Ontario Animal Health Network (OAHN)
Poultry Expert Network
Quarterly Producer Report
Aortic rupture in Ontario meat turkeys
Presently in Ontario, there are increased reports of aortic ruptures in older meat turkeys between 12 and 14 weeks of age. Although the cause of aortic ruptures could be multifactorial, preliminary discussions with international turkey veterinarians indicate that reovirus infections can have multiple clinical presentations including lameness or aortic ruptures or lameness followed by aortic ruptures predominantly in older tom turkeys. Therefore, Ontario turkey flocks presenting with lameness and/or aortic ruptures should be tested for evidence of reovirus infection as one potential cause. Hock joint and/or digital flexor tendon VTM (virus transport media) swabs (individually or in pools of 5) should be collected aseptically for reovirus PCR testing (remember that reovirus is also shed in the feces). PCR testing is preferred over virus isolation because it provides an estimate of viral load in tested samples. Gastrocnemius tendon and digital flexor tendons should be submitted in formalin for histology. Gastrocnemius and digital tendon ruptures have been associated with reovirus infections. In cases of aortic rupture, sections of vessels from near the site of rupture should be collected for histology.
Evaluation of lameness in successive flocks at earlier ages is also suggested for these infections are likely initiated earlier in the life of the flock when infected birds may have a higher reovirus load (lower reovirus PCR Ct values) but clinical presentation is more apparent in older turkeys.
In addition to reovirus testing, ruling out other causes of lameness, including Mycoplasma synoviae infection (the same VTM swab of joint/tendons can be tested for MS), bacterial osteomyelitis, synovitis and tenosynovitis, tibial dyschondroplasia, tendon rupture from other causes, articular cartilage erosions, and footpad dermatitis should also be conducted. Some of these lame birds may also have aortic ruptures, so collection of aorta near the site of rupture for histology is also requested.
Poultry Veterinarian Survey Highlights – Q1
Broilers
Early systemic bacterial infections (<14 days) were stable to increased this quarter. Escherichia coli continues to be commonly identified from these cases, with one case of E. coli with Enterococcus cecorum.
Late systemic bacterial infections (>14 days) were also stable to increased this quarter with E. coli as the main cause and fewer cases of E.coli with Enterococcus cecorum, E. coli and Pseudomonas aeruginosa and lone Enterococcus cecorum.
Other causes of early mortality were stable to increased with dehydration and runtings reported by one practitioner. A case of mixed bacterial and fungal pneumonia was reported in 17 day-old broilers.
Reovirus-associated lameness cases were stable to increased this quarter. One practitioner diagnosed Variant D infections in multiple flocks from both domestic and non-domestic sources which resulted in elevated culling rates. A small cluster of Variant A infections was also diagnosed during this quarter. Two cases with clinical signs of lameness were positive for an uncommonly identified strain, US AVS-BRSS, with only very mild lesions visible on histology. One case had a 93.2% best match with Georgia and Ontario variant F strain and two other submissions were positive for BC strains.
Escherichia coli, Enterococcus cecorum and Staphylococcus aureus continued to be identified as causes of bacterial lameness this quarter with most practitioners reporting stable to increased prevalence.
The number of cases of nutritional and developmental lameness remained stable this quarter with splayleg and long bone deformities being noted.
Both coccidiosis and necrotic enteritis cases were reported as stable to decreased by practising veterinarians. The AHL reported small intestinal coccidiosis or mixed small intestinal and cecal coccidial burdens, and fewer submissions with only cecal coccidiosis. Two cases of necrotic enteritis were associated with small intestinal/cecal coccidiosis.
Inclusion body hepatitis (IBH) cases were reported to be stable to increased this quarter by the practitioners. Confirmed cases were identified as species E (serotype 8) and those that were genotyped as 100% similar to serotype 8b. Two cases were positive for both species E and D but serotyping was not possible as there was more than one virus per sample. AHL data indicates that the samples they received were from flocks ranging in age from 14-29 days.
The number of flocks with infectious bronchitis virus (IBV) were reported as stable to increased this quarter by the poultry practitioners.
Infectious bursal disease virus (IBDV) infections were stable this quarter. One case had a high viral load and, when genotyped, was 100% match to Winterfield IBD Blend 2512 which is a classic vaccine strain.
