Clinical History

An 8-year-old neutered male buff domestic short-haired cat was presented in April 2009 for a 2 month history of intermittent vomiting and focal trembling. Past medical history (2005) included chronic nasal discharge and congestion, and intermittent ulcerative skin disease manifested around the ears and feet. Rhinoscopy at that time revealed chronic and severe lymphoplasmacytic, neutrophilic and eosinophilic rhinitis, and biopsies of the nasopharynx showed eosinophilic pharyngitis. Long term treatment consisted of prednisone (2.5 mg EOD) and cefpodoxime 25 mg twice weekly which controlled clinical signs. Due to possible allergy, the cat was fed a lamb based diet.

Physical and Neurological Examination
Well circumscribed ulcerative skin lesions were present on the head and feet. Popliteal lymph nodes were prominent bilaterally. Ascultation of the heart and lungs, and abdominal palpation, was normal. The cat was alert but would walk with a crouched gait, was reluctant to jump and occasionally would fall over or stumble (Go to video clip). Neurolocalization was to the neuromuscular and possibly the central nervous systems.

Diagnostic Testing
CBC – Absolute eosinophilia 2145 (0-1500 /µl) with a normal white blood cell count

Chemistry Panel - AST (SGOT) 110 (5-55 U/L) and Creatine Kinase (CK) 12,980 (64-440 U/L)

At this time the cat was sent home on an increased dosage of prednisone (2.5 mg every other day) with a recheck planned for 2 to 3 weeks. The cat then presented on emergency for collapse and worsening tremors. Further diagnostics were performed.

CBC – Eosinophil count 8250 with an increased white blood cell count (27.5) and neutrophilia.
Chemistry Panel – CK 10,219 U/L, ALT (SGPT) 369 (28-100 U/L)
T4 – 1.2 (0.5-5.8 µg/dL)

Feline serology screen – Negative for FeLV antigen, FIV antibody, FeCoV (FIP) antibody,
Toxoplasma IgM and IgG, and feline heartworm antibody

Abdominal and thoracic ultrasound – No abnormalities found

Muscle biopsy – Since the CK was persistently elevated (further elevated on additional examination at 19,233 U/L) and weakness evident, biopsies were collected from the biceps femoris and triceps muscles and evaluated in frozen sections. The predominant abnormalities included scattered necrotic fibers undergoing phagocytosis (Fig. 1) and myofibers containing areas with autophagic vacuoles (Fig. 2). A necrotizing myopathy was diagnosed.

Additional Laboratory Testing
Serum vitamin E 268 (800-2000 µg/dl)
Serum selenium 0.51 (1.7-2.5 ppm)

Vitamin E and selenium concentrations were both low so supplementation was initiated. Selenium was prescribed at ¼ of a 50 microgram tablet orally once daily and vitamin E 100 IU orally every 24 hours. Treatment with prednisone 2.5 mg every other day and cefpodoxime at 25 mg twice weekly was continued.

Outcome
The cat was reevaluated 2 months after initiation of vitamin E and selenium supplementation. There was a modest weight gain, the skin lesions resolved, and the cat in general was doing well.  The gait was stronger without falling or stumbling (Go to video clip). Repeat laboratory evaluation showed persistence of eosinophilia (5408) and a decrease in the serum CK activity (2874 U/L).  The plan is to continue supplementation and recheck serum vitamin E and selenium levels in about 6 weeks.  Results of further testing and a follow-up clinical status will be posted as soon as available.