First, we have a paper describing a modified approach to neurologic examination of African pigmy hedgehogs (Atelerix albiventris). Neurologic disease is common in this species, but little information is available regarding diagnosis and treatment. Also, it is a challenge to evaluate their nervous system due to defensive postures they take on, and hedgehogs frequently present in torpor or severe weakness secondary to other disease, which mimics neurologic disease. Therefore, the authors goal was to develop a standardized approach to neurologic examination in hedgehogs.

They used 12 awake adult hedgehogs and evaluated aspects of the standard neurologic examination of dogs and cats. From there, approaches were modified to evaluate their normal behavior and mentation, as well as select cranial nerves and reflexes, and gait. Behavioral analysis and gait analysis were per­formed by using video recordings of hedgehogs in a novel environment. The performability and repeatability of all feasible aspects of the neurologic ex­amination were also assessed. 

Most aspects of the standard neurologic examination could be successfully performed, with repeatable results. However, olfaction, taste, pupillary light reflex, oculocephalic reflex, corneal reflex, or gag reflex were not evaluated because of poor compliance. For pupillary eye reflex, miotic pupils were also a factor that impacted on the evaluation.

When exposed to new environments, the hedgehogs quickly explored with a low posture and pulling mantle over their eyes/face. All hedgehogs lacked a menace response, but displayed a contraction of the frontodorsalis muscle when their faces were approached, but after a few attempts it was possible to perform the tests. The assessment of spinal nerves and postural reactions of the pelvic limbs were challenging. Facial sensation testing was unreliable. 

Second, we have a prospective study on the variability of serum aldosterone concentrations in ferrets (Mustela putorius furo). Hyperaldosteronism has been described in ferrets, with clinical signs such as weakness, decreased activity, hypokalemia, and hypertension. This condition results in excessive urinary potassium losses, sodium retention, and sometimes hypertension and metabolic alkalosis. The differentiation between primary and secondary forms are needed for prompt treatment: the primary form is also called low-renin hyperaldosteronism – disorder, characterized by autonomous hypersecretion of aldosterone by adrenal glands;  the secondary form results from continued stimulation of the renin-angiotensin system as a result of cardiac, renal, or liver disease. The authors’ goals were to explore sources of serum aldosterone concentration variability in a population of healthy and diseased ferrets, to determine a preliminary 1-sided reference interval for serum aldosterone concentration in healthy ferrets, and to identify a decision limit to differentiate healthy from diseased ferrets on the basis of serum aldosterone concentration. 

A total of 78 (healthy n = 56, diseased n= 22) ferrets were used for measurement of serum aldosterone concentrations. Their results showed that measurements of serum aldosterone concentrations in the ferrets showed wide variability, with a median concentration of 4.75 pg/mL (range, 0.02 to 283.9 pg/mL) and 76% (59/78) of samples having concentrations < 18 pg/mL. Ferrets that were healthy, older, or sexually inac­tive had significantly lower aldosterone concentrations. The upper limit of the reference interval for healthy ferrets was 13.3 pg/mL. 

The results suggested that high aldosterone concentrations should not be con­sidered diagnostic of primary hyperaldosteronism in ferrets, as in other mammals. Therefore, better tests to identify primary hyperaldosteronism need to be developed. It is important to note that ferrets commonly have adrenal gland enlargement, so the utility of diagnostic imaging for diagnosis is limited, making hyperaldosteronism challenging to diagnose.

Lastly, we have a case report on multiple myeloma with aberrant CD3 expression in a red-lored Amazon parrot (Amazona autumnalis). This one is co-authored by one of our instructors, Dr. Miranda Sadar!

Multiple myeloma is a relatively rare lymphoproliferative disorder characterized by a systemic proliferation of plasma cells or their precursors that can result in excessive secretion of immunoglobulins. Organ damage is usually found in the form of hypercalcemia, renal insufficiency, anemia, and bone lesions.

A 20-year-old, female, red-lored Amazon parrot was presented for a 2-week history of weakness. On physical examination, the bird was quiet, fluffed, weak, and had a distended coelom. Radiographic and ultrasound imaging revealed coelomic distention, increased pulmonary parenchymal opacity, renomegaly, dilated intestines, and a thickened ventricular wall.

The results of a complete blood cell count indicated the patient was anemic and had intermediate to large lymphocytes with immature chromatin that were suspected to be neoplastic. Immunocytochemistry on peripheral blood determined that the suspected circulating neoplastic cells were cluster of differentiation (CD) 3þ and occasionally expressed multiple myeloma oncogene 1 (MUM1). Abnormalities from a plasma biochemistry panel were moderate hyperphosphatemia (6.8 mg/dL), marked hyperproteinemia (13.6 g/dL), analbuminemia (0 g/dL), and marked hyperglobulinemia (13.6 g/dL).

Agarose gel plasma protein electrophoresis documented the presence of albumin (1.2 g/dL, characterizing pseudoanalbuminemia) and monoclonal bands which, on reduced lithium dodecyl sulfate polyacrylamide gel electrophoresis, resolved as 60-kd and ~25-kd bands consistent with immunoglobulin Y (IgY) heavy and light chains. IgY is the predominant immunoglobulin in avian plasma and is homolog of mammalian IgG, and is sometimes called avian IgG; it is, structurally, more similar to mammalian IgE.

On the basis of these findings, multiple myeloma was diagnosed. Because of a poor prognosis, the bird was euthanized for postmortem examination. Bone marrow cytology from samples collected during the postmortem examination revealed 17.4% plasma cells and 24% large immature cells with occasional plasmacytoid features. Histopathologic findings included aggregates of neoplastic plasma cells in the bone marrow, spleen, kidney, liver, gastrointestinal tract, muscle, ovary, and brain. The neoplastic cells were strongly immunoreactive for MUM1 and cluster of differentiation 3 (CD3), but negative for CD79a, paired box protein 5, and CD20. This confirmed the clinical diagnosis of multiple myeloma. 

Use of immunohistochemistry MUM1 and CD3 helped to diagnose in this case. Disease and treatment course for this condition in birds is currently unknown. The take home message is: IgY secreting multiple myeloma should be considered in parrots presenting with monoclonal gammopathy.