Gangrenous dermatitis (GD) is a disease of chickens and turkeys that causes severe economic losses in the poultry industry worldwide. Clostridium septicum, Clostridium perfringens type A, and occasionally Clostridium sordellii are considered the main causes of GD, although Staphylococcus aureus and other aerobic bacteria may also be involved in some cases of the disease. GD has become one of the most significant diseases of commercial turkeys in the United States. Several infectious and/or environmental immunosuppressive factors can predispose to GD. Skin lesions are considered to be the main portal of entry of the microorganism(s) involved. GD is characterized by acute onset of mortality associated with gross skin and subcutaneous tissue lesions consisting of variable amounts of serosanguinous exudate together with emphysema and hemorrhages. The underlying skeletal muscle can also be involved. Ulceration of the epidermis may be also noticed in cases complicated with S. aureus. Microscopically, necrosis of the epidermis and dermis, and subcutaneous edema and emphysema are commonly observed. Gram-positive rods can be identified within the subcutis and skeletal muscles, usually associated with minimal inflammatory infiltrate. A presumptive diagnosis of GD can be made based on history, clinical signs, and gross anatomic and microscopic lesions. However, confirmation should be based on demonstration of the causative agents by culture, PCR, immunohistochemistry, and/or fluorescent antibody tests.

Two adult male Crimson rosellas (Platycercus elegans) and an adult female eastern rosella (Platycercus eximius) were found dead in their cages in a private aviary in March 2009, April 2010, and February 2010, respectively, without premonitory signs. Their postmortem examination showed pectoral muscle atrophy and a distended proventriculus. The proventricular mucosal surface was covered with a gelatinous, whitish material, where a large number of nematode parasites identified as Dispharynx nasuta were present. A histologic examination revealed a hyperplastic mucosa, spirurid nematodes in the mucosal layer and inflammatory mononuclear cells in the lamina propria. This is the first report of a D. nasuta infection associated with proliferative proventriculitis and subsequent death in psittacine birds.

Adult chinchillas (Chinchilla lanigera) that had suddenly died in a commercial farm located in La Plata City, Buenos Aires Province, Argentina, in July 2012 were macroscopically, histopathologically, and microbiologically examined. Salmonella enterica serovar Typhimurium (S. Typhimurium) was isolated from the liver, spleen, heart, lungs, kidneys and intestines from each of the five animals evaluated. The five strains were susceptible to ampicillin, cephalotin, cefotaxime, nalidixic acid, gentamicin, streptomycin, chloramphenicol, fosfomycin, nitrofurantoin and trimethoprim-sulfamethoxazole, and resistant to tetracycline. Each of the five S. Typhimurium isolates was analyzed by XbaI- pulsed-field gel electrophoresis (PFGE), showing an identical electrophoretic profile with 15 defined bands, which was found to be identical to pattern ARJPXX01.0220 of the PulseNet Argentine National database of Salmonella PFGE patterns. This is the first work describing the postmortem diagnosis of an outbreak of salmonellosis in chinchillas by using molecular methods such as PFGE.

Cases of sodium toxicosis (ST), although reported infrequently, can result in acute morbidity and mortality and extensive losses in affected poultry. We analyzed the clinical, pathologic, and toxicologic findings of 7 diagnosed cases of ST in chicken autopsy submissions at the California Animal Health & Food Safety Laboratory System (CAHFS), University of California–Davis, from 2014 to 2023. We also evaluated the brain sodium concentrations in 10 clinically normal broiler chickens to elucidate potential differences with salt-intoxicated chickens, and reviewed the literature of field cases of ST in chickens and turkeys. Lesions of anasarca described in the 7 ST cases (66 chickens) identified from the CAHFS database included: ascites (62 of 66; 6 of 7 cases); hydropericardium and cardiomegaly (54; 6 of 7); edematous, congested lungs (24; 6 of 7); enlarged, pale kidneys (24; 6 of 7); subcutaneous edema (17; 4 of 7); cystic testes (14; 6 of 7); and cerebral edema (7; 4 of 7). Brain sodium concentrations exceeded 1,800 ppm in only 4 of 24 brains analyzed in our case series. In the feed samples analyzed from 5 ST cases, sodium concentrations exceeded the recommended 2,000 ppm; concentrations detected were 2,500–12,000 ppm. In brains from the 10 clinically normal chickens evaluated, brain sodium concentrations were 1,500–1,700 ppm.

Transmissible viral proventriculitis (TVP) and chicken proventricular necrosis virus (CPNV) affect the broiler industry globally and are emerging diseases of economic importance. Here, we present the findings of TVP from processed broiler carcasses in Argentina following marked condemnation at the processing plant. We studied a total of 122 abnormally presenting proventriculi at processing from 42-to-50-day-old, male Cobb500^™ broiler chicken carcasses from 11 farms belonging to the same company in 13 episodes of proventriculi–gizzards condemnation between December 2021 and April 2022. The proventriculi were enlarged and pale with a widened gastric isthmus. A histopathologic lesion score system was developed based on the presence of a combination of key microscopic findings, the distribution, and the severity of the lesions. Scoring of the affected proventriculi revealed 65% (79/122) with a score of 4, 23% (28/122) with a score of 3, and 12% (15/122) with a score of 2. Focal to multifocal immunoreactivity against the VP2-CPNV antigen within the necrotic glandular epithelial cells was noted in the affected proventriculi using immunohistochemistry. We found 84.4% (103/122) of the studied proventriculi with TVP lesions grossly and microscopically scored were positive for CPNV by RT-PCR. The sequencing results of the PCR product showed a high nucleotide sequence similarity (88.97%) to previously published VP1-CPNV sequences. We confirmed CPNV infection in most of the TVP affected proventriculi in all condemnation episodes at a broiler chicken processing plant in Argentina during the studied period. This study documents TVP associated with CPNV detection at processing plants in Argentina for the first time.