Toxocara Vitulorum Found In Calves - VLA Report

The most commonly diagnosed causes of diarrhoea were cryptosporidiosis and rotavirus in young calves, coccidiosis in older calves and Johne’s disease in adult cattle, reports the UK's Veterinary Laboratory report for August 2011.
calendar icon 7 November 2011
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Alimentary tract diseases

Twin ten-week old Charolais calves passed 30cm long worms which were identified as Toxocara vitulorum by Langford. T vitulorum is an ascarid nematode with a high prevalence in water buffalo, cattle and zebu in tropical/sub-tropical regions of the world; it has been detected previously in calves in Wales and Norfolk. T vitulorum undergoes a period of arrested development in the somatic tissues of adult cattle and is transmitted to suckling calves by the intramammary route. It may cause ill thrift and diarrhoea with slight abdominal distension in calves up to six months old. Once the parasite is established in a herd, control will require the implementation of specific measures. The prevalence of infection can be reduced by anthelmintic treatment of calves at three and six weeks old, to prevent worms developing patency.

Respiratory Diseases

Many Regional Laboratories reported diagnoses of lungworm, mainly by demonstration of larvae in faeces. Exposure can be demonstrated by serology: seroconversion occurs four to six weeks after exposure and antibody titres remain high for up to five months. Common presenting signs were acute coughing and dyspnoea amongst grazing cattle. In one herd, 30 per cent of 150 adult dairy cows were affected.

Bacterial pneumonia and low liver selenium concentration of 2.3 µmol/kg DM (adequate is >5.0 µmol/kg DM) was diagnosed by Aberystwyth in a four month old weaned beef calf at grass. It came from a group of 30 in which 13 of the younger animals failed to thrive. There was severe pneumonia caused by mixed infection with Histophilus somni, Pasteurella multocida and Arcanobacterium pyogenes. Selenium deficiency could have contributed to poor immunity in the group and blood testing others was recommended.

Nervous diseases

A four-week-old Holstein Friesian heifer presenting nervous disease and blindness was necropsied at Starcross. Histopathology revealed changes in the liver and brain consistent with hepatic encephalopathy as a result of vascular anomalies within the liver leading to shunting and hyperammonemia, which affects the function of the CNS.

Musculoskeletal diseases

Aberystwyth investigated deformities of the limbs and skull in a stillborn beef suckler calf, suggestive of congenital chondrodystrophy. The dams had been fed only grass silage during pregnancy with no supplementation. Similar congenital deformities have been associated with dams receiving a predominantly grass silage diet (of more than 75 per cent of the diet dry matter) during mid-pregnancy.

Blackleg caused by Clostridium chauvoei was commonly diagnosed by many Regional Laboratories. Bury diagnosed white muscle disease associated with selenium deficiency as the cause of unsteady gait in two, three-month suckler calves in a group of 60. One of the calves also had diarrhoea and this calf had a GSH-Px level of 13.3u/ml RBCs (reference range >30). There was a history of selenium deficiency on farm.

Other diseases

Haemorrhagic diseases in young calves

Langford diagnosed colisepticaemia in a neonatal calf with widespread haemorrhages, and mesenteric lymph node enlargement, dark yellow joint fluid and purulent material within the hocks and carpi. Starcross diagnosed concurrent BVD type one and Bibersteinia trehalosi infection in a three week old calf with multiple haemorrhages. Bovine neonatal pancytopenia (BNP) was diagnosed by Carmarthen, Thirsk and Penrith, all by histological demonstration of bone marrow trilineage hypoplasia. These cases illustrate the need to distinguish BNP from other haemorrhagic diseases in young calves.


Bury diagnosed babesiosis in two geographically close herds. A two-year-old beef animal in a group of 30 at grass was affected in one herd and the second case involved a five-year-old suckler cow in a group of 50 at grass. Red urine was observed from both animals. Cases were also reported by Penrith, Starcross and Winchester.

Iodine deficiency

Bury diagnosed low iodine and copper status in suckler calves that developed non-specific malaise in the first week of life with lethargy and occasional knuckling on forelimbs. Five of 40 calves in the group were affected. The iodine deficiency was a likely cause of weakness in the calves. Shrewsbury diagnosed iodine deficiency as the likely cause of five stillborn and weak calves in a suckler herd of 50 cows.

Sweet potato poisoning

Luddington diagnosed mycotoxicosis associated with mould-contaminated sweet potatoes as the cause of death of six cattle over two days; some were found dead and others showed dyspnoea without coughing. The animals were grazing and received supplementary vegetable waste. Necropsy findings in one cow of pulmonary oedema and extensive interlobular emphysema were consistent with Ipomoea batatas (sweet potato) poisoning, caused by a mycotoxin produced by the fungus Fusarium solani that grows on the tubers.

November 2011
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