Ontario Animal Health Network (OAHN)
Poultry Expert Network
Quarterly Producer Report
Outbreak of Highly Pathogenic Avian Influenza (HPAI) in Ontario: H5N1
Dr. Emily Martin, Animal Health Laboratory, University of Guelph
(NOTE: Information presented on Tuesday April 26, 2022 for the AVIA, OAPV and WAPV Webinar. See References.)
There is currently an outbreak of Avian Influenza (AI) occurring within Ontario and across Canada. The strain identified is H5N1 and has evolved from the H5 Gs/GD (Goose Guangdong) Eurasian lineage of HPAI that started circulating in 1996. This is the second time there has been an incursion into North America, the first being in 2014-2015. The virus is categorized into clades, the current being in the 5th clade (18.104.22.168b) having evolved since 2014. The natural reservoir for the virus is migratory aquatic birds resulting in the virus having wide geographic distribution through numerous overlapping migratory flyways.
The disease in wild birds is monitored by the Canadian Wildlife Health Cooperative (CWHC) through a network across Canada. In Ontario, there is a CWHC veterinary pathologist located on the University of Guelph campus. The first case of H5N1 was detected mid-March 2022 in a red-tailed hawk. Since then, a variety of waterfowl and raptors have been identified with H5N1, the most common being Canada geese, bald eagles, and turkey vultures. You can find a list of affected bird species and affected provinces here:
Wild birds are often found dead but the most reported clinical signs are neurological. These include: trouble standing, walking or flying; abnormal head or neck movements; and occasionally seizures. In Ontario, to report sick or deceased birds to CWHC:
Phone: 1-866-673-4781 Online: http://www.cwhc-rcsf.ca/report_and_submit.php
In North America, cases of H5N1 have been spreading across the continent from east to west. There have been more wild bird cases identified and a wider variety of wild birds affected compared to 2015 including: waterfowl (ducks, geese, swans), raptors (hawks, owls), shorebirds (gulls), crows, and songbirds. In the US, compared to 2015 there are more commercial and backyard flock cases detected in the same time period (up to April) and there are a higher proportion of backyard flocks affected. Shedding of the virus is known to last 7-10 days in poultry and approximately 14 days in waterfowl.
Clinical signs between chickens and turkeys differ.
-1-2 days post exposure: severe early illness, ruffled feathers, severe lethargy
-3 days post exposure: cyanotic necrotic combs, leg hemorrhages, periorbital edema
Turkeys: appear to be more susceptible.
-Disease not apparent until close to death
-Severe lethargy, huddling and ruffled feathers
-Trouble walking, neurologic signs
More information on Avian Influenza in the US can be found here:
In Ontario, the Poultry Industry Council is maintaining a resource page you can access here:
- Update on the Current Avian Influenza Wave through the US. Dr. David Swayne
Phibro Academy, April 20, 2022
- Germeraad EA, Sanders P, HagenaarsTJ, Jong MCM, Beerens N, Gonzales JL. Virus Shedding of Avian Influenza in Poultry: A Systematic Review and Meta-Analysis. Viruses. 2019 Sep 2;11(9):812.
- Martin E. Highly Pathogenic Avian Influenza: Diagnostic Challenges. AVIA, OAPV and WAPV. April 26, 2022. Webinar.
Poultry Veterinarian Survey Highlights – Q1 2022
ILT was detected in a commercial broiler flock in December 2021 and the outbreak is under control with no other events reported in the area.
Early systemic bacterial infections (<14 days) were generally stable to slightly increased this quarter as reported by practitioners. Escherichia coli in combination with Enterococcus cecorum and Clostridium perfringens were identified by practitioners. Salmonella isolations were reported as stable. The AHL reported confirmed cases due to mixed infection of E. coli with or without E. cecorum.
Other causes of early mortality (<14 days) were reported as stable by practitioners. AHL identified a case of oral mucosal necrosis and ulceration.
Late systemic bacterial infections (>14 days) were reported as stable to slightly increased by practitioners. E. coli and Enterococcus cecorum were the main bacteria isolated and reported by veterinarians. AHL reported stable numbers of cases attributed to either E.coli and/or E. cecorum, or both in combination with S. aureus, or S. Enteritidis. Practitioners reported 2-45% of E. coli isolates have been resistant to Trimethoprim sulfa (TMS).
C. perfringens was detected in the past 3 quarters in either early/late bacterial infections or both. It was not detected in either early or late systemic bacterial infections in this quarter.
The number of cases of nutritional and developmental lameness were reported as stable by the responders. Slippery flooring being noted as a diagnosis by a practitioner. AHL also reported 5 cases of tibial dyschondroplasia.
