Canine & Feline Parvo Flashcards
(34 cards)
1
Q
What is the structure of viruses in the family Parvoviridae?
A
- 5kb ssDNA
- Noneveloped
*
2
Q
How stable are parvo viruses?
A
- Highly resistant to disinfection/temperature/pH
- Infectious for months to years
3
Q
How do parvo viruses replicate in the host?
A
- Occurs in cells with high mitotic rates
- No viral DNA polymerase
- Requires host nucleoprotein synthesis (DNA replication)
- Primary sitesL
- tissues undergoing organogenesis in fetal or neonatal development
- Enteric epithelial crypt cells, hematopoietic and lymphoid tissues
4
Q
What is Canine Parvovirus (CPV-2)?
A
- 1978 - now present worldwide
- Infects dogs, coyotes, wolves, foxes, raccoons, sknks
- 3 main variants ( 2a, 2b, 2c)
- similar virulence
- 2b - most commonly associated with illness
- 2c - most recent emergence
5
Q
How is CPV-2 transmitted?
A
- Direct: oronasal contact with infectious feces
- Indirect: oronasal contact with contaminated fomites
- environment, personnel, equipment
- D
6
Q
When do infected dogs start shedding the CPV-2 virus?
A
- 4-5 dpi
- can occur prior to clinical onset of disease
- continues up to 10 days after clinical resolution
7
Q
What happens during phase 1 of CPV-2 infection?
A
- Initial replication in oropharyngeal lymphoid tissue
- Subsequent replication in Peyer’s patches and GI lymphoid tissue
8
Q
What happens during phase 2 of CPV-2 infection?
A
- Virus spreads by blood and lymphatics to secondary sites of replication
- Targets rapidly dividing cells:
- SI crypt epithelium
- Bone marrow
- Primary and secondary lymphopoietic tissue
9
Q
What is the pathogenesis of CPV-2 in the lymphopoietic/hematopoietic cells/tissues, intestinal crypt epithelium, or in utero infection?
A
- Lymphopoietic/hematopoietic cells/tissues:
- Leukopenia (lymphopenia, neutropenia
- Immunosuppression
- Intestinal crypt epithelium:
- epithelial necrosis and villus atrophy
- Impaired absorptive capacity
- Disrupted gut barrier - bacterial translocation
- In utero / < 8 week sw/out maternal antibodies:
- Myocarditis
- Myocardial necrosis
10
Q
What are the 2 disease syndromes of CPV-2?
A
- Myocarditis
- acute enteritis
11
Q
What happens with CPV-2 associated myocarditis?
A
- Infection in utero or < 8 weeks
- Clinical presentation:
- acute cardiopulmonary failure or delayed, progressive cardiac failure
- +/- enteritis
- acute cardiopulmonary failure or delayed, progressive cardiac failure
- Less common
- maternal antibodies from vaccination or exposure are protectie
12
Q
What happens with CPV-2 associated acute enteritis ?
A
- Most common
- Young puppies (6wk - 6 mo)
- waning maternal antibodies
- unvaccinated or incomplete vaccination
- Breed susceptibility: Dobermans, rottweilers, labs, pit bulls
- Co-morbidities affect disease severity
- Elevated stress, poor nutrition, GI parasites, others
- Intussusception can occur
13
Q
What is the clinical presentation of CPV-2 enteritis?
A
- Clinical signs develop w/in 5-7 dpi and last between 2-14 days
- Early signs can be nonspecific - lethargy, decreased appetite
- Progresses to vomiting and small-bowel diarrhea (often hemorrhagic) w/in 24-48 hrs
- Depression, pyrexia, dehydration, abdominal pain, dilated and fluid-filled intestinal loops
- Septic shock: weak femoral pulse, prolonged CRT, tachycardia, hypothermia, collapse
14
Q
What are the results of a CBC on a CPV-2 infected dog?
A
- Moderate to severe leukopenia characterized by lymphopenia and neutropenia
15
Q
What are the serum chemistry results associated with CPV-2?
A
- Prerenal azotemia, hypoalbuminemia (protein loss through GI tract) hyponatremia, hypokalemia, hypochloremia, hypoglycemia, increased liver enzymes
16
Q
What gross necropsy lesions are associated with CPV-2?
A
- Thickened and discolored intestinal wall
- Watery, mucoid, or hemorrhagic intestinal contents
- Edema and congestion of lymph nodes
- Thymic atrophy
17
Q
What histopathologic lesions are associated with CPV-2?
A
- Multifocal necrosis of intestinal crypt epithelium
- Intestinal villus blunting and sloughing
- Lymphoid depletion
- Bone Marrow hypoplasia
18
Q
Hos is CPV-2 diagnosed?
A
- High index of suspicion at presentation:
- young, incomplete or no vaccination, compatible clinical signs
- may be newly acquired - incomplete medical history
-
SNAP test - ELISA for CPV-2 capsid antigen in feces
- Widely available, easy to use, rapid results
- Detects all subtypes, minimal reactivity with MLVs
- Good specificity; sensitivity depends on virus shedding
- Test at presentation/onset of clinical illness
- Negative w/ high index of suspicion should be re-tested in 1-2 days
- Detection of virus/antigen in feces
- PCR, EM, VI
- Detection of CPV-2 antibodies
- 4x increase in IgG titer over 14 day period
- IgM antibody without recent vaccination (>4wks)
19
Q
What is the treatment for CPV-2?
