A Retrospective Analysis to Identify Epidemiologic Patterns of the Infectious Coryza Outbreak in California 2016-22.

In 2017, the Turlock branch of the California Animal Health & Food Safety laboratory system received a significant increase in infectious coryza (IC) necropsy cases, with a total of 54 submissions originating from commercial broilers (n = 40), commercial layers (n = 11), and backyard chickens (n = 3). Layer flocks positive for IC were distributed within the adjacent counties of Merced and Stanislaus, while broiler flocks were concentrated within Merced County. The backyard flocks were located in Alameda and Sacramento counties. The clinical and pathologic presentation was consistent with IC, although septicemic lesions were also noticed. Avibacterium paragallinarum was isolated and identified by PCR from the respiratory tract as well as from extrarespiratory sites. Polymicrobial infections involving other viral (infectious bronchitis virus, infectious bursal disease virus) and bacterial (Mycoplasma spp., Escherichia coli, Ornithobacterium rhinotracheale, Gallibacterium anatis biovar haemolytica) agents were commonly reported. Thirteen selected Av. paragallinarum isolates were successfully characterized as serovar C (Page scheme) and serovar C2 (Kume scheme). They shared a unique enterobacterial repetitive intergenic consensus (ERIC) PCR, differing from the four reference strains, and showed consistent high minimum inhibitory concentration values for tetracycline, suggesting a common origin from a single clone. Based on these results, high biosecurity standards and proper immunization of susceptible, multi-age flocks should always be implemented and adjusted as needed. The importance of backyard flocks should not be underestimated due to their unique epidemiologic role.

In January 2015, a highly pathogenic Eurasian lineage H5N8 avian influenza (AI) virus (AIV) was detected in a commercial meat turkey flock in Stanislaus County, CA. Approximately 3 wk later, a similar case was diagnosed in commercial brown layers from a different company located in Kings County, CA. Five 14-wk-old turkey hens were submitted to the California Animal Health and Food Safety Laboratory System (CAHFS), Turlock, and eleven 12-wk-old chickens were submitted to CAHFS, Tulare laboratory due to an acute increase in flock mortality. Gross lesions included enlarged and mottled pale spleens and pancreas in turkeys and chickens. Histologically, the major lesions observed in turkeys and chickens were splenitis, pancreatitis, encephalitis, and pneumonia. In both cases, diagnosis was based on real-time reverse transcriptase PCR (RRT-PCR), sequencing, and virus isolation from oropharyngeal and cloacal swabs. Confirmatory diagnosis and AIV characterization was done at the National Veterinary Services Laboratory, Ames, IA. The sequence of the AIV from both cases was 99% identical to an H5N8 AI virus (A/gyrfalcon/Washington/41088-6/2014) isolated from a captive gyrfalcon (Falco rusticolus) from Washington State in December 2014. Immunohistochemistry (IHC) performed on various tissues from both cases indicated a widespread AIV tissue distribution. Except for minor variations, the tissue distribution of the AI antigen was similar in the chickens and turkeys. There was positive IHC staining in the brain, spleen, pancreas, larynx, trachea, and lungs in both chickens and turkeys. Hearts, ovaries, and air sacs from the turkeys were also positive for the AI antigen. The liver sections from the chickens had occasional AI-positive staining in mononuclear cells, but the IHC on liver sections from the turkeys were negative. The bursa of Fabricius, small intestine, kidney, and skeletal muscle sections were negative for the AI antigen in both chickens and turkeys.

Infectious coryza is a severe respiratory disease of chickens associated with large economic losses in affected commercial flocks. The fastidious causative pathogen, Avibacterium paragallinarum, is difficult to recover and identify, resulting in delayed diagnosis and enhanced spread of the agent. Small poultry flocks are increasingly common in rural and suburban environments. We assessed the frequency of A. paragallinarum using real-time PCR and clinical conditions present in samples from such flocks submitted to the California Animal Health and Food Safety Laboratory System (Davis, CA) in 2018. From the 294 samples collected for our study, 86 (30%) were PCR-positive for A. paragallinarum. Juvenile birds (≤1 y) were significantly more likely to be PCR-positive ( p = 0.017), and birds diagnosed with respiratory disease had lower Ct values ( p = 0.001) than those without. Concurrent infections were also identified, including with Mycoplasma gallisepticum (18.6%), M. synoviae (18.6%), infectious bronchitis virus (12.8%), and infectious laryngotracheitis virus (7.0%). Only 46.5% of PCR-positive chickens had antemortem respiratory signs, making endemic infections in these flocks highly likely. Our study demonstrates that A. paragallinarum is present in small-flock operations including those without respiratory disease and may present a risk for airborne pathogen transmission to commercial poultry operations.

