Animal Health Monitor FEBRUARY 2020 Volume 12, Issue 1

Animal Health Monitor FEBRUARY 2020 Volume 12, Issue 1 Editorial by Dr. Jane Pritchard sibility, the office of the Chief Veterinary Officer of BC, the Executive Director (ED) for the Plant and Animal Health Articles of Interest: Branch and the Director of Confirmation of Asian the Animal Health Centre, Giant Hornet in Just before I fade away into the veterinary diagnostic lab Coastal BC retirement from the Executive for the province will be sepa- Director of the Plant and Ani- rated. This was done so that Director of the Animal Health mal Health Branch role, I they can bring a better focus Infectious Centre have been determined wanted to take this opportuni- to their roles and to bring Laryngotracheitis in there will be communication ty to thank all the individuals, more attention to animal wel- Chickens in BC in out to the livestock, poultry 2019 and organizations that support fare in the province. The new and veterinary communities, the Branch. I have worked Executive Director for the but you can always connect closely with some of you, com- Plant and Animal Health with either through municated with many of you Branch has been selected and [email protected], or by calling and enjoyed supporting all of it is my pleasure to announce 604-556-3001. Inside this issue: you. that Ursula Viney, who has served as our Director of Op- Again. thank you for your sup- Animal Health is an increas- Confirmation of 2 erations, was successful in the port in guarding the health of ingly demanding area with Asian Giant competition and assume the all animals in the province. almost constant challenges Hornet in ED duties in February. Coastal BC from new and emerging diseas- Infectious 3 es that spread with increasing In the mean time, before I go, Laryngotrache- rapidity around the world. I will be organizing one last itis in Chickens The continual threat of Afri- shipment of vaccine for Rab- in BC in 2019 can Swine Fever and the cur- bit Haemorrhagic Disease. Milk Culture 5 rent human health pandemic The next order will be carried Results with COVID19 (Wuhan out by the new CVO which is Corona virus) are the latest yet to be determined. If you Blue Tongue 6 reminders of that. This is also have not ordered vaccine Virus ELISA an area challenged to keep up through the CVO office and with the demands of public wish to do this please email trust as we continue to evalu- me at ate our roles and responsibili- [email protected] so ties within our duties for the that you can be on the email care of all animals. Going for- contact list. ward my three areas of respon- When the new CVO and new Animal Health Monitor FEBRUARY 2020 Page 2 Confirmation of Asian Giant Hornet in Coastal BC by Paul van Westendorp Two specimens of “large hornets” were caught and pre- assumption may need to be challenged with the confirmation served by a beekeeper in Nanaimo on or about August 15. of a single adult specimen of V. mandarinia in a residential The two specimens were submitted to the Biodiversity Re- area of White Rock in mid-October. Then, in mid-December, search Centre at UBC and were identified as Asian Giant a single specimen was collected near Blaine WA, at a rural Hornets, Vespa mandarinia. site about 17 km south-east of the White Rock site. While the distance is beyond the foraging range of V. mandarinia it The Nanaimo beekeeper reported that two hornets were points to the presence of a nest and its likely establishment as predating simultaneously on honeybees in his apiary. This an invasive species. Its continued activity in the fall and win- was clear evidence of a nest and its possible establishment ter season indicates that V. mandarinia readily adapts to west as an invasive species in BC. V. mandarinia is a ground nest- coast conditions. er in forest habitats with a foraging radius of up to 8 kilo- meters. Based on its native distribution in East Asia, this Plans are underway to apply DNA analysis on the Nanaimo species is expected to readily adapt to Southern British Co- and Blaine specimens to determine whether they are of the lumbia conditions. same origin or from different sources. The single White Rock specimen was destroyed and not retrievable. Comprehensive While V. mandarinia is recognized as a serious predator of monitoring and eradication programs are being developed honeybees, the primary concern is its threat to public health for the 2020 season. and safety. In Japan, this hornet species is responsible for several dozen human fatalities each year. Stinging incidenc- The sighting of any suspect insect can be reported to the In- es mostly involve mass attacks in response to accidental nest vasive Species Council of BC www.bcinvasives.ca or contact disturbance. Hornets can deliver multiple stings and its Paul van Westendorp, Ministry of Agriculture, venom contains a peptide