Ferret/Mink/Canine Coronavirus Flashcards
What is Epizootic Catarrhal Enteritis (ECE)
- Caused by Ferret enteric coronavirus (FRECV)
- First described in 1993 in US
- Asymptomatic of self-limiting enteritis
- Foul-smelling green diarrhea with high mucus content, lethargy, anorexia and vomiting
- Transmitted by the fecal-oral route
- High morbidity, low mortality (<5%)
- Affects all age groups but disease is most severe in older ferrets
How is ECE diagnosed?
- History, clinical signs and microscopic findings
- Clinical hx of a number of ferrets with varying stages of diarrhea following the introduction of new ferrets is classic for ECE
- Typical intestinal coronavirus infection:
- vacuolar degeneration and necrosis of villous enterocytes, villous atrophy, blunting and fusion
How is ECE treated?
Supportive therapy - fluids, bland diet
How can ECE be prevented?
- No vaccine
- Quarantine and cleaning of environments
- Affected ferrets can shed virus for months
What is Ferret Systemic Coronavirus Infection?
- First described in 2004 in Spain
- Sporadic occurrence
- Young ferrets <2yr most affected
- Clinical findings are similar to FIP - dry form is more common
- Highly fatal
What are the clinical findings associated with Ferret systemic Coronavirus infection
- Anorexia
- lethargy
- weight loss
- diarrhea
- intra-abdominal masses
- paralysis
- CNS signs
- Ocular diseases
- (pyo)granulomatous lesions in multiple organs
What are the lab results common with Ferret Systemic Coronavirus Infection?
- Hyperglobulinemia
- Anemia
- Leukocytosis
- Thrombocytopenia
How is Ferret systemic Coronavirus infection diagnosed?
Definitive dx requires detection of coronavirus antigen in macrophages within areas of granulomatous inflammation
What is Mink Coronavirus?
- Alphacoronavirus
- Infects Mink
- “Epizootic catarrhal gastroenteritis (ECG) reported in 1975
- Occurs seasonally (fall)
- Usually in >4month old mink
- High morbidity and low mortality (<5%)
- Co-infections may enhance severity (ex MEV)
What are the clinical sings of Mink Coronavirus?
- Anorexia
- Mucoid diarrhea 2-6 days after infection
What is Canine coronavirus (CCoV)?
- alphacoronavirus
- First in 1971 in military canine unit
- CCoV type 1 and 2 (subtypes 2a and 2b)
- Prevalence:
- 20% CCov-1
- 44% CCoV
- 36% co-infection of 1 & 2
What is Canine Enteric Coronavirus (CECoV)?
- CCoV-1, 2a, or 2b
- Usually affects <6 week old puppies
- Usually asymptomatic but mild, self-limiting diarrhea of a short duration may occur
- Severe disease can occur with co-infection with another GI pathogen (distemper, parvovirus)
Is there a vaccine for canine coronavirus?
- Vaccines in US for 6 weeks of age or older
- NOT recommended by AAHA - low chance of illness, generally occurs in dogs 6 weeks of age or younger
What is Canine Pantropic Coronavirus?
- First isolated in dead pups in 2005 in Italy - currently in EU and Asia
- All identified pantropic CCoV belong to CCoV-IIa
- Prior enteric CECoV infection (or vaccines) does not prevent infection with the pantropic variant
what are the clinical symptoms of CCoV-IIa?
- Sever gastrointestinal disease
- vomiting, profuse diarrhea
- Fever
- lethargy
- hemorrhagic diarrhea
- lymphopenia
- neuro signs - ataxia, seizures
- Death
What lesions are common with Canine Pantropic Coronavirus?
- Hemorrhagic lesions in:
- lungs
- spleen
- liver
- intestines
- kidneys
How is CCoV-IIa diagnosed?
- Cannot be made based on clinical and post-mortem findings
- Serology (Ab) is NOT useful
- Detection of CCoV-IIa in extra-intestinal tissues (IHC)
What is Canine Respiratory Coronavirus?
- Betacoronavirus
- CrCoV mainly causes respiratory infections
- alone or as co-infection
- first detected in 2003 UK
- oldest sample positive in 1996
- Emerging infection, in US ~50% of dogs have Ab
Is there a vaccine for Canine Respiratory Coronavirus?
