Submitted to: International Seminar of Avian Pathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/15/1999
Publication Date: N/A
Citation: Interpretive Summary: Broiler chickens identified as exhibiting lesions of multicentric histiocytosis (MH), a cancer-like condition of unknown etiology, are condemned at the processing plant. Experimental inoculation of broiler and leghorn chickens with materials obtained from affected broilers lead to development of characteristic lesions of MH. However, we were not able to unequivocally demonstrate a viral etiology of the condition. The data suggest that avian tumors viruses are probably not the primary etiologic agent for MH. This will be the basis for research to identify other agents that can cause this condition.
Technical Abstract: Three-day-old broiler chicks and specific pathogen free leghorn chicks were injected with either saline or 0.5 ml of a homogenate prepared from organs from broilers diagnosed with naturally occurring multicentric histiocytosis (MH). Ten weeks later, nine broilers had well developed gross and microscopic MH lesions. The distribution and histologic appearance of lesions in these experimental chicks was similar to lesions described in naturally-occurring field cases. Six leghorns had lesions similar to lesions found in their broiler counterparts; however, the cellular masses contained increased numbers of lymphocytes, and tumors were found in the gizzard musculature. One gizzard contained a sarcoma. Chickens that were injected with MH had lower packed cell volume and weighed less than their control counterparts. Sequences specific for reticuloendotheliosis virus (REV) were found in the MH homogenate, in organs from most affected leghorns and broilers, and in organs from a control broiler, however, REVs were not isolated from these tissues nor were specific REV or avian leukosis/sarcoma virus (ALV) antibodies found in their serum. ALVs were isolated from affected leghorns and broilers. Sequences specific for Marek's disease herpesvirus were not identified by polymerase chain reaction. The etiology of MH remains not known.