Formative Assessment Flashcards
(42 cards)
Explain the role of Ctenocephalides felis in the transfer of Feline Infectious enteritis
The flea takes a blood meal from the infected host and jumps onto the next host to feed.
It transfers the FIE through the saliva when it takes it’s next blood meal from the uninfected host.
Explain the role of Ctenocephalides felis in the transfer of Diplydium caninum.
Segments from DC are passed in the faeces and the eggs are released into the environment.
These are eaten by the larval flea and a cysticercoid develops as the flea develops.
The infected flea moves slowly and clumsily on the animal and is groomed off the host.
The cysticercoid is released into the small intestine and attaches to the intestinal mucosa and grows into an adult DC in 3 weeks.
Please explain the procedure used to perform a packed cell volume test on a cat.
Wear gloves.
Select EDTA sample and agitate gently.
Place a plain microhaematocrit capillary tube into the sample and hold the sample
tube at an angle.
Draw blood up into a plain capillary tube – 3/4 full.
Place a finger over the top of the microhaematocrit tube and remove it from the sample.
Wipe the outside of the tube with tissue.
Stop up one end with clay sealant (cristaseal).
Place in microcentrifuge – clay plug outwards fitted against rim.
Balance the centrifuge with another tube opposite Screw down inner safety plate and lock outer lid.
Spin at 10000rpm for 5 minutes (or fast setting).
Dispose of any used capillary tubes and waste as hazardous waste.
Remove tube from centrifuge and measure PCV using a Hawksley Microhaematocrit Reader.
Place tube in groove on reader with the clay seal pointing downwards.
Line up the top of the seal (bottom of the RBC’s) with the zero line at the bottom of the reader.
Move the tube holder across the reader until the top of the plasma lines up with the diagonal line at the top of the reader on 100%.
Move the adjustable PCV reader line so that it intersects with the top of the rbc column and read the measurement on the scale on the right side as a percentage.
Which parameters can be assessed through the use of a packed cell volume test?
Anaemia, haemorrhage or dehydration
When spun down, what are the three layers of a PCV called?
RBC’S, Buffy Coat and plasma
What is the normal PCV range for a cat?
24-45%
What is the normal PCV range for a dog?
37-55%
Which blood tube would you use to take a sample for a PCV test
EDTA
Please explain the procedure to carry out a differential white blood cell count
Wear gloves.
Collect a microscope slide and clean with ethanol (or absolute alcohol methanol) to remove grease.
Dry with a tissue (lint free). Select an EDTA blood tube and agitate gently. Insert a plain capillary tube into the EDTA sample and draw blood into the tube.
Place finger over top of capillary tube to prevent blood escaping.
`Remove capillary tube and place one drop of blood at one end of the microscope slide.
Place capillary tube into hazardous waste.
Select a glass spreader, which is a glass microscope slide with a corner removed.
Make sure it is free of grease.
Hold the microscope slide on the work surface and place the spreader at opposite side to the drop of blood.
Draw the spreader slide back at a 45º angle towards the blood and allow the blood to run along the spreader edge.
Push the spreader forward along the slide with a smooth motion until the drop of blood is spread evenly as a film.
Do not have too large a drop of blood or the film will be too thick.
Allow the film to air dry thoroughly and quickly before attempting to stain.
Label one end with a chinagraph pencil including the date and your initials.
Check and comment on the smear that has been produced.
Stain with Diff-quick stain.
Prepare a small pot of each solution – deep enough to dip a slide completely.
Dip the dried blood smear slide into solution A (blue) for 5 x 1seconds.
Then shake off the excess. Repeat for solutions B (red) and C (purple).
Carefully rinse off the excess solution 3 with distilled water.
Air dry.
What is the normal range of SG for a cat?
1.035 - 1.060
What is the normal range of SG for a dog?
1.015 - 1.045
Please explain the significance of a low urine specific gravity.
Dilute urine.
The animal may have Polydipsia, Chronic renal failure,Diabetes insipidus,
IV Fluid therapy
corticosteroid treatment
Please explain the significance of a high urine specific gravity.
Concentrated urine.
The animal may have Dehydration, Acute renal failure,
Diabetes mellitus, Shock, Sediment eg: crystals
Please describe the process of viral replication.
Virion attaches to the host cell membrane at receptor sites (if no receptor sites
the cell is resistant).
In the case of bacteriophages the bacterial cell wall is softened by lysozyme from the tail plate.
The tail plate then contracts and the virus or viral nucleic acid enters the cell.
If the whole virus enters it must be uncoated to release DNA or RNA.
The virus takes over control of cells metabolism – redirecting it to produce large numbers of viral components.
Components are re-assembled into fully infective viral particles and released either by a, rupture ( lysis) of the cell. b, budding through the cell membrane (so gain an envelope).
Please explain the process of bacterial replication
Binary fission is the asexual division of a bacterial cell into 2 identical daughter cells.
The cell grows and the chromosome replicates.
The cell membrane grows inwards and then the cell wall to form a septum which splits the cell into two identical cells
Which organisms may be assessed through the use of a skin scrape?
Demodex canis, Sarcoptes scabeii
Which organisms may be assessed through the use of a coat brushing?
Ctenocephalides canis,
Ctenocephalides felis,
Trichodectes canis,
Felicola subrostratus,
Linognathus setosus,
Cheyletiella yasguri
Please explain the procedure used to assess if an animal has Microsporum canis.
In some cases of ringworm infection, the hairs will fluoresce when exposed to ultra-violet light (i.e. a Woods lamp).
This procedure should be performed in a darkened room.
Allow the lamp to warm up before shining it onto the animal’s coat. 50% of Microsporum canis isolates will fluoresce an apple green colour.
However this technique is not fool proof and as mentioned only 50% of cases fluoresce so alternative methods should also be used in conjunction with the lamp if the result appears to be negative.
Other substances that fluoresce include surface scale, talc and starch from inside gloves, however they do not appear apple green.
Please describe how Toxoplasma gondii reproduces
The final host is the cat.
Oocysts are passed in the faeces of the cat and eaten by an Intermediate host (mouse etc).
These reproduce asexually in the intestine of the Intermediate host.
They can travel to the tissues and divide to form tachyzoites then bradyzoites.
These remain in the Intermediate hosts tissue until the Intermediate host is eaten by the cat.
What ratio of tissue to fixative volume is there when sending a sample to a laboratory for tests?
1:10
Describe the procedure used to send a sample to a laboratory for testing.
To avoid cross contamination and zoonosis, wear PPE. Check that the sample is preserved correctly, ie: is there adequate formalin? Ensure the container is labelled with the animal’s name, species, breed, age,sex, owner’s name and date. Ensure the container is airtight, moisture proof and robust. Ensure the total volume/mass of the sample in one package does not exceed 50ml or 50g. Wrap the container in sufficient absorbent material to absorb the total volume of fluid in the sample should the container leak or break. Place the sample in a secondary layer eg: plastic biohazard bag. Ensure the laboratory paperwork/form has been completed and place this in a plastic bag separate from the sample. Place all the items into the tertiary layer eg: a prepaid padded bag supplied by the laboratory. Ensure the outer packaging contains the senders name and address. Ensure the outer packaging states the nature of the sample and any special instructions eg: handle with care, fragile, pathological specimen. Ensure the sample is sent by first class post or via a courier
What is the term used for assessing a tissue sample?
Histology
What colour blood tube would be used to assess for glucose in a sample?
Yellow
What does the term lipaemia mean?
Fat globules in the blood
