Pathogens: Viruses, Bacteria, Fungi
The purpose of this section exists to educate those who have rats/mice on the vast amount of pathogens that affect our rats (and sometimes other species, including humans) and Charles River laboratory fact sheets about each pathogen which includes their description and symptoms, among other information.
I have seen far too many unknowing and well-intentioned pet rat owners lose rats after bringing in a new one, due to the high prevalence of rat pathogens that are rampant among rat "mill breeders," pet stores, or those breeding with little to no knowledge about rat disease, bacteria, and fungi, some of which is transferred to other species. It is not the pet rat owners fault, nor even new breeders, as knowledge of these pathogens, unfortunately, is not commonplace or even readily available if you're not a member of the right groups or if you don't know what you're looking for.
PREVENTION IS KEY! While it is impossible to prevent every virus listed below, taking special precautions can drastically reduce the likelihood of your rat (or you!) contracting an illness. Some of the illnesses will not show up during quarantine and may never present with symptoms, but quarantining for the ones that do, does make a difference. To do a proper quarantine, the new rat must stay in a completely separate airspace from your current rats, which means it should be in a different house without contact with you until at least 2, but ideally 4-8 weeks for the quarantine to be truly effective. Or, you can adopt from a reputable, ethical breeder with rats having no negative health symptoms.
If you want to know exactly what your current rats have, or new rat has while still in quarantine, ask your exotic animal veterinarian to test through IDEXX; I would recommend doing the Comprehensive Panel or Global panel (they are expensive at $100+ per rat). To learn about what is offered in each package, go to http://www.idexxbioresearch.com/serology-testing-profiles#rat
Below is the name and Charles River fact sheet link to each pathogen screened in laboratory rats and mice via the comprehensive/global panels per IDEXX Bioresearch, important points summarized by me, treatment, and symptoms.
Clostridium Piliforme/Tyzzer's Disease
Link: https://www.criver.com/sites/default/files/resources/ClostridiumpiliformeTyzzer%27sDiseaseTechnicalSheet.pdf
Note: Transmission occurs through spores, which are active for at least one year. Upon necropsy, the liver, heart, and parts of the intestines have been affected.
Treatment: Infection clears within a few weeks but spores remain active for at least one year.
Symptoms: Symptoms are rare unless the rat is immunocompromised. Most likely to present in recently weaned young as:
Sendai Virus (SV)
Link: https://www.criver.com/sites/default/files/resources/SendaiVirusTechnicalSheet.pdf
Note: Species specific (rodents), very contagious, mostly affects immocompromised rats, aerosol transmission.
Treatment: Cease breeding for a few months and do not bring in new rodents.
Symptoms: Few symptoms present in rats, such as:
Mycoplasma Pulmonis ("myco")
Link: https://www.criver.com/sites/default/files/resources/MycoplasmapulmonisTechnicalSheet.pdf
Note: Species specific, extremely prevalent in pet rats. Considered "endemic" in the USA. Aerosol transmission. Becomes subclinical with flareups.
Treatment: Although myco cannot currently be cured, broad spectrum antibiotics are used to treat clinical symptoms.
Symptoms: Include:
CAR Bacillus (Cilia-Associated Respiratory Bacillus)
Link: https://www.criver.com/sites/default/files/resources/Cilia-AssociatedRespiratoryBacillusTechnicalSheet.pdf
Note: Species specific, nearly as prevalent as myco (mycoplasma) with similar symptoms. Transmission through "direct contact."
Treatment: Although it cannot currently be cured, broad spectrum antibiotics are used to treat symptoms.
Symptoms: Symptoms are often not present, but if they are (usually in immunocompromised rats), they consist of:
RCV (Rat Coronavirus)/SDAV (Sialodacryoadenitis Virus)
Link: https://www.criver.com/sites/default/files/resources/SialodacryoadenitisVirusTechnicalSheet.pdf
Note: Death rate low, infection rate high. Highly contagious airborne virus. Compromises immune system. May yield life-long respiratory or eye damage.
Treatment: IF no new rats are exposed, the virus runs its course in 7-10 days (self-limiting). Secondary infections due to weakened immune system may persist & require antibiotic treatment.
Symptoms: If first exposure, rats may start showing symptoms a few days after being affected. Not all show symptoms. Symptoms include:
Rat Parvoviruses (RPV-1, RPV-2, H-1, RMV, KRV/RV)
Link: https://www.criver.com/sites/default/files/resources/RatParvovirusesTechnicalSheet.pdf
Note: Species specific (rat and mouse). Very common. Transmission via bodily fluids. Can be transmitted via feed/bedding.
