Lab 3.2, 3.3, 3.4 Flashcards
Results of virus neutralization test
Healthy cells
* virus must have been neutralized because animals had lots of antibodies
Dying cells with CPE
* Not enough antibodies at this dilution to neutralize the virus and protect the cells
What type of detection test is commonly used for canine parvovirus
Direct ELISA looking for antigen
Sam is a 6-months-old male dog brought to the clinic after
experiencing severe vomiting and diarrhea within the last 2 days.
* Diarrhea is watery, with no blood, strong/bad smell
What is in your list of differential diagnosis of viral disease(s) affecting Sam?
Parvovirus
Distemper
Coronavirus
Rotavirus
if you suspect a virus infected animal what precautions should be taken prior to the physical exam?
When you suspect a virus infected animal please make sure you take extra caution and wear personal protective equipment (gloves, lab coat, mask and eye protection) prior to conducting physical examination
How to diagnose CPV?
- Detection of parvovirus antigen by ELISA (Ag in feces)
- Identification of viral nucleic acid in feces by PCR (used to confirm Snap test)
-there are others but these are best
why might we get a false negative early on in a CPV case?
False-negative results can be seen early in the course of the disease (before peak viral shedding), because of the dilutional effect of large volume diarrhea
-The sample collected did not have enough of the viral antigen in it to be able to detect with the test
General approaches to treatment of CPV
- Intravenous fluids (balanced electrolyte solution)
- Antibiotics to prevent secondary bacterial infection
- Antiemetics (persistent, severe vomiting)
Prognosis of CPV
- 68-92% of puppies administered appropriate supportive care will survive, having developed long-term (potential life-long) immunity against the virus.
recovery time of CPV
Approximately 1 week after surviving the first 3-4 days of illness
What to expect in post-mortem after CPV
- Small intestine:
> Severe necrotic and hemorrhagic enteritis - Necrosis in the Peyer’s patch
- Lymph nodes (intestinal, mesenteric):
> Multifocal hemorrhage - Thymus:
> Severe diffuse hemorrhage (not pictured)
Vaccination strategies for Parvovirus
- Inactivated and modified-live vaccine at 6–8, 10–12, and 14–16 weeks
- Booster administered 1 year later and then 3 year later
- Usually given as a combination CORE vaccine→ DAPP (Distemper, Adenovirus, Parvovirus, Parainfluenza) or DHPP (Distemper, Hepatitis, Parvovirus, Parainfluenza)
- Inactivated vaccines for pregnant bitches (reduced risk of abortion)
Why vaccines fail?
- Faulty vaccine - improper storage or administration
- State of immune system at time of vaccination
○ Immature immune system and/or dog is unhealthy at time of vaccination - Breed Differences!
○ Rottweilers and Dobermans are more susceptible to developing parvovirus enteritis despite vaccination! - Maternal immunity - maternal antibodies block the live attenuated vaccine challenge
> Ideal timing of vaccination: when the maternal antibodies levels will be low enough to no longer protect the dog
when is a vaccinated puppy most vulnerable to CPV? why?
Puppy is most vulnerable to CPV-2 if infected between 8 to 16 weeks old
-maternal antibodies are waning, while vaccine antibodies are not yet at protective levels in this window of susceptibility
how is CPV shed? for what timeframe?
Virus is shed in the feces of infected dogs within 4–5 days of exposure (often before clinical signs develop), throughout the period of illness, and for ~10 days after clinical recovery
how do we disinfect an area contaminated with CPV?
- Killing parvovirus (small naked DNA virus) requires strong disinfectants:
● Bleach (sodium hypochlorite)
● Potassium peroxymonosulfate
● Hydrogen peroxide - Quaternary ammonium (soap) disinfectants do not kill parvovirus
Clinical signs:
-Inflamed nasal mucosa +/- nasal discharge +/- some areas of mucosal ulceration
-Difficult breathing, fever
-Conjunctivitis
-A few larger bulls have vesicles at the base of the penis
What is your differential diagnosis?
- Bovine herpesvirus 1 (IBR)
- Bovine viral diarrhea virus – BVDV (Flavivirus)
- Bovine respiratory syncytial virus (Paramyxovirus)
- Bovine parainfluenza virus 3 (Paramyxovirus)
postmortem findings for Infectious bovine rhinotracheitis (IBR)- Bovine Herpesvirus 1
-Fibrinonecrotic rhinitis
-tracheitis, pneumonia
-congested tracheal mucosa and nasal mucosa
Infectious bovine rhinotracheitis (IBR)- Bovine Herpesvirus 1
>clinical signs
-fever
-nasal discharge
-conjunctivitis
> can also cause reproductive signs:
-infectious pustular vulvovaginitis
-balanoposthitis
- Respiratory and reproductive diseases are rarely diagnosed simultaneously
What samples should we send to the lab to look for Infectious bovine rhinotracheitis (IBR)- Bovine Herpesvirus 1
- Live animal samples: nasal, ocular swabs, swabs from genital lesions, semen
- Ideal: bronchoalveolar and/or transtracheal wash
post mortem samples for Infectious bovine rhinotracheitis (IBR)- Bovine Herpesvirus 1
- Post-mortem samples: trachea, lung, bronchial lymph node tissues
what lab test are the best to look for infectious bovine rhinotracheitis?
Target antigen detection: PCR panel
Target antibody detection on serum: Virus neutralization test (VN), ELISA
-there are others, eg immunofluorescence
vaccine availability for IBR? what is a useful vaccination protocol?
=>Vaccines are available!
- DIVA/Marker vaccine(thymidine kinase and glycoprotein E genes (gE) are deleted from the vaccine strain): used in IBR eradication programs
- Modified live vaccine for bovine respiratory disease complex: IBRV, BVDV, BRSV, PI3, Mannheimia haemolytica
- An ELISA test can naturally infected animals from vaccinated cattle when used in IBR control programs together with gE- deleted IBR vaccines
is IBR reportable?
yes to OIE but not federally?????
What are OIE listed diseases?
Transmissible diseases that have the potential for very serious and rapid spread, irrespective of national borders, that are of serious socio-economic or public health consequence and that are of major importance in the international trade of animals and animal products
who do we report a reportable viral disease to in canada?
to a CFIA district veterinarian
what is an immediately notifiable disease? who should contact CFIA?
- “In general, immediately notifiable diseases are diseases exotic to Canada for which there are no control or eradication programs.”]
lab notifies