Bacterial lameness was reported as stable for this quarter and was attributed to E. coli and E. cecorum, alone or in combination. AHL reported decreased bacterial osteomyelitis and tenosynovitis. E.coli and E. cecorum were isolated from the case of vertebral osteomyelitis. Tenosynovitis cases were primarily diagnosed on histopathology.
Reovirus-associated lameness cases were reported as stable to decreased by practitioners with fewer strains identified. AHL reported a decrease in confirmed and suspect cases. As usual, a variety of strains were detected but these were fewer in number and similar to strains identified in previous quarters. Only Alberta 14-0838 field strain had not been identified in the past year.
Infectious bursal disease virus (IBDV) infections were reported as stable to slightly increased this quarter by practicing veterinarians and stable by AHL. This increase may be partially related to increased testing due to industry research. As a result, more sequencing has been pursued and more strains have been identified. While the strains are divided almost equally between field strains (5) and vaccine strains (4), more field strains were isolated with the most common being Pennsylvania (USA PA105-2014 field strain).
The number of flocks with infectious bronchitis virus (IBV) were reported as stable to increased this quarter by the majority of poultry practitioners and AHL. It was noted late breaks were very common in the past 3 months. Two strains of DMV (IBV_DMV_ON_21-017385 and IBV_DMV_ON_15-077145) were identified by AHL. The most common isolate was IBV_DMV_ON_21-017385.
Submissions to the AHL of confirmed runting and stunting syndrome (RSS) caused by astrovirus were stable this quarter. AHL reported 8 compatible and 9 suspect lesions in broilers at <14 days of age and 3 compatible and 4 suspect lesions in broilers >14 days of age.
Histomoniasis was reported stable by practitioners.
Ascites was reported by practitioners as stable to increased and there were questions if some cases may be associated with infectious bronchitis
Inclusion body hepatitis (IBH) cases were reported to be stable to slightly increased compared with last quarter by most respondents and increased by AHL. AHL is reporting fewer strains for this quarter. Genotyping on confirmed cases identified mainly FAdVE of the species E viruses in birds both <14 days and >14 days old as well as FAdVE with either FAdVAC or FAdVD (>14days). AHL reported primarily FAdV08b (<14 days and >14 days old) as well as 1 case of FAdV11 in birds >14 days old.
Coccidiosis and necrotic enteritis cases were reported as stable by the practitioners. The AHL also reported stable coccidiosis cases, identifying the lesions in the small intestine, ceca or both.
Spiking mortality was reported as stable this quarter by practitioners.
Condemnation issues were reported as stable to slightly increased by veterinarians this quarter and included cellulitis, ascites, air sacculitis, and hepatitis.
Proventricular and ventricular lesions were reported as stable to increased by AHL with 6 proventricular dilations, 11 ventricular lesions, and 8 proventriculitis/adenitis.
Other diagnostic findings reported by AHL were: uveitis/conjunctivitis/blepharitis, heterophilic pneumonia with fungal granuloma, lymphoid neoplasia, liver hemorrhage, and renal/visceral gout.
Slaughter provincial plants: Processing volume ranged between 1.53M to 1.89M. The top 2 condemnation conditions were reported as cellulitis and dead on arrival (DOA).
Slaughter federal plants: Processing volume ranged between 15.3M to 22.2M. Cellulitis, hepatitis and ascites were reported as the main conditions for condemnation.
Early systemic bacterial infections (<14 days) were reported as stable to slightly increased by practitioners. Bacteria isolated included E. coli and E. cecorum. AHL reported stable numbers compared to the previous quarter. E. coli continues to be the most common isolate either alone or in combination with E. cecorum.
Other causes of early mortality reported by practitioners and AHL were stable to slightly increased this quarter. Practitioners mentioned lower rates of dehydration and starve out. AHL diagnosed dehydration, tenosynovitis, and toe dubbing/osteomyelitis.
Pre-lay mortality (> 14 days, < 20 weeks) diagnosed by AHL were due to intussusception, emaciation, and bacterial septicemia (due to S. aureus alone, with E.coli, or E. coli combined with E. cecorum). Cases of tenosynovitis/osteomyelitis involved either S. aureus alone or E. coli combined with E. cecorum.
In-lay bacterial septicemia was reported as stable to slightly increased by practitioners and slightly decreased by AHL. Both practitioners and AHL listed E.coli, E. cecorum and G. anatis as commonly isolated bacteria. AHL had 2 cases with pure culture of S. aureus; however, mixed cultures were more commonly identified. For this quarter 2 to 4 bacteria were isolated from cases including: S. aureus with E. coli and G. anatis, and E. coli with E. cecorum as well as G. anatis and/or C. perfringens. Practitioners continue to report a stable to slight increase in cases of multi-drug resistant E. coli.