A
- Fluid therapy
- lactated ringers or 0.9% saline
- SQ fluids for mild dehydration (<5%)
- IV fluids for moderate to sever dehydration
- +/- dextrose and KCl supplementation
- +/- colloid for sever hypoproteinemia
- Antibiotics
- prevent secondary infection
- broad-spec w/ good gram negative coverage (enterics)
- ampicillin-sulbactam IV - inpatient
- Cefovecin - outpatient
- Antiemetics - prolonged/intractable vomiting
- Nutritional support
- small amounts of bland flood when vomiting resolved
20
Q
What is the prognosis of CPV-2?
A
- W/out treatment:
- death can occur w/in 1-3 days of clinical onset
- mortality can be >90%
-
W/ supportive treatment:
- 70-90% of dogs with enteritis survive
- most pups that survive the first 3-4 days will recover
21
Q
What biosecurity measures should be taken with CPV-2?
A
- Limit environment contamination and spread
- Isolate positive patients - separate housing and equipment
- consider moving suspect animals out of the waiting room
- Proper PPE
- Frequent cleaning/disinfection:
- Bleach (1:30), Virkon-S, accelerated hydrogen peroxide
22
Q
What is the CPV-2 vaccine?
A
- AAHA Core vaccine
- Modified-live vaccine
- initial 6-8wks, 10-12 wks, 14-16 wks
- Booster 1 year later, then every 3 yrs
- Inactivated vaccine
- pregnant dogs or colostrum deprived pups
- Protective against different subtypes
23
Q
What is Feline Panleukopenia Virus (FPV)?
A
- “Feline distemper”
- Before 1900
- Worldwide distribution - infrequent due to vaccination
- Causes disease in felids, raccoons, foxes and mink
24
Q
How is FPV transmitted?
A
- Oronasal exposure - direct or indirect
- virus is abundant in all secretions/excretions during acute phase of illness
- Shedding typically occurs over a short period (1-2 days) but up to 6 wks has been reporterd
25
What is the pathogenesis of FPV in pregnant queens?
* Virus may spread transplacentally
* Embryonic resorption, fetal mummification, abortion/stillbirth
26
What is the pathogenesis of FPV in Perinatal kittens?
* Virus infects the germinal epithelium of the cerebellum (dividing neuroblasts)
* **Cerebellar hypoplasia:**
* ataxia, tremors, blindness, hypermetric movements
* Syndrome has become rare due to passive maternal antibody transfer
27
What is phase one of FPV infection?
* Initial replication in oropharyngeal lymphoid tissue
* subsequent replication in Peyer's patches and GI lymphoid tissues
28
What is phase two of FPV infetion?
* Hematogenous spread (viremia) to secondary sites of replication
* Targets rapidly dividing cells:
* SI crypt epithelium
* Bone Marrow
* Primary and secondary lymphopoietic tissue
* Viremia usually resolves within 5-7 days due to induction of neutralizing antibodies
29
What is the clinical presentation of FPV?
* Most infections are subclinical
* Clinical disease most common in cats 3-5 months of age
* Disease more common with rescues and groups of unvaccinated cats
* Peracute cases - may die suddenly
* Acute:
* Clinical signs appear within 2-7 dpi, last approx 4-7 days
* **Pyrexia, decreased appetite, depression,** +/- transient diarrhea, vomiting, **dehydration**, +/- abdominal pain, thickened intestinal loops, enlarged mesenteric lymph nodes
* CBC/chem: similar to CPV-2
* Septic shock: hypothermia, DIC
30
What are the lesions associated with FPV?
* Dilated intestinal loops with thickened and hyperemic walls
* Petechiae on intestinal serosal surfaces
* Dilated intestinal crypts
* Necrotic intestinal epithelial cells
* Villus blunting and fusion
31
How is FPV diagnosed?
* Presumptive: hx, vaccination status, clinical signs, leukopenia
* **Fecal antigen/virus detection**
* **Rapid ELISA antigen test**: false negative possible = short duration of virus shedding
* **PCR** - more sensitive
* FPV antibody tests - mainly for retrospective use
32
What is the treatment for FPV?
* Fluid therapy and parental broad-spectrum antibiotics
33
What is the prognosis for cats with FPV?
* Better for cats receiving adequate supportive therapy
* mortality highest in kitten s\< 5 month
* prognosis is poorer with low total WBC (\<2,000/uL)
* Cats will be briefly immunosuppressed following FPV infection
34
What is the FPV vaccine?
* AAFP Core Vaccine
* Modified live virus
* begin at 6-9 wks
* boost every 3-4 weeks until 16-20 wks of ag
* Booster at 6 months, 1 year, and then every 3 years
* Inactivated vaccines:
* safer for pregnant, immunosuppressed, FIV or FeLV + cats
