Ontario Animal Health Network (OAHN)
Poultry Expert Network
Quarterly Veterinarian Report

Turkey Viral Hepatitis (TVH) vs. Turkey Hepatitis Reovirus (THRV)

Emily Martin, Animal Health Laboratory, University of Guelph

Turkey viral hepatitis (TVH) is a picornavirus that causes a subclinical infection in young turkeys (less than 6 weeks of age). Clinical signs are not clearly defined but may be found in cases of sudden death or when investigating concurrent infections. Lesions can be identified in the liver and pancreas causing inflammation and multifocal areas of necrosis. On histopathology, within and adjacent to the areas of liver necrosis, there can be formation of syncytial cells. This has been a key finding in diagnosing THV.

However, recently there has been evidence that an emerging reovirus called turkey hepatitis reovirus (THRV) can produce similar lesions to TVH. Consultation with another histopathologist in the US (Dr. Tahseen Aziz) confirmed that in order to differentiate TVH and THRV, he requests that fresh liver (in addition to fixed tissue) be submitted for reovirus PCR. There is no PCR available for picornavirus.

Based on the above information, AHL would like to request that in cases of liver necrosis in turkeys that veterinarians submit both fixed tissue (liver and pancreas) for histopathology and fresh liver (without fecal contamination) for reovirus PCR. This will help differentiate these 2 diseases and attempt to determine if THRV is in Ontario flocks.

Figure 1. Liver. Area of hepatic necrosis (large circle). Syncytia (small circle).

Aortic rupture: A Cause of Sudden Death in Turkeys

Emily Martin, Animal Health Laboratory, University of Guelph

Aortic rupture, or dissecting aneurysm, can be a cause of death in rapidly growing turkeys ranging in age from 7 – 24 weeks of age with peak mortality usually occurring between 12 – 16 weeks of age. Mortality usually ranges between 1-5% but can reach as high as 50% in some cases. Males are primarily affected. The birds will be in good body condition, laying on their breast or side, and the carcass will be pale. Blood may be noted on the beak, at the nares, and in the mouth. On postmortem examination the celomic cavity will be filled with extensive blood clots primarily surrounding the kidneys. If the blood has penetrated adjacent air sacs then blood may have flowed into the air sacs, through the lungs, up the trachea and into the oral cavity creating blood clots in these organs. Clotted blood may also be identified within the pericardial sac. The internal hemorrhage is caused by longitudinal tears or rupture of posterior abdominal aorta and its branches between the celiac (most common) and ischiatic arteries (Figure 1). This could also occur in the coronary artery (near base of heart, supplies the nutritional and respiratory circulation to heart muscle). On histopathology the tunica intima and media will be thrown into deep folds and partially separated from the tunica adventitia (Figure 2 and 3). The tunica media fibres may show degenerative changes with infiltration of heterophils and macrophages. In the region of the rupture there is often marked thickening of the intima or a large fibrous plaque.

Suggested predisposing factors include: copper deficiency, hypertension, hormonal influences, diet, zinc deficiency, pharmaceuticals, management and parasites. There is no specific treatment other than recommendations to reduce flock stress and limit feed intake during rapid growth. This condition has also been described in chickens, ostriches and emus.

Figure 1. Bird – Major systemic arteries.

 

Figure 2. Normal artery. Figure 3. Aortic rupture (oval) and partial fracture (rectangle, tunica intima and tunica media are torn and folded allowing blood to flow into, fill and expand these areas).

References:

  1. Rocio Crespo, Developmental, Metabolic, and Other Noninfectious Disorders. In: Diseases of Poultry, 14th edition, 2020. Edited by David E. Swayne, Martine Boulianne, Catherine M. Logue, Larry R. McDougald, Venugopal Nair, David L. Suarez, Sjaak de Wit, Tom Grimes, Deirdre Johnson, Michelle Kromm, Teguh Yodiantara Prajitno, Ian Rubinoff, Guillermo Zavala. Pgs: 1286-1329.
  2. H. L. Shivaprasad , Rocio Crespo & Birgit Puschner (2004) Coronary artery rupture in male commercial turkeys, Avian Pathology, 33:2, 226-232
  3. https://www.thepoultrysite.com/disease-guide/dissecting-aneurysm-aortic-rupture
  4. Edward M. Dzialowski, Dane A. CrossleyII, The Cardiovascular System. In: Sturkie’s Avian Physiology, 6th edition, 2015. Edited by Colin G. Scanes. Pg: 208.

