Farm December Newsletter 2024

Dedicated farm line – 01626 357776

This newsletter is sent by e-mail to each vet practice but if you would like a copy sent to your individual e-mail account please contact us at dsfarm@axiomvetlab.co.uk and we can add you to our circulation list.

Changes to Camelid profile

In our constant search to provide you with the most useful diagnostic options and following a literature review and advice from experts in camelid medicine and nutrition, we have elected to amend our camelid profile to improve our ability to pick up, in particular, cases of hepatic lipidosis. From the beginning of January, we will be replacing BHB, bilirubin and GLDH with bile acids, triglycerides, AST and CK.

Animal Health & Welfare Pathway – worm egg counts now available

Please note that we are now participating in the worm egg counting part of the AHWP for sheep. However, we are unable to post out sampling kits. Consumables can be ordered from us in the usual way. WHEN SUBMITTING POST TREATMENT SAMPLES, PLEASE ENTER THE ACCESS (REPORT) NUMBER FOR THE PRE-TREATMENT SAMPLE RESULTS AS A PREVIOUS REFERENCE ON THE SUBMISSION FORM. We can then provide you with a % change in the strongyle egg count after treatment.
We are a UKAS accredited lab and provide ISO17025 accredited tests so we can carry out any of the follow up endemic disease testing for both cattle and sheep.

The diseases and conditions to be sampled for sheep include:
Border disease (BD), caseous lymphadenitis (CLA), enzootic abortion of ewes (EAE), Johne’s disease, Maedi Visna (MV), toxoplasmosis, tick-borne fever, pulpy kidney, lamb dysentery, ewe nutrition status, lamb nutrition status & trace elements.

Incorrectly submitted samples

Samples received into the lab that are incorrectly packaged require more time and equipment to process and in some instances present an unnecessary Health and Safety risk to our Lab staff. Examples of incorrectly packaged samples include:

Samples submitted in rubber gloves rather than the correct sample pots, e.g. faecal samples.
Non serum gel tubes for clotted blood samples (we would ask you to use serum gel tubes provided by Axiom Laboratories which substantially decrease sample processing time and reduce the need for additional plastic consumables as the analyser can test direct from these tubes).
Cases that contain multiple samples from different animals that are either unlabelled or that have been packaged out of the numerical sequence written on the accompanying submission form.
No list of animal IDs and tube numbers received with herd or flock screens. This list is essential for booking in samples in the office.
Where needles have been included in the packaging along with the samples.
The submission of whole animals and foetuses as we do not have a PM room to handle these.

Continuing to submit incorrectly packaged samples affects our ability to get results to you quickly and efficiently while keeping our prices as low as possible.

The above list is only an example of scenarios, however where we experience additional time and cost in processing poorly submitted samples we reserve the right to charge an additional fee towards the admin time incurred e.g. for blood samples that fee would be 25p per tube.

Using detachable bar codes on herd screen submissions

Sending us a complete and accurate ID reference list with your herd/multiple animal submissions for checking and booking in your samples is an essential part of the procedure.
This is facilitated by using the detachable bar codes supplied on our preferred serum gel tubes. Simply record the animal ID on the Axiom submission form (or your own list/table) then remove the barcode strip from the tube and place it alongside the corresponding ID in order for us to associate each specific tube with the relevant animal. There is no need to write out the bar code numbers by hand on the list.
Please remember always to provide such a list and, when using a Field Kit for larger herd submissions, be sure to populate the polystyrene rack IN THE SAME ORDER AS YOUR ID LIST. This means that we will be able to check, process, and forward your samples to the relevant laboratory department for testing in a far more efficient manner, in turn allowing us to deliver your results in the shortest possible timeframe.

Would you like to send the Axiom farm vets photos of PMEs to allow us to assist with sample selection and diagnosis? Please send photos by WhatsApp to 07944 649222.

Please provide your name, practice, the farmer and farm names so that we can link the photos to the relevant submission and please also indicate which Axiom vet you discussed the case with. We may wish to use some of the photos in our newsletter so please indicate if you are not happy for this to be done. All cases are anonymised and credited to the submitting vet. Please note that this number is just for sharing photos. If you wish to discuss a case for which you do not have photos, please ring 01626 357776 as usual.

