trimethoprim--sulfamethoxazole-drug-combination and Encephalomyelitis

An adult female sea otter housed for 5 years in an outdoor habitat in an aquarium developed signs of neurologic disease. Bilateral caudal paresis was evident initially and other neurologic signs consistent with CNS disease developed rapidly. Diagnostic work-up included CBC, serum biochemical analyses, determination of serum antibody titers, radiography of the vertebral column, CSF analysis, muscle biopsy, computed tomography of the brain, and assays for mercury, lead, and thiamine. A tentative diagnosis of encephalitis caused by a Sarcocystis neurona-like organism was made on the basis of detection of CSF antibodies by use of Western blot analysis. Response to treatment was not satisfactory and the sea otter was euthanatized. Immunohistochemical staining revealed S neurona-like organisms within foci of inflammation in the brain and spinal cord. This report provides evidence that, for sea otters, there may be a mode of transmission of an S neurona-like organism that does not involve opossums.

Topics: Animals; Animals, Zoo; Anti-Infective Agents; Antiprotozoal Agents; Brain; Dexamethasone; Encephalomyelitis; Fatal Outcome; Female; Glucocorticoids; Lumbar Vertebrae; Magnetic Resonance Imaging; Microscopy, Electron; Muscle, Skeletal; Otters; Paresis; Pyrimethamine; Sarcocystis; Sarcocystosis; Tomography, X-Ray Computed; Trimethoprim, Sulfamethoxazole Drug Combination

Three weak, recumbent neonatal foals with skin lesions, including a thin wooly coat, were born to mares being treated for equine protozoal myeloencephalitis. Mares received sulfadiazine or sulfamethoxazole-trimethoprim, pyrimethamine, folic acid, and vitamin E orally. Foals were anemic, leukopenic, azotemic, hyponatremic, and hyperkalemic. Serum folate concentrations in the 3 foals and 2 mares were lower than those reported in the literature for clinically normal brood mares. Treatment was unsuccessful. For each foal, necropsy revealed lobulated kidneys with thin cortices and a pale medulla, and the spleen and thymus were small. Histologic examination revealed marked epidermal necrosis without inflammatory cells, thin renal cortices, renal tubular nephrosis, lymphoid aplasia, and bone marrow aplasia and hypoplasia. These observations indicate that oral administration of sulfonamides, 2,4-diaminopyrimidines (pyrimethamine with or without trimethoprim), and folic acid to mares during pregnancy is related to congenital defects in newborn foals.

Topics: Abnormalities, Multiple; Administration, Oral; Animals; Animals, Newborn; Anti-Infective Agents; Bone Marrow; Encephalomyelitis; Female; Folic Acid; Folic Acid Antagonists; Horses; Kidney; Pregnancy; Pregnancy Complications, Parasitic; Protozoan Infections, Animal; Pyrimethamine; Skin Abnormalities; Sulfadiazine; Trimethoprim, Sulfamethoxazole Drug Combination; Vitamin E

To determine the clinical findings, course of treatment, and long-term outcome of horses on a farm in central Kentucky during an epizootic of equine protozoal myeloencephalitis (EPM).. Cohort study.. 21 horses on a farm in central Kentucky, 12 of which developed clinical signs of EPM.. Horses on the farm were serially examined for signs of neurologic disease and serum and CSF antibodies to Sarcocystis neurona. Horses were considered to have EPM if they had neurologic signs and positive test results for antibodies to S neurona in CSF. Blood values were monitored for evidence of abnormalities resulting from long-term pyrimethamine and trimethoprim-sulfamethoxazole administration Physical, neurologic, and fetal necropsy examinations were performed as needed. Horses were treated for EPM until they had negative test results for CSF antibodies to S neurona.. Of 21 horses on the farm, 12 had EPM over the course of 6 months. The duration of treatment ranged from 45 to 211 days, excluding 1 horse that persistently had CSF antibodies to S neurona. Adverse effects from pyrimethamine and trimethoprim-sulfamethoxazole administration included transient fever, anorexia, and depression (n = 2); acute worsening of ataxia (2); mild anemia (4); and abortions (3).. EPM may develop as an epizootic. In the horses of this report subtle clinical signs that were originally considered unimportant ultimately progressed to obvious neurologic signs. Adverse effects associated with EPM treatment included worsening of neurologic signs, anemia, abortion, and leukopenic and febrile episodes.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Antibodies, Protozoan; Antimalarials; Clonixin; Cohort Studies; Disease Outbreaks; Encephalomyelitis; Female; Horse Diseases; Horses; Kentucky; Male; Neurologic Examination; Pyrimethamine; Sarcocystis; Sarcocystosis; Treatment Outcome; Trimethoprim, Sulfamethoxazole Drug Combination