infectious dz: Dog 3 Flashcards
What human virus is canine distemper very close to?
measles
paramyxoviridae
How is canine distemper virus spread?
thru water droplets –> upper respiratory tract epithelium –> multiplies in tissue macrophages –> spreads to local lymphatics in tonsils and bronchial LN
by 2-4 days post infection viral number increases in tonsils and retropharyngeal and bronchial LN
By 4-6 days post infection, where is the canine distemper virus replicating in the body?
Lymphoid follicles of the spleen and gut associated lymphatic tissue (stomach and small intestine, mesenteric LN) and kupffer cells in the liver
**causes pyrexia and lymphopenia (T and B cells)
What kind of fever is noted with canine distemper virus?
Biphasic temperature spikes
noted upon initial viremia and multiplication and then widespread viral proliferation
On days 8-9 post infection, where has the distemper virus spread to?
Epithelial tissue and CNS
By what day post infection will patients with adequate distemper antibody titers cna cell mediated cytotoxicity clear the virus from most tissues?
Day 14 post infection
poor immunity will lead to spread in the skin, exocrine, endocrine glands, and epithelium of the GI, Resp, and genitourinary tract, and to the brain
What are some characteristic clinical signs of canine distemper virus?
Listlessness, anorexia, fever, URI, GI signs - dhr with blood and mucus
- *bilateral serous oculonasal d/c - becomes mucopurulent
- *biphasic pyrexia
- *Keratoconjunctivitis sicca (dry eye)
Skin lesions - vesicles and pustules, nasal and digital hyperkeratosis
When are neuro signs typically noted in patients with canine distemper virus? What are they?
Noted 1-3 weeks post recovery from systemic illness
hyperaesthesia and cervical/paraspinal rigidity - meningeal inflammation
Sz, cerebellar and vestibular signs
***Myoclonus (with or without other neuro signs)
Who is your typically CDV patient?
3-6 month old unvaccinated or inadequately vaccinated puppy
When looking for antibodies to CDV - in the first two weeks of infection the patient will have an increase in ____ antibodies, and in weeks 2-4 there will be an increase in ____ antibodies
IgM peaks at two weeks (usually before neuro signs set in)
IgG peaks at 4 weeks
What diagnostic tests can be performed if you suspect CDV?
PCR (whole blood, serum, CSF)
Serum antibody testing: Gold standard = Neutralizing antibodies - look at IgG levels
*Indirect FA testing titers
peripheral blood smear - inclusion bodies in erythrocytes
CSP tap
MRI
Chest rads
What is the most common type of vaccine used for canine distemper virus?
Modified live vaccine
offers strong protection
When might you have vaccine failure?
- failure to properly control vaccine temp
- maternal antibodies present
- Can result in adverse reaction
What is the pathogen for Canine infectious hepatitis?
Canine Adenovirus Type 1 (CAV-1)
T/F: Canine adenovirus is highly resistant to environmental inactivation
TRUE
steam cleaning is effective and caustic disinfectants
After infection with CAV-1 the virus is found in what tissues?
within all tissues - but by day 10-14 post infection the virus is found only in the kidneys and excreted in the urine for at least 6-9 months
When does severe viremia occur with canine adenovirus?
4-8 days post infection - then will spread through all tissues including hepatic cells, vascular endothelium, and CNS (high concentrations)
How are dogs exposed to canine adenovirus?
Oronasal exposure
antibodies start to form within ___ days post infection with CAV-1
seven days
What is the usual cause of death associated with CAV-1 infections?
acute hepatic necrosis = hepatic failure = hypoglycemia
What animals have the highest mortality associated with canine infectious hepatitis?
Young puppies - will usually die within a few hours after onset of clinical signs
Dogs less than 1 year are usually infected
all unvaccinated dogs can develop this dz
What clinical signs can be seen with canine infectious hepatitis?
Pyrexia, tachycardia, tachypnea, coughing, tonsillar enlargement and lymphadenopathy, hemorrhagic diathesis, widespread bleeding
*icterus is uncommon, bc most patients will die before this is noted
Why aren’t neuro signs often noted in patients with infectious hepatitis?
Increased ammonia levels will cause neuro signs, but the patient will become hypoglycemic and die before that can happen
Dogs who survive canine adenovirus will have what lesion?
Blue eye - corneal edema and anterior uveitis