Treatment: None. Can become subclinical but rats maintain positive results via testing for life.
Symptoms:
Rat Theiloviruses (RTV, MEV)
Link: https://www.criver.com/sites/default/files/resources/TheilovirusesTechnicalSheet.pdf
Note: Species specific. Very common. Transmitted via oral ingestion of feces.
Treatment: MEV is shed two months post infection then clears. RTV duration/treatment is unknown.
Symptoms: Rarely causes symptoms
Pneumocystis (P. carinii, P. wakefieldae)
Link: https://www.criver.com/sites/default/files/resources/PneumocystisP.murinaP.cariniiP.wakefieldaeP.oryctolagiTechnicalSheet.pdf
Note: Species specific. Very common. Aerosol transmission.
Treatment: Depends: rats with healthy immune systems will eliminate the virus completely; Immunodeficient rats will shred it indefinitely. Treat symptoms with sulfa drugs.
Symptoms: Symptoms most often present in immunodeficient rats as:
Encephalitozoon cuniculi
Link: https://www.criver.com/sites/default/files/resources/EncephalitozooncuniculiTechnicalSheet.pdf
Note: Zoonotic (severely immunodeficient humans). Uncommon in rats. Fungus. Transmittable via ingestion of spores excreted in urine.
Treatment: None. However, spores rarely shred (therefore, unlikely to be transmittable) after 3 months post initial infection.
Symptoms: Virus is usually subclinical in infected rats with no symptoms unless immunocompromised:
Pneumonia Virus of Mice (PVM)
Link: https://www.criver.com/sites/default/files/resources/PneumoniaVirusofMicePVMTechnicalSheet.pdf
Note: Species specific to rodents. Not common. Transmitted via aerosol.
Treatment:
Symptoms: There are no clinical symptoms in rats.
Reovirus Type 3 (REO-3)
Link: https://www.criver.com/sites/default/files/resources/ReovirusTechnicalSheet.pdf https://www.sciencedirect.com/topics/medicine-and-dentistry/reovirus
Note: Species specific to certain rodents although humans can carry the virus. Common in pet rats. Airborne transmission from feces or ingestion of feces.
Treatment: None listed.
Symptoms: Will not usually show symptoms;
Mouse Adenovirus (Mav1, MAV2)
Link: https://www.criver.com/sites/default/files/resources/MouseAdenovirusTechnicalSheet.pdf
Note: Species specific, uncommon, and transmitted through bodily fluids.
Treatment: None, as there are no symptoms documented and the virus runs its course for about 3 weeks.
Symptoms: None
Lymphocytic Choriomeningitis Virus (LCMV)
Link: https://www.criver.com/sites/default/files/resources/LymphocyticChoriomeningitisVirusTechnicalSheet.pdf
Note: Zoonotic (transferable to people). Rats are naturally resistant to LCMV, therefore, cannot transmit it.
Treatment: N/A
Symptoms: N/A
Hanta Viruses (Seoul, Hantaan, Puumala, Dobrava, Sin Nombre)
Link: https://www.criver.com/sites/default/files/resources/HantavirusesTechnicalSheet.pdf
Note: Zoonotic (transferable to people), rare in lab rats, common in wild rats and pet rats in certain areas. Shred through bodily fluids.
Treatment: No treatment available for affected rat. People only require treatment if symptoms present.
Symptoms:
I have seen far too many unknowing and well-intentioned pet rat owners lose rats after bringing in a new one, due to the high prevalence of rat pathogens that are rampant among rat "mill breeders," pet stores, or those breeding with little to no knowledge about rat disease, bacteria, and fungi, some of which is transferred to other species. It is not the pet rat owners fault, nor even new breeders, as knowledge of these pathogens, unfortunately, is not commonplace or even readily available if you're not a member of the right groups or if you don't know what you're looking for.
PREVENTION IS KEY! While it is impossible to prevent every virus listed below, taking special precautions can drastically reduce the likelihood of your rat (or you!) contracting an illness. Some of the illnesses will not show up during quarantine and may never present with symptoms, but quarantining for the ones that do, does make a difference. To do a proper quarantine, the new rat must stay in a completely separate airspace from your current rats, which means it should be in a different house without contact with you until at least 2, but ideally 4-8 weeks for the quarantine to be truly effective. Or, you can adopt from a reputable, ethical breeder with rats having no negative health symptoms.
