Abstract. Microsporidia have been recognized recently as opportunistic pathogens in acquired immunodeficiency syndrome patients. In an attempt to develop an animal model of enteric microsporidiosis, adult (5 to 6 months old) male Flemish Giant rabbits from a closed New York colony were administered 5 x 10 3,5 X 10 5 , and 5 x 10 7 Encephalitozoon cuniculi per rectum. Rabbits given 5 x 10 5 and 5 x 10 7 E. cuniculi had moderate granulomatous periportal infiltrates, characterized by the presence of numerous macrophages, epithelioid cells, and a few multinucleated giant cells, lymphocytes, and plasma cells. Inflammatory cells also were seen infiltrating the tunica adventitia and tunica media of hepatic portal veins and branches of the hepatic artery. This study demonstrates that administration of E. cuniculi per rectum to rabbits results in infection that is characterized by high frequency and severity of hepatic lesions.

AAPA 2021 POSTER SESSION ABSTRACTS PURPOSEThyrotoxic hypokalemic periodic paralysis (THPP) is an uncommon diagnosis presenting with painless, fl accid paralysis, generally provoked through exercise or dietary changes. Diagnosis is made by the demonstration of paralysis, hyperthyroidism, and hypokalemia that can lead to fatal dysrhythmias. The typical patient is male and of Asian descent; incidence is 2%. Most cases are inherited in an autosomal dominant pattern; however, acquired cases have been reported. The defi nitive treatment of THPP is by pharmacological therapy, radioactive iodine, or surgery. This case examines a man who developed THPP in the presence of multifocal papillary thyroid carcinoma. CASEA 52-year-old Native American man without signifi cant past medical history presented to the ED with abrupt paralysis of the lower extremities bilaterally. He denied similar previous episodes. A review of the patient's medical record revealed longstanding treatment with methimazole 10 mg and metoprolol 25 mg for hyperthyroidism. He denied a family history of thyroid disorders. Physical examination demonstrated proximal muscle group weakness of the legs with hyporefl exia. Cardiovascular examination revealed regular rate and rhythm. Lungs were clear to auscultation with no accessory muscle use. His extraocular movements were intact. The differential in a patient with fl accid paralysis includes THPP, myasthenia gravis, botulism, Guillain-Barré syndrome, transverse myelitis, and tickborne myopathies.