fowlpox
{{short description|Viral disease of poultry}}
{{Distinguish|Chickenpox}}
{{Virusbox
| name = Fowlpox virus
| image = File:Fowlpox.jpg
| image_caption = Example of clinical signs produced by Fowlpox virus
| parent = Avipoxvirus
| species = Avipoxvirus fowlpox
}}
Fowlpox is the worldwide disease of poultry caused by viruses of the family Poxviridae and the genus Avipoxvirus. The viruses causing fowlpox are distinct from one another but antigenically similar, possible hosts including chickens, turkeys, quail, canaries, pigeons, and many other species of birds. There are two forms of the disease. The first (dry form) is spread by biting insects (especially mosquitoes) and wound contamination, and causes lesions on the comb, wattles, and beak. Birds affected by this form usually recover within a few weeks. The second (wet form) is contracted by inhalation or ingestion of the virus via dust (i.e. dander, representing virus-infected cells shed from cutaneous lesions) or aerosols, leading to the 'diphtheritic form' of the disease, in which diphtheritic membranes form in the mouth, pharynx, larynx, and sometimes the trachea. The prognosis for this form is poor.{{cite book |doi=10.1016/B978-012374410-4.00403-9 |chapter=Fowlpox Virus and Other Avipoxviruses |title=Encyclopedia of Virology |year=2008 |last1=Skinner |first1=M.A. |pages=274–284 |isbn=978-0-12-374410-4 }}
Fowlpox in chickens
Fowlpox is a common disease in backyard chickens that have not been vaccinated. Most birds survive the infections, although very young or weak birds may be lost. The lesions initially looks like a whitish blister and appear on the comb, wattles and other skin areas. In rare cases lesions can be found on the body, legs and even sometimes the softer parts of the beak. The blisters develop into a dark scab and take about three weeks to heal and drop off. Fowlpox lesions, when in the infected birds mouth and throat can cause difficulty breathing, even death.{{cite book |last1=Butcher |first1=Gary D |last2=Rossi |first2=Fred |title=Prevention and Control of Fowl Pox in Backyard Chicken Flocks |date=1996 |publisher=University of Florida Cooperative Extension Service, Institute of Food and Agriculture Sciences, EDIS |oclc=48524703 |url=https://edis.ifas.ufl.edu/vm021 }} Scarring may result and consequently exhibition poultry breeders prefer to vaccinate and avoid this disease. Management of the mosquito population can help reduce outbreaks of fowlpox.{{cn|date=November 2022}}
Fowlpox has demonstrated the capacity to contain integrated sequence from Reticuloendotheliosis virus (REV).{{cite journal |last1=Zhao |first1=Kui |last2=He |first2=Wenqi |last3=Xie |first3=Shengnan |last4=Song |first4=Deguang |last5=Lu |first5=Huijun |last6=Pan |first6=Wei |last7=Zhou |first7=Ping |last8=Liu |first8=Wenfeng |last9=Lu |first9=Rongguang |last10=Zhou |first10=Jiyong |last11=Gao |first11=Feng |title=Highly Pathogenic Fowlpox Virus in Cutaneously Infected Chickens, China |journal=Emerging Infectious Diseases |date=July 2014 |volume=20 |issue=7 |pages=1208–1210 |doi=10.3201/eid2007.131118 |pmid=24963887 |pmc=4073872 }} Integrated sequence of REV may contain the complete REV provirus sequence or fragments of genome sequence.{{cite journal |last1=Koo |first1=B. S. |last2=Lee |first2=H. R. |last3=Jeon |first3=E. O. |last4=Jang |first4=H. S. |last5=Han |first5=M. S. |last6=Min |first6=K. C. |last7=Lee |first7=S. B. |last8=Kim |first8=J. J. |last9=Mo |first9=I. P. |title=An Outbreak of Lymphomas in a Layer Chicken Flock Previously Infected with Fowlpox Virus Containing Integrated Reticuloendotheliosis Virus |journal=Avian Diseases |date=December 2013 |volume=57 |issue=4 |pages=812–817 |doi=10.1637/10551-041113-Case.R1 |pmid=24597128 |s2cid=22026537 }}{{cite journal |last1=Singh |first1=Pratik |last2=Schnitzlein |first2=William M. |last3=Tripathy |first3=Deoki N. |title=Reticuloendotheliosis Virus Sequences within the Genomes of Field Strains of Fowlpox Virus Display Variability |journal=Journal of Virology |date=15 May 2003 |volume=77 |issue=10 |pages=5855–5862 |doi=10.1128/JVI.77.10.5855-5862.2003 |pmid=12719579 |pmc=154015 }}{{cite journal |last1=Davidson |first1=Irit |last2=Shkoda |first2=Irena |last3=Perk |first3=Shimon |title=Integration of the reticuloendotheliosis virus envelope gene into the poultry fowlpox virus genome is not universal |journal=Journal of General Virology |date=1 October 2008 |volume=89 |issue=10 |pages=2456–2460 |doi=10.1099/vir.0.2008/001313-0 |pmid=18796713 |doi-access=free }} Not all fowlpox isolates contain REV integrates.