Cattle parasitology Flashcards
What is the intermediate host for liver fluke (Fasciola hepatica)?
Mud snails
Galba truncatula
Mud snails (Galba trunculata) can become infected in fluke in which two seasons? What conditions increase fluke populations?
Summer
Winter
(When temp above 10 degrees C and rainy - can forecast fluke)
What are some risk factors for fluke?
Co-grazing sheep and cattle (both get fluke)
Overwintering sheep at pasture
Areas of wet, boggy ground
Wet and warm weather
Animals with little/no immunity or immune modulation
What are the 3 different clinical presentations of liver fluke infestation?
Acute disease - 2-6 wks post infection
Chronic disease - 10-12 wks post infection
Subclinical (very common)
What are the clinical signs of CHRONIC liver fluke infestation?
Chronic anaemia
Hypoalbuminaemia (bottle jaw)
Weight loss and poor BCS
Subclinical liver fluke infestation is very common. Although there are little clinical signs, what may be noticed about that animal’s production?
Ongoing losses with growth and milk yield
Reduced fertility
Acute liver fluke infestation can cause haemorrhage and anaemia. Why?
Juvenile flukes migrating through liver parenchyma
Cause tissue damage and haemorrhage
How can liver fluke be diagnosed?
Signalment, history, clinical signs (difficult if subclinical)
Serum biochemistry (non-specific for fluke)
Fluke egg sedimentation (low sensitivity)
Copro-antigen ELISA
Antibody ELISA
Post-mortem (gold standard)
What 3 GI nematodes do cattle get in their abomasum?
HOT
Haemonchus contortus
Ostertagia ostertagi (T. circumcincta in sheep)
Trichostrongylus axei
What 3 GI nematodes do cattle get in their small intestine?
CNT
Cooperia spp (C. oncophora, surnabada, pectinate, punctate)
Nematodirus spp (N. helvetianus and spathiger)
Trichostrongylus colubriformis
What 3 GI nematodes do cattle get in their large intesine?
COT
Chabertia spp
Oesophagostomum spp
Trichuris spp
PGE is commonly seen in what age animals? Why?
Youngstock
Immunity (incomplete) acquired over 1-2 grazing seasons
Ostertagia osteragi is a nematode found in the abomasum of cattle. What is it commonly known as?
Brown stomach worm
What are the two types of ostertagiosis and how do they differ?
Type I - infection in Summer, dairy replacement cows
Type II - yearling calves, late Winter/early Spring HYPOBIOSIS (less common)
Which species of worm cause PGE in cattle?
Ostertagia ostertagi
Cooperia spp
Co-infection causes D+, poor appetite, weight loss
How is PGE diagnosed?
Grazing history and signalment Clinical signs and seasonality Plasma pepsinogen - Ostertagiosis Faecal egg counts (not particularly useful for type II Ostertagiosis) Post mortem Antibody ELISAs
What is the main disadvantage of antibody ELISAs for diagnosis of PGE?
Indicates exposure, not infection
Control of cattle parasites should be focused on….
Management strategies - e.g. pasture movement
Limit reliance on anthelmintics –> resistance
There is a vaccine available for which parasite in cattle?
Lungworm
live attenuated vaccine
What are the 3 groups of anthelmintics that can be used to treat/prevent PGE and lungworm?
- Benzimidazoles - white drenches (oral)
- Levamisole - yellow drenches (oral)
- Macrocyclic lactones - clear drenches (injectable & pour on)
Which anthelmintics are licensed against type II ostertagiosis?
Group 3 macrocyclic lactones
Some group 1 benzimidazoles
When should the lungworm vaccine be given?
2 doses, 4 weeks apart
2nd dose 2 weeks before turnout
(calves > 8 wks old)
Does the lungworm vaccine provide full immunity?
No
Subsequent natural exposure essential for full immunity to develop
When a group of cows are affected lungworm, what should your treatment plan be?
Treat all animals in affected group (animals on same pasture also at risk)
Move affected animals to safe pastures or well ventilated housing (if cannot move, treat with long acting MLs)
Check for secondary infections - antibiotics, NSAIDs
Remember milk withdrawal in lactating animals
The 5 R’s are an essential part of reducing resistance to anthelmintics. What are the 5 Rs?
Right product Right animal Right time Right dose Right administration route
What organism causes rumen fluke?
Calicophoron daubneyi
What is the intermediate host for rumen fluke (Calicophorn daubneyi)?
Mud snails - same as liver fluke
Galba truncatula
Is rumen fluke (Calicophoron daubneyi) pathogenic?
Probably not in adults (incidental PM finding)
Some cases in juveniles with heavy burden
How are rumen fluke eggs (Calicophoron daubneyi) detected?
Faecal sedimentation
What is the only licensed product for rumen fluke (Calicophorn daubneyi)?
Oxyclozanide
Cryptosporidium is a ZOONOTIC protozoa. What age calves does it affect?
Young calves
14-21 days old
(environmental build up, oocysts persistent in environment)
What are the clinical signs of Cryptosporidium infection in calves?
Diarrhoea and dehydration of calves 2-3 weeks old
Co-infection with viral pathogens common
How is cryptosporidium diagnosed?
History and clinical signs
Faecal smears (Ziehl-Nielsen staining)
Pen-side antigen test strips
How is crytosporidium treated and controlled?
Halofuginone (prophylaxis at 1-2 days old, reduces symptoms in clinical cases)
Reduce stocking density, good hygiene, supportive Tx
Coccidiosis affects young calves. What 2 agents most commonly cause coccidiosis in calves?
Eimeria zuernii
Eimeria bovis
Where do Eimeria zuernii and E. bovis replicate?
Caecum
Colon
Is coccidiosis (E. zuernii/bovis) in housed or grazing animals? When is coccidiosis seen?
Both!!
Seen 3-4 weeks post-weaning
What are the clinical signs of coccidiosis?
Bloody dysentery (inflm of colon) and tenesmus Chronic wasting, poor appetite
How is coccidiosis diagnosed?
History and clinical signs
Post-mortem and histopath
Oocysts - wet smears or McMaster
What 2 drugs can be used to treat and prevent coccidiosis (E. zuernii and E. bovis)?
Toltrazuril
Diclazuril
Is flystrike common in cattle?
No - very rare!
Which months are most common for biting and nuisance flies?
May-October
Apart from causing worry and avoidence behaviour and irritation, what is a worry of biting and nuisance flies in cattle?
Disease vectors
Hydrotea irritans spreads what disease in cattle?
Summer mastitis
Culicoides midges spread what 2 diseases in cattle?
Bluetongue
Schmallenberg
Muscidae flies spread what disease in cattle?
New Forest Eye
What can be used to control biting/nuisance flies in cattle?
Spot-on/pour-on synthetic pyrethroids
Tail bands/ear tags
Pasture management
What chewing louse is seen in cattle?
Bovicola
What sucking louse is seen in cattle?
Linognathus
What 3 mites can be seen in cattle?
Chorioptes bovis
Psoroptes bovis
Sarcoptes scabei
Ixodes ricinus ticks are vectors for what diseases in cattle?
Babesiosis (Redwater fever)
Anaplasmosis
Louping ill
Etc
Lice and mites are common in cows in what season? Are they more common in housed or outdoor cattle?
Winter
Housed animals
