Viral Disease in Hamster & Gerbils
A .viral disease in hamster:-
1. Lymphocytic Choriomeningitis:-
a) Etiology:-
Lymphocytic choriomeningitis is caused by an Arena virus (Arenaviridae). LCMV is an enveloped RNA virus (The name comes from "arena," referring to "sand," because virions look like sand from the electron microscope . Related agents include Lassa, Machupo, and Junin hemorrhagic fever viruses.)
b) Epizootiology:
1. LCMV is important point of view in public health hazard.
2. LCM in persons usually is not a severe disease, but it can be serious.
3 .All infected hamsters shed virus through the urine, and it is easily transmitted. Transmission can also take place through placenta in rodents..
3. Pathogenesis & pathology:
1. The manifestations of LCM infection are dependent on genetically determined factor of both host and virus.
2.PD4 and NHA inbred hamsters were highly susceptible to the infection.(Genovesi and Peters,1987)
3. But CB and LSH hamsters were resistant to the infection. Other strains were intermediate in susceptibility to the virus. 4. The WE strain of virus was the most virulent strain in the hamsters, whereas the Armstrong strain was not virulent for hamsters of any strain of the virus,
5. Although the two virus strains were same immunogenic to the hamsters.
6. In experimental infections, most new hamsters and about half of young adults develop persistent viremia leading to immune complex glomerulopathy and vasculitis (panarteritis), with lymphocytic inflammatory lesions in the liver, kidney, lung, pancreas, spleen, meninges, and brain.
7. The other half of young adults and nearly all adults eventually clear the infection. (LCM is a classic example of immune-mediated viral disease; immunosuppression decreases severity of lesions.)
4. Diagnosis & control:
Detectable by commercially available serologic test In the well establish lab.
Treatment: – only symptomatic treatment can be given. Disease can be prevented by maintaining hygiene in the farm,
2. Transmissible Lymphoma
1. Cause:
recent evidence indicates that the actual cause may be a papovavirus.
2. Epizootiology:
More than half of the hamsters 1 to 21 days old exposed in Coggin's facilities developed lymphoma. (Between 1975 and 1979, there were 3,749 individual cases.) . Several epizootics among their hamsters, and epizootics also have occurred elsewhere.(Coggins and et.al) The disease can be transmitted by direct contact or aerosally or by ingesting litter contaminated with urine and faeces. Hamsters to die of diarrhoeal disease after exposure to hamsters carrying the lymphoma agent
3. Clinical sign:
1. Emaciation
2. Weakness
3. Lethargy
4. Diarrhoea
5. Rectal and abdominal bleeding
6. Subcutaneous masses.
4. Pathology:
Lymphomas mainly affect the large and small intestine and mesenteric lymph nodes. Eye, stomch, perineal lymph node, cervical lymph node, thymus, kidney, liver can affect in ascending order of frequency. Most lymphomas are originated from B-cells, some are T-cell, and lymphomas are composed of immature lymphoid cells, with rare to frequent mitotic figures. Some tumors are more pleomorphic, and some were classified as plasmacytomas.The cause of the diarrhoea is not apparent from published descriptions; intestinal lesions are characterized as "nonbacterial." In young animals there is watery intestinal content with intussusceptions in a few hamsters; in adults hemorrhagic enteritis is common and many affected hamsters have intussusceptions. Papillomas are histological typical.
5. Diagnosis & control:
1. Demonstration of the causative agent is difficult; lymphoma cells are not permissive for papovavirus replication and no virions are produced.
2. Viral DNA present in the cell in small amounts..
3. Thus it is difficult or impossible to detect.
4. Pappillomas do not contain demonstrable virus.
5. The agent is very resistant and easily transmissible, making control difficult.
Hamster leukaemia virus: caused due to a retrovirus.
2. Cytomegalovirus: caused due to a herpes virus, infects salivary glands, no disease known.
3. Hamster polyoma virus (HaPV)- cause epizootic lymphoma in young Syrian hamsters and epitheliomas in older enzootically infected hamsters. When first introduced into a naive population of breeding Syrian hamsters, HaPV results in an epizootic of lymphoma. Lymphomas occur in the mesentery some time occur in the axillary and cervical lymph nodes. Once enzootic in a hamster population, the occurrence of lymphoma declines to a much lower level. Enzootically infected Syrian hamsters develop HaPV skin tumors rather than lymphoma. HaPV lymphoma–affected Syrian hamsters become thin and with palpable masses are present in the abdomen part. Often, they have demodectic mange due to either Demodex criceti or D aurati.
5. Parainfluenza Infection in Hamsters
Parainflueza infection in hamster caused by highly contagious Sendai virus (SeV).Infected hamster exhibit pneumonia like symptoms and death occurs in many such cases. Many hamster having infection without any illness and symptoms are called as carriers
Treatment of this infection is very costly and impractical. Bacterial infection can occur as secondary infection in SeV infection. Thus antibiotic and fluid therapy helps the hamster to recover.
Symptoms
• Fever
• Reduction in body weight
• Depression
• anorexia
• Dyspnoea
• Discharge from nose
• Sudden death (in some instances)
Causes
1. The infection of parainfluenza is caused due by the Sendai (parainfluenza type 1) virus.
2. It can be transmitted from one hamster to another hamster through sneezing and coughing.
3. Some hamster are the carriers of the disease does not exhibit any symptom
4. Young hamster can be affect with infection due to weak immune system.
Diagnosis
1. Disease is diagnosed based upon the symptoms.
2. Also various laboratory tests are use for the diagnosis including blood analysis.
Treatment
Treatment of hamster infected with SeV is very costly and impractical. There is no specific treatment only symptomatic treatment can be given. Antibiotics are used to avoid secondary bacterial infection.
Living and Management:-
1. Cleaning and disinfection of the cage in which disease hamster was kept.
2. Keep diseased hamster separate from other healthy hamster to prevent the spread of disease by direct contact.
3. Take precaution while handling the diseased hamster as the SeV is contagious to the human.
Viral disease in gerbils
1. There is no evidence of viral disease in gerbils
2. Gerbils can infect with viral disease only by experimentation.