Poultry Veterinarian Survey Highlights – Q3 2022

Broilers

Early systemic bacterial infection (<14 d old)

AHL: The number of cases were increased from last quarter. All cases had at least E. coli isolated either in pure culture or in combination with primarily 1 other bacteria (S. aureus, E. cecorum, C. perfringens, and P. aeruginosa). In 1 case E. coli was isolated with 3 other bacteria (E. cecorum, Clostridium novyi, and C. perfringens).

Practitioners:  A similar number of practitioners indicated stable or increased cases this quarter. Escherichia coli, Enterococcus cecorum, Staphylococcus, and Pseudomonas were identified by practitioners.

Other causes of early mortality (>14 d old)

AHL: Numbers of cases were similar to previous quarters. Two cases of mycotic pneumonia identified.

Practitioners: Generally stable cases this quarter with stall out mentioned as a cause of mortalities at this age.

 

Late systemic bacterial infection (>14 d old)

AHL: The number of cases were increased from previous quarters. E. coli was isolated in pure culture as well as combined with 1 other bacteria (E. cecorum, C. perfringens, and P. aeruginosa). In 1 case E. coli was isolated with 2 other bacteria (E. cecorum, and G. anatis).

Practitioners: Equal numbers of practitioners reported stable to increased numbers this quarter with E. coli listed as the main bacteria identified. Practitioners reported that 2-30% of E. coli isolates have been resistant to Trimethoprim sulfa (TMS).

Lameness – viral

AHL: The numbers are slightly increased this quarter but still not as high as the same quarter in 2021. There are 4 different strains identified this quarter: SK_R12, ON_variant_E_12-090746, ON_variant_A_12-073195, and ON_variant_H_18-008168.

Practitioners: Cases were reported as stable to slightly increased with Reovirus variant H the common serotype identified.

Lameness – bacterial

AHL: Cases were slightly increased compared to last quarter. Primarily diagnosed on histology with 1 case of E. coli and 1 case of E. coli plus E. cecorum tenosynovitis.

Practitioners: Reported as stable to slightly increased for this quarter with cases attributed to E. coli and E. cecorum.

Lameness – developmental

AHL: Cases of tibial dyschondroplasia were stable from the previous quarter but both Q3 and Q4 2022 have increased cases from the previous 3 quarters.

Practitioners: Stable cases this quarter with one case identified as tibial dyschondroplasia.

Lameness – nutritional

AHL: Multiple related cases/barns diagnosed with Riboflavin deficiency this quarter. Multiple practitioners involved. Please see the upcoming March 2023 AHL Newsletter for lesion description.

Practitioners: Equal numbers of responders reported as stable to increased. One case of rickets and three cases of Riboflavin deficiency were noted as the causes for nutritional lameness.

Ascites

AHL: No cases of ascites were diagnosed this quarter.

Practitioners: Reported as stable.

Coccidiosis and necrotic enteritis

AHL: Cases of coccidiosis and necrotic enteritis were slightly increased compared to previous quarters. However, in some cases lesions are not obvious on gross examination and require histopathology to confirm the presence of necrotic enteritis lesions and if there is an underlying coccidial infection. One case had a diagnoses of E. necatrix.

Practitioners: Cases were reported as stable.

Inclusion body hepatitis (IBH)

AHL: Histologic cases were stable but viral isolations were increased. As in the previous quarter, on sequencing the primary strain identified was FAdV08b (i.e. FAdV08b_AHL_16-049095_ON and FAdV08b_AHL_18-057921_ON). Viral isolation also identified FAdV11_USA_1047, and FAdV11_USA_Stanford.

