Parasitology - Lecture 25 (Ruminant Parasites)

Question 1

Discuss common ruminant parasites

Answer 1

Nematodes –> GI; lungworms
Trematiodes –> liver flukes
Tapeworms 00> larval and adult
Protozoa: coccidia, cryptosporidium, toxoplasma, and tritrichomonas

Question 2

When considering strongyles of the GI tract in ruminants, which spp lives herw

Answer 2

Ruminant abomasal strongyles –> HOT complex
- Haemonchus –> most important in small ruminants
- Ostertagia –> most important in cattle
- Trichostrongylus –> moderate importance in all

Question 3

Discuss the HOT complex –> the gernal life cycle

Answer 3

• All 3 have very similar life cycles with short PPP
• **Inhibited dvelopment ** can stop develoment and necyst in tissue
  - Pasture L3 –> L4 in mucosa for 3+ months –> adult
  - Indicued by enviornmental cues
  - Geogrpahic variation
  -

Question 4

Regarding the HOT complex, discuss the soriung rise

Answer 4

• Perparturent rise (spring rise)
• increase in egg output in the spring –> especially periparturent ewes
• Mostkly due to maturatioin of mucosal inhibited L4 into adults
• Seeds the pasture with eggs –> L3 –> lambs, kids, calves

Question 5

When consideing the ruminant abosmasla parasites, discuss Haemonchus cortortus

Answer 5

Haemonchus contortus –> sheeps and goats
H. placei –> cattle (not as important)

• Most important parasite in small ruminats; feeds on blood; high reproductve capacity

Life cycle:
adult in abomasum –> eggs –> pasture, L1, L2, L3 –> L3 ingesteed by host –> mucosa –> L4 –> adult

Inhibited L4s survive winter in host
spring rise –> pasture contamination
Low survival of L3s in hot/dry or cold –> irrigation in summer improves survival

Question 6

Discuss the poathology and clinical signs of Haemonchus contortus

Answer 6

Pathology: acute disease in young animals; chronic disease in older naimals

Clinical signs:
- Anemia
- acute: rapid onset –> possible death
- cxhronic: copenated
- chronic: deocmpensated –> clinical disease
- Pallor of skin and mucous membranes
- Submanidbular edema: **bottle jaw* results from a loss of serum proteins that cuases tisssue edema
- Appetite is fine, usually no diahhrea

Question 7

Discuss the diagnosis of Haemonchus contortus

Answer 7

Cliincial signs: anemai, bottle jaw
– EPG –> strongygle eggs in the high 100s
Postmortem –> adulkt in abomasum

Question 8

Discuss the treatment and control for Haemonchus contortus

Answer 8

• Treat clinical cases immediately and move to clean pasture –> FBZ, ALBZ, macrocyclic lactones (ivermectin), pyrantell and morantel
• Tactical treatments –> as needed
• ## Increasing prtoein content in ewe feed in spring helps prevent spring rise

Question 9

When considering the HOT complex, discuss the Spring rise in relation to egg ouput

Answer 9

• Treat in spring –> to lower pasture contamination and protect lambs from developing clinical burden
• Treat in fall –> to prevent larval inhibition

Question 10

Discuss treatment and control of Haemonchus Contortus

ALso discuss the prevention for it

Answer 10

Drug resistance –L> against all major classes of anthelminitcs –> especially in goats and sheep
- perrform FECRT to make sure the enthe,intic is appropriate for the hrd

Selective dowmoing –> ytreat only those that need therapy –> FAMACHA technique (this is essentially a color chart for inner eyelid coloring)
NOTE that it is importnat to understand that the selective deowrming technique (and also the FAMACHA technique) is applicable to the Haemonchu species

Prevention: Vaccine