BVD Cymru accredited lab

We are an accredited lab for the Welsh BVD eradication programme. BVD antibody and antigen results will be uploaded if samples are submitted on a BVD Cymru form. As was the case with BVD Free England there is a small charge for the uploading of the results of 50p per sample for BVD antibody testing and 25p for a BVD antigen test.

Please note that all fields on the BVD Cymru submission form must be completed (including the keeper’s phone number and email address) otherwise there is a block on the results uploading.

New multiplex PCR test for investigating ruminant abortions.

The diagnostic rate for bovine abortions through veterinary laboratories has always been relatively low. There can be a number of reasons for this – the cost of testing for the large range of possible causes makes it cost prohibitive to do a comprehensive screen, the degree of autolysis, lack of availability/testing of placenta and of course some will have been aborted for non-infectious reasons e.g. nutritional, physical or genetic reasons. With sheep abortions the diagnostic rate is higher but screening is usually limited to the most common causes. In an attempt to increase the diagnostic rate of infectious causes of ruminant abortions we are introducing a ten agent multiplex PCR test. It will screen for the following agents:
Anaplasma phagocytophilum (TBF), Campylobacter fetus, Chlamydophila spp. (includes EAE), Coxiella burnetii (Q fever), Leptospira spp., Listeria monocytogenes, Neospora caninum, Salmonella spp., Toxoplasma gondii & Brucella sp. These agents are often found systemically in a foetus but can vary as to which viscera they are found in and also the levels at each site. Placenta is often a very good sample to include in a pool of tissues however if it is contaminated with faeces this can be detrimental. Faeces can contain Campylobacter fetus and also Chlamydia pecorum (a Chlamydophila sp. that does not cause abortions) which could lead to a mis-diagnosis. If placenta is faecally contaminated then it is better to sample tissues, using clean instruments and gloves, from within the carcase. The following fresh tissues, which we will test as a pooled sample, are likely to give a very good chance of detecting the above agents if they are present:
Brain (or uncontaminated placenta) & liver & foetal stomach contents (FSC)
Or if no foetus available:
Vaginal swab (plain) & uncontaminated placenta
Clean the vulva with paper towel and part the vulval lips to avoid faecal contamination of the swab and take the sample from the ventral aspect of the cranial vagina. Please note that if only a vaginal swab is submitted (taken up to five days after parturition) and no placenta is sampled then testing is unlikely to detect the presence of Neospora, Toxoplasma and probably also TBF – though serology could be done for these agents instead.
The screen does not include BVD virus (foetal fluid can be tested for BVD antigen and antibodies or there is the more expensive PCR test using fresh spleen or liver) or IBR (we have a PCR test using fresh liver, as an add on).
Please note that the screen also includes Brucella species so if a positive result is obtained for this APHA would need to be informed, with it being a notifiable disease.

Discounted test rates for Johne’s disease & Neospora herd screens or regular batch testing

Our Johne’s & Neospora Monitoring programmes give farmers access to discounted test rates for whole herd or regular batch testing. There is no membership fee and no set rules to follow. Johne’s serology is from £4.25 per sample and Neospora serology costs from £5.90 per sample. It works out cheaper than testing through a CHECS cattle health scheme so is ideal for herds that are testing for disease control and management purposes. Advice is provided in the lab report and farmers can be e-mailed a copy if required. Our turnaround times are very fast– often same day but within three working days for both tests. Batch testing herds also get their results in a cumulative spreadsheet. Contact us for more information at DSFarm@axiomvetlab.co.uk or on 01626 357776.
In order to avoid any unnecessary confusion, please can we ask that submission forms are only sent in with the samples and not in advance of the samples. Thank you for your cooperation.

Did you know that you can email us any additional test requests for your submissions?

You may find this is a more efficient way of making requests than phoning the farm team, saving you time in your busy day. Our farm team also find it a more efficient way of dealing with your requests.
The email address for test requests is: DSFarm@axiomvetlab.co.uk

Liver fluke – what is the situation so far in 2024?

It appears that this year is again a low risk one for liver fluke however there does appear to be an increase in infections compared to the last two years, presumably due to the wetter weather.
We use three test methods for liver fluke diagnostics – coproantigen ELISA on faeces, fluke microscopy for eggs and liver fluke serology on bloods and milk samples. Pooling has been validated for the ELISA that we use for liver fluke serology on bloods – up to ten bloods can be included in a pool. In recent years seroprevalence within groups has often been low so it can be useful to sample eight to ten animals to increase the chances of detecting exposure. The pooled test uses a lower cut-off than individual serology to avoid loss of sensitivity.