If you want to know exactly what your current rats have, or new rat has while still in quarantine, ask your exotic animal veterinarian to test through IDEXX; I would recommend doing the Comprehensive Panel or Global panel (they are expensive at $100+ per rat). To learn about what is offered in each package, go to http://www.idexxbioresearch.com/serology-testing-profiles#rat
Below is the name and Charles River fact sheet link to each pathogen screened in laboratory rats and mice via the comprehensive/global panels per IDEXX Bioresearch, important points summarized by me, treatment, and symptoms.
Clostridium Piliforme/Tyzzer's Disease
Link: https://www.criver.com/sites/default/files/resources/ClostridiumpiliformeTyzzer%27sDiseaseTechnicalSheet.pdf
Note: Transmission occurs through spores, which are active for at least one year. Upon necropsy, the liver, heart, and parts of the intestines have been affected.
Treatment: Infection clears within a few weeks but spores remain active for at least one year.
Symptoms: Symptoms are rare unless the rat is immunocompromised. Most likely to present in recently weaned young as:
- Poor appetite
- Thin
- Ruffled fur
- Distended abdomen
- Acute/sudden death with no prior clinical signs
Sendai Virus (SV)
Link: https://www.criver.com/sites/default/files/resources/SendaiVirusTechnicalSheet.pdf
Note: Species specific (rodents), very contagious, mostly affects immocompromised rats, aerosol transmission.
Treatment: Cease breeding for a few months and do not bring in new rodents.
Symptoms: Few symptoms present in rats, such as:
- Mostly affects reproduction, causing infertility or small litter size
- Minor changes to the respiratory tract
- Increased susceptibility to secondary bacterial infections
Mycoplasma Pulmonis ("myco")
Link: https://www.criver.com/sites/default/files/resources/MycoplasmapulmonisTechnicalSheet.pdf
Note: Species specific, extremely prevalent in pet rats. Considered "endemic" in the USA. Aerosol transmission. Becomes subclinical with flareups.
Treatment: Although myco cannot currently be cured, broad spectrum antibiotics are used to treat clinical symptoms.
Symptoms: Include:
- Weight loss
- Ruffled fur
- Hunched posture
- Respiratory distress [sneezing, wheezing, sniffling, chattering, snuffling, labored breathing]
- Lethargy
- Chromodacryorrhea [porphyrin, or "red tears" of eyes and nose]
- Arthritis
- Can also affect reproduction, causing infertility, miscarriage, stillborn, neonatal death, and low birth weight
CAR Bacillus (Cilia-Associated Respiratory Bacillus)
Link: https://www.criver.com/sites/default/files/resources/Cilia-AssociatedRespiratoryBacillusTechnicalSheet.pdf
Note: Species specific, nearly as prevalent as myco (mycoplasma) with similar symptoms. Transmission through "direct contact."
Treatment: Although it cannot currently be cured, broad spectrum antibiotics are used to treat symptoms.
Symptoms: Symptoms are often not present, but if they are (usually in immunocompromised rats), they consist of:
- Respiratory distress [sneezing, wheezing, sniffling, chattering, snuffling, labored breathing]
- Chromodacryorrhea [porphyrin, or "red tears"]
- Weight loss
- Ruffled fur
- Lethargy
RCV (Rat Coronavirus)/SDAV (Sialodacryoadenitis Virus)
Link: https://www.criver.com/sites/default/files/resources/SialodacryoadenitisVirusTechnicalSheet.pdf
Note: Death rate low, infection rate high. Highly contagious airborne virus. Compromises immune system. May yield life-long respiratory or eye damage.
Treatment: IF no new rats are exposed, the virus runs its course in 7-10 days (self-limiting). Secondary infections due to weakened immune system may persist & require antibiotic treatment.
Symptoms: If first exposure, rats may start showing symptoms a few days after being affected. Not all show symptoms. Symptoms include:
- Sniffling
- Sneezing
- Chromodacryorrhea [porphyrin, or "red tears"]
- Photophobia [extreme sensitivity to light]
- Submandibular swelling [swelling below the jaw]
- Specific to SDAV:
- megaloglobus [enlargement of eyeball]
- corneal ulceration [abscess/sore in the eye]
- Specific to RCV:
- respiratory tract inflammation from nose to lungs
- may be fatal in immunocompromised rats due to secondary infections
Rat Parvoviruses (RPV-1, RPV-2, H-1, RMV, KRV/RV)
Link: https://www.criver.com/sites/default/files/resources/RatParvovirusesTechnicalSheet.pdf
Note: Species specific (rat and mouse). Very common. Transmission via bodily fluids. Can be transmitted via feed/bedding.
Treatment: None. Can become subclinical but rats maintain positive results via testing for life.
