Bacterial Diskospondylitis Associated with Posterior Paresis/Paralysis in North American Farmed Mink (Mustela vison)

Abstract

Abstract. Posterior paresis/paralysis in farmed mink is responsible for significant morbidity and mortality, with individual farms reporting the loss of as many as 700 animals each year. Although this disease has been recognized by North American mink farmers for approximately 40 years, there are few published reports focusing on this entity. The objective of this study was to investigate the etiology and pathogenesis of the disease. Complete necropsy examinations were done on 40 clinically affected mink, ranging from 7 to 10 weeks of age, and on three normal animals in the same age range from two mink farms. Thirty-two of the 40 clinically affected animals had an isolated vertebral lesion characterized by bone lysis and proliferation that usually was centered on an intervertebral disk space in the midthoracic area. An inflammatory reaction, composed primarily of neutrophils, was present within the vertebral sections in 25 of the 40 affected animals (62.5%), and the presence of gram-positive cocci was confirmed in 8 of 10 animals (80%) in which bacterial organisms were observed histologically. Bacterial cultures from 15 affected animals yielded Streptococcus sp. from the intervertebral disk space in 13 of 15 (86.7%) animals and from heart blood in 6 of 8 (75%). A farm visit revealed no history or evidence of traumatic wounds as a source of infection in these animals, and the diet appeared to be adequate for skeletal development. We conclude that posterior paresis/paralysis in farmed mink is associated with bacterial diskospondylitis, likely occurring secondary to bacteremia/septicemia.

Spinal Arthropathy Associated with Ochrobactrum anthropi in Free-ranging Cane Toads (Chaunus [Bufo] marinus) in Australia

“…2,4,9,19,26 In affected toad Nos. 12-15 from which O. anthropi was recovered from intervertebral lesions, the blood cultures were negative, indicating that concurrent bacteremia was not present.…”

“…24,42 Inflammatory conditions of the vertebral bodies and intervertebral joints were reported in various captive species, including canids, swine, mink, poultry, and snakes, as well as in numerous species of free-ranging large mammals, including whales. 8,9,12,15,19,25,26,33,34,39,43 Despite intensive interest in skeletal abnormalities of amphibians, descriptions of degenerative diseases or spinal pathology are rare and limited to scoliosis. 1,28,36 Cane toads (Chaunus [Bufo] marinus) were introduced into coastal Queensland, Australia, from Hawaii in 1936 in a strategy to control the sugar cane beetle.…”