Rabbit Hemorrhagic Disease and Vaccination

Bunny Love by David-O

Photo credit: David-O via Flickr Creative Commons

 

 

Abstract

Rabbit hemorrhagic disease (RHD) is a usually fatal disease affecting almost exclusively lagomorphs caused by the rabbit hemorrhagic disease viruses (RHDV). While initial outbreaks of RHDV-1 occurred in Europe and Asia, RHDV-2 has emerged and spread across the globe within the span of the last 10 years. RHDV-2 has resulted in major outbreaks of RHD in wild and domestic rabbits in Washington State and the North American Southwest (USA and Mexico) since 2020.

RHDV-2 causes a severe necrotizing hepatitis in lagomorphs that results in secondary disseminated intravascular coagulation and death. Death is often peracute and other signs may not be recognized prior to death. RHDV-2 is a calicivirus that is environmentally stable and transmitted primarily by fomites via the oral-fecal route. Due to the ease in inadvertent exposure via fomites and the seriousness of the disease, vaccination is recommended as the primary means to prevent infection. Initial importation of unapproved European killed vaccines was allowed for affected states only and were difficult and expensive to acquire.

Medgene Labs has recently received United States Department of Agriculture Center for Veterinary Biologics (USDA-CVB) emergency use approval for their inactivated recombinant subunit protein vaccine, increasing availability and ease of acquiring vaccines across the country. Due to vaccine developments, vaccination against RHDV-2 for domestic rabbits is now widely available and strongly encouraged.

 

Outline

  • History of RHDV
    1. RHDV general information
    2. Initial emergence of RHDV-1 and RHDV-2
    3. North American outbreak and progression
    4. RHDV-1, RHDV-2 pathological differences
  • Pathology
    1. Transmission
    2. Clinical disease
    3. Pathophysiology
    4. Diagnostics
    5. Case study
  • Vaccines
    1. European vaccines
      1. Overview
      2. Adverse Events
    2. Medgene vaccine
      1. Overview
      2. Safety
      3. Adverse events
      4. Label requirements
Bunny Cuddle

Photo: Alex via Flickr Creative Commons

Cottontail rabbit

 

About the presenter

Dr. Amanda Jones is a consultant for Medgene Labs, and a supervising veterinarian for the Medgene Labs Texas Field Safety Site. Dr. Jones is also the owner of Central Texas Rabbit Herd Management in Killeen, Texas and an associate veterinarian for Animal Emergency Services of Killeen. Dr. Jones is a 2014 Cum Laude graduate of the Texas A&M College of Veterinary Medicine and… [MORE]

 

Webinar recording

 

 

Post-test

Complete the brief quiz. With a passing grade of 70% or higher, you can download your continuing education (CE) certificate for 1 hour of CE credit in jurisdictions that recognize American Association of Veterinary State Boards (AAVSB) Registry of Approved Continuing Education (RACE) approval.

Test your knowledge

 

 

Expert Q&A

Dr. Jones generously answered virtually every question entered during the live event. A few remaining questions were answered by email and are now posted below:

I have heard of some practices opening the vaccine, drawing it up into individually dosed syringes, and they will then use these syringes up to at least several days after they have been drawn into the syringes. Generally, with other vaccines, they are supposed to be discarded if they have been in the syringe over 24 hours, so I was curious if this is a safe way to try to use the vaccine over a longer period of time or if this is not recommended. If this is a possible solution to make the vaccine last longer, how long can they be kept in the syringes? 

I would not recommend storing the vaccine in individual syringes over keeping it in the glass vial it comes in. We know that the vaccine is stable in the glass vial and that glass is unreactive. Plastic can occasionally bind proteins and no research has been done on the vaccine stability stored in a syringe. Without research to verify there is no impact on the vaccine, I would not recommend it as a general practice.

 

How do you handle a case where you have suspicion for this disease but unconfirmed and owner declines any treatment other than supportive and takes pet home to die later and was buried by owner. 

Unfortunately, there isn’t much that can be done. If you are very suspicious, you could call the state vet for guidance and if they have additional resources to ensure proper testing.

 

At the USAHA meeting, Medgene gave a presentation that discussed some mortality cases (multiple but details were not provided on exact numbers) shortly after vaccination that was attributed to transport stress. Was curious how that information ties into the information provided today? 

As I did not attend that presentation, I am not sure of exactly what was said. Medgene strived to have necropsies performed for any rabbit that died in temporal association with the vaccine. All necropsies I reviewed showed either an underlying condition that was responsible for death or were inconclusive due to advanced decomposition.  There have been some cases where rabbits had episodes of GI stasis in close timing with vaccination that may have been associated with the stress of traveling, but those rabbits recovered with supportive care.

