Protozoal Gut Infections

Question 1

What are the three common features of gut protozoa?

Answer 1

• Via faecal/Oral Transmission
• Have at least one life stage in the GIT
• they shed environmentally resistant stages into the faeces

Question 2

What two species make up coccidia?

Answer 2

Eimeria and Isospora species
* they are obligate intracellular pathogens
* usually host specific
* most of their life stages are non-motile

Question 3

How do Eimeria reproduce?

Answer 3

via schizogony (asexual reproduction via multiple fission)

Question 4

What animals does coccidiosis effect?

Answer 4

Primarily young animals, e.g poultry, lambs and calves

Question 5

What is the primary clinical sign of coccidiosis?

Answer 5

Bloody Diarrhoea

coccidiosis is the cause of major production losses

Question 6

How may you diagnose coccidiosis in poultry?

Answer 6

• Clinical signs
• Lesion location
• Microscopy (content, intestinal wall scrapes, oocytes, histopathology)

Question 7

What is the epidemiology of coccidiosis in day old chicks?

Answer 7

They start with no immunity
there is then rapid parasite multipilication
many oocysts shed after 7 days

Question 8

What are coccidiosis infections like?

Answer 8

Infections are often self-limiting and followed by immunity
the disease is most common in young birds of 3-8 weeks

Question 9

What two species cause ovine coccidiosis?

Answer 9

E. crandallis & E. ovinoidalis

Question 10

What parts of the GIT does ovine coccidiosis effect?

Answer 10

• Ileum, also caecum and colon

Question 11

What does ovine coccidiosis look like histologically?

Answer 11

– villous atrophy, crypt hyperplasia, cellular infiltration, oedema &
haemorrhage

Question 12

What is the multiplier effect with lamb coccidiosis?

Answer 12

lambs shed many more oocytes than they ingest

Question 13

What causes lambs to be the most susceptible to ovine coccidiosis?

Answer 13

• they are 4-12 weeks old
• With no previous exposure
• Stressed due to cold, wet weather, and poor nutrition
• If there is co-infection with Nematodirus

Question 14

What causes a high oocyte of ovine coccidiosis?

Answer 14

• There is faeces in the water or food supply
• there is dirty conditions around the food and water troughs
• overstocking
• the older lambs were previously on grazing or in building

Question 15

What increases the chances of bovine coccidiosis?

Answer 15

• Intensive Rearing
• Cattle are young, 1-2 months to 1 year
• it is less common in older animals

Question 16

What are the sub-clinical, clinical and severe symptoms of bovine coccidiosis?

Answer 16

Subclinical
* faecal staining of perineum, reduced feed efficiency, oocysts in normal faeces

Clinical
* Watery diarrhoea but with little to no blood, lasts a few days

Severe
* Bloody diarrhoea or thin faeces
* anorexia, depression, dehydration

Question 17

What are the key factors for Cryptosporidium?

Answer 17

• It is apicomplexan
• A common GI infection of mammals
• Primarily waterborne
• found in fresh produce
• undergoes zoonotic transmission

Question 18

What are the clinical signs of bovine cryptosporidious?

Answer 18

• Common cause of scouring in calves
• high morbidity, low mortality
• yellow-green diarrhoea with mucus
• mild dehydration
• The diarrhoea is due to the loss of the absorptive intestinal lining

Question 19

What is the epidemiology of bovine cryptospridiosis?

Answer 19

• The older animals tend to be carriers and shed low numbers of oocytes
• environmental contamination and disease in the second half of the calving period
• transmission from lambs, cat and vermin
• oocysts can survive several months in cool, moist conditions

Question 20

What parasite causes Giardia?

Answer 20

Giardia duodenalis

Question 21

What animals are most at risk of giardia?

Answer 21

It is a parasite of young animals, the adults act as carriers

Question 22

What is the epidemiology of Giardia

Answer 22

Parasite attaches to cells of the small intestine- non invasive
Dense layer of parasites interferes with absorption
Can damage epithelial cells and cause inflammation

Question 23

What does the Giardia severity depend on?

Answer 23

• Parasite strain
• Immune status
• Gut flora

Question 24

What is giardiasis like in cattle?

Answer 24

• Often asymptomatic but can cause diarrhoea in young animals
• Clinical signs- pasty diarrhoea, weight loss, lethargy

Question 25

What is giardiasis like in dogs and cats?

Answer 25

• Majority of dogs & cats are asymptomatic
• Severity higher in puppies/kittens – danger of dehydration
• Cats – clinical cases may be associated with FeLV, FIV
• Problem in catteries, kennels, shelters, multi-pet households

Question 26

How can you diagnose cryptospridiosis and giardia?

Answer 26

• Oocysts in a faecal smear
• staining of oocysts
• pathology
• parasites
  *

Question 27

What does Feline Tritrichomonas foetus cause in cattle?

Answer 27

abortion and infertility

Question 28

What does Feline Tritrichomonas foetus cause in cats?

Answer 28

• Intractable large bowel diarrhoea (5 – 24 months)
• Colitis → frequent passage of liquid/semi-formed yellow-green faeces, often
  with bloody mucus
• Anorexia, vomiting, weight loss in some cats

Question 29

How can you diagnose Tritrichomonas?

Answer 29

• Direct faecal smear
• faecal PCR

Question 30

How can you treat coccidiosis in chickens?

Answer 30

• anti-coccidial drugs in feed for the first 6 weeks
• build up resistance
• treat affected birds and allow the development of the parasite in non affected birds

Question 31

What vaccination can you give to treat paracox in chickens?

Answer 31

live attenuated oocyst suspension

Question 32

How can you treat ovine coccidiosis?

Answer 32

• Creep feed over the period at risk (this is only effective in the small intestine)
• Drenches (Distinguish lambs by age and risk and target specific lambs at correct time
• Outbreak – treat all lambs over 3 weeks

Question 33

How can you treat cryptosporidious and giardiasis?

Answer 33

• Hydration with oral electrolytes
• One drug licenced for prevention/treatment of diarrhoea caused by C. parvum
• No licenced drugs for giardiasis in animals
• Anthelmintics can be effective