Acute fasciolosis in an alpaca: a case report

Background

The popularity of new world camelids, particularly alpacas, is growing rapidly in Ireland, presenting a clinical challenge to veterinary practitioners who may not have worked with these species previously. To the authors’ knowledge, the clinical course of a case of acute fasciolosis in an alpaca has not previously been reported, and fasciolosis has not been reported at all in alpacas in Ireland, making this case report a valuable addition to the current literature.

Case presentation

A three-year-old male castrated huacaya alpaca was admitted to UCD Veterinary Hospital with a two-day history of colic and tenesmus. He had been treated with albendazole, dexamethasone and potentiated amoxycillin by the referring veterinary practitioner with no response. On initial clinical exam, sensitivity to abdominal palpation was the only abnormality. However, the alpaca proceeded to show abnormal lying positions, tenesmus and reduced faecal output over the next 24 h. A general blood panel demonstrated moderate anaemia, marked hyperglobulinaemia and moderately increased hepatocellular and hepatobiliary enzyme activity. Abdominal radiography revealed enlargement of the first forestomach compartment without evidence of gastrointestinal obstruction or peritonitis. An abdominal ultrasound exam revealed an elongated, heterogenous mass in the caudoventral abdomen that appeared to be contiguous with the liver. FNA of this mass revealed that it was in fact a liver lobe with biliary stasis and inflammation. Faecal sedimentation demonstrated Fasciola hepatica eggs. In spite of treatment with triclabendazole and supportive treatment including blood transfusion, the alpaca’s condition continued to deteriorate and he was euthanised. On post-mortem exam, acute fasciolosis was diagnosed.

Conclusions

The clinical presentation and course of a case of acute fasciolosis in an individual alpaca is described, including the results of a range of diagnostic tests that were carried out. The final diagnosis is supported by a description of post-mortem findings. This information will serve as a resource for veterinary practitioners involved in the diagnosis and treatment of similar cases.

The effect of dairy heifer pre-breeding growth rate on first lactation milk yield in spring-calving, pasture-based herds

Optimising heifer growth rate may offer an opportunity to improve lifetime milk yield per cow, enhancing the environmental and economic efficiency of dairy farming operations. The effect of dairy heifer pre-breeding average daily weight gain (ADG_PB) on first lactation milk yield was investigated. This observational study employed a data set comprising 265 Holstein-Friesian, or Holstein-Friesian-cross-Jersey heifers from seven commercial, spring-calving, pasture-based dairy herds, where the major component of the diet was grazed grass. These were weighed at birth and prior to breeding and ADG_PB was calculated. Milk recordings were performed throughout the heifers' first lactation and 305-day yield figures calculated from these records. Yields were corrected to 4% fat and 3.1% protein to create standardised 305-day milk yield (SMY), which was the outcome of interest. Median ADG_PB was 0.72 kg/day. Median 305-day yield was 5 967 kg. Linear regression was used to investigate the effect of weight and genetic, age and first calving factors on SMY. Pre-breeding average daily weight gain, age at first calving and predicted transmitting abilities for milk protein production and calving interval were all significant in the final model, which also included the random effects of farm and month of calving within year. ADG_PB was quadratically related to first lactation SMY, with an ADG_PB of 0.82 kg/day corresponding to the maximum predicted SMY. The model predicted that a heifer growing at 0.82 kg/day would produce 1 120 kg more SMY than a heifer growing at 0.55 kg/day, 218 kg more than a heifer growing at 0.7 kg/day and 103 kg more than a heifer growing at 0.90 kg/day. Manipulation of heifer growth rate may offer a viable method of increasing first lactation milk yield.

Current antimicrobial use in farm animals in the Republic of Ireland

Antimicrobial resistance has been recognised as one of the most difficult challenges facing human and animal health in recent decades. The surveillance of antimicrobial use in animal health plays a major role in dealing with the growing issue of resistance. This paper reviews current data available on antimicrobial use in farmed animals in the Republic of Ireland, including each of the major livestock production sectors; pigs, poultry, dairy, beef and sheep. A systematic literature search was conducted to identify relevant published literature, and ongoing research was identified through the network of authors and searches of each of the research databases of the main agriculture funding bodies in Ireland. The varying quantities and quality of data available across each livestock sector underlines the need for harmonisation of data collection methods. This review highlights the progress that has been made regarding data collection in the intensive production sectors such as pigs and poultry, however, it is clear there are significant knowledge gaps in less intensive industries such as dairy, beef and sheep. To comply with European regulations an antimicrobial data collection system is due to be developed for all food-producing animals in the future, however in the short-term surveillance studies have allowed us to build a picture of current use within the Republic of Ireland. Further studies will allow us to fill current knowledge gaps and build a more comprehensive overview of antimicrobial use in farm animals in Ireland.