Practitioners: The majority of practitioners reported increased cases compared with last quarter. Responders learned that Adenovirus killed vaccines have limitations. If the birds have field exposure in addition to 2 killed vaccines, then there is good protection. It there is no field exposure then the killed vaccines do not work as well.

Infectious bursal disease

AHL: Decreased cases compared to last quarter with decreased variability of strains that are predominantly field strains (i.e. UK Faragher 52-70 vaccine, USA Del-E field strain, Ont 05-SA08-03-25355 field strain, and USA PA105-2014 field strain). One case of BC 586-03-42857 was identified.

Practitioners: Reported as stable to slightly increased cases this quarter.

Infectious bronchitis (IBV)

AHL: The number of pathology cases are increased but the number of viral isolations is stable for this quarter compared to the previous quarter. However, both Q3 and Q4 2022 have decreased numbers compared to Q1 and Q2 of 2022. More vaccines strains are identified on sequencing (i.e. IBV_Mass-MA5 vaccine, IBV_Mass-H120 vaccine, IBV_Conn vaccine, and IBV_DMV_ON_21-017385).

Practitioners: Equal number of responders reported stable to increased cases.

Spiking mortality

AHL: One case suspicious on histology for this quarter.

Practitioners: Reported as stable for this quarter.

Salmonella

Practitioners: Salmonella isolations were reported as stable to slightly decreased this quarter.

Histomoniasis (blackhead)

AHL: No cases diagnosed this quarter.

Practitioners: Reported as stable.

Runting and Stunting Syndrome (RSS)

AHL: Confirmed cases of RSS (diagnosed on histology) were decreased this quarter, particularly in birds >14 days of age.

Practitioners: RSS caused by astrovirus were reported as stable to slightly decreased.

Other diagnostic findings

AHL: Other diagnoses made at the AHL included cellulitis, conjunctivitis/blepharitis, bacterial vertebral osteomyelitis, osteomyelitis, meningoencephalitis, and bacterial ophthalmitis.

Practitioners: No specific findings this quarter.

Condemnation issues

Practitioners: Issues were reported as stable to increased by veterinarians this quarter. Cellulitis and colibacillosis were the most common causes of condemnations.

Slaughter provincial plants: Processing volume average 1.73M per month. The top 3 condemnation conditions were reported as dead on arrival (DOA), cellulitis and ascites.

Slaughter federal plants: Processing volume average 18.1 M per month. Sub-cutaneous lesions and DOA were reported as the main conditions for condemnation.


Broiler-Breeders

Fowl cholera

AHL: Occasionally isolated from lameness cases from vaccinated flocks.

Practitioners: Reported stable.

Early bacterial infection (<14 d old)

AHL: The number of cases were stable from the previous quarter. Cases had either E. coli in pure culture or in combination with E. cecorum. There was also 1 case of osteomyelitis in this age group.

Practitioners: Reported a shift from stable to increased cases.  The main bacteria isolated was E. coli.

Other causes of early mortality (<14 d old)

AHL: None diagnosed this quarter.

Practitioners: Reported as stable this quarter.

Lameness – bacterial

AHL: The case numbers were increased slightly from Q3 and had similar numbers to Q2 2022. Cases consisted of primarily pure culture of S. aureus. Other cases consisted of S. aureus combined with 1 other bacteria including E. coli, E. cecorum or P. multocida (vaccinated flocks). A case of osteomyelitis had isolation of S. aureus and E. coli.

Practitioners: Stable to slightly increased. Staphylococcus aureus and E.coli  have been the most common bacterial causes of lameness.

Lameness – viral, developmental and nutritional

AHL: No cases diagnosed this quarter.

Practitioners: All reported as stable.