Submissions to the AHL diagnosed with runting and stunting syndrome caused by astrovirus were sharply increased this quarter over last quarter. Affected birds were 7-19 days of age. A few submissions had typical pancreatic lesions, while one submission (19 days of age) had both small intestinal and pancreatic lesions. Determining the cause of runting in flocks can be quite frustrating especially if there is no grossly or histologically identifiable disease process such as systemic bacterial infections, astrovirus associated RSS, mobility issues, causing evaluation of husbandry procedures.
Over this quarter, there have been continued reports of proventricular dilation syndrome on farm with no breed specificity, as well as increased condemnations at processing for feed contamination as a result of delayed emptying. The AHL continues to have numerous submissions of dilated proventriculi for histologic evaluation. Histologic features most commonly are of glandular ductal epithelial proliferation and fibrosis with some also having variable degrees of ductal dilation. The trend of reduced inflammation continues with mostly very mild, mild to moderate, and, infrequently, marked inflammation. One case of proventricular dilation from processing was also tested for copper levels and was normal. Elevated dietary copper has been linked with proventricular dilation. Discussions with the industry are being held to determine the best method to investigate this syndrome as both production and processing are being impacted.
Three cases of inhaled foreign body pneumonia associated with peat moss bedding in 16 and 20 day-old broilers were reported by AHL this quarter. Farm workers are also exposed to this aerosolized particulate material, therefore this may also be a human health issue and further air quality investigations are warranted.
Four cases of ventriculitis with adenoviral inclusions in the mucosal villi were identified by the lab this quarter. All four cases were also positive for Inclusion Body Hepatitis (IBH) so it is not surprising to have spillover of the adenovirus into other tissues. One case of ventriculitis contained bacteria resembling Clostridium perfringens and 5 other cases had intralesional bacteria.
Condemnation issues were stable this quarter and included localized cellulitis and dermatitis, woody breast, dilated proventriculi with histologic evidence of dilated glandular ducts and mild proventriculitis.
Acute right-sided heart failure was one of the causes of elevated DOAs and IBV was considered as a underlying factor.
Broiler-Breeders
Early systemic bacterial infections (<14 days) with and without associated yolk sacculitis were stable this quarter. Escherichia coli continues to be the most commonly identified bacterial pathogen with fewer cases of E.coli with other pathogens including E. cecorum and Staphylococcus aureus. A couple of cases of Salmonella Kiambu septicemia mixed with E. cecorum and/or E. coli were also reported.
Other causes of early mortality included dehydration and starve-out. Only two cases of intestinal intussusception were reported this quarter, at 4 weeks of age with cecal coccidial cores and at 9 weeks of age.
Lameness due to bacterial infection was stable this quarter. Organisms implicated included Staphylococcus aureus,
Enterococcus cecorum and E. coli, often in mixed cultures.
Gangrenous cellulitis and myositis caused by Clostridium septicum mixed with S. aureus and E.coli septicemia and S. aureus tenosynovitis was reported in pre-lay breeders shortly after transfer. The isolation of C. perfringens is more common than C. septicum in these lesions.
IBV infections were stable to decreased in Q1 with DMV strains associated with egg production drops and both CA and DMV strains linked to spikes in mortality in flocks just coming into lay. One case of cystic oviducts was also seen in a young layer flock.
The number of coccidiosis cases reported by practitioners was stable to decreased this quarter. AHL reported one case of E. necatrix coccidiosis and three cases of cecal coccidiosis.
A mild burden of roundworms was noted in a couple of submissions. In one submission of spiker roosters, the roundworm infestation was moderate in degree and was contributing to clinical signs of enteritis.
One case of cellulitis and myositis secondary to more deeply placed oil adjuvanted vaccines in the neck muscles was reported. Birds presented with crooked, swollen necks. There has also been shortterm issues with vaccine shortages resulting in increased numbers of injections and more vaccine injection site reactions. The consistent supply of vaccines has recently been re-established.
Two cases of Mycoplasma synoviae infections were reported. In the one case, the infection was detected via routine serology as there were no clinical signs. The flock has been depopulated. Biosecurity issues included a nearby flock of table egg layers.
Layers
The issue that continues to be of the most concern to the layer industry is the lack of approved antibiotics for laying hens; this is being addressed, however progress is slow.
Bacterial peritonitis/salpingitis due to E. coli remained stable.
Early systemic bacterial infection (<14 days) was stable.
Early mortality due to visceral and articular gout was reported by the lab in one case. One practitioner reported increased
mortality of undetermined cause.
