PATHOLOGY - Gastrointestinal Viral Infections Flashcards
What are the two key parvoviral infections in veterinary medicine?
Canine parvovirus 2 (CPV-2)
Feline panleukopenia virus (FPV)
What is the pathogenesis of parvoviral infection?
These viruses undergo oronasal exposure and are taken up into the tonsils and Peyer’s patches where they will invade and undergo viral replication within the lymphocytes. The virus will undergo systemic dissemination either within the lymphocytes or as free viral particles (cell-free viraemia) and travel to the crypt enterocytes where they will invade and undergo viral replication, resulting in necrosis. These viral particles will also disseminate into the bone marrow resulting in hypocellularity and necrosis. Parvoviruses have a tissue tropism for rapidly dividing cells such as intestinal epithelial cells and haematopoietic cells, resulting in intestinal mucosal damage and neutropenia which increase the risk of translocation of enteric bacteria and sepsis
Which intestinal lesions result due to the parvoviruses?
Haemorrhagic-necrotising enteritis
Fibrino-necrotising enteritis and exudate
What are the histological features of the parvoviruses?
Necrosis of the crypt epithelial cells
Crypt dilatation with necrotic debris
Villous atrophy
Necrosis of the lymphoid tissue in the Peyer’s patches
Intranuclear inclusion bodies (only in early disease)
Epithelial regeneration (only in late disease)
Which extra-intestinal lesions result due to parvoviral infection in the dog?
Bone marrow hypocellularity and necrosis
Lymphocytolysis (lymphopenia)
Necrotising myocarditis
Generalised necrosis of the organs
Which signalement is susceptible to generalised necrosis of the organs due to parvoviral infection?
Neonates
Which extra-intestinal lesions result due to parvoviral infection in the cat?
Bone marrow hypocellularity and necrosis
Lymphocytolysis (lymphopenia)
Cerebellar hypoplasia
Which region of the intestine is specifically targeted by coronavirus?
Tips of the villi
List examples of coronaviruses
Porcine epidemic diarrhoea virus (PEDV)
Transmissible gastroenteritis virus (TGEV)
Bovine coronavirus (BCoV)
Equine coronavrus (ECoV)
Which signalement is typically affected by porcine epidemic diarrhoea virus (PEDV)?
Suckling piglets
Which signalement is typically affected by transmissible gastroenteritis virus (TGEV)?
Suckling piglets
What histological lesions result due to porcine epidemic diarrhoea virus (PEDV) and transmissible gastroenteritis virus (TGEV)?
Intestinal villous blunting and fusion
Which signalement is typicaly affected by bovine coronavirus (BCoV)?
Neonatal calves
Which disease process is caused by bovine coronavirus (BCoV) in adult cattle?
Winter dysentry
Which intestinal lesions result due to equine coronavirus (ECoV)?
Red discolouration of the intestinal mucosa
Ulcerative enteritis
Red tinged intestinal contents
Which histological lesions result due to equine coronavirus (ECoV)?
Necrotising enteritis
Villous blunting and fusion
Neutrophilic and fibrinous exudate
Crypt necrosis and abscessation
Microthrombosis
Haemorrhage
Intranuclear inclusion bodies (rare for coronaviruses)
Which histological lesions result due to rotavirus?
Villous atrophy and fusion
Which disease is associated with equine adenovirus 1 (EAdV-1)?
Upper respiratory tract infections
Which disease is associated with equine adenovirus 2 (EAdV-2)?
Gastrointestinal tract infections
Which gross lesions result due to equine adenovirus 2 (EAdV-2)?
Necrosis and ulceration of distal oesophagus
Necrosis and ulceration of squamous gastric mucosa
Soft to semi-fluid filled ingesta
Villous atrophy of the small intestine
Which histological lesions result due to equine adenovirus 2 (EAdV-2)?
Intranuclear inclusion bodies of the small intestine
Villous atrophy of the small intestine
What are the potential causes of equine grass sickness?
Oxidative stress
Fungal toxins
Weather changes
Clostridium botulinum C toxin
Why is clostridium botulinum C toxin a controversial potential cause of equine grass sickness?
Clostridium botulinum C toxin is a controversial cause of equine grass sickness as it could be causal but could also be a manifestation of secondary bacterial overgrowth
What are the risk factors for equine grass sickness?
Pasture grazing
Recent move to new pasture
Horses aged 2 - 7
Spring to early summer
High metal concentrations in the herbage
High abundance of buttercups
Cool, dry weather with irregular frost
What are the gross pathological lesions resulting from acute/subacute equine grass sickness?
Gastric distension with pale to tan mucinous fluid
Gastric rupture
Excess intestinal fluid contents
Large intestinal impaction with dry, possibly blackened contents
Small colon impaction with small, dry, possibly blackened contents
What are the gross pathological lesions resulting from chronic equine grass sickness?
Marked decrease in alimentary contents
Hypertrophy of the intestinal musculature
What are the key histological lesions resulting from equine grass sickness?
Chromatolysis with dispersion and loss of nissl substance
Neuronal cytoplasmic swelling and vacuolation
Peripheral displacement of nuclei of affected neurones
There are required for histopathological diagnosis
What is nissl substance?
Nissl substance is the neuronal rough endoplasmic reticulum
