Strict adherence to biosecurity protocols was a common denominator as guest speakers offered insight into recent poultry disease outbreaks in Canada and the United States, during meetings hosted by the Poultry Industry Council (PIC).
During the organization’s annual research day in early May, and at the annual health day in late June, attendees were provided with an update on the spread of infectious coryza (IC) in Pennsylvania.
Why it matters: While avian influenza (AI) and necrotic enteritis are highest on the prevention priority list for producers and producer organizations, various other diseases can also have devastating effects in poultry barns.
A recent outbreak of Newcastle disease in California was give a close-up look at the health day, along with repeated incidences of Infectious Laryngotracheitis (ILT) stretching back to 2017 in Quebec and Ontario.
Predominantly an upper respiratory infection characterized by facial swelling and nasal discharge, the northeast U.S. outbreak of IC was first brought to PIC’s attention in May by Penn State University extension specialist Emily Lhamon. She told the research day audience the first instances, in poultry-dense Lancaster County, were reported in late March.
IC doesn’t discriminate by age or type of chicken, she said and good biosecurity practices should serve producers well in preventing its arrival.
In his update on the poultry-related work of the Ontario Animal Health Network to PIC’s annual health day on June 25 in Stratford, Dr. Csaba Vaga confirmed the importance of a good biosecurity program involving not just the farm but also anyone coming onto the farm. Given the region’s proximity to Ontario, “the potential of introducing this new infection (into the province) is real,” he said of IC.
Managing Newcastle disease
California’s ongoing battle with Newcastle disease presents a lesser risk of crossing the border into Ontario.
“It’s hard to know why it blew up this time — if they didn’t throw enough horses at the problem early on and it got away on them,” said Dr. Tom Baker of the Feather Board Command Centre — jointly supported by Ontario producer organizations for chicken, turkey, table eggs and hatching eggs.
“But one thing we do know,” he said, is that a significant number of flock owners in the state chose to ignore a crucial element of an effective, jurisdiction-wide bio-security program. People didn’t report when flocks became infected because they were afraid of losing their birds as a result of an order to euthanize.
“They didn’t want the big, bad guys coming in and killing them all.”
Baker described the outbreak, which at that point had reached 445 properties in five California counties as well as smaller sections of Utah and Arizona, as “not very typical.” However, cases had levelled off as of June 25, with the most recent new flock infection reported approximately three weeks previous.
Six commercial and industrial table egg operations accounted, at that time, for about 1.1 million of the euthanized birds. Another 120,000 euthanized birds were from backyard operations, mainly fighting cocks.
“These roosters, they have quite the active social life,” Baker said.
State and federal governments have thrown $72 million plus approximately 300 employees into combatting the outbreak and compensating flock owners.
Baker said that includes $1.9 million for backyard flocks and $3 million to commercial flocks. A ban on visits by any inspector or service provider to any affected farm was expected to stay in place until July and be re-assessed at that time.
While it’s almost certain the number of birds raised as fighting cocks in Ontario is minuscule compared to California, and Newcastle disease is only known to be present in Canada among isolated populations of double-crested cormorants, Baker said that’s no reason to be complacent.
In California, after all, there is at least some level of understanding about how many domestic fowl exist.
“You have to appreciate that, in Ontario, there’s no database of backyard birds,” he said.
A similar outbreak in California in 2002-03 resulted in an estimated financial loss of US$5 billion, and euthanization of more than three million birds. Clinical signs of the virus include neurologic effects, hemorrhage, egg drops and immune suppression. Control is accomplished through biosecurity to reduce infection pressure, enhancing the housing environment, and vaccination.
Baker also provided health day attendees with an update on an ongoing ILT outbreak mainly among broilers that began with nine farms in Quebec in 2017, followed by eight in Quebec in 2018, and “was quite devastating for the farms involved.”
So far in 2019, there has been just one farm in Quebec affected, and Ontario saw much smaller numbers of affected farms over the same time period.
One challenge with ILT is that birds can be infected for 28 to 35 days without showing symptoms. The potential to spread the infection is high during this period, the Feather Board Command Centre veterinarian noted, leading to the oft-repeated words of wisdom that: “The first case is not the first case.”
Symptoms include dirty or foamy eyes, heavy and/or open-mouthed breathing, extended neck, and high-pitched vocalizations.
U.S. cases in recent history have indicated a genotype originating in vaccinated birds. But that’s not the case with the Canadian outbreak; it’s thought to have come from a wild bird genotype.
A strong biosecurity program with highly restricted access is crucial to prevent spread. Airborne transmission has been shown to occur over as much as 300 metres. This means large risk zones should be established, and trucks need to be rerouted away from infected farms or vaccinated flocks.
Quebec now has ILT insurance in place. Ontario currently only has avian influenza insurance but Baker expects there will be some pressure for Ontario to follow Quebec’s lead.