Infectious coryza, caused by Avibacterium paragallinarum, is an acute respiratory disease of poultry that can result in substantial morbidity, mortality, and economic losses. In March 2017, the Turlock branch of the California Animal Health and Food Safety laboratory system encountered an unusual clinical and pathologic presentation of infectious coryza in 6 live, 29-d-old, commercial broiler chickens that were submitted for diagnostic investigation. Antemortem evaluation revealed severe neurologic signs, including disorientation, torticollis, and opisthotonos. Swollen head-like syndrome and sinusitis were also present. Histologically, severe sinusitis, cranial osteomyelitis, otitis media and interna, and meningoencephalitis were noted, explaining the clinical signs described. A. paragallinarum was readily isolated from the upper and lower respiratory tract, brain, and cranial bones. Infectious bronchitis virus (IBV) was also detected by PCR, and IBV was isolated in embryonated chicken eggs. Based on sequencing analysis, the IBV appeared 99% homologous to strain CA1737. A synergistic effect between A. paragallinarum and IBV, resulting in exacerbation of clinical signs and increased mortality, may have occurred in this case. A. paragallinarum should be considered among the possible causes of neurologic signs in chickens. Appropriate media should be used for bacterial isolation, and the role of additional contributing factors and/or complicating agents should be investigated in cases of infectious coryza.

Yersinia pseudotuberculosis is a recognized zoonotic food-borne pathogen; however, little is known about the ecology and epidemiology of diseases caused by the bacterium in California. The objective of the current study was to contribute to the knowledge of the diseases caused by Y. pseudotuberculosis in goats, the animal species most frequently reported with clinical yersiniosis to the California Animal Health and Food Safety Laboratory System, to better understand the epidemiology of this disease. A 23-year retrospective study was conducted to characterize the syndromes caused by the bacterium in goats and their temporospatial distribution, and to determine the number of cases in other animal species. Yersinia pseudotuberculosis-associated disease was diagnosed in 42 goats from 21 counties, with a strong seasonality in winter and spring. Most cases (88%) were observed within particular years (1999, 2004-2006, 2010-2011). The most frequently diagnosed syndrome was enteritis and/or typhlocolitis (64.3%), followed by abscessation (14.3%), abortion (11.9%), conjunctivitis (4.75%), and hepatitis (4.75%). Among other animal species, 59 cases were diagnosed in non-poultry avian species and 33 in mammals other than goats.

Fowl cholera is caused by the bacterium Pasteurella multocida and is known to cause significant economic losses in the commercial turkey industry. Four hundred and thirty cases of P. multocida in commercial turkeys, submitted to the California Animal Health and Food Safety Laboratory System (CAHFS) from January 1, 1991, to December 31, 2017, were analyzed. Records examined included CAHFS branch location, date of submission, clinical signs, company and premise of origin, age and sex of submitted turkeys, macroscopic findings, organs in which P. multocida was isolated, and serotype and fingerprint information. Increased mortality as high as 1200 birds per day was the most common complaint at submission, with acute septicemic lesions observed in the majority of cases. The mean age of turkeys diagnosed with fowl cholera was 14 wk, with a median age of 17 wk. Cases most frequently occurred from September to November, with 36% of cases occurring during this time period. Serotyping was performed in 350 cases, while fingerprinting was performed in 171 cases. Serotypes 3 and 3,4 were frequently identified in the 26-yr time period, while the fingerprints identified varied over time. Despite the decreasing population of commercial turkeys in California since the 1990s, fowl cholera continues to be an economically significant disease in this sector.

Veterinary RecordVolume 156, Issue 10 p. 317-318 Short Communication Pyogranulomatous meningoencephalitis in a goat due to Corynebacterium ulcerans W. E. Morris DVM, MSc, W. E. Morris DVM, MSc National Institute...

Infectious coryza (IC) is an infectious disease caused by Avibacterium (Av.) paragallinarum. IC is known to cause economic losses in the poultry industry via decreased egg production in layers. Between 2012 and 2013, Av. paragallinarum was isolated from seven chicken farms by Chungbuk National University. We identified Av. paragallinarum, the causative pathogen of IC by polymerase chain reaction (PCR) and serovar serotype A, by multiplex PCR. Antibiotic sensitivity tests indicated that a few field-isolated strains showed susceptibility to erythromycin, gentamicin, lincomycin, neomycin, oxytetracycline, spectinomycin, and tylosin. A serological survey was conducted to evaluate the number of flocks that were positive for Av. paragallinarum by utilizing a HI test to determine the existence of serovar A. Serological surveys revealed high positivity rates of 86.4% in 2009, 78.9% in 2010, 70.0% in 2011, and 69.6% in 2012. We also challenged specific pathogen-free chickens with isolated domestic strains, ADL121286 and ADL121500, according to the measured efficacy of the commercial IC vaccine, PoulShot Coryza. We confirmed the effectiveness of the vaccine based on relief of clinical signs and a decreased re-isolation rate of ADL121500 strain. Our results indicate IC is currently prevalent in Korea, and that the commercial vaccine is effective at protecting against field strains.