In-lay bacterial septicemia

AHL: Cases decreased slightly from Q3 to match case numbers in Q2 2022. There were a few pure bacterial cultures of E. coli or S. aureus. It is more common to identify combined infections of 2-3 different bacteria. Combinations often included E. coli with E. cecorum or E. coli with S. aureus. E. coli and E. cecorum were also isolated in combination with one of S. aureus, C. perfringens, or G. anatis. One case had isolation of 4 bacteria: E. coli, S. aureus, C. perfringens, and G. anatis.

Practitioners: Septicemia was reported as stable.

IBV- decreased production/ abnormal eggs

AHL: One case with this history had IBV identified by PCR this quarter.

Practitioners: Stable this quarter.

IBV – sudden spike in mortality

AHL: The virology lab identified fewer strains this quarter (i.e. IBV_Mass-MA5 vaccine, IBV_USA_Conn_AHL21-008165 vaccine, IBV_DMV_ON_21-017385, and IBV_DMV_ON_15-077145).

Practitioners: Stable.

Disease related hatchability issues and mycoplasmosis

AHL: One case of Mycoplasma synoviae.

Practitioners: Reported as stable for this quarter. One case of Mycoplasma synoviae was mentioned by one respondent.

Necrotic enteritis

AHL: One case identified with an underlying coccidial infection.

Practitioners: The number of necrotic enteritis cases were reported as stable this quarter.

Coccidiosis

AHL: Increased cases from previous quarters. Identified coccidia from small intestines and ceca as well as specific identification of E. necatrix.

Practitioners: Stable number of cases reported.

Fowl pox and ILT

AHL: No cases diagnosed in this quarter.

Practitioners: Remained stable to slightly decreased for this quarter.

Salmonellosis (clinical)/Salmonella isolation

Practitioners: Stable to slightly decreased this quarter. Practitioners reported a variety of Salmonella isolates including S. Livingstone, S. Kiambu and S. Mbandaka.

Aggression and cannibalism

AHL: One case of vent trauma, ulceration and evisceration diagnosed.

Practitioners: Cases were reported as generally stable.

Multi-drug resistant E. coli (resistant to >3 drugs)

Practitioners: Reported as stable.

Histomoniasis (blackhead)

AHL: Case numbers were slightly increased this quarter with age of infection ranging from 4 to 34 weeks of age.

Practitioners: Stable to slightly increased cases. Although this condition is rarely reported in broiler breeders, three cases were identified this quarter by responders.

White Chick Syndrome

AHL: One case diagnosed this quarter.

Other

AHL: A case of swollen wattles had a mixed culture of S. aureus and E. coli isolated. Cases of cellulitis/dermatitis had isolation of E. coli or E. cecorum and S. aureus while one case was related to vaccine deposits. Cases of intestinal parasitism included Ascaridia and Capillaria. Other diagnoses included adenocarcinoma, emaciation, amyloidosis, and vaccine reaction (neck).

Practitioners: Choking and feed aspiration were other diagnoses reported by responders.


Layers

Overall, good and stable health status for this quarter.

Osteoporosis

Practitioners: Stable.

Bacterial peritonitis/salpingitis

Practitioners: Stable cases with E.coli, Enterococcus cecorum and Gallibacterium anatis   isolated.

Early systemic bacterial infection (<14 old)

AHL: One case of septicemia diagnosed on histopathology. Also 1 case of starveouts.

Practitioners: Reported stable by responders.

Other causes of early mortality (>14 d old)

AHL: One case of septicemia identified on histology.

Practitioners: Stable with no identification of other causes of early mortality.

Focal duodenal necrosis

AHL: No cases diagnosed this quarter.

Practitioners: Equal numbers of responders were reporting stable and increased cases for this quarter. Since fresh tissues are needed for diagnosis, need to specifically look for this condition or may be missing the diagnosis.

IBV- production drop/abnormal eggs and respiratory issues

AHL: Cases are low but stable in the last 3 quarters. Case numbers substantially decreased from 1 year ago (Q4 2021). However, there was greater variability in strains the were primarily not vaccine related this quarter (i.e. IBV_DMV_ON_15-077145, CU82792 AHL 09-002204, CU82792 AHL 07-21349, IBV_CA_1734_04_ON_12-025379, IBV_ONT_22-001651, IBV_Mass-MA5 vaccine, IBV_Mass-H120 vaccine, IBV_Conn vaccine).