Relative effect of milk constituents on fertility performance of milk-recorded, spring-calving dairy cows in Ireland

Several studies have reported associations between milk composition data and fertility performance. However, no work to date has estimated the effect of milk constituents on fertility performance in cows with low milk constituent concentrations. The objective of this study was to assess the association between milk constituents, animal characteristics, and time from mating start date (MSD) to conception using survival analysis. Furthermore, we aimed to investigate the relative effect of each variable by predicting median times to conception for animals with different combinations of characteristics and milk compositions. The final data set consisted of 87,227 cow lactation records from 64,519 cows in 2,049 herds with calving dates from 2010 to 2013. Milk recording data from each lactation were used, including test day recordings at 0 to 30, 31 to 60, and 61 to 90 d in milk (DIM). The analysis was limited to spring-calving cows (i.e., animals calving from January to May inclusive). Mating start date was determined for each unique herd in each year. A cow-specific MSD (MSD_cow) was defined taking into consideration the MSD for each herd and the calving date and a minimum calving to insemination interval of each herd year. The conception date for each cow was estimated using the subsequent calving date. Cows with no subsequent calving date were assumed not to have conceived. Time from MSD_cow to approximate conception date was analyzed using survival analysis. Cox proportional hazard models were constructed for each of the 3 recording windows: 0 to 30, 31 to 60, and 61 to 90 DIM. A fourth model was used to assess the dynamics of milk composition over the 3 windows. To investigate the effect of these variables, model outputs were used to create parametric accelerated failure time models to predict median survival times for animals at the 10th and 90th percentiles of the variable of interest but otherwise identical across the rest of the variables. Results demonstrated that fertility breeding subindex had the largest effect on time from MSD_cow to conception, with an additional 62 d open for those in the 10th percentile versus those in the 90th percentile. Of the milk constituents, milk lactose concentration had the greatest effect on MSD to conception, particularly when measured from 0 to 30 DIM. An additional 10 d open resulted from comparing those in the 10th and 90th percentiles. Milk protein concentration, although statistically significant, had a lower effect on fertility outcome when comparing cows in the 10th and 90th percentiles for this exposure variable. The greatest effect was found in the 61 to 90 DIM recording window, where cows in the 10th percentile had an additional 9 d open at the subsequent breeding season compared with those in the 90th percentile. Overall, our study shows that although the associations between milk constituents and fertility are statistically significant, their overall influence in determining MSD to conception in this study population is relatively modest, particularly compared with fertility breeding subindex, when comparing cows at the 10th and 90th percentiles. Of the milk constituents measured, milk lactose concentration measured at 0 to 30 DIM had the greatest effect in determining fertility outcome when comparing cows at the 10th and 90th percentiles. The predictive value of early-lactation test day milk composition data on hazard of pregnancy during the following breeding period, within a spring-calving context, appears to be relatively modest at the individual-cow level. Further work is required to test the usefulness of these associations at the herd level.

The effect of growth rate on reproductive outcomes in replacement dairy heifers in seasonally calving, pasture-based systems

The effect of average daily gain (ADG) on reproductive outcomes in replacement dairy heifers was investigated. All heifers were managed in the typical Irish spring calving, pasture-based system, where the herd calves in 1 block between January and April and the majority of the diet comprises grazed grass. Heifer calves (n = 399) from 7 herds were weighed at birth and at the beginning of the breeding season, and ADG was calculated. Service dates and pregnancy diagnosis results were recorded, and conception dates were calculated. Days open (DO) was defined as the number of days between the beginning of the breeding season and conception. Genetic data were retrieved from the Irish Cattle Breeding Federation database. A Cox proportional hazard model was constructed to identify variables with a significant effect on DO. An accelerated failure time model was used to predict survival curves and median survival times for different combinations of the significant variables. The ADG ranged from 0.41 to 0.91 kg/d, with a median of 0.70 kg/d. Frailty effect of farm within year, maintenance subindex of the economic breeding index, and ADG had a significant effect on DO. Derived from the final accelerated failure time model, the predicted median DO for a heifer with an ADG of 0.40, 0.70, or 0.90 kg/d aged 443 d at the beginning of the breeding season and with a maintenance subindex in the second tercile were 27, 16, and 11 d, respectively.

Dermatosparaxis in two Limousin calves

Background

An unusual presentation of skin disease was identified in two related neonatal Pedigree Limousin calves presented to University Veterinary Hospital, University College Dublin, following detailed post mortem examination a diagnosis of dermatosparaxis was made. Dermatosparaxis in animals or Ehlers Danlos Syndrome, which is the analogous condition seen in humans, is a connective tissue disorder characterised by extreme skin fragility. To the authors’ knowledge this is the first report of such a diagnosis in the Limousin breed and the features of this lethal phenotype were severe in comparison to previous reports of the condition.

Case presentation

Two calves, which were full siblings, a pedigree Limousin bull (Calf A) and pedigree Limousin heifer (Calf B) were examined clinically after presenting collapsed since birth, both had grossly abnormal skin with multiple skin fissures visible and both calves were subsequently euthanised. Both calves underwent gross post mortem examination, after which histological samples were reviewed and electron microscopical examination of selected skin samples was carried out. Histological features of dysplastic dermal collagen were identified. The diagnosis of dermatosparaxis in the Limousin breed was confirmed. Genetic testing was conducted to determine if the current cases had the same mutation as has previously been described in Belgian Blue cattle. Some common parentage was traced but genetic testing did not show a similar mutation to that previously described in cattle. The specific genetic cause in this case is unknown.

Conclusions

This is the first report of dermatosparaxis in the Limousin and the presentation of the dermatosparaxis phenotype has some noteworthy features thus further genetic testing is required to pinpoint the causative mutation or other genetic defect. Given the popularity of the breed and the lethal nature of the phenotype in this case it is important to raise awareness of the condition.