Coproantigen ELISA
We had a couple of positive results in July this year, one of which was in a lamb so data was reviewed for the five-month period from the beginning of July to the end of November. More typically the liver fluke risk period would start from September and a review of the data for the three-month period September to November produced very similar figures to that for the five-month period so the more typical early season risk period (Sept to Nov) data has been presented below.

Coproantigen ELISA results for the three-month periods Sept-Nov each year:

It can take three to four weeks for animals to seroconvert to liver fluke and up to 12% of the herd may need to be seropositive to trigger a positive result on bulk milk serology. Therefore, if bulk milk (or blood) serology has been carried out in the autumn it is worth repeating it now in case the situation has changed e.g. if there was insufficient time for them to seroconvert or exposure to challenge after sampling.
The results for both tests show that in the majority of cases animals are unlikely to be infected with liver fluke so it worth advising farmers to consider testing before automatically treating as it could save them time and money.

Interesting cases in November

Cattle

Abortions

Listeria monocytogenes was isolated from the stomach contents of a foetus aborted by an Aberdeen Angus cow at seven months’ gestation. The cow was pyrexic at the time of abortion (41oC). L. monocytogenes abortion is often caused by ingestion of mouldy, spoiled or soil-contaminated silage although other spoiled feeds may be implicated.
Evidence of Neospora exposure and foetal infection was once again reported on several occasions this month. In one Holstein herd, six or seven abortions had occurred recently at six to seven months’ gestation. Samples were received from two foetuses and bloods from five recently aborted cows. Neospora was detected by PCR in the brainstem of one of the two foetuses and all five cows were seropositive. Histopathology of foetal heart and ideally foetal brain is required to confirm neosporosis as the cause of abortion.
Salmonella Mbandaka was isolated from placenta from an aborting cow; histologically, there was evidence of a placentitis. The cow was also seropositive for Neospora.

Respiratory disease

IBR infection was confirmed by PCR on at least six occasions, including a 22-month-old British Blue cross, one of ten animals out of a group of 60 with pneumonia, pyrexia and conjunctivitis. In another case, in one of a number of weaned beef calves, vaccinated with RSV, PI3 and IBR before weaning, there was evidence on histopathology of an ongoing necrotising bronchiolitis likely caused by the IBR virus detected on PCR. This had been followed by a secondary bacterial infection, causing a necrosuppurative and fibrinous bronchointerstitial pneumonia, potentially due to one or a combination of the bacteria also detected on PCR (Pasteurella multocida, Mannheimia haemolytica and Histophilus somni).
IBR and PI3 viruses were detected together by PCR on pooled nasopharyngeal swabs from animals in one herd with presumed respiratory disease.
PI3 and RSV were detected together by PCR in at least seven cases, including on pooled swabs from post weaned Hereford cross calves that had been treated with gamithromycin but died overnight, with bullae being found in the lungs on PME.
PI3 virus was detected by PCR on at least another five occasions, including in a group of four to six-week-old unvaccinated dairy calves with increased respiratory effort, coughing, pyrexia and nasal discharge.
RSV was detected by PCR on at least another 12 occasions, including from both nasopharyngeal swabs taken from a group of unvaccinated spring born calves that suddenly developed pneumonia and were coughing, pyrexic, with serous nasal discharge and harsh lung sounds on auscultation.
Coronavirus was detected by PCR alongside other viruses and bacteria on many occasions this month. The role of coronavirus in bovine respiratory disease in the UK remains somewhat unclear, being found also on swabs from healthy animals, but it may play a synergistic role with more recognised respiratory pathogens in the development of disease.
A significant rise in antibodies to Mycoplasma bovis was seen with paired serology in a Holstein-Friesian cow with pneumonia.
Lung histopathology consistent with previous pneumotropic viral infection, virulent Mycoplasma bovis infection and concurrent infection with members of the Pasteurellacae was reported in a five-month-old crossbred calf that died during an outbreak of pneumonia in 150 bought in calves, PME revealing extensive pulmonary consolidation and microabscesssation. At least two other cases reported also had evidence on histopathology of probable mixed infection typical of Bovine Respiratory Disease complex.
Necrotising and suppurative bronchopneumonia, most likely consistent with a descending bacterial infection involving members of the Pasteurellacae, was diagnosed on histopathology in a four-year-old Holstein-Friesian cow that presented with a relatively acute pneumonia but took a week to die.
A ten-week-old, unvaccinated crossbred calf died acutely and, on PME, there was evidence of severe pleurisy and some peritonitis. The histological appearance of the lung was of a severe fibrinosuppurative pleurisy accompanied by bacteria, extending along the interlobular septae to involve the lung to some degree, but overall appearing to be a primary pleurisy, rather than a primary bronchopneumonia. This may suggest that the lesion was secondary to haematogenous spread of bacteria, or potentially spread from a peritonitis, or focal inflammation such as an abscess. Gram staining suggested a somewhat mixed bacterial population. A second case was seen on histopathology in one of two calves in excellent condition to die following acute onset of respiratory signs. Two pens were affected and these were overstocked. All calves were coughing and some calves had ocular signs similar to New Forest eye. On PME, there was extensive fibrinous pleurisy with the lungs adhered to the ribs and Mannheimia haemolytica and Pasteurella multocida were found on PCR of pooled lung swabs from the calves. A third case was reported in a three-month-old Holstein-Friesian calf, vaccinated against Mycoplasma bovis, RSV and PI3. There had been high morbidity in the group and four out of 500 had died. On PME, there was marked pleurisy, fibrin in the thorax and pulmonary consolidation, evidence of extension of infection into the lung on histopathology and Mycoplasma bovis, Histophilus somni, Pasteurella multocida and Mannheimia haemolytica were detected by PCR in lung. In a fourth case, a three-month-old Holstein-Friesian calf, with fibrinous adhesions between lung and thoracic wall and yellow turbid fluid in the pleural cavity, it was unclear if the histopathology findings were consistent with a bronchopneumonia that had progressed to pleuropneumonia, or a primary pleurisy which had extended into the lung.
At least three cases of lungworm were diagnosed on Baermann’s testing. These included a South Devon cross autumn born steer, that had been grazing but was later housed, that had a slower growth rate than its peers and then started coughing and had noisy lung fields on auscultation. In another herd, three out of four, six to nine-month-old Aberdeen Angus cross calves at grass, that had pneumonia one month earlier, were seropositive for lungworm.