Other causes of in-lay mortality identified by the AHL included salpingitis, cannibalism, liver hemorrhage, amyloidosis, and renal interstitial fibrosis (unknown cause).
Bacterial, viral, developmental and nutritional lameness were reported as generally stable by practitioners with only a slight increase in bacterial lameness for this quarter. S. aureus was the most common bacterial cause of lameness reported by practitioners and AHL. At AHL there were also some mixed infections of E. coli combined with either S. aureus or E. cecorum. Practitioners also mention E. coli and occasionally P. multocida. One practitioner indicated improved ventilation led to improved leg health.
Cellulitis/ dermatitis was not diagnosed at AHL this quarter.
IBV infections were reported as stable to increased by the practitioners and AHL. The main strains detected were: CU82792, DMV, and vaccine strains (H120). Two DMV strains were detected with IBV_DMV_ON_21-017385 being the most common. Two cases of cystic oviducts were identified at AHL.
Fowl cholera was reported by practitioners as stable to increased and associated with lameness. One practitioner indicated a rare vaccine strain was isolated. Another practitioner mentioned positive cases after the 11 week vaccination with isolates having different resistance patterns.
The number of coccidiosis and necrotic enteritis cases reported by practitioners were stable this quarter. One practitioner mentioned an unusual case of necrotic enteritis. AHL reported a slight decrease in both necrotic enteritis and coccidiosis affecting the small intestines and ceca.
Histomoniasis and Fowl pox remained stable as reported by practitioners.
The aggression, cannibalism, disease related hatchability issues, and mycoplasmosis were reported as stable for this quarter. One practitioner reported no cases of Mycoplasma synoviae since the summer/fall seasons.
Poultry practitioners reported a variety of Salmonella isolates including: S. Kentucky, S. Kiambu, S. Livingstone, S. Hadar, and S. Putten. It was mentioned that Kentucky and Kiambu are the most common. Another practitioner mentioned that Kentucky was the only serotype found in a rare fluff sample while the rest were found on farm.
Other diagnoses reported by AHL included hemorrhagic bacterial pneumonia, pneumonia due to E. coli and G. anatis, proventriculitis/proventricular dilation, and dehydration. There were also 2 cases of lymphoma and 1 was PCR positive for Marek’s disease.
Overall, good and stable health status for this quarter.
Early systemic bacterial infections (<14 days) were stable for this quarter. AHL isolated E. coli from cases of yolk sacculitis. Practitioners identified dehydration, chick quality, and brooding management as other causes of early mortality.
In-lay mortality (>20 weeks) was increased at AHL. Cases of septicemia identified mixed infections with 2 to 3 bacteria including E. coli in combination with Streptococcus gallolyticus, G. anatis, or E. cecorum and G. anatis. Other causes of mortality included: liver hemorrhage, urate nephrosis/gout, and emaciation.
Bacterial peritonitis/salpingitis due to E. coli, E. cecorum, and G. anatis were stable as reported by practitioners. Also, multi-drug resistant E.coli was reported as stable.]
Focal duodenal necrosis (FDN) was reported as stable by practitioners and no cases were diagnosed at AHL.
IBV with drop in production and abnormal eggs was reported as stable to decreased by practitioners and
IBV with respiratory issues was reported as stable by practitioners. Overall, IBV had less impact on the industry partly due to better management. Practitioners reported that IBV was encountered mostly in pullets and the strains isolated were mostly California, and DMV. At AHL, IBV cases decreased since last quarter and fewer strains were identified: CU82792, DMV, and vaccine (Mass MA5, Conn) strains.
Necrotic enteritis and coccidiosis cases were reported as stable by practitioners.
Aggression and hysteria were reported by practitioners as stable for this quarter.
The most common Salmonella isolate was S. Enteritidis. SE has a serious impact on the layer industry due to the zoonotic potential of this organism.
Other diagnoses at AHL included: vent trauma, blepharitis/conjunctivitis, and peripheral neuritis (suspect Marek’s disease).
Early systemic bacterial infection (<14d) was reported as stable by practitioners with E. coli being the primary bacteria. At AHL, bacterial culture identified S. aureus and P. aeruginosa. Multi-drug resistant E.coli was stable this quarter.
Other causes of early mortality (<14d) were stable. At AHL 1 case of sinusitis (S. aureus, P. aeruginosa) and 1 case of round heart were diagnosed.
Late systemic bacterial infections (>14d) were stable. AHL reported isolation of E.coli in combination with S. Muenchen or E. cecorum (with or without S. aureus).
Practitioners reported stable to decreased mycotic respiratory disease (usually related to wet shavings or straw bedding). AHL reported only 1 case of mycotic airsacculitis and 2 cases of bacterial pneumonia due to E. coli alone or combined with E. cecorum and S. aureus. One practitioner also reported E.coli pneumonia.