Infectious coryza disease is an upper respiratory disease of avian species, commonly affecting chickens. It is caused by Avibacterium paragallinarum, a gram-negative bacterium. Infectious coryza poses a threat to the economy due to increased culling rates of infected chickens and a decrease in egg production of up to 40%. This study aimed to determine the spatial and temporal distribution of Infectious Coryza disease in Mashonaland West Province of Zimbabwe across seven districts from 2018- 2021, with a focus on disease prevalence and risk assessment. A retrospective method was used using a database obtained from the Central Veterinary Laboratory, which indicated infectious coryza disease cases in Mashonaland West Province of Zimbabwe. Data was examined using correlation analysis to determine the relationships between the total number of cases and deaths, and chi-square test to evaluate infectious coryza prevalence across districts .Prevalence of infectious coryza among districts was significant (p<0.05 )for the period of 2018 -2021.Low disease incidence was reported in 2018 across all the seven districts ;2019 had a peak increase of infectious coryza disease prevalence across all the districts with Zvimba district having cases above 2500.A weak correlation between total cases and deaths (co efficient 0.115 ), not statistically significant (p> 0.05), indicating other factors influencing the mortality rates. These findings highlight the need to improve management practices and vaccination programs in poultry production across Mashonaland West Province of Zimbabwe.

Infectious coryza (snot) is one of acute respiratory disease in breeders, layers, and broilers caused by Avibacterium paragallinarum (Av. paragallinarum). This disease is very harmful because of its cause decrease in egg production and high morbidity. Snot incident in Indonesia still is reported. Vaccination is one of the best preventive measures, but reports about Av. paragallinarum serotype at the field so lack so that the correspondence between serotype Av. paragallinarum in the field to those used for vaccination is unknown. Av. paragallinarum has strains with different antigenicity and until now known three serotypes there are serotypes A, B and C. Serotypes A and C are pathogenic then serotypes B. The purpose of this study was to isolate, identify and to determine the serotype of Av. paragallinarum from the commercial layer that showing symptoms of snot. Samples were taken from layer which showed symptoms of snot (nasal foul smelling exudate, infra-orbital and wattle swelling, conjunctivitis, and snoring) from some layer farms. Samples were cultured on chocolate agar and then incubated in a candle jar at 37 ᴼC for 18-24 hours. Bacteria colony and cell morphology were observed and performed biochemical tests (catalase, oxidase, urease, indole, and fermentation of carbohydrates) in suspected colonies. Serotypes test was conducted using plate agglutination test (PAT). This study revealed 4 isolates Av. paragallinarum with 2 isolates are serotype B and 2 other are serotype C.

Bromethalin, a rodenticide, is increasingly used due to restrictions on other rodenticides. The study aimed to analyze the frequency, demographics, clinical signs, and diagnostics of suspected bromethalin intoxication in dogs and cats. Two hundred twenty-three cases (249 samples) involving 123 dogs and 100 cats suspected or confirmed to have bromethalin intoxication were submitted to the toxicology laboratory at the California Animal Health and Food Safety Laboratory. This was a retrospective cohort study. Between 2010 and 2023, Liquid Chromatography-Mass Spectrometry was used to detect desmethylbromethalin (DMB), bromethalin's metabolite, in various tissues and serum. Cases increased 2.8-fold from 59 (2010-2016) to 164 (2017-2023). Cats were significantly younger (median 24 months, IQR: 41.5) than dogs (36 months, IQR: 60.0; p = 0.016) and were more likely to have confirmed DMB exposure (60% vs. 25%, p < 0.0001). Submitted samples for analysis were adipose tissue (37%), liver (20%), and brain (19%). Clinical signs included seizures, tremors, weakness, and paralysis. Magnetic resonance imaging (MRI) findings in 17 dogs and cats were consistent with bromethalin intoxication in 77% of cases. Autopsies (33 cases) revealed CNS lesions compatible with bromethalin toxicosis in 2/8 dogs and in 24/25 cats. Bromethalin exposure is increasingly prevalent in pets. Adipose tissue remains the most reliable sample for diagnosis; cats are more likely to test positive for DMB and exhibit compatible autopsy results. MRI findings can also support the diagnosis. These insights could assist in diagnosing and managing bromethalin intoxication in pets.