 

 

RACE approval

This program is approved by the American Association of Veterinary State Boards (AAVSB) Registry of Continuing Education (RACE) to offer a total of 1.00 CE credits to any one veterinarian and/or 1.00 veterinary technician.

 

References

References

Abade dos Santos F, Pinto A, Burgoyne T, et al. Spillover events of rabbit haemorrhagic disease virus 2 (recombinant GI.4P‐GI.2) from Lagomorpha to Eurasian badger. Transbound Emerg Dis. 2022;69(3):1030-1045. doi: 10.1111/tbed.14059. Epub 2021 Mar 30. PMID: 33683820.

Asin J, Rejmanek D, Clifford D, et al. Early circulation of rabbit haemorrhagic disease virus type 2 in domestic and wild lagomorphs in southern California, USA (2020–2021). Transbound Emerg Dis. 2022;69(4):e394-e405. doi: 10.1111/tbed.14315. Epub 2021 Sep 16. PMID: 34487612.

Baratelli M, Molist-Badiola J, Puigredon-Fontanet A, et al. 2020. Characterization of the maternally derived antibody immunity against rhdv-2 after administration in breeding does of an inactivated vaccine. Vaccines. 2020;8(3):484. doi: 10.3390/vaccines8030484. PMID: 32872139; PMCID: PMC7564433.

Bonvehí C, Ardiaca M, Montesinos A, et al. Clinicopathologic findings of naturally occurring rabbit hemorrhagic disease virus 2 infection in pet rabbits. Vet Clin Pathol. 2019;48(1):89-95. doi: 10.1111/vcp.12701. Epub 2019 Mar 12. PMID: 30861586.

Desselberger U. Caliciviridae other than noroviruses.Viruses. 2019 Mar 21;11(3):286. doi: 10.3390/v11030286. PMID: 30901945; PMCID: PMC6466229.

Duarte M, Carvalho C, Barros S, et al. A real time taqman RT-PCR for the detection of rabbit hemorrhagic disease virus 2 (RHDV2). J Virol Methods. 2015;219:90-95. doi: 10.1016/j.jviromet.2015.03.017. Epub 2015 Mar 28. PMID: 25823548.

Eden J, Read A, Duckworth J, Strive T, Holmes E. Resolving the origin of rabbit hemorrhagic disease virus: insights from an investigation of the viral stocks released in Australia. J Virol. 2015;89(23):12217-20. doi: 10.1128/JVI.01937-15.

Hall R, King T, O’Connor T, et al. Age and infectious dose significantly affect disease progression after RHDV2 infection in naïve domestic rabbits. Viruses. 2021 Jun 21;13(6):1184. doi: 10.3390/v13061184. PMID: 34205750; PMCID: PMC8234499.

Henning J, Meers J, Davies P, Morris R. Survival of rabbit haemorrhagic disease virus (RHDV) in the environment. Epidemiol Infect. 2005;133(4):719-30. doi: 10.1017/s0950268805003766. PMID: 16050519; PMCID: PMC2870301.

Mahar J, Hall R, Peacock D, et al. Rabbit hemorrhagic disease virus 2 (RHDV2; GI.2) is replacing endemic strains of RHDV in the Australian landscape within 18 months of its arrival. J Virol. 2018;92(2):e01374-17. doi: 10.1128/JVI.01374-17. PMID: 29093089; PMCID: PMC5752944.

Mahar J, Nicholson L, Eden J, et al. Benign rabbit caliciviruses exhibit evolutionary dynamics similar to those of their virulent relatives. J Virol. 2016;90(20):9317-29. doi: 10.1128/JVI.01212-16. PMID: 27512059; PMCID: PMC5044836.

Müller C, Hrynkiewicz R, Bębnowska D, et al. Immunity against lagovirus europaeus and the impact of the immunological studies on vaccination. Vaccines (Basel). 2021;9(3):255. doi: 10.3390/vaccines9030255. PMID: 33805607; PMCID: PMC8002203.

Trzeciak-Ryczek A, Tokarz-Deptuła B, Deptuła W. The importance of liver lesions and changes to biochemical and coagulation factors in the pathogenesis of RHD. Acta Biochim Pol. 2015;62(2):169-71. doi: 10.18388/abp.2014_943. Epub 2015 Apr 23. PMID: 25918886.

United States Department of Agriculture APHIS. 2020-2022 Rabbit Hemorrhagic Disease. USDA APHIS website. Available at:  https://www.aphis.usda.gov/aphis/maps/animal-health/rhd. Accessed March 23, 2022.

To cite this page:

Jones A. Rabbit hemorrhagic disease and vaccination. Dec 5, 2022. LafeberVet web site. Available at https://lafeber.com/vet/rabbit-hemorrhagic-disease-and-vaccination/