James Patrick Crilly

Ruminant coprological examination: beyond the McMaster slide

Sustainable and effective control of nematode and trematode infections of ruminants requires an understanding of the farm-specific epidemiology of the parasites. To this end, a variety of diagnostic and monitoring techniques can be employed by the veterinary practitioner, of which the most commonly used is the faecal worm egg count (FWEC). This article discusses other techniques which can add detail to the information gained from FWECs and detect parasites not amenable to egg flotation techniques.

Control of tapeworms in sheep: a risk-based approach

Canine tapeworms that have sheep as their intermediate host can be responsible for unpredictable significant economic losses for individual farms. In addition, one of these dog-sheep tapeworms, Echinococcus granulosus, is zoonotic, causing cystic echinococcosis in humans, which can be fatal. Given that detection of tapeworm infestation is often only achieved at postmortem abattoir inspection, reactive control measures are limited. The aim of this article is to illustrate how the principles of the Hazard Analysis and Critical Control Points (HACCP) system, which is widely used in the food industry, can be used to identify proactive control measures. The role of the small animal veterinary surgeon in control is also discussed.

Patterns of faecal nematode egg shedding after treatment of sheep with a long-acting formulation of moxidectin.

Much of the current information on the effects of long-acting anthelmintics on nematode populations derives either from research farms or mathematical models. A survey was performed with the aim of establishing how moxidectin is currently being used on sheep farms in the south-east of Scotland. A study was undertaken on a subsection of the surveyed farms to examine the effects of long-acting moxidectin treatments in both spring and autumn on faecal nematode egg output. The survey showed that whole flock treatments of injectable 2% moxidectin were used to control sheep scab on 21% of farms. Injectable 2% moxidectin and oral moxidectin were used to control the periparturient rise in faecal nematode egg shedding by ewes on 13% and 55% of farms respectively. The effects of injectable 2% moxidectin treatment on faecal nematode egg shedding post-treatment in both the autumn and spring were investigated by faecal nematode egg counts at the time of treatment and at 2-weekly interval thereafter on eight and six farms in the autumn and spring, respectively. Faecal egg shedding recommenced at 8 weeks (autumn) and 4 weeks (spring) post-treatment. Counts increased to a peak and then declined. The mean (95% confidence interval) peak counts post-treatment were 2.8 (0.6, 5.1), 3.6 (1.7, 5.5) and 53.5 (25.1, 82.0) eggs per gram (EPG) for autumn-treated ewes, autumn-treated lambs and spring-treated ewes respectively. The spring treated sheep showed a statistically significantly earlier return to faecal egg shedding (p=0.0125, p=0.0342) compared to both other groups, statistically significantly higher peak in egg counts than the autumn treated sheep (p<0.001) and a statistically significantly longer period of positive egg counts (p=0.0148). There was no statistically significant difference in the timing of the peak FECs between autumn and spring (p=0.211). The FECs of all groups of sheep treated with an injectable long-acting formulation of moxidectin became positive earlier than would be expected from the period of persistence given on the datasheet, but post-treatment FECs were very low compared to pre-treatment counts.

Serological survey of British sheep flocks for evidence of exposure to ovine pestiviruses

Ovine pestiviruses have the potential to reduce productivity in the British sheep flock. However, their prevalence and impact are currently poorly understood. This study aimed to estimate the exposure to pestiviruses in adult breeding ewe stock. Blood samples collected for metabolic profiling before lambing were tested using an ELISA that detected antibodies raised to both bovine viral diarrhoea virus and Border disease virus. A group of 15 animals were tested per flock. A total of 34 farms were tested, of which 13 had at least one seropositive animal. In those positive flocks between one and nine of the animals tested antibody-positive. Positive flocks were identified in all regions of Great Britain. This work suggests that exposure to ovine pestiviruses is widespread, and that it is timely to investigate flock-level prevalence and possible production impacts of endemic infection.

Successful treatment of a multidrug resistant Pseudomonas aeruginosa infection following a digit amputation in a Belgian Blue calf

Digit amputation is a commonly performed surgery in cattle practice. The most frequent reason for digit amputation is septic pedal arthritis, but other indications include severe trauma, pedal osteitis, non-healing sole, wall or toe ulcers, osteomyelitis of P2, septic tenosynovitis of the distal digital flexor tendons and other infectious processes of the deep digital structures. The procedure is considered a salvage procedure, but good rates of success are reported. The size of the patient is one of the key determinants of prognosis, with reported success rates varying between bulls, cows and calves. Reported complications include haemorrhage, avascular necrosis of the phalangeal fragments, wound infection and fracture of the partner claw. In this case report the authors describe digit amputation under regional and general anaesthesia for the treatment of proximal interphalangeal septic arthritis and the subsequent wound management in the face of a multidrug resistant Pseudomonas aeruginosa infection.

