Midterm 2 Infectious and Non-infecteous Disease Flashcards
How much of the dog population should be vaccinated for rabies to create sufficient herd immunity
70%
Why is Diclofenac –a non-steroidal anti-inflammatory– problematic to use?
The drug is toxic to vultures
How does vulture decline affect humans?
- The corpses become available to the the feral dog population, allowing the population to grow and increasing the amount of dog induced human rabies cases
- Corpses are inefficiently scavenged and they provide excellent breeding grounds for bacterial pathogens
What are common ways that vulture populations are reduced?
Poisoning
-poachers lace animal carcasses (elephants and rhinos) with poison to
intentionally kill vultures that might tip off park rangers
Herders poison felled livestock (killed by predators) to kill the predator
What is the most deadly zoonotic disease?
Rabies
What is the R0 of rabies in humans?
0
-We tend not to bite each other
This is the reason why the emphasis on rabies treatment is on dogs and not humans
What is the R0 of Rabies in dogs?
R0 >1
Structure and shape of rabies virus
RNA virus
-bullet shaped
-enveloped
-species specific variants
hydrophobia
An old term for rabies (specifically in humans)
-refers to a late stage symptom where the infected develops an apparent fear of water
How many human rabies cases occur due to dog bites?
95%
How long does it take for a human to start displaying symptoms of rabies?
3-12 weeks
It takes a long time for the disease to progress up the spinal cord and into the neck
-for this reason you may be vaccinated AFTER the initial infection and develop immunity*
*note that treatment must be administered before clinical signs
How does rabies spread?
Saliva
What was the original rabies vaccine made from?
Ground spinal cord of rabies infected rabbits
-The powder was left to dry to make it less virulent (rabies is very sensitive to hot temperatures and dried conditions)
Parvoviruses
A family of viruses
-Highly contagious (non-enveloped)
-DNA virus
-Type A
-Not spread via vector (must be fomites or environmental infection)
-Diarrheal disease
Type 2 Canine Parvovirus
Not zoonotic
-Very pathogenic
-Wildlife is fairly immune to it (doesn’t usually cause outbreaks)
-Can remain in the environment for up to 7 months
-Common in rescue dogs (if you adopt a “parvo-puppy” of them you aren’t allowed another puppy for a few months)
What makes canine parvovirus so deadly?
It damages the intestinal lining (enterocytes)
-This causes the inflammation and diarrhea
-Bacteria that normally stays in the gut (microbiome) moves into the bloodstream
The electrolyte loss causes problems too
Can Canine Parvovirus get treated?
If it is caught early
Vector
living agents that can transmit disease (mosquito, other animals)
Fomite
A non-living agent that can spread the disease
Valvular Disease
Enlarged heart
Multifactorial
-Genetics
-Diet
-Prior or concurrent health conditions
-Exercise
Many animals are predisposed to this
Has 4 stages (A, B 1 & 2, C, and D)
Stage A of Valvular disease
We may not find it
Stage B of Valvular disease
B1. The heart does not appear enlarged or changed
-You may hear a heart murmur
B2. Heart becomes enlarged
Stage C of Valvular disease
C. Evidence of heart failure is visible and treatment is necessary
-Changes in breathing
-Changes in behaviour
Stage D of valvular disease
Heart failure is getting hard to manage and is not responding to normal treatment
-At this stage euthanasia may be the right call