Review Flashcards
Trichuris (Enoplid) L1
Trichuris, general name? pathogenic? Expression of disease? Where do you see this parasite frequently?
*(whipworms)- embed anterior end under the mucosal lining to sit in tunnels and absorb nutrients, digest juices with stickosome oesophagus
* Mostly non-pathogenic- Immune response is not protective, so “accumulation” of infection– animals do not get rid of them like other parasites
* Occurs in the LI
* Typhlocolitis, colitis, mucoid enteritis and mucoid diarrhoea
* Large burdens = bleeding, blood in faeces
* large numbers of eggs excreted
* Seen in kennel situations
Ascaris suum, where? Migration? Who? Transmission route? Unique characteristics?
Ascaris suum
* Impacting large intestine
* HP migration- massive immune response
* Generally in young animals
* transmission route: simplest version of any ascarid: DIRECT– infective egg in the environment
* Prolific egg layers- sticky eggs
* Sandy environments- you can get rid of them- but generally in the environment they are difficult to get rid of especially in humid environments
* L3 is the infective stage- egg shell is still there in order to get through the stomach and to the SI
* Earthworms can carry eggs but MOST infections arise after ingesting L3 contaminated foodstuffs
Trichinella L1 in muscle
* 12 different species around the world; T. pseudospiralis and T. papua (Northern AUS)- not a major issue in AUS
* human health issue (raw meat contaminated)- induce acute GIT infection
* worms mate, produce larvae, and are injected into the lacteals in the SI–> muscles–> use their stillette to get in–> undergo muscle to moult so they can survive
* Main pathogenic effect in muscle: fever, myositis, myalgia (muscle pain)
* Hard to diagnose in animals
T. spiralis or Trichinella
T. papuae or T. pseudospiralis
Physocephalus sexalatus (via beetle) (Spiruroid)
Ascarops strongylina (pig– via beetle) (Spiruroid)
Why do we need to know the PPP?
To break the cycle with drugs
Where would you find these eggs? PPP?
Oxyuris equi- lays eggs around the anus
* PPP= 3 months
What might this be?
Where would the two possibilities normally occur?
Habronema microstoma or H. muscae or Draschia megastoma (Spiruroids)
* mostly occur in the stomach
* need the stomach to produce adults, to produce eggs to be excreted into the environment
Draschia megastoma (Spiruroid- horse)
Habronema microstoma or Habronema muscae (Spiruroid- horse)
Onchocerca gibsoni (Filarioids)
Heterakis
Toxocaris canis (Ascarid)
What’s the difference between T. cati and Toxocaris canis life cycle?
T. cati only Transmammary
Toxocara canis & cati (PPP is only different), stage passed in faeces? infective stage in soil? duration taken to reach infectivity in soil? PPP? What illness could a puppy have?
Stage passed in faeces: Egg- embryonated
Infective stage in soil: Larvae in the egg (L3)
Duraction taken to reach infectivity in soil: 2 weeks
How long will the eggs survive in soil: 5-10 years (thick and resistant)
PPP: Toxocara canis: 2-3 weeks (transplacental) to 4-5 weeks (ingestion egg)
* Toxocara cati 4 weeks (transmammary), to 6-8 weeks (ingestion)
* puppies get pneuomonia as well but not T. cati (not as pathogenic)
Why wouldn’t you expect to find Toxascaris leonina to be in a puppy?
No transmammary or TP transmission
* only way to get infected is by eating an IH like a mouse
* also because the PPP= 3 months– you wouldn’t see eggs in its poo for at least 3 months
Toxascaris leonina (Ascarid)
How would you treat current infection in pups and bitch Toxocara canis? Recommendations to breeder for future prevention of roundworm in bitch and pup? Breeder has a toddler at home, what advice would you give them?
Bitch before whelping: macrocyclic lactones– monthly (moxidectin or selemectin or injectable– kills larvae in circulation) **(may have encysted larvae– no way of telling)
Pups: pyrantel (every 2 weeks) until 2 weeks after weaning 3 months, then every month
** only drugs you can give puppies: drontel puppies (pyrantel and something else) or milbermycin (expensive) or pyrantel only.
** prevents A. caninum as well!!
** soil is contaminated– eggs stay in soil for years
What are the two main diseases in humans from Toxocara?
Visceral larva migrans (urticaria or fever, hepatomegaly, eosinophilia, cough) and ocular larva migrans (8 year old is mean age of presentation– causes blindness)
Trichuris vulpis
Would you expect egg to be infective upon passing?
No. It occurs in the environment.
Why would you never expect Trichuris vulpis in a puppy?
Because there is a long PPP. 10-12 weeks. Minimum age is 5-6 months.
What would you expect to see with heavy infections of Trichuris vulpis?
Typhlitis, colitis, diarrhoea with mucous +/- fresh blood, anaemia, tenesmus (straining to defecate)
Post-mortem stray dog in Delhi- aorta
Spirocerca lupi
What is the IH of Spirocerca lupi? DH?
Dung beetle (L3 develops within) and Dog
Spirocerca lupi
What may occur with a dog infected with S. lupi?
Aortic rupture, oesophageal granuloma– fibrosarcoma (eventually kills because it can’t eat), ectopic migration (paralysis, seizures)
How you do diagnose S. lupi? Prognosis?
Eggs look similar to another stomach worm AND eggs may not be present in faeces.
Endoscopy and radiography
** anorexia
Gnathostoma
Gnathostoma sprinigerum (humans)
When do you test for heart worm? What can indicate heartworm in a dog? What to treat? How to diagnose?
After 6 months– for example, they were taken off MLs for a period of time.
* Develops over 6-9 months
* Develop signs of coughing prior to 6 months
* Moxidectin (ML)- up to the age of 54-60 days
* Blood look for microfilaria & ELISA antigen
What happens with myointimal proliferation in heartworm?
* pulmonary artery thickens- becomes less elastic– needs to be elastic in order to comply with the heart pumping–> cause hypertension to develop
* leakage into the lung (congestion of the lung)
* leads to right sided congestive heart failure
* exacerbated by microthrombi from the worms
Toxocara canis
Macracanthorhynchus hirudinaceus
True or false Pseudophyllidea lay operculated eggs.
True
What clinical signs does Diphyllobothrium latum cause? LC? Is it in AUS?
* D. latum affects humans and carnivores
* Causes diarrhoea and abdominal discomfort, sometimes slight to severe anaemia due to vitamin B12 deficiency (assimilated by the worm) when worms are situated in the upper small intestine
* Egg–> coracidium–> procercoid (copepods)–> plerocercoid (freshwater fish)–> adult (humans, dogs, cats)
Diphyllobothrium latum (Pseudophyllidea)
Diphyllobothrium latum (Pseudophyllidea)
Diphyllobothrium latum