Serious viral diseases: significant threats
Myxomatosis and rabbit hemorrhagic disease (RHD) are two viral diseases of major clinical significance in rabbits. These serious and widespread diseases put all rabbits at risk of high morbidity and mortality. More recently with the emergence of a new variant form of RHD, the threat to your patients needs a more comprehensive answer.
Myxomatosis
Myxomatosis is a serious and widespread viral disease of both wild and domestic rabbits that is typically fatal once contracted1. It is one of the top 8 causes of death in UK pet rabbits2.
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About Myxomatosis
- Mortality of up to 100%3
- Caused by the myxoma virus (a poxvirus)3
- Mainly transmitted by biting insects (e.g mosquitoes and fleas) but can also be spread between rabbits via infected ocular and nasal secretions1
- Typically causes severe, tumour-like swellings (myxomas) around the eyes, nose and mouth, ears and abdominal region1
- The virus also causes immunosuppression and secondary bacterial infections that cause severe respiratory disease4
In its classic form it is a highly distressing disease which cannot be successfully treated, however vaccination is very effective at reducing the risk of disease1.
Rabbit Hemorrhagic Disease
A highly infectious and widespread disease caused by a calicivirus and often resulting in swift and sudden death5.
Until recently, this disease was caused by ‘classic’ strains of RHD virus (RHDV-1) and effective vaccines were available. In 2010, a new pathogenic variant RHD virus was reported to be causing severe disease in Europe, against which the classic strain vaccines were much less effective. This variant strain (RHDV-2) has since spread throughout Europe and is causing disease in both wild and pet rabbits5-7.
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About RHDV-1
- Present in Europe since 19865,8
- Caused by classic (RHDV-1) strains of the virus
- 1- to 3-day incubation period8
- Can cause very high mortality (70–100%)5
- The virus causes an acute necrotising hepatitis and a widespread coagulopathy resulting in haemorrhages in many organs8
- In many cases the disease can be peracute with sudden death as the only sign8
- Very young rabbits (<6–8 weeks of age) are naturally resistant to the disease
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About RHDV-2
- Present in Europe since 20107
- Caused by a variant (antigenically distinct) virus strain now referred to as RHDV5,7
- May present a longer course of disease than RHDV-1 in many cases, with more subacute and chronic cases9
- Unlike RHDV-1, very young rabbits (<6 weeks of age) are also susceptible to disease5-7
For comprehensive protection a vaccine needs to demonstrate efficacy against both forms of RHD.
Date of preparation: May 2022
Nobivac® Myxo-RHD PLUS contains live myxoma vectored RHD virus strain 009 and MK 1898. POM-V
MSD Animal Health UK Limited. Registered office Walton Manor, Walton, Milton Keynes MK7 7AJ, UK. Registered in England & Wales no. 946942.
Further information is available from the SPC, Datasheet or package leaflet. Advice should be sought from the medicine prescriber.
Use medicines responsibly
References
1. Farrell, S. et al. (2020). Seasonality and risk factors for myxomatosis in pet rabbits in Great Britain. Prev Vet Med 176 104924.
2. Rouco C. et. al. (2019). Worldwide rapid spread of the novel rabbit haemorrhagic disease virus (GI.2/RHDV2/b). Transbound Emerg Dis. 2019;66:1762–1764.
3. Silverio D. et al. (2018). Insights into the evolution of the new variant rabbithaemorrhagic disease virus (GI.2) and the identification of novel recombinant strains.Transbound Emerg Dis.2018;65:983–992.
4. Spibey, N. et al. (2012). Novel bivalent vectored vaccine for control of myxomatosis and rabbit haemorrhagic disease. Vet Record. 170: 309.
5. Capucci, L. et al. (2017), Increased pathogenicity in rabbit haemorrhagic disease virus type 2 (RHDV2). Veterinary Record, 180: 426-426.
6. Rouco, C. et al. (2019). Worldwide rapid spread of the novel rabbit haemorrhagic disease virus (GI.2/RHDV2/b). Transbound Emerg Dis. 66:1762–1764.
7. Silverio, D. et al. (2018). Insights into the evolution of the new variant rabbit. haemorrhagic disease virus (GI.2) and the identification of novel recombinant strains. Transbound Emerg Dis. 65:983–992.
8. Abrantes, J. et al. (2012). Rabbit haemorrhagic disease (RHD) and rabbit haemorrhagic disease virus (RHDV): a review. Veterinary Research, 43(1), 12.
9. Spickler, Anna Rovid. Rabbit Haemorrhagic Disease & Other Lagoviruses. June 2020. At cfsph.iastate.edu/diseaseinfo/factsheets/
