Vet News – Exotics News

Vet NewsOur newest addition to the team is Charlotte Hitch, who has come on board the good ship Vet School Success to bring you some fascinating articles with a more exotic flavour. It’s great to have Charlotte on the team and she takes up the role of Vet News Exotics Editor. Welcome Charlotte 🙂

EXOTICS:

Lymphocytic Choriomeningitis Virus (LCMV) in Marmosets

Charlotte Hitch (Vet News Exotics Editor)

Lymphocytic choriomeningitis is an infectious zoonotic viral disease which affects a family of New World monkeys called Callitrichids, including the species Callithrix jacchus, or the common marmoset, an increasingly popular exotic pet especially in the United Kingdom and USA. In 1991, in a zoo in Texas, 5 of 7 pygmy marmosets died after exposure to infected neonatal mice. Hence, the LCM virus, once present in a population of Callitrichids, poses a significant risk to simian health.

The secondary effects of contracting LCM, an arenavirus-induced condition, include aseptic meningitis and Callitrichid hepatitis (CH), a commonly fatal disease which presents itself in the form of clinical signs such as dyspnoea (shortness of breath), anorexia (loss of appetite), lethargy (extreme tiredness), and jaundice (yellowish pigmentation of the skin and the ocular sclera). In basic terms, the pathology of CH consists of an inflamed liver which may be likely to develop cirrhosis or fibrosis, and metabolic disorders often follow.

Group of MarmosetsThe LCM virus can be carried by the common house mouse, Mus musculus, and can be caught through exposure to the faeces, saliva, milk, nasal secretions, semen or urine of an infected specimen. M. musculus are a reservoir species; they are able to carry and spread the virus to other species without being harmed or killed by it. Captive marmosets are particularly at risk due to unnatural contact with infected house mice, and also because of the difficulty in controlling such carriers.

Transmission can also be vertical, i.e. to unborn foetuses in utero through the placenta – possibly producing infected offspring.

While its effectiveness has not yet be confirmed, the drug ribavirin may be used on a trial basis to treat the initial LCMV infection; however once CH develops, the chances of survival are greatly reduced. Additionally, ribavirin is teratogenic (may lead to the formation of teratomas). The virus may be inactivated by hypochlorite solution, heat, UV light or gamma irradiation if disinfecting a contaminated area. Corticosterone, an anti-inflammatory drug, may be used to treat the encephalitic effects of the infection – reducing the cerebral and spinal cord inflammation.  It is also highly recommended to avoid feeding captive marmosets mouse pups, as other proteinous food items such as mealworms should suffice; however this preventative method will be ineffective once infection has already occurred.

Currently, Callitrichid Hepatitis is incurable but treatable with increased rest and diet regulation, through reduction of dietary fats. Future developments in regenerative medicine may allow treatment of CH through intravenous transplantation of cord blood stem cells into the liver, replacing damaged hepatocytes and restoring normal hepatic and immune function. While these ideas are still in the development and pre-testing stages, precautions must be taken to control reservoir species such as mice to prevent rodent-borne transmission to captive marmosets.

 

References:

http://wildpro.twycrosszoo.org/S/00dis/viral/LCM/LCM.htm

Pathology and Immunohistochemistry of Callitrichid Hepatitis, an Emerging Disease of Captive New World Primates Caused by Lymphocytic Choriomeningitis Virus, American Journal of Pathology, Vol. 148, No. 5, November 1995

http://www.eaza.net/activities/tdfactsheets/010%20Callitrichid%20%20Hepatitis.doc.pdf

http://www.cdc.gov/ncidod/dvrd/spb/mnpages/dispages/Fact_Sheets/Lymphocytic_Choriomeningitis_Fact_Sheet.pdf

http://www.merckmanuals.com/vet/management_and_nutrition/nutrition_exotic_and_zoo_animals/nutrition_in_primates.html?qt=callitrichid%20hepatitis&alt=sh

http://hepatitis.stemcellcentre.org/en/

 

Picture credits:

http://www.rspca.org.uk/ImageLocator/LocateAsset?asset=image&assetId=1232729045758&imageSize=xLarge&mode=prd

Vet News – Farm News

Vet NewsEmma’s article this month is on the concerns that the Schmallenberg virus may be present in wild animal populations, acting as a reservoir for the important infection.

FARMING:

Scientists believe that SBV may affect wild animals

Emma Plowright (Vet News Farm Animal Editor)

Scientists in Europe are concerned that wild animals may be acting as a ‘reservoir’ for the midge-bourne Schmallenberg virus (SBV) which has been detected on nearly 1,000 farms in England and Wales.

A team from the Universite de Liege in Belgium who have been monitoring the disease in wildlife have noted that it can also affect roe deer and red deer. One member of the team has called for “specific surveillance of wild animals for SBV”

If pregnant ewes are infected, the virus causes deformities and neurological abnormalities in. An expert at the University of Nottingham has stated that although we can confirm that deer get the disease, it is not currently known how they will be affected.  The placental structure of a deer differs from that of cows and sheep meaning that, at present, it is not known if the virus can cross the placenta.

SBV has a huge economic impact and figures from the University of Nottingham show that some farms are suffering up to 30% losses; this can have a devastating effect on farmers’ livelihoods. Professor Trevor Drew of the UK government’s Animal Health and Veterinary Laboratories Agency spoke recently of the difficulties in trying to control the disease: it is midge Bourne and “It is just impossible to control midges across an area the size of Europe”

Alick Simmons, the UK’s chief veterinary officer, has stated that he believes the disease “will either through vaccination or through natural spread become less of a problem over time”, adding that several vaccines are currently being developed. He also pointed out that some areas which were affected by the virus last year were not affected so severely this year.

 

References:

http://mrcvs.co.uk/en/news-story.php?id=9178

http://www.farmersguardian.com/home/hot-topics/schmallenberg-virus/schmallenberg-has-infected-majority-of-english-and-welsh-farms/52237.article

http://www.farmersguardian.com/home/hot-topics/schmallenberg-virus/farmers-warned-of-schmallenberg-effects/52227.article