Symptoms:
- H-1, RPV-1, and RMV have no clinical signs
- RV/KRV infections in adult rats may rarely cause:
- Hemorrhage of scrotum (blood accumulation in testicles)
- Lymph node congestion
- Decrease in body fat
- RV/KRV in pregnant rats may:
- Affect fetal development
- Cause infertility
- Cause re-absorption/stillborns
- Yield small litter sizes
Rat Theiloviruses (RTV, MEV)
Link: https://www.criver.com/sites/default/files/resources/TheilovirusesTechnicalSheet.pdf
Note: Species specific. Very common. Transmitted via oral ingestion of feces.
Treatment: MEV is shed two months post infection then clears. RTV duration/treatment is unknown.
Symptoms: Rarely causes symptoms
- Will very rarely cause inflammation of the brain
Pneumocystis (P. carinii, P. wakefieldae)
Link: https://www.criver.com/sites/default/files/resources/PneumocystisP.murinaP.cariniiP.wakefieldaeP.oryctolagiTechnicalSheet.pdf
Note: Species specific. Very common. Aerosol transmission.
Treatment: Depends: rats with healthy immune systems will eliminate the virus completely; Immunodeficient rats will shred it indefinitely. Treat symptoms with sulfa drugs.
Symptoms: Symptoms most often present in immunodeficient rats as:
- Pneumonia
- Weight loss
- Hunched posture
- Ruffled fur
- Labored breathing seen in later stages
Encephalitozoon cuniculi
Link: https://www.criver.com/sites/default/files/resources/EncephalitozooncuniculiTechnicalSheet.pdf
Note: Zoonotic (severely immunodeficient humans). Uncommon in rats. Fungus. Transmittable via ingestion of spores excreted in urine.
Treatment: None. However, spores rarely shred (therefore, unlikely to be transmittable) after 3 months post initial infection.
Symptoms: Virus is usually subclinical in infected rats with no symptoms unless immunocompromised:
- Affects kidneys which shows in necropsy
Pneumonia Virus of Mice (PVM)
Link: https://www.criver.com/sites/default/files/resources/PneumoniaVirusofMicePVMTechnicalSheet.pdf
Note: Species specific to rodents. Not common. Transmitted via aerosol.
Treatment:
Symptoms: There are no clinical symptoms in rats.
- Rarely upon necropsy, lesions are visible on lungs
Reovirus Type 3 (REO-3)
Link: https://www.criver.com/sites/default/files/resources/ReovirusTechnicalSheet.pdf https://www.sciencedirect.com/topics/medicine-and-dentistry/reovirus
Note: Species specific to certain rodents although humans can carry the virus. Common in pet rats. Airborne transmission from feces or ingestion of feces.
Treatment: None listed.
Symptoms: Will not usually show symptoms;
- Possible symptoms in rats not specified.
Mouse Adenovirus (Mav1, MAV2)
Link: https://www.criver.com/sites/default/files/resources/MouseAdenovirusTechnicalSheet.pdf
Note: Species specific, uncommon, and transmitted through bodily fluids.
Treatment: None, as there are no symptoms documented and the virus runs its course for about 3 weeks.
Symptoms: None
- No symptoms have been seen in rats infected with this virus
Lymphocytic Choriomeningitis Virus (LCMV)
Link: https://www.criver.com/sites/default/files/resources/LymphocyticChoriomeningitisVirusTechnicalSheet.pdf
Note: Zoonotic (transferable to people). Rats are naturally resistant to LCMV, therefore, cannot transmit it.
Treatment: N/A
Symptoms: N/A
Hanta Viruses (Seoul, Hantaan, Puumala, Dobrava, Sin Nombre)
Link: https://www.criver.com/sites/default/files/resources/HantavirusesTechnicalSheet.pdf
Note: Zoonotic (transferable to people), rare in lab rats, common in wild rats and pet rats in certain areas. Shred through bodily fluids.
Treatment: No treatment available for affected rat. People only require treatment if symptoms present.
Symptoms:
- Affected rats do not show symptoms.
- Humans infected may show flu-like symptoms and can suffer from kidney damage
ECOR Seoul Results
I had two cages of rats at the time of and prior to testing: one for males and the other for females. One rat from each cage was tested for SEOUL. Both rats are NEGATIVE! Please note the only way to be 100% sure any rattery is free of the virus is to test every single rat over 12 weeks weeks of age. However, I have no reason to believe my rattery is at risk and therefore, the testing I did was simply precautionary. FYI: Seoul is a member of the Hantaan virus.
https://www.cdc.gov/hantavirus/technical/hanta/virology.html
Please see below results:
https://www.cdc.gov/hantavirus/technical/hanta/virology.html
Please see below results: