Infectious laryngotracheitis (ILT) is an acute respiratory disease of poultry caused by infectious laryngotracheitis virus (ILTV). Control of the disease with live attenuated vaccines administered via eye drop build upon immune responses generated by the eye-associated lymphoid tissues. The aim of this study was to assess cytokine and lymphocyte changes in the conjunctiva-associated lymphoid tissues (CALT) and Harderian gland (HG) stimulated by the ocular inoculation of the ILTV chicken embryo origin (CEO) vaccine strain and virulent strain 63140. This study offers strong evidence to support the roles that the CALT and HG play in the development of protective ILTV immune responses. It supports the premise that ILTV-mediated immunomodulation favors the B cell response over those of T cells. Further, it provides evidence that expansions of CD8α⁺ cells, with the concomitant expression of the Granzyme A gene, are key to reducing viral genomes in the CALT and halting ILTV cytolytic replication in the conjunctiva. Ultimately, this study revealed that the early upregulation of interleukin (IL)-12p40 and Interferon (IFN)-γ cytokine genes, which shape the antigen-specific cell-mediated immune responses, retarded the decline of virus replication, and enhanced the development of lesions in the conjunctiva epithelium.

Avian respiratory disease causes significant economic losses in commercial poultry. Because of the need to protect long-lived poultry against respiratory tract pathogens from an early age, vaccination programs for pullets typically involve serial administration of a variety of vaccines, including infectious bronchitis virus (IBV), Newcastle disease virus (NDV), and infectious laryngotracheitis virus (ILTV). Often the interval between vaccinations is only a matter of weeks, yet it is unknown whether the development of immunity and protection against challenge when vaccines are given in short succession occurs in these birds, something known as viral interference. Our objective was to determine whether serially administered, live attenuated vaccines against IBV, NDV, and ILTV influence the development and longevity of immunity and protection against challenge in long-lived birds. Based on a typical pullet vaccination program, specific-pathogen-free white leghorns were administered multiple live attenuated vaccines against IBV, NDV, and ILTV until 16 weeks of age (WOA), after which certain groups were challenged with IBV, NDV, or ILTV at 20, 24, 28, 32, and 36 WOA. Five days post-challenge, viral load, clinical signs, ciliostasis, tracheal histopathology, and antibody titers in serum and tears were evaluated. We demonstrate that pullets serially administered live attenuated vaccines against IBV, NDV, and ILTV were protected against homologous challenge with IBV, NDV, or ILTV for at least 36 weeks, and conclude that the interval between vaccinations used in this study (at least 2 weeks) did not interfere with protection. This information is important because it shows that a typical pullet vaccination program consisting of serially administered live attenuated vaccines against multiple respiratory pathogens can result in the development of protective immunity against each disease agent.

Four young broiler chickens affected by multiple melanotic tumors are described. Grossly, there were multiple tumors composed of melanocytes within the skin, skeletal muscle, and multiple visceral organs. Tumors ranged from flattened macules to masses that extensively replaced viscera. Microscopically, melanocytes were often well pigmented, and while there was moderate nuclear anisokaryosis, mitotic rates were low. Immunohistochemical staining of some melanomas with antibodies to S100 proteins, Melan-A, vimentin, or neuron-specific enolase after bleaching of tumor cells with potassium permanganate revealed lack of immunostaining of tumor cells with antibodies to S100, strong positive staining of tumor cells for neuron-specific enolase, moderate staining with antibodies to vimentin, and faint staining for Melan-A. Only neuron-specific enolase staining was evident in unbleached tumor cells. Attempts to identify exogenous avian leukosis viruses in these tumors were unsuccessful.

Formalin-fixed suspect tumors were submitted to the Poultry Diagnostic and Research Center at the University of Georgia (Athens, GA) for diagnosis. Samples were from fancy breed chickens with a history of increased tumor prevalence in both hens and roosters. Microscopically, in all the samples, there were neoplastic proliferations of spindle-shaped cells. The matrix surrounding tumor cells stained positively with Alcian blue at pH 2.5, but neoplastic cells did not stain with periodic acid-Schiff. Immunohistochemistry stains were positive for vimentin and neuron-specific enolase and negative for desmin, smooth muscle actin, and S-100 protein. Tumors were determined to be myxosarcomas. All samples were positive for PCR targeting the gp85 avian leukosis virus (ALV) envelope protein. However, analysis of the predicted amino acid sequences in the envelope gene from three separate samples showed high similarity between them and to ALV subgroup A.

Broiler chickens on several farms from a single poultry company experienced neurological signs and mortality in chicks between 3 days and 10 days of age over a 3-week period after use of a fowlpox-vectored infectious laryngotracheitis virus vaccine in ovo. At necropsy the lungs contained numerous tan or gray, opaque to translucent, 0.5- to 2.0-mm nodules in the parenchyma. Microscopic lesions were a multifocal severe lymphohistiocytic and heterophilic bronchopneumonia. Immunohistochemistry was positive for fowlpox virus in macrophages and lymphocytes, and polymerase chain reaction on paraffin-embedded lung tissues was positive for a fowlpox vector virus commonly used as a vaccine. The cause of the neurological signs was not determined.

Interweaving diversity, equity, and inclusion (DEI) into the standards for accreditation requires veterinary schools to review their curriculum and determine what framework works best for them to implement those changes. The Competency-Based Veterinary Education framework is one that is available via the American Association of Veterinary Medical Colleges (AAVMC) to reach those standards. Five standards have DEI components versus having a single standard of DEI as previously Standards of Accreditation by the Council on Education had approved.