No
What co-infections are common with CrCoV?
- canine adenovirus 2
- distemper virus
- influenza virus
- herpesvirus
- parainfluenza virus
- Bordetella bronchiseptica
- Streptococcus equi ssp zooepidemicus
- Mycoplasma spp
What are the clinical signs of CrCoV?
- Sudden onset of coughing, sneezing, discharge from nose/eyes
- self-limiting and resolve in 1-2 weeks
How contagious is CrCoV?
- Highly contagious
- Very common in dogs of all ages
How is CrCoV diagnosed?
- Multiple dogs are affected, progressively worsening signs of illness
- detection of a pathogen in nasal/oral swabs - PCR-based panel
What is Rabbit Hemorrhagic Disease (RHD)?
- Non-enveloped
- +ssRNA virus
- Genus: Lagovirus
When was RHDV discovered?
- Serotype 1
- 1984 in China - rabbits imported from Germany
- endemic in most of the world (except US)
- Serotype 2 (RHDV2)
- Emerged in EU in 2010
- Endemic in most of the word (some parts of US)
How is RHDV used as a biocontrol agent in Australia?
- 1996 - Release of RHDV Czech strain ⇢ ~90% reduction in rabbits
- genetic selection for resistance + native benign virus RCV-A1 in 2009 = reduced mortality of rabbits
- 2015 - HDV2 first detected in Australia
- 2017 - Release of RHDV K5 strain ⇢ ~36% mortality
Has RHDV2 reached the US?
- 2020 New Mexico - 1st detection in wild rabbits and hares
- spreading across multiple states
what is the incubation period for RHDV2?
1 - 9 days
What is the mortality rate of RHDV2
2-80% (classical RHDV 30-100%)
What are the different forms of disease that RHDV2 causes?
-
Peracute/Acute:
- death w/in 1-3 days
- usually good body condition
- Sudden collapse and death w/out obvious signs, fever, blood-tinged nostrils, vocalization, paddling, jaundice
-
Subacute/Chronic:
- some may die in 1-2 weeks due to liver dysfunction
- Jaundice, anorexia, lethargy
-
Subclinical:
- shed for months
What are the target organs in RHDV2?
- Liver (fulminant hepatitis)
- lungs
- spleen
- *Petechia seen in almost all organs due to DIC from severe hepatic necrosis
Compare and contrast RHDV and RHDV2
- RHDV:
- 8-10 weeks of age
- known to infect European rabbits
- RHDV2:
- All ages
- infects our native wild rabbits and several hare species
- Both:
- highly stable - viable virus found in tissue after 3 months in the field
- survives freezing, 122F heat for 1 hr
- highly stable - viable virus found in tissue after 3 months in the field
How are the RHD Viruses (classical and RHDV2) transmitted?
- Highly contagious
- Virus present in all secretions and excretions
- Oral> conjunctival and respiratory, urine, feces, and skin trauma
- Direct contact with live/dead rabbits
- Fomites - chilled/frozen meat, food, fur, bedding, water, vehicle tires, clothing
- Mechanical vectors - flies, mosquitos, other insects and birds
- Predators - through feces after consuming infected rabbits
- Surviving/asymptomatic rabbits can shed virus for months
How is RHDV diagnosed?
- USDA Foreign Animal Disease Diagnostic Lab (FADDL) and other designated labs
- Contact Lab/State veterinarian:
- sick rabbits w/suspected RHD signs after exposure to other rabbits or to a human who has recently handled other sick or dead domestic/wild rabbits
- Submit: Liver, lung, spleen, Whole blood
- ELISA and RT-PCR (Antigen) or Antibodies
*
What are the differential diagnosis for RHDV?
- Poisoning, trauma, heat exhaustion
- Bacterial infection:
- Tularemia, plaque, Septicemic pasteurellosis, atypical myxomatosis, enterotoxaemia (E. coli or clostridium perfringens Type E
- Any other causes of severe septicemia and secondary DIC
What Biosecurity measures should be followed for rabbits with RHDV?
- Isolate sick rabbits
- Asymptomatic and recovered rabbits can transmit virus - considered possible reservoirs for up to 2-4 months
- Maintenance of closed colonies or isolating new rabbits
- Some states have movement restrictions for rabbits/hares, their products or equipment/items