Practitioners: Stable cases reported by respondents.

Salmonellosis (clinical) / Salmonella isolation

Practitioners: Reported as stable.

Overall, Salmonella isolations were greater in turkeys than chickens. For chickens there were 339 isolations for the past 12 months, and 44 isolations for this quarter. The most common isolates in chickens were S. Heidelberg, S. Typhimurium, and S. Enteritidis.

Ontario Hatchery and Supply Flock Policy (OHSFP) – Isolates of Salmonella in chicken with the following subtypes: S. Enteritidis, S. I:8, 20: -: z6, S. Livingstone variant 14+, S. Kiambu and S. Kentucky.

ILT

AHL: No cases identified this quarter.

Practitioners: Stable.

Mycoplasma species

Practitioners: Stable to slightly increased. The main isolate reported was M. gallisepticum.

Coccidiosis and necrotic enteritis

AHL: Two cases of coccidiosis and 1 case of necrotic enteritis (with coccidia) diagnosed.

Practitioners: Stable to slightly increased cases. Respondent emphasises paying attention to coccidiosis cycles and timing of vaccine administration.

Aggression, cannibalism and hysteria

Practitioners: All reported as stable.

Multi-drug resistant E. coli (resistant to >3 drugs)

Practitioners: Stable.

Histomoniasis (blackhead)

AHL: No cases diagnosed this quarter.

Practitioners: Stable.

Other

AHL: Diagnoses included osteomyelitis, tenosynovitis, arthritis (heterophilic and lymphoplasmacytic), ventriculitis, panniculitis, and botulism.

Practitioners: None reported.


Turkeys

Overall stable health with early and late systemic bacterial infections more commonly seen in the field.  Avian influenza is still a big threat in turkey flocks as H5N1 strain is more transmissible from turkey to turkey and it takes a lower inoculation dose to infect turkeys than chickens.

Fowl cholera

Practitioners: Stable.

Erysipelas

AHL: No cases identified this quarter.

Practitioners: Stable to slightly increased.

Early systemic bacterial infection (<14 day old)

AHL: One case diagnosed on histopathology.

Practitioners: Stable to slightly increased cases.

Other causes of early mortality (<14 d old)

AHL: One case of yolk sacculitis (histopathology).

Practitioners: Reported stable for this quarter. Stall out and necrotic hepatitis were the main causes of other mortalities. Necrotic hepatitis with reoviral origin that is mostly identified in USA and not in Canada.

Late systemic bacterial infection (>14 d old)

AHL: Three cases diagnosed. Two with E. coli and 1 on histopathology.

Practitioners: Stable to slightly increased cases reported. E.coli was the main bacteria identified by multiple practitioners to be responsible for late systemic bacterial infection.

ORT

Practitioners: Stable this quarter.

Mycotic respiratory disease

AHL: No cases diagnosed this quarter.

Practitioners: Stable to slightly increased. One practitioner reported one case of pneumonia due to Aspergillosis.

Other respiratory disease, Coccidiosis, Round heart, Reovirus tenosynovitis and Multi-drug resistant E. coli (resistant to >3 drugs)

AHL: Three cases of coccidiosis (small intestine). One case of reovirus diagnosed on histopathology.

Practitioners: Stable.

Necrotic enteritis and enteritis

AHL: Two cases of necrotic enteritis with underlying coccidiosis.

Practitioners: Generally, stable to slightly increased this quarter.

Mycoplasma (species)

Practitioners: Stable to decreased cases.

Salmonellosis (clinical)/Salmonella isolation

Practitioners: Stable. Subtypes identified included S. Hadar, S. Uganda, S. Agona, S. Cerro, S. Brandenburg, S. Typhimurium, S. Branderup, and S. Schwarzengrund.