causing necrosis of the sting site [email protected]. resulting in bleeding and infection potential. In cooperation with the Invasive Species Council of BC, a number of sightings of adult hornets were reported. Geo- graphic coordinates of all sightings enabled us to extrapo- late the likely location of nests. Local beekeeper involve- ment proved instrumental in the successful location and eradication of the nest. A few additional sightings were reported after nest eradication but all were regarded as strag- glers from the original nest. Prior to the Nanaimo incident, a similar “large Asian hornet” was collected at Vancouver harbour and subsequently identified as Vespa ducalis, a specialized predator of South Asian wasp species. The identification was later revised to Vespa soror, a sister species of V. mandarinia with similar nesting habits and geographic distribution in East Asia. The fact that two separate Asian Hornet species were collected within a few months is highly unusual. Since only one V. soror specimen was collected at the harbour without any further sightings, it is assumed that it didn’t establish itself in BC. Both findings were at or near harbours and it was assumed these incursions were inadvertently introduced through container or bulk carriers originating in East Asia. This Animal Health Monitor Page 3 FEBRUARY 2020 Infectious Laryngotracheitis in Chickens in BC in 2019—Summary by Nancy deWith, Tony Redford and Victoria Bowes Background gross and microscopic lesions in the trachea that are used to confirm a clinical case. Infectious laryngotracheitis (ILT) is caused by an avian her- pes virus that infects chickens, pheasants, partridges and Infectious laryngotracheitis is a reportable disease under the peafowl. Turkeys are not affected. Clinical signs generally Reportable and Notifiable Disease Regulations of the Ani- appear 6-12 days after natural exposure to the virus, and mal Health Act. This allows notification to the commercial most chickens recover in 10-14 days. poultry industry so that steps can be taken to limit spread. Figure 1. Opened trachea of a chicken with ILT Clinical features include acute death, respiratory distress showing a blood clot in the lumen with extended neck and gasping, gurgling, coughing and discharge from the mouth. Subacute and chronic disease may be indistinguishable from other respiratory diseases of poultry, with conjunctivitis, sinusitis and mucoid tracheitis. Post-mortem findings usually include hemorrhagic tracheitis, with blood clots, mucoid rhinitis, and blood-stained mucus along the length of the trachea (Figure 1). Hemor- rhage is frequently absent from subacute and chronic cases, but diphtheric and caseous necrotic plaques and plugs are often found in the trachea, larynx and mouth. Compatible gross and/or histologic lesions (Figure 2) along with polymerase chain reaction (PCR) testing is used to diagnose clinical ILT in BC. Vaccinated and recovered Figure 2. Histopathology of ILT from the trachea of birds may harbour the ILT virus without showing clinical a chicken. The circles indicate syncytia (cell clus- illness, a term called latency. Latently infected birds may be ters containing multiple intranuclear viral inclusion positive by serology and PCR but would lack the compatible bodies) Current situation: From January 1 to November 30, 2019, the AHC laboratory has received 28 submissions that were either suspect or positive for ILT by PCR (1 suspect and 27 positive). A diagnosis of clinical infectious laryngotracheitis was made by a pathologist on 21 occasions. One of these was located in the interior of BC. The remaining 20 cases represent 18 different poultry premises located in the Fraser Valley, including 17 commercial poultry farms and one small flock. These premises are geographically diverse, ranging in location Langley to Chilliwack. Apart from February, there has been at least one diagnoses each month, with 40% of the cases (8/20) occurring in the two-month time frame from Oct 1 – Nov 30 (Figure 3). The cases were most often in broiler breeder (hatching egg) chicken (45%) and broiler and Taiwanese chicken (40%), with only two cases in a table egg layer (10%) (Table 1). One diagnosis was made in a small flock with birds of mixed types. Animal Health Monitor Page 4 FEBRUARY 2020 Infectious Laryngotracheitis in Chickens in BC in 2019—Summary continued by Nancy deWith, Tony Redford and Victoria Bowes Figure 3. Epidemic curve of 2019 ILT Fraser Valley cases Comparison with previous years by location. A comparison of PCR test results (note that a positive PCR test result is not the same as a diagnoses of ILT by a pathologist) was made for 2019 compared to previous years. As can be seen in Figure 4, the year 2009 was an exceptional year, with 79 submissions suspect/positive for ILT on PCR.

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