WRML. pictorial follow-up to the recent post on liver fluke
The recent post: https://wormmailinthecloud.wordpress.com/2013/05/07/wrml-aprilmay-fluke-drench-and-feeding-sheep-and-other-livestock/
A nice pic
Photo source/owner: Jim Meckiff There are also nice pics in Dr Boray’s Primefact: http://www.dpi.nsw.gov.au/agriculture/livestock/sheep/health/liverfluke-disease-sheep-cattle
Last Friday Armidale Sheep and Wool Officer Jim Meckiff was at Tamworth abattoir to see lambs from a prime lamb competition.
260 lambs about 7 months old from ~ 25 properties were slaughtered. ~20 lambs out of the 260 had ‘flukey’ livers.
Jim was not in a position to ascertain from which or how many farms the ‘flukey’ lambs came.
Despite the low-res image, you can see adult fluke on the surface of the liver which have escaped from bile ducts after the liver has been sliced open post-mortem.
Some of the liver appears fibrosed (an attempt at healing) and the lobe to the right shows signs of necrotic tracts (dead tissue associated with immature migrating fluke). (nekros(Gk)=dead)
Quite possibly this liver contains fluke of varying ages: from immatures right through to adults.
If you are not sure whether or not you have liver fluke, now is a good time to test (despite the dry conditions).
Talk to your vet or other well-informed advisor about which test to use.
Most labs (e.g. DPI, VHR) offer a liver fluke egg count. (This uses a different technique from roundworm egg counting, because liver fluke eggs are relatively dense and do not float in saturated NaCl (salt) solution).
The NSW DPI lab, and possibly others offers a blood test which detects antibodies to liver fluke.
The lab at CSU Wagga also have a kit-based test from Europe that detects liver fluke antigen in faeces. (Virbac (Dr G Kelly et al) assisted in the validation of the test). You will need to ring CSU Wagga about this (or talk to your vet etc): unfortunately the CSU website website at this stage tells you very little about the test. http://www.csu.edu.au/vetservices/vdl
More information on fluke control (incl. drenches) in sheep (see also Boray of course!) : http://www.wormboss.com.au/programs/tas/appendices/liver-fluke-control.php
Information on tests: http://www.dpi.nsw.gov.au/agriculture/vetmanual/specimens-by-discipline/parasitology/fasciola
Don’t assume you don’t have or won’t get fluke (‘don’t guess, test’)
‘Some interesting information from Liz Braddon, Senior District Vet, Lachlan LHPA (based at Young).
The ELISA Liz refers to is an ELISA detecting antibodies to Fasciola hepatica. See: http://www.dpi.nsw.gov.au/agriculture/vetmanual/specimens-by-discipline/parasitology/fasciola
The ‘pools’ are blood samples that are pooled and tested at EMAI/the State Vet Lab (NSW DPI).
"We have actually had a positive (all >150 ELISA positive pools in 20 head) on a property that suffered flooding in the past two summers. Cows still looked pretty good but had a couple that were a bit ordinary. Producer had never had confirmed liver fluke in previous 20 years. I was bleeding for Q fever project and offered to do liver fluke to prove / disprove the theory … bit of a surprise. We are going to check a few others that have flooded as well to see if they have action as well. Eliz Braddon 9/4/13 (or 4/9/13 given that Liz is from North America 🙂 – Editor)
We have “checked a few others” with some interesting results:
* One property all pools >150 – Limousin cattle, mixed ages but good body condition and soft shiny coats – eg. no evidence of clinical disease!
* One had 1 pool 240, rest negative (<30) – mixed bunch but nothing out of the ordinary noticed when testing
* One all negative (<30) "
Nik’s comment was that she was surprised that with this level of infestation, there were no visible signs of production loss. Belinda threw out the possibility that older cattle can develop immunity to a certain extent which minimises losses but obviously act then as a reservoir for the disease!?- Eliz Braddon 9/5/13."
(Nik Cronin and Belinda Edmonstone are District Vets in the Lachlan LHPA (located at Forbes)
(Image source: http://www.lhpa.org.au/districts/lachlan )
Cattle, if not young cattle, tend to handle liver fluke better than small ruminants and alpacas. However, just as with roundworms, they can suffer significant if not obvious production losses (especially in high producing animals like lactating dairy cattle) in the absence of clinical disease. Clinical disease is the tip of the iceberg.