title: Actinobacillus lignieresii infection in two horses.
abstract: A 10-year-old pregnant Norwegian Fjord horse was examined for gross swelling of the muzzle of 2 years' duration. Examination of biopsy specimens revealed diffuse dermal fibrosis, micropustule formation, and vascular thrombosis; large numbers of Actinobacillus lignieresii were isolated in pure culture. Prolonged treatment with i.v. administration of sodium iodide and oral administration of trimethoprim-sulfamethoxazole caused regression of the swelling and did not induce abortion. A 5-month-old American Paint filly was examined for swelling in the udder region. Bacteriologic culture of purulent material obtained from the left teat revealed A lignieresii. Treatment with oral administration of rifampin and trimethoprim-sulfamethoxazole resulted in complete resolution of clinical signs. To the authors' knowledge, these findings represent the first report of mastitis and chronic nasal cellulitis caused by A lignieresii infection in horses.
authors.affiliation: Department of Veterinary Internal Medicine, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Canada.
authors.forename: J L
authors.initials: JL
authors.lastname: Carmalt
authors.forename: K E
authors.initials: KE
authors.lastname: Baptiste
authors.forename: J M
authors.initials: JM
authors.lastname: Chirino-Trejo
mesh_terms: D000187:Actinobacillosis / Q000188:drug therapy / Q000382:microbiology*; D000188:Actinobacillus / Q000302:isolation & purification*; D000284:Administration, Oral; D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000627:therapeutic use; D005260:Female; D006734:Horse Diseases / Q000188:drug therapy / Q000382:microbiology*; D006736:Horses; D007275:Injections, Intravenous / Q000662:veterinary; D008321:Mammary Glands, Animal / Q000382:microbiology / Q000473:pathology*; D009668:Nose Diseases / Q000188:drug therapy / Q000382:microbiology / Q000662:veterinary*; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000188:drug therapy / Q000382:microbiology / Q000662:veterinary*; D012293:Rifampin / Q000008:administration & dosage / Q000627:therapeutic use; D012974:Sodium Iodide / Q000008:administration & dosage / Q000627:therapeutic use; D015662:Trimethoprim, Sulfamethoxazole Drug Combination / Q000008:administration & dosage / Q000627:therapeutic use
chemical_list: D000900:Anti-Bacterial Agents; D015662:Trimethoprim, Sulfamethoxazole Drug Combination; D012974:Sodium Iodide; D012293:Rifampin