Gastrointestinal disease

A multiresistant F5 (K99) associated enterotoxigenic E. coli was isolated from the faeces of a two-day-old dairy calf that died suddenly.
Coccidiosis was diagnosed in scouring calves on at least three farms. In one case, some weaned dairy calves that were still scouring after treatment with diclazuril had a coccidial oocyst count of 1050 opg of which 89% of oocysts were of pathogenic Eimeria species (E. bovis and E. zuernii).
Parasitic gastroenteritis was diagnosed in a group of bought in six-month-old calves that were in poor body condition, had chronic pneumonia and ringworm. A pooled faeces sample had a strongyle egg count of 3650 epg. A strongyle egg count of 9050 epg was reported in a sick seven-month-old calf that had been out on very wet pasture and not received any anthelmintic treatment. Haemonchosis was raised as a possible cause of the high count but confirmatory testing was not carried out.
Fasciolosis was diagnosed on a number of occasions this month, primarily on microscopy. In one case, a three-year-old cow had the classic signs of ill thrift, bottlejaw and scour.
In November, a total of 484 submissions for Johne’s disease serology and faecal PCR testing from cattle were received, with 175 submissions, including a total of 303 individual samples, testing positive. The youngest confirmed case this month was a 14-month-old Limousin cross that had been purchased a month earlier and had not done well since; the animal had soft faeces and was also pyrexic. There were also at least four bulls that tested positive.
Salmonella Dublin was isolated from faeces samples on at least nine occasions, from animals with a history of scour and ranging in age from two-week-old calves to adult cows. One scouring dairy cow in a 400 cow spring block calving herd was pyrexic and also aborted at five months’ gestation. The farm also has a separate autumn
block calving herd which had a history of S. Dublin and around 30 vaccinated cows had been moved from that herd to the spring herd recently. There had been two abortions in less than two weeks.
Salmonella Typhimurium was isolated from two pooled faeces samples from Holstein cows and heifers that developed scour and pyrexia within eight days of calving and also from a faeces sample from a two-year-old dairy heifer with presumed scour. A monophasic variant of S. Typhimurium, Salmonella 4,5,12:a:-, was also isolated from cattle with presumed scour.
Yersinia pseudotuberculosis was isolated from a blood-tinged faeces sample from a six-month-old calf that was negative for coccidia on in house testing and also for Salmonella on culture. This is a rare cause of enteritis in calves which may be linked to faecal contamination by wild birds or rodents.