The industry is still focussed on the DMV strain of infectious Bronchitis, however, at present, there are no cases of false
layers in Ontario in fully vaccinated birds. In addition to adequate vaccination, the implementation of very high biosecurity, especially during the first four weeks of life, is also a critical piece to controlling this condition.
There was one case of IBV causing a drop in egg production diagnosed based on increased titres and compatible histologic lesions. Infrequent cases of DMV strain IBV infections are seen but overall the vaccination programs are working well.
Both coccidiosis and necrotic enteritis were noted by one practitioner to be increased and this is not unexpected for the time of year as the humidity is higher. Floor barns, aviaries and furnished cages all have more challenges.
There are more reports of higher roundworm burdens in laying hens raised on the floor. In addition to secondary enteric diseases, the possibility of roundworm larvae being incorporated into eggs is also a concern. Because of this concern, more fecal flotations are being conducted at the time of moving, on flocks of hens housed on the floor. The Animal Health Lab has received inquiries regarding fecal flotation testing (test code: fflot) and this methodology will detect roundworm and coccidial eggs but may not be able to positively identify cecal worm eggs. Eggs from tapeworms are less often identified as this is a function of shedding patterns. Results are qualitative- ie 1+, 2+, 3+ and 4+. As per the AHL user’s guide, the appropriate sample is 2-3 golf ball size feces that do not include litter, collected throughout the barn, submitted in a sturdy ziplock plastic bag. Turnaround time is 2 business days.
One report of hysteria resulted in leg injuries and trauma. Various factors including breed, cage and group size and lighting issues such as flickering are risk factors.
One case of MS infection was reported through the clinical impressions survey and this is not uncommon in multiage facilities.
Turkeys
Cases of early mortality in two and three week old poults were diagnosed at AHL with turkey viral hepatitis based on characteristic histologic liver lesions. Secondary septicemia was also present in one of these cases due to E. coli, and in another case Salmonella Heidelberg and Streptococcus gallolyticus were isolated.
Early systemic bacterial infection <14 days were stable this quarter. E. coli continues to be commonly identified in young poults and E. coli was mixed with S. Shwarzengrund in another submission. A case of pseudomoniasis with brain and ocular involvement was also diagnosed with another case of septicemia with extremely elevated brain sodium levels however whether this was due to excessive salt ingestion or marked dehydration could not be determined.
Poultry practitioners reported a slight increase in coccidiosis and salmonellosis in young poults this quarter.
One practitioner reported a case of multi-drug resistant Ornithobacterium rhinotracheale (ORT) that had an atypical clinical presentation. The birds were depressed, had swollen sinuses and no elevation in mortality. Because of the multi-drug resistance antibiogram, the response to antibiotic treatment was moderately successful and the bird activity level slowly returned to normal.
There were no reports of fowl cholera this quarter. Two cases of erysipelas were reported.
The AHL also reported 5 cases of proliferative and mixed inflammatory synovitis and tenosynovitis in 12 week old toms. Only one was positive for reovirus with a high Ct with PCR testing.
Rural/Backyard/Non-Quota Flocks
Ten cases of Marek’s disease were diagnosed at AHL.
One case of histomoniasis was diagnosed in small turkey flock.
Two cases of E.coli septicemia and one case of bacterial stomatitis and esophagitis with unusual appearing intralesional bacteria were reported by the AHL.
Intestinal parasites continue to be detected in small chicken flocks this quarter, including roundworms.
Events and News
Poultry Industry Council events: https://www.poultryindustrycouncil.ca/poultryindustry-events/2019-12/
Poultry Health Research Network information, events, and lectures can be accessed on the PHRN website: https://phrn.net/ or on the PHRN YouTube channel: https://www.youtube.com/user/PoultryHRN
Check out the OAHN poultry resources at https://oahn.ca/networks/poultry/
Thank You!
We thank the following poultry veterinarians who completed the veterinary survey: Dr. Elizabeth Black, Dr. Peter Gazdzinski, Dr. Shahbaz Haq, Dr. Genevieve Huard, Dr. Mike Joyce, Dr. Anastasia Novy, Dr. Mike Petrik, Dr. Cynthia Philippe, Dr. Joanne Rafuse, Dr. Fernando Salgado-Bierman, Dr. Kathleen Sary, Dr. Ben Schlegel, Dr. Chanelle Taylor, Dr. Lloyd Weber, Dr. Alex Weisz, and Dr. Jessalyn Walkey.