Overall, Salmonella isolations were more in turkey than chickens. For turkeys there were 374 isolations for the past 12 months, 70 isolations for this quarter.

Ontario Hatchery and Supply Flock Policy (OHSFP) Salmonella isolated in turkey with the following subtypes: S. Schwarzengrund, S. Brandenburg, S_I: ROUGH-O:z10:e,n,x, S. Uganda and S. Hadar.

Aggression and cannibalism

Practitioners: Stable to slightly increased with poor beak trim at hatchery as the main cause of this issue.

Histomoniasis (blackhead)

AHL: One case diagnosed on histopathology.

Practitioners: Reported mainly stable but equal number of responders with slightly increased and decreased cases.

Other

AHL: Additional diagnoses included dissecting aneurysm, atherosclerosis, suspect ionophore toxicity, and heterophilic tenosynovitis.

Practitioners: None listed.

Provincial slaughter plants: Processing volume average of 13,000/month. The top 3 conditions of condemnation were abscesses, cellulitis and airsacculitis.

Federal slaughter plants: Processing volume average of 675,000 per month. The top conditions of condemnation were subcutaneous lesions.

Autogenous vaccines were used against: Reovirus, ORT, Erysipelas and H3N2 influenza.


Rural/Backyard/Non-Quota Flocks

Less respiratory disease over the summer. Sinusitis with increased swelling had Streptococcus suis isolated. Reproductive diseases included E.coli salpingitis, and age related tumors. Increased fecal testing revealed a variety of parasites. Starting to see neurologic signs from chicks hatched in the spring (likely Marek’s disease). Lameness cases can present unilaterally with splayed toes, no mobility and swollen hock but unable to diagnose the cause due to lack of testing.

 

Marek’s disease

Neurologic forms continue to be diagnosed and the number of cases increased this quarter.

The most encountered clinical cases reported by practitioners in urban poultry were diarrhea and endoparasites, bumblefoot, mites, lice, respiratory disease (CRD, sinusitis) reproductive disease (egg yolk peritonitis, neoplasia), lameness, wounds, and nutritional issues.

The infectious and parasitic agents identified by the practitioners in urban flocks were: Marek’s disease, Mycoplasma gallisepticum and M. synoviae, S. suis, E.coli, coccidia, roundworms, Capillaria, and Heterakis.

Practitioners reported respiratory issues, lice and mites as well as S. suis with hobby flocks.

Responders were finding coccidia infection in non-quota commercial flocks for personal/local consumption of eggs or meat.

AHL:

Chickens: Cases at AHL had a variety of diagnoses for parasites (coccidia, Ascaridia), and tumours (Marek’s, adenocarcinoma, leiomyoma, lipoma). Respiratory infections included mycotic pneumonia and bacterial pneumonia (E. coli and S. aureus). Other diagnoses included necrotic enteritis, salpingitis, and cellulitis/panniculitis. There was one case of ILT typed as a Niagara-like field strain (CAGG cluster).

Duck: Diagnoses included a suspicious case of Leukocytozoonosis, P. multocida septicemia, and airsacculitis/pneumonia.

Goose: One case of airsacculitis/pneumonia.

Turkey: One case of omphalitis and yolk sacculitis.



Events and News

Poultry Industry Council events: https://www.poultryindustrycouncil.ca/events

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

Thank You!

We thank the following poultry veterinarians who completed the veterinary survey:

Dr. Elizabeth Black, Dr. Joanne Rafuse, Dr. Shahbaz Haq, Dr. Elana Huong, Dr. Anastasia Novy, Dr. Mike Petrik, Dr. Erin Preiss, Dr. Joanne Rafuse, Dr. Fernando Salgado-Bierman, Dr. Kathleen Sary, Dr. Ben Schlegel, Dr. Brenna Tuer, Dr. Lloyd Weber, Dr. Alex Weisz, and Dr. Jessalyn Walkey.

Report 32

SEP-OCT-NOV

2022

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