Skin and eye disease

At least two cases of MCF were confirmed on PCR testing this month, including a Holstein cow with pyrexia, severe nasal ulceration, bilateral corneal ulceration and conjunctivitis, and ocular discharge.
Mycoplasma bovis was detected by PCR on ocular swabs taken from two out of three Holstein-Friesian calves aged less than two months in a group of calves with a history of corneal ulcers, there having been 15 cases over the last two weeks. There had also been some ocular lesions in bulling heifers.

Systemic and miscellaneous disease

A total of 369 submissions were received for BVD antigen testing in cattle in November, with 28 submissions, including a total of 50 individual samples, testing positive.
A one-year-old suckler animal was off colour for 4 days before going down. Respiratory signs and anaemia were noted on clinical examination. On histopathology there was necrosis of the liver which may have been due to terminal hypoxia, or a toxic insult could also have been a possible cause. Adult rumen fluke (considered incidental and non-pathogenic) were also found in the rumen.

Rising antibody levels to Mycoplasma bovis were seen in a cow, one month post calving, with pyrexia, swollen joints, milk drop and a slightly increased respiratory rate in a herd with a history of head tilting in calves.
A five-month-old Holstein calf had a five-day history of malaise before dying. On PME, the mucous membranes were icteric, the cut surface of the liver was orange in colour, the gall bladder was markedly distended and there was petechiation of the peritoneum. The group was being fed weaner pellets plus chopped hay and straw and this was the only animal affected in a group of 60 animals. There was no evidence of haemoglobinuria or scour. Biochemistry run on a blood sample presumably taken post mortem found a markedly elevated GLDH (4976 U/l) consistent with hepatocellular damage and elevated total bilirubin (92.7 μmol/l). Salmonella Dublin was isolated from a liver swab. The liver copper level was not consistent with toxicity. The liver pathology would be consistent with cholecystitis and possible necrotising hepatitis, which are not uncommon in cases of Salmonella Dublin infection.
A six-year-old Shorthorn cow in Denbeighshire presented with nasal crusting and erosions, mucoid discharge from the nose and eyes, scleral congestion and conjunctivitis, tachypnoea, tachycardia, pale mucous membranes and pyrexia (39.8oC). The animal’s condition improved with NSAIDs and amoxycillin. MCF was ruled out on PCR but there was a marked regenerative anaemia on haematology and red blood cell inclusions consistent with babesiosis. There was also a marked azotaemia present, which could be due to haemoglobinuric nephrosis.

Sheep and goats

Respiratory disease

A four-month-old dairy ewe-lamb had a history of ill-thrift and eventually died. At PME there was evidence of poor body condition and chronic-active suppurative pneumonia. Bibersteinia trehalosi, Trueperella pyogenes, Fusobacterium necrophorum and Candida albicans were isolated in cultures of lung. The changes seen on histopathology were consistent with atypical/enzootic pneumonia in sheep. Lambs with enzootic pneumonia normally present with ill thrift and a mild cough in these cases. Death can however be seen when a secondary fulminating bacterial bronchopneumonia occurs. There was evidence in this case of marked bronchiolitis fibrosa obliterans indicating a previous severe necrotising bronchiolitis, which in sheep is most often caused by a virulent viral infection such as RSV or PI3.
Ovine pulmonary adenocarcinoma was identified by histopathology of lung tissue from a two-year-old Balwen ewe which had shown a poor response to treatment for respiratory signs. There was a positive wheelbarrow test and lesions which appeared suspicious of OPA were identified on ultrasound prior to euthanasia. At PME the right middle lung lobe and part of the caudal lung lobe had a consolidated appearance. In advanced cases of OPA the lungs typically are heavier than normal (>2kg) and the tumours which often occur in the cranioventral lung fields appear solid and grey.
Staphylococcus aureus was isolated from the lung tissue of a ewe lamb which presented as a sudden death. S. aureus can cause respiratory disease and septicaemia in sheep and can occur secondary to tick borne fever (Anaplasma phagocytophilum) infection.
PME of a thin ewe from a Maedi-visna accredited flock revealed a heavy burden of lungworm. On Baermann’s examination larvae resembling Dictyocaulus filaria and Muelleris capillaris were observed. Of these two species D. filaria is considered more pathogenic although clinical disease due to lungworm is uncommon in sheep. In another case a four year-old Texel ram had a history of episodes of respiratory issues, pyrexia, weight loss and eventual death. Multiple grey and firm, granulomatous lesions of around 1-2cm in diameter were seen over the dorsal lung lobes and on histopathology the lesions were considered consistent with the effects of lungworm.