Diagnosing limb paresis and paralysis in sheep

Paresis and paralysis are uncommon problems in sheep but are likely to prompt farmers to seek veterinary advice. A thorough and logical approach can aid in determining the cause of the problem and highlighting the benefit of veterinary involvement. While this may not necessarily alter the prognosis for an individual animal, it can help in formulating preventive measures and avoid the costs – both in economic and in welfare terms – of misdirected treatment. Distinguishing between central and peripheral lesions is most important, as the relative prognoses are markedly different, and this can often be achieved with minimal equipment. This article describes an approach to performing a neurological examination of the ovine trunk and limbs, the ancillary tests available and the common and important causes of paresis and paralysis in sheep.

Endocarditis and ventricular wall abscessation in a vasectomised Herdwick ram

A four-year-old vasectomised Herdwick ram presented with a two-day history of inappetence, lethargy, weakness and exercise intolerance. Clinical examination revealed mild tachypnoea and hyperpnoea and marked tachycardia and pallor. No anaemia was present. Thoracic ultrasonography revealed thickening of the right ventricular wall and increased pericardial and peritoneal fluid. A diagnosis of congestive heart failure was made and the animal was euthanased. Necropsy revealed a subendocardial abscess adjacent to the right atrioventricular valve, the leaflets of which were distorted. The gross appearance of this lesion is similar to that described for valvular ring abscesses in human beings.

Retinopathy and optic neuropathy following closantel treatment of ewes

An outbreak of sudden onset blindness subsequent to dosing with oral closantel affecting 1 per cent of a six hundred ewe flock was investigated. Clinical examination and histopathology both revealed features fully consistent with closantel toxicity despite the maximum dose received by the affected sheep not exceeding 14.5 mg/kg (recommended dose rate 10 mg/kg). The interval between dosing and the onset of clinical signs had been recorded accurately (minimum interval eight days) and was found to be longer than in previous reports.

Practical Lambing and Lamb Care: A Veterinary Guide

. Chapter 1 General Lambing Management . Chapter 2 Specific Causes of Lamb and Kid Mortality . Chapter 3 Husbandry and Health Planning to Prepare for Lambing or Kidding: Ensuring Pregnancy in Ewes and Does . Chapter 4 Husbandry and Health Planning to Prepare for Lambing: Nutritional Management of Pregnant Ewes and Does . Chapter 5 Husbandry and Health Planning to Prepare for Lambing: Health Management of Pregnant Ewes and Does . Chapter 6 Identifying Unwell Ewes and Lambs, Does and Kids . Chapter 7 Legislation . Index

Proof of concept of ovine artificial insemination by vaginal deposition of frozen-thawed semen under UK sheep-farming conditions

ARTIFICIAL insemination (AI) by intravaginal deposition of frozen-thawed semen (Fairnie and Wales 1982) is simple, non-invasive and requires little specialised equipment. In Norway and Sweden, the technique is widely performed by farmers themselves. Mean conception rates of 50 per cent in Sweden (L.Soderquist, pers.obs.) and 67 per cent in Norway (Paulenz and others 2005) have been reported. Flocks in Scandinavia are small relative to the UK (Ulvund 2012) and sheep are frequently housed during the mating period. AI is performed to natural oestrus. Heat detection is performed using halter-trained entire rams wearing aprons. Optimal results are obtained with three times a day heat detection and insemination 12–24 hours after standing oestrus is detected. A dose of 200×106 spermatozoa is used (Paulenz and others 2005). To the best of authors’ knowledge, there has been no previous trial of this technique in the UK. The object of this study was to test the viability of this method of AI in sheep that are at pasture during the mating period. A four-year-old Texel ram with no detectable abnormalities (Boundy 1992, Gouletsou and Fthenakis 2010) was submitted to an ovine semen collection centre (AB Europe, Ormiston, East Lothian, UK). Semen was collected using an artificial vagina and a teaser ewe; it was of …