Exam 2 Flashcards
Canine Parvovirus
Non-Enveloped Virus
• Early replication in lymphoid tissue
• Later invasion of rapidly dividing cells in intestinal crypt epithelium and bone marrow
Fetus, intestinal epithelium, hematopoetic system
Cause: enteritis and myocarditis
Fecal oral
• Virus is shed 4-5 days after exposure (prior to clinical signs) and up to 10 days after recovery
• Enters cells via cell mediated endocytosis
• Leukopenia and lymphopenia decrease ability for host response
ELISA
Survival months to years away from sunlight and disinfectants
Campylobacter
Spiral, Gram (-) Bacteria
• Intestinal Epithelial cells
• Cells of the lamina propria Fecal oral
• Persistant in host, part of normal flora
• Produces enterotoxins and cytotoxins
• Has cell adherence properties
• Enters cell via receptor mediated endocytosis
• Can persist for a long time in feces, milk, water, urine
• May become dormant and then be reactivated
Rhodococcus equi
Gram (+) Bacteria
Macrophages *Animals exposed all the time
- Animals that lack IFN-y increases risk of clinical disease
- Foals 1-4 mo most susceptable
• Large amount of bacteria shed in infected foals
• Host factor associated with disease: bacterial replication increase when macrophage fails to create a phagolysosome – no respiratory burst
• Ubiquitous in environment
Equine Influenza
Enveloped Virus
• maintained in the equine population via clinical cases and inapparent infection in susceptible horses
• Host factor for disease: exposure to naïve population
• Antigenic drift common
• Poor – enveloped virus
Porcine Reproductive and Respiratory Syndrome (PRRS)
Enveloped Virus
RNA virus Macrophage cell tropism – viremia spread (Trojan horse concept) Direct Contact (Oral, respiratory, semen)
Indirect Contact via fomites
• Highly persistent (not latent) in pig
• Demonstrates a high degree of mutation – helps evade immune system
• Expect to see a humoral (antibodies) and cell mediated immune response
• Decreased stability in environment – enveloped virus
Ascaris suum
mucosa of the small intestine
Fecal oral
Paratenic via Earthworm • Direct life cycle
• Parasites migrate through tissues resulting in secondary bacterial infection in lung
• Adult worms live in small intestine
• Infection induces Th2 response that promotes EOSINOPHILLA
• 2nd stage larvae infective to pig
• chitin ‘shell’ protects from thermal and environmental degradation
• protein coat makes parasite sticky to prevent washing away
Canine Influenza
Enveloped Virus
Direct contact (aerosol or droplets)
• Canine influenza is not persistent in the host – persistent within the population
• Viral shedding occurs first 2-4 days during incubation, but can shed for 10-14 days
• Host does not shed virus after the clinical symptoms conclude
• Does not survive well in environment – can live on surfaces for 24-48 hours
Equine Infectious Anermia
Retrovirus, Lentiviris (Enveloped?) Macrophages Direct contact (Flies– intermittent feeding) • Exhibits Viremia • Can cause both acute and chronic infections • Tests: Coggins Test - Abs
Toxocara Canis
Parasite
* Roundworm GI tract Direct:
Fecal Oral
THIS IS ZOONOTIC!
Vertical transmission from dam
Horizontal transmission Fecal oral
• Puppies most severe in young puppies
• Shedding of adult worms in feces or vomit may occur at 4-6mo of age
• Eggs resistant to harsh environmental conditions and disinfectants
• Egg pitted shell and sticky protein prevent washing away
• An adult female worm can lay 85,000 eggs per day!
Tapeworms
Tapeworms
GI Tract Fecal oral?
• Individual proglottids are shed in feces of infected animals
• Hosts are generally asymptomatic
Porcine Epidemic diarrhea Virus (PEDV)
Enveloped Virus
Epithelial cells of Small intestine and colonic villi Oral contamination from food or environment/
fecal oral
• Disease causes profuse watery pale white diarrhea
• Helical nucleocapsid made by viral N proteins present
• N proteins are known to antagonize interferon production to help virus evade the immune system
• Easily destroyed by disinfectants and dehydrating protocols
6 to knows for all diseases
ADTPDP
Agent characteristics, disease(s) caused by agent, transmission of disease (lifecycle for parasites), pathogenesis, diagnosis, prevention and control
ascarids in general
Who: Young animals of *every species* PPP: Short ~ 1mo (except A. Suum, P. Equorum) Life Cycle: Direct Infective Stage: Egg / L2 in egg Eggs Shape: Sphere or oval Shell: Thick, pitted Short-term desiccation and freezing resistance Environmental development → infective
Adults
Large, spaghetti
1 pair = 100K eggs/d
Where: Small Intestine
Diagnostic Tests: fecal flotation
Ascara suum
Swine roundworms
Direct
Hosts: Pigs
Paratenic host: earthworms, dung beetles
Fecal/oral/Paratenic
hepatic -tracheal migration
L2 in the egg infective
PPP 56 days (8 weeks) - unusual for ascarids
Clinical signs: Pneumonia, weight loss, biliary obstruction +/- jaundice, “thumps” or cough in a lighter infection
Diagnosis: Via a fecal test with zinc sulfate or magnesium, or on necropsy (milk spots, visible worms in the small intestine)
Prevention and control
Easier to prevent than to treat. More common on overcrowded, open pasture settings. Deworm sows before moving to a clean pasture, and before farrowing. Routine deworming recommended.