Postmortem Survey of Disease Conditions in Backyard Poultry

Liposarcomas are a malignant neoplasm of adipocytes, and are rarely diagnosed in avian species. This case report describes the evidence supporting a diagnosis of metastatic liposarcoma in a backyard silkie chicken. On September 28, 2017, a dead 3-yr-old backyard silkie chicken, with a history of unknown skin lesions involving the entire body and severe weight loss, was submitted to California Animal Health and Food Safety Laboratory System-Turlock branch for necropsy. At necropsy, raised necrotic lesions involving the majority of the skin and multiple nodules in the liver, spleen, and bone marrow were noticed. Microscopically, stellate, spindle, and myxoid cells containing large vacuoles, which were confirmed as lipid droplets by Oil Red O, were observed infiltrating the dermis and underlying a necrotic epidermis, with metastasis to liver, spleen, bone marrow, and ovary being the most significant findings. PAS, Oil Red O, Ziehl-Neelsen, Congo red, Gram, and Von Kossa stains, along with immunohistochemistry for pan cytokeratin, vimentin, S100, CD3, pp38, and Meq were used to classify the lesions. Intensely positive vimentin immunohistochemistry, along with large quantities of Oil Red O-positive lipid droplets within the neoplastic cells, were supportive of our diagnosis of liposarcoma. The incidence of neoplastic diseases diagnosed in backyard flock submissions to CAHFS system wide from 2008 to 2017 was also reviewed.

In February 2015, two Eurasian collared doves (Streptopelia decaocto) were submitted dead to the California Animal Health and Food Safety (CAHFS) Laboratory, Turlock branch, from a private aviary experiencing sudden, high mortality (4/9) in adult doves. In both doves, the gross and histologic lesions were indicative of acute, fatal septicemia. Grossly, there were numerous pale yellow foci, 1 to 2 mm in diameter, in the liver and spleen. Microscopically, these foci were composed of acute severe multifocal coagulative necrosis of hepatocytes and splenic pulp with infiltration of heterophils mixed with fibrin and dense colonies of gram-negative bacteria. Yersinia pseudotuberculosis was isolated from the lung, liver, spleen, heart, ovary, kidney, and trachea. The organism was susceptible to most antibiotics it was tested against, except erythromycin. Based on a retrospective study of necropsy submissions to CAHFS between 1990 and 2015, there were 77 avian case submissions of Y. pseudotuberculosis. There were 75/77 cases identified from a wide range of captive avian species from both zoo and private facilities and 2/77 cases from two backyard turkeys submitted from one premise. The largest number of cases originated from psittacine species (31/77). The lesions most commonly described were hepatitis (63/77), splenitis (49/77), pneumonia (30/77), nephritis (16/77), and enteritis (12/77). From 1990 to 2015, there was an average of three cases of avian pseudotuberculosis per year at CAHFS. Although there were no cases diagnosed in 1993 and 1994, in all other years, there were between one and eight cases of Y. pseudotuberculosis detected from avian diagnostic submissions.

This is the first extensive report on the identification and characterization of Avibacterium paragallinarum (AVP) isolates obtained from outbreaks of infectious coryza (IC) in IC-vaccinated layer flocks from Sonora State in Mexico. Isolates obtained from IC outbreaks during the years 2007, 2014, 2015, 2017, and 2019 were identified by conventional PCR test and 16S rRNA gene analysis, serotyped by Page serotyping and genotyped by the recently described partial sequence analysis of the HPG2 region. Furthermore, antimicrobial susceptibility profiles were determined by a recently improved minimal inhibitory concentration (MIC) test. The conventional PCR test and the 16S rRNA analyses confirmed the isolates as AVP. Serotyping results showed the involvement of isolates belonging to serotypes A, B, and C in the IC outbreaks. Genotyping of the HPG2 region revealed the presence of sequence type (ST)1, ST4, and ST11, of which the latter has also been identified in Europe. The MIC susceptibility test showed that all tested isolates were susceptible for the majority of tested antimicrobials, including erythromycin and tetracycline, which are important antibiotics for the treatment of IC. The IC situation in Sonora State, Mexico, is complex because of the presence of serotypes A, B, and C. This finding emphasizes the importance of biosecurity in combination with the application of the most optimal vaccination programs in the control of IC in Sonora State, Mexico.