Gastrointestinal disease

In October, a total of 102 submissions for Johne’s disease serology and faecal PCR testing from sheep and goats were received, with 16 submissions, including a total of 20 individual samples, testing positive. In one case a goat had a positive Johne’s PCR result with MAP detected in faeces at a Ct of 33 indicating moderate shedding and likely clinical Johne’s disease. Johne’s serology in this animal was flat negative with a Johne’s positivity of 0% in the ELISA test. No clinical history was available but it was noted that as in cattle some clinical cases fail to seroconvert to Johne’s disease even in the later clinical stages of the disease.
A newly bought-in tup was found to have a high strongyle egg count of 950 epg indicating gastrointestinal parasitism and on Baermann’s examination Protostrongylus sp. larvae were observed indicating concurrent lungworm infection. Lungworm infections are most often subclinical in sheep and in this screening test no clinical signs of PGE had been identified prior to sampling. There were plenty more incidences of parasitic gastroenteritis this month in sheep and goats. Many cases had very high strongyle counts suggestive of possible haemonchosis. In one submission a five-year-old Anglo Nubian goat had a strongyle egg count of 5600 epg which in itself was suspicious of haemonchosis. Haematology was also carried out and indicated significant regenerative anaemia. Anaemia is one of the main clinical findings in affected animals. The goat also had a low copper level and it was noted this may be secondary to parasitic gastroenteritis rather than being due to dietary insufficiency. Another sick goat which had been treated with monepantel two days prior to testing had a strongyle egg count of 17,100 epg and Fasciola hepatica eggs were also seen on microscopy.
Post-mortem tissues were received from an eight-month-old Ryeland ram lamb. Ram lambs were reported to be in very poor condition after suffering from heavy worm burdens over summer which showed evidence of resistance to treatment with ivermectin. Although a recent worm egg count was low the owner opted for euthanasia of this individual and further investigation. Histopathology revealed a marked, chronic, extensive, eosinophilic enteritis with villus atrophy consistent with chronic damage due to intestinal parasitism. Diffuse, moderate, chronic, epithelial hyperplasia was observed in the rumen tissue suggesting possible ongoing poor rumen function although without an age matched control it was difficult to know the significance of the finding. In the lung various stages of nematodes were visible although the lung changes were noted to be mild and therefore likely to be an incidental finding.
Haemonchosis was confirmed in a Valais blackneck goat with a strongyle egg count of 4950 epg of which 99% were confirmed as Haemonchus species.
Nematodirosis was confirmed by faecal egg testing in lambs this month. In all cases a high strongyle egg count was also present. One lamb which was reported as being ill-thrifty since the summer had a strongyle egg count of 5500 epg and 350 egp Nematodirus battus. Autumn / winter nematodirosis is difficult to diagnose with certainty on the basis of a Nematodirus egg count alone; a total worm count is ideally required. It is likely that the Nematodirus eggs in most cases are an incidental finding as older lambs are likely to be solidly immune. The strongyle worms are much more likely to be clinically significant
Anthelmintic treatment failure was identified in a flock when a count of 1087epg strongyles was recorded at a post-dosing worm egg count for the Animal Health and Welfare Pathway. In another submission, treatment failure was suspected in a sick seven-month-old Lincoln Longwool lamb had a faecal strongyle egg count of 2000 epg, three weeks after being given moxidectin. However, the route and dose were not confirmed. The route of administration is critical to know because oral moxidectin has no claim for persistence against Trichostrongylus colubriformis/vitrinus (it does against susceptible T. circumcincta and H. contortus), but injectable moxidectin preparations (1% and 2%) do have a persistent action claim. The optimal interval for post-dosing sampling for moxidectin is 2 weeks; anthelmintic resistance cannot be diagnosed with certainty if the post-dosing interval is three weeks without worm speciation. Speciation of strongyle eggs (with the exception of H. contortus) is unfortunately not widely available. In a different group of ram lambs in another flock the strongyle egg count was 1050 epg two weeks after being given a benzimidazole anthelmintic drench, consistent with treatment failure.
A Toxocara vitulorum ovum was observed in a faecal sample from a sheep. There was no clinical history available. T. vitulorum is rarely recorded in sheep as it is considered to be a bovine parasite and is transmitted to young calves via the dam’s milk. It was considered to be an incidental finding in this case and not clinically significant.
A group of ill-thriven weaned lambs were highly positive for antibodies to Fasciola hepatica on pooled serology testing. All six tested lambs also had evidence of selenium deficiency on GSH-Px testing, three had low vitamin B12 levels and one of the six had a low copper level. Evidence of exposure to liver fluke was also identified in numerous other cases this month.
Fascioliasis was identified by faecal coproantigen ELISA or microscopy with accompanying clinical history in more than 20 cases. In one submission, which was positive on coproantigen testing, there had been five losses over a weekend in a group of ten-month old crossbreed lambs. In the remainder of the group weakness, lethargy and loss of condition were noted. In a group of Texel cross shearlings, where there had been several sudden mortalities, abnormal livers and anaemic looking carcasses were noted at PME but no flukes were visible. Faecal samples tested positive for liver fluke antigen.
In two submissions faecal samples taken from sheep 14 days post treatment with triclabendazole remained positive in the fluke coproantigen ELISA indicative of flukicide treatment failure.
An Abermax tup was found dead unexpectedly and underwent PME. The lungs appeared congested and rumen and abomasum were distended. A lump of fibrous material was present in the pyloric region and a large focal ulcer was observed at the pyloric sphincter. Histopathology of the abomasum revealed severe, extensive, chronic-active, necrosuppurative abomasitis with granulation tissue, intralesional bacteria and
fibrinosuppurative peritonitis. The ulcer in the abomasum was observed to be severe, chronic and ongoing. The entrapped bacteria within the abomasal lesion were most suggestive of Fusobacterium necrophorum. However, bacterial cultures were not carried out to confirm this. Systemic listeriosis can also occasionally cause abomasal ulceration in sheep.