Not zoonotic
Distinguishing feature/hint to remember
***Unusual PPP for ascarids, no transmammary, no transplacental, no percutaneous transmission, milk spots
Parascarus equorum
Equine roundworms
Direct
Horses (usually foals)
Fecal oral
Ingestion of egg, develop in sm intestine (Hepatic-Tracheal)
10-15 weeks
Coughing/fever, nasal discharge, poor growth, colic, summer colds in foals, rough hair coat, colic
Fecal float (Primary), seeing worms (on necropsy)
Pasture management, prevent eggs from getting eaten
Not zoonotic
***Horizontal transmission, no vertical
Toxocara canis
Canine roundworms
Direct. Eggs shed in feces, can be ingested by dogs, or by paratenic hosts.
Definitive: dogs. Paratenic: small mammals (e.g. rabbits).
Per-os, transplacental, transmammary. Once in animal, can do hepatotracheal or somatic migration depending on age of dog
Eggs are infective after 2-4 weeks in envt
PPP: 30-35 days
Newborn: verminous pneumonia, pulmonary hemorrhage.
Nursing puppies: potbellied appearance, vomiting, lethargic, dull.
Adults: usually asymptomatic
Fecal float.
Clinical signs. Worms visible in vomitus or diarrhea. History (if bitch has hx of passing on larvae to multiple litters)
Reduce environmental contamination. Reduce exposure. Reduce contact w/ paratenic hosts. Treat puppies at 2, 4, 6, 8 weeks. Treat lactating bitch @ 2-3 wks post-whelping
Yes zoonotic- can cause Visceral Larva Migrans (VLM)
***Potbellied appearance. Hepatotracheal and Somatic migration. Main source of infection in adult dogs: paratenic hosts.
Toxocara cati
Feline roundworms
Direct
Cats are definitive hosts. Paratenic hosts are small mammals.
Per-os (affects all ages), transmammary (most common route of infection for kittens), paratenic (no transplacental)
4-5 weeks
Verminous pneumonia, eosinophilia, vomiting, diarrhea, intestinal obstruction, pot bellied appearance in kittens, unthrifty
Fecal floatation, identification of large, white worms in vomit or stool with cervical alae
Environmental control
Yes zoonotic
***No transplacental migration.
Heterakis Spp. (Bird)
Poultry cecal worm direct Paratenic: earthworm Definitive host: domestic and wild fowl Fecal oral Infective egg (L2)
Fecal float for eggs and necropsy for large worms in cecum
not zoonotic
***Eggs can act as a vehicle for Blackhead (Histomonas melagridis)
Canine Hookworms
Canine hookworm (Ancylostoma caninum, Ancylostoma braziliense- causes cutaneous larval migrans in humans, or Uncinaria stenocephala)
Direct
Paratenic hosts- mice, rats, beetles and roaches. Definitive hosts- dogs (there is also feline hookworm). I think humans would be an accidental host- but not 100% sure.
Per os, paratenic, transmammary (MOST IMPORTANT IN PUPPIES), transplacental (not as common), percutaneous.
Free larvae (L3)
Short! 2-3 weeks
BLOOD LOSS. Pale mucous membranes from anemia. Bleeding, malabsorption, pain. SI diarrhea.
Fecal flotation!!! Can do a hookworm ELISA- only identifies protein on adult worms. Eggs are morulated, thin-shelled, and ovoid.
Sanitation around home and routine fecal exams.
YES ZOONOTIC
***Blood suckers. Transmammary is most important ROI in puppies. THEY CAN GO THROUGH SKIN. Iron deficiency anemia.
Ruminant Hot Complex
gastroenteritis direct Definitive: ruminants Fecal oral L3 larvae
***There is no transplacental or transmammary infection.
Ostertagia Ostertagi
Brown stomach worm
Direct
Definitive: cattle
Fecal oral
L3 larvae
3 weeks
Young animals. Hypoalbuminemia. Diarrhea, weight loss, inappetance, bottle jaw (hypoalbuminemia). Moroccan leather gastric gland appearance. Type 1: bright green diarrhea. Type 2- hypoalbuminemia.
Egg looks like hookworm egg, so if we see hookworm eggs on a ruminant, it is strongyle type so HOT. Type 1- fecal egg counts. Type 2- fecal egg counts can be negative.
Anthelminthics. Type 2 is harder to treat than type 1. Need to address the hypobiotic larvae. Move to pasture not grazed by cattle the same year. Move animals off pasture and graze pasture with sheep or goats until June.
not zoonotic
***Most important nematode in cattle worldwide! Can become hypobiotic.
Haemonchua contortus
arber pole worm direct Definitive: sheep, goats, camelids Fecal oral L3 18-21 days Anemia, blood loss edema (hypoproteinemia), dehydration, weight loss. NOT DIARRHEA. FEC and FAMACHA Blood transfusions.
***Anemia. No diarrhea.
N. Helvetianus
Thin necked intestinal worm Direct-similar to other strongyles Cattle Fecal-oral Egg (larval stage developing inside) 15-26 days Larval stages can cause damage to intestinal wall resulting in unthriftiness, poor weight gain, and diarrhea. Large worm burden may retard growth in younger animals Fecal float or quantitative fecal floatation
***Eggs are HUGE!
Equine Large strongyles
Colic and thrombocolic direct Definitive: horses and donkeys Fecal oral L3 6-7 months Can result in severe blood loss and ulceration. May see thrombi formation.
***Migrate to the root of the cranial mesenteric artery
Equine Small Strongyles
Cyathostomes Direct Definitive: Horses and donkeys Fecal oral L3 6-14 weeks Dependent on worm burden and infected with larvae or adults. Neutrophilia, hypoalbuminemia, hyperglobulinemia, acute diarrhea, larvae in feces. Eggs in feces cannot differentiate species.
Good management and strategic deworming program with FEC. Strict sanitation. Good pasture management. Compost manure. Good nutrition.
not zoonotic