{{cite journal |last1=Biswas |first1=Sanchay K. |last2=Jana |first2=Chandrakanta |last3=Chand |first3=Karam |last4=Rehman |first4=Waseem |last5=Mondal |first5=Bimalendu |title=Detection of fowl poxvirus integrated with reticuloendotheliosis virus sequences from an outbreak in backyard chickens in India |journal=Veterinaria Italiana |date=April 2011 |volume=47 |issue=2 |pages=147–53 |pmid=21706467 |url=https://www.izs.it/vet_italiana/2011/47_2/147.pdf }} Studies analyzing samples from 50 years ago have detected evidence of REV integrated sequences suggesting the integration of REV may not be a new emergence.{{cite journal |last1=Webb |first1=P. I. |last2=Hays |first2=G. C. |last3=Speakman |first3=J. R. |last4=Racey |first4=P. A. |title=The functional significance of ventilation frequency, and its relationship to oxygen demand in the resting brown long-eared bat, Plecotus auritus |journal=Journal of Comparative Physiology B |date=March 1992 |volume=162 |issue=2 |pages=144–147 |doi=10.1007/BF00398339 |pmid=1592909 |s2cid=19898021 }} Fowlpox with integrated REV sequences have been identified in some live fowlpox vaccine lots, in backyard chickens and in wild birds. Fowlpox infections with integrated REV sequence are linked with the development of lymphoma.{{cite journal |last1=Fadly |first1=A. M. |last2=Witter |first2=R. L. |last3=Smith |first3=E. J. |last4=Silva |first4=R. F. |last5=Reed |first5=W. M. |last6=Hoerr |first6=F. J. |last7=Putnam |first7=M. R. |title=An outbreak of lymphomas in commercial broiler breeder chickens vaccinated with a fowlpox vaccine contaminated with reticuloendotheliosis virus |journal=Avian Pathology |date=March 1996 |volume=25 |issue=1 |pages=35–47 |doi=10.1080/03079459608419118 |pmid=18645835 }}
Clinical signs
There are 2 types of fowlpox: wet pox and dry pox. In all outbreaks, wart-like lumps are visible on many birds, which is a reliable guide to diagnosis.{{cite web |publisher=Agriculture and Fisheries, Queensland Govt |title=Fowl pox |url=https://www.business.qld.gov.au/industries/farms-fishing-forestry/agriculture/livestock/animal-welfare/pests-diseases-disorders/fowl-pox |website=Business Queensland |access-date=11 June 2022 |language=en-AU |date=14 March 2017}} 50px Text was copied from this source, which is available under a [https://creativecommons.org/licenses/by/4.0/ Creative Commons Attribution 4.0 International License].{{cite web | url=https://www.cdc.gov/poxvirus/diseases.html | title=Poxvirus Diseases | Pox Viruses | CDC | date=3 January 2019 }}
Dry pox is the most common and develops as wart-like eruptions. Fleshy pale lumps form yellow pimples that may enlarge and run together to form masses of yellow crusts. These scabs darken and fall off in about a week. They occur mainly on the comb, wattle and face but can occur on other parts of the body.
Wet pox (diphtheritic) forms as ulcerous cheesy masses in the mouth, nose and sometimes throat areas, which can interfere with eating and breathing. Birds with wet pox can appear unwell and in some cases may die.
Mortality is usually low in affected flocks. Reduced egg production and poor weight gains are the greatest impacts.
Treatment
Vaccines are available for fowlpox (ATCvet code: {{ATCvet|I01|AD12}}). Chicken are usually vaccinated with pigeonpox virus. This vaccine is usually given to chickens when between the age of 8–14 weeks of age, via the wing web method of injection. When a bird is given the vaccine they are exposed to a mild version of the active virus, so they should be completely healthy to prevent severe illness. Turkeys are also routinely vaccinated.{{cite web|author1=Carter, G.R. |author2=Wise, D.J. |year=2006|title=Poxviridae|work=A Concise Review of Veterinary Virology| url=http://www.ivis.org/advances/Carter/Part2Chap10/chapter.asp?LA=1|access-date=2006-06-13}} Once a bird is infected there are no treatments, just preventive measures including the vaccine and mosquito management.[https://poultrypioneers.net/fowl-pox-vaccine-2023/ Fowl Pox Vaccine 2023: A Breakthrough in Poultry Health] poultrypioneers.net
See also
References
{{Reflist}}
External links
{{Wikispecies}}
- [https://www.cabi.org/isc/datasheet/82898 Fowlpox - CABI datasheet]
- [https://www.msdvetmanual.com/poultry/fowlpox Fowlpox in Chickens and Turkeys - Poultry - MSD Veterinary Manual, Merck & Co., Inc., Rahway, NJ, USA]
- [http://forum.backyardpoultry.com/viewtopic.php?f=5&t=7971445 Fowlpox at Backyard Poultry], Information and pictures.
- [https://www.invasivespeciesinfo.gov/profile/fowlpox Species Profile - Fowlpox (Avipoxvirus)], National Invasive Species Information Center, United States National Agricultural Library. Lists general information and resources for Fowlpox.
{{Taxonbar|from=Q571218}}
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