ORT was reported as stable to decreased by practitioners.
Necrotic enteritis, enteritis and coccidiosis were reported as stable by practitioners.
Veterinarians and AHL reported tenosynovitis due to reovirus was stable this quarter. AHL had only 1 case that was suspicious for reovirus on histopathology. The use of autogenous vaccines in breeders has had a significant impact on controlling this disease.
Aggression and cannibalism were reported as stable by practitioners.
Two cases of gangrenous dermatitis were reported by one practitioner. Can treat with Penicillin but tends to recur after treatment. Birds sent for processing. Affected birds should not be composted near the barns.
Histomoniasis (blackhead) was reported as stable this quarter and no cases were diagnosed at AHL.
Poultry practitioners reported two Salmonella serotypes: S. Hadar and S. Uganda. Clinical Salmonella cases were reported as stable this quarter by practitioners.
Provincial slaughter plants: Processing volume ranged between 1,400 to 50,000. The top 2 conditions of condemnation were air sacculitis and abscesses.
Federal slaughter plants: Processing volume ranged between 500,000 to 900,000. The top 2 conditions of condemnation were dead on arrival (DOA) and cellulitis.
AHL continues to receive increasing submissions from backyard flocks. The majority of cases include various breeds of chickens, but turkey, geese, and duck cases also reported.
Fewer small flocks are seen by practitioners in the winter months. For this quarter, practitioners typically identified more respiratory disease and parasites. Mycoplasma gallisepticum identified multiple times per week and more Mycoplasma synoviae has been seen recently.
A decrease in intestinal parasitism was reported by AHL with primarily coccidiosis (small intestine and ceca) and nematodes (Ascaridia and Heterakis) being identified.
Marek’s disease continues to be diagnosed but the number of cases decreased this quarter. Other neoplasia included: oviductal leiomyoma, squamous cell carcinoma, and adenocarcinoma.
Seeing more cases of Streptococcus suis infections that tend to occur in specialized breeds/show birds.
The most encountered clinical cases reported by practitioners were related to bumblefoot, Mycoplasma synoviae, Mycoplasma gallisepticum, Marek’s disease, Streptococcus suis, hardware disease/heavy metal, lice, mites and cannibalism.
Two cases of ILT were diagnosed by AHL in small/exhibition flocks: 1 Niagara-like field strain CAGG cluster, and 1 USA vaccine-like strain TCAA cluster.
AHL reported a large variety of diagnoses: salpingitis, bacterial pneumonia (E. coli and E. cecorum), bacterial sinusitis, stomatitis/tracheitis/sinusitis, urate nephrosis/visceral gout, Mycoplasma gallisepticum, cannibalism, emaciation, frostbite, fungal proventriculitis, gizzard foreign body, gizzard diverticulum/impaction/regional peritonitis, pendulous crop, and necrotic enteritis.
Other species examined at AHL included: One pheasant with E. coli septicemia, intestinal parasitism, and emaciation. Two duck cases, one with pododermatitis and 1 with zinc toxicity. One goose that had septicemia and visceral gout. One turkey that had intestinal torsion and hemorrhage.
Poultry research from Ontario and beyond
The potential of house flies to act as a vector of avian influenza subtype H5N1 under experimental conditions The potential of house flies to act as a vector of avian influenza subtype H5N1 under experimental conditions – PubMed (nih.gov)
Photohydroionisation for disinfection of poultry litter- Photohydroionisation for disinfection of poultry litter – PubMed (nih.gov)
Researchers Work to Develop Bird Flu Vaccine to Contain Future Outbreaks- Researchers Work to Develop Bird Flu Vaccine to Contain Future Outbreaks – University of Wisconsin School of Veterinary Medicine
Biosecurity risk factors for highly pathogenic avian influenza (H5N8) virus infection in duck farms, France- Biosecurity risk factors for highly pathogenic avian influenza (H5N8) virus infection in duck farms, France – PubMed (nih.gov)
Which factor is more important: Intensity or duration of episodic heat stress on broiler chickens? – Which factor is more important: Intensity or duration of episodic heat stress on broiler chickens? – PubMed (nih.gov)
Events and News
Poultry Industry Council events: https://www.poultryindustrycouncil.ca/events
We thank the following poultry veterinarians who completed the veterinary survey: Dr. Elizabeth Black, Dr. Peter Gazdzinski, Dr. Shahbaz Haq, Dr. Geneviève Huard, Dr. Anastasia Novy, Dr. Mike Petrik, Dr. Joanne Rafuse, Dr. Kathleen Sary, Dr. Ben Schlegel, Dr. Chanelle Taylor, Dr. Lloyd Weber, Dr. Alex Weisz, and Dr. Jessalyn Walkey.