Pulpy kidney disease (C. perfringens type D enterotoxaemia) was suspected to be the cause of sudden death in four easy-care ewe lambs over 48 hours. Bloodstained intestinal contents and congestion of subcutaneous blood vessels were observed at post mortem and C. perfringens epsilon toxin was detected in intestinal contents. Neuropathology is required for definitive diagnosis but was not carried out in this case. Detection of epsilon toxin along with a history consistent with Pulpy Kidney disease was recorded on at least a further three occasions this month.

Skin and eye disease

Mycoplasma conjunctivae was detected by PCR of eye swabs from a two-year-old tup which had a relapse of pink eye (infectious keratoconjunctivitis) despite treatment. Reinfection is extremely common and problematic in IKC due to the poor immunity to the pathogen.
Staphylococcus aureus was isolated from swabs taken from skin lesions around the eyes, ears and horn base of a Portland sheep. Trauma to the skin can allow entry of the bacteria, which can cause severe local infection. Insufficient space at feed troughs can be an inciting cause. In another flock with a similar presentation two of six sheep were affected with lesions around the eyes and S. aureus was isolated from swabs of the lesions consistent with a diagnosis of periorbital eczema.
A ten-month-old Suffolk tup presented with a proliferative lesion on the lower limb which had been present for at least eight weeks and appeared unresponsive to topical and parenteral antimicrobials. Biopsy of the lesion and histopathology revealed severe, diffuse, chronic active, hyperplastic, pustular and ulcerative dermatitis with ballooning degeneration and intracytoplasmic eosinophilic inclusion bodies. The presence of typical inclusion bodies and the other histopathological features were considered characteristic of parapox (orf) infection. Local abrasion is likely to have predisposed to infection by the parapox virus. It was suggested that a skin/scab sample could be tested by PCR to confirm the presence of parapox virus. In a more typical case of orf, a Whitefaced Woodland sheep had scabby lesions around the mouth and a sample of these tested positive by PCR for parapox virus.
Ringworm was detected by dermatophyte PCR in sheep which had skin lesions typical of ringworm but also had facial abscesses from which Trueperella pyogenes and Streptococcus ovis were cultured. Both isolates were thought to be significant and acting as opportunistic pathogens in this case.
Squamous cell carcinoma was suspected on histopathological examination of a biopsy of a 2-3cm mass which had appeared on the rectum of an adult male pygmy goat and was increasing in size.

