wall thickness and motility and no obstructive process was evident. The pancreas appeared normal. One lymph node in the cranial abdomen appeared enlarged. No effusion was detected.

At this point, Pickles was admitted to the ICU for treatment, including IV LRS at 1.5 times maintenance and 5mg/kg doxycycline PO BID, with plans to recheck the PCV/TS and transfuse if necessary.

24-hours post-admission, blood tests showed:

Test Value Reference Range Test Value Reference Range
pO2 30.8 27.0 – 50.0 mmHg Chloride 124 111 – 128 mmol/L
cSO2 58.1 50.0 – 80.0 % Calcium, ionized 1.20 1.21 – 1.51 mmol/L
pCO2 32.8 31.0 – 51.0 mmHg Anion gap 16 9 – 26 mmol/L
Bicarbonate 18.9 15.0 – 27.0 mmol/L Lactate 1.02 0.50 – 3.20 mmol/L
cTCO2 19.9 17.0 – 26.0 mmol/L Glucose 131 63 – 133 mg/dL
pH 7.368 7.250 – 7.430 HCT 21 L 28 – 50 %
BE, ECF -6.4 L -5.0 – 2.0 mmol/L
Sodium 155 148 – 163 mmol/L PCV 23%
Potassium 3.7 3.6 – 5.6 mmol/L TS 7.8g/dL

With improvement in the acid-base balance and normalization of lactate and glucose values and no worsening of the PCV despite fluid therapy, Pickles owners were advised optimistically. Pickles was eating and drinking. Doxycycline was continued for presumed mycoplasma.

Pickles was discharged on 5mg/kg PO BID doxycycline for 14days, pending PCR results, with plans for his PCV/TS to be rechecked in two days.

Diagnosis

The next day, the Feline Hemoplasma PCR Panel returned positive for Mycoplasma haemofelis and negative for Mycoplasma Haemominutum and Mycoplasma turicensis. Two days post-discharge, Pickles returned to recheck his PCV/TS. His PCV/TS was now 27/8.5. A follow-up in seven days with a PCV/TS recheck was recommended as well as three weeks of doxycycline therapy.

Mycoplasma Haemofelis, formerly Hemobartonella felis, is a cause of infectious anemia in cats, now often referred to as feline hemotropic mycoplasmosis. Following a bite from an infected flea, feline red cells are exposed to mycoplasma organisms, and the cat’s immune system mounts a response. As antibodies bind the mycoplasma, the infected red cells are marked for removal and destruction. Affected cats become pale and weak from anemia.

“When a cat is newly infected, it can take up to one month before there are adequate numbers of parasites to actually make the cat sick. Mortality is highest during the month following this initial stage. If the cat recovers, it becomes a permanent carrier, though stress can re-activate the infection,” reports Wendy Brooks, DVM, DABVP.

As Mycoplasma Haemofelis cannot be cultured, diagnosis can be problematic. With large number of organisms present, they may be observed in a blood smear, but the number of organisms varies extensively hour-by-hour. PCR testing is recommended, and is best sent prior to the administration of antibiotics.

PCR testing has shown that up to 10% of healthy cats are carriers of Mycoplasma Haemofelis. Cats at highest risk are those most at risk for flea infestation. Infection with the feline leukemia virus has a negative impact, with immunosuppression allowing proliferation of the Mycoplasma and the FeLV preventing best marrow response.

Mycoplasma infections are responsive to treatment with tetracycline and doxycycline. Quinolones are also effective. Antibiotic treatment should continue for three weeks. Steroid treatment may be used concurrently to suppress the immune response and slow the destruction of red cells. Transfusions(s) may be needed. Only cats with active infections are treated, not carrier cats.

Dr. Sharon Finster is available for consultation or for referral of patients. You can reach her at 828-328-6697.

Recent Posts