Systemic and miscellaneous disease

A group of older mule ewes which had some neurological signs and some animals going off their legs were blood sampled and five out of eight tested were seropositive for Maedi-visna caused by the Small Ruminant Lentivirus. Maedi-visna infects sheep of all ages but the clinical signs of the disease normally appear in older sheep over 3 years of age. Visna is the less common, neurological, form of the disease and can present in younger sheep, with signs including progressive weakness and hindlimb ataxia eventually leading to paralysis. In another flock a three-year-old Swaledale tup was losing weight. He tested positive for antibodies to Maedi-visna indicating MV infection and faecal testing detected Mycobacterium avium ssp. paratuberculosis (MAP) indicating that the tup was also affected by Johne’s disease. In one flock screening of 18-month-old sheep which were the progeny of ewes previously identified as Maedi-visna seropositive were tested. Of the 142 samples, 22 were positive for antibody to MV (15%). In the same flock a screening of the young ewes which had been born to MV infected dams and had been screened negative in the previous year was carried out. Of 107 tested three further animals had now seroconverted to Maedi-visna.
Systemic pasteurellosis/bibersteiniosis was diagnosed in weaned lambs on several occasions this month following sudden deaths and typical post-mortem findings. On one farm lambs which had been bought-in 12 days previously were reluctant to move and two were found dead. The lambs had received the first dose of a multivalent clostridial and Pasteurella vaccine shortly after arrival. Tissues from one of the dead lambs were submitted for testing. Bibersteinia trehalosi was isolated in pure growths from a lung swab. On histopathology of lung tissue colonies of bacteria were observed within the alveolar capillaries, indicating haematogenous spread to the lungs and consistent with bacteraemia. Gram stains showed the colonies to consist of Gram negative short bacilli and were supportive of a gram negative sepsis being the cause of death.
A Romney ewe which was thin underwent PME where multiple abnormalities were observed. Corynebacterium pseudotuberculosis, the causative pathogen in CLA was isolated from mediastinal lymph nodes confirming this was a case of visceral CLA.
A Moorland ewe was showing neurological signs and had shown little response to treatment with Vitamin B1, meloxicam and penicillin-streptomycin. HAIT serology testing for Louping ill virus revealed a high antibody titre (1/2560 of which IgG was only 1/150) consistent with recent exposure to the pathogen.
Dichelobacter nodosus, the causative pathogen in of footrot was detected by PCR of swabs from interdigital lesions in a Zwartble ewe.

Camelids

Gastrointestinal disease

An 18-year-old alpaca which had a two-month-old cria at foot was reported to have had significant scour in the previous four days and had a strongyle egg count of 750 epg indicating parasitic gastroenteritis.
Patent fascioliasis was diagnosed in two out of three camels tested from a group of eight. All three animals also had high strongyle egg counts indicative of PGE. Fascioliasis was also identified by coproantigen testing in a 13-year-old alpaca which had become recumbent in the field.
Rumen fluke eggs were observed, likely as an incidental finding, in one of two faecal samples submitted from adult alpacas.

Other Species

Bacterial bronchopneumonia was identified by histopathology of one of several four-month-old pigs which died suddenly on a unit. Congested lungs and mediastinal lymph nodes were observed and there were fibrin tags in the abdomen. The unit was known to be positive for PRRS but the animals had been vaccinated prior to arrival. Histopathology identified evidence of a bacterial bronchopneumonia in the lung. Possible suggested pathogens included Pasteurella multocida, Streptococcus suis, Bordetella bronchiseptica, Glaesserella (Haemophilus) spp and Actinobacillus suis. However, bacterial cultures were unrewarding. A lymphoplasmacytic infiltrate suggested a possible concurrent mycoplasma infection (most likely Mycoplasma hyopneumoniae) and PCR testing was suggested for possible further investigation.
A firm golf-ball sized pedunculated mass, which was reported to be increasing in size and which had become ulcerated, was surgically removed from the inguinal area of a nine-year-old pet sow. Histopathology identified the mass to be a round cell tumour most likely lymphoma.
Escherichia coli was isolated in profuse and pure growths from cultures from PMEs of four 60-week-old Lohmann brown classic hens. The flock was reported to have had ongoing issues with cases of peritonitis. E. coli is commonly isolated in cases of peritonitis in poultry.

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