Validation of the FAMACHA eye color chart for detecting clinical anemia in sheep and goats on farms in the southern United States

Recent studies on sheep and goat farms in the southern United States indicate that multiple-anthelmintic resistance in Haemonchus contortus is becoming a severe problem. Though many factors are involved in the evolution of resistance, the proportion of the parasite population under drug selection is believed to be the single most important factor influencing how rapidly resistance develops. Therefore, where prevention of resistance is an important parallel goal of worm control, it is recommended to leave a portion of the animals untreated. Recently, a novel system called FAMACHA was developed in South Africa, which enables clinical identification of anemic sheep and goats. When H. contortus is the primary parasitic pathogen, this system can be applied on the farm level to reduce the number of treatments administered, thereby increasing the proportion of the worm population in refugia. Since most studies validating the FAMACHA method have been performed in South Africa, it is important that the method be tested in other regions before its use is broadly recommended. We performed a validation study of FAMACHA by testing the system in sheep (n = 847) and goats (n = 537) of various breeds and ages from 39 farms located in Arkansas, Georgia, Louisiana, Florida, and the US Virgin Islands. The color of the ocular conjunctiva of all animals were scored on a 1-5 scale using the FAMACHA card, and blood samples were collected from each animal for determination of packed cell volume (PCV). Fecal samples were also collected from a majority of the animals tested for performance of fecal egg counts (FEC). Correlations between PCV and eye scores, PCV and FEC, and FEC and eye scores were all highly significant for both sheep and goats (P < 0.001). Data for both FAMACHA scores and PCV were evaluated using two separate criteria for anemia: eye score values of 3, 4 and 5 or 4 and 5, and PCV values of < or =19 or < or =15 were considered anemic. Specificity was maximized when eye score values of 4 and 5 were considered anemic and PCV cut off for anemia was < or =19, but sensitivity was low. In contrast, sensitivity was 100% for both sheep and goats when eye score values of 3, 4 and 5 were considered anemic and PCV cut off was < or =15, but specificity was low. In both sheep and goats, predictive value of a negative was greater than 92% for all anemia and eye score categories, and was greater than 99% for both eye score categories when an anemia cutoff of < or =15 was used. Predictive value of a positive test was low under all criteria indicating that many non-anemic animals would be treated using this system. However, compared to conventional dosing practices where all animals are treated, a large proportion of animals would still be left untreated. These data indicate that the FAMACHA method is an extremely useful tool for identifying anemic sheep and goats in the southern US and US Virgin Islands. However, further studies are required to determine optimal strategies for incorporating FAMACHA-based selective treatment protocols into integrated nematode control programs.     

Pancreatic exocrine secretion and plasma concentration of some gastrointestinal hormones in response to abomasal infusion of starch hydrolyzate and/or casein

Eight Angus steers (290 +/- 8 kg), surgically prepared with pancreatic pouch-duodenal reentrant cannulas and abomasal infusion catheters were used in a replicated 4 x 4 Latin square experiment to investigate the effects of abomasal infusion of starch hydrolyzate (SH) and/or casein on pancreatic exocrine secretion and plasma concentration of hormones. Steers were fed a basal diet of alfalfa (1.2 x NEm) in 12 equal portions daily. Abomasal infusion treatments (6-L total volume infused per day) were water (control), SH [2.7 g/(kg BW x d)], casein [0.6 g/(kg BW x d)], and SH + casein. Periods were 3 d for adaptation and 8 d of full infusion. Pancreatic juice and jugular blood samples were collected over 30-min intervals for 6 h on d 11. Weight and pH of pancreatic samples were measured, and a 10% subsample was composited and frozen until analysis of total protein and pancreatic enzyme activities. The remaining sample was returned to the duodenum. Plasma was harvested and frozen until analyzed. Pancreatic juice (67 mL/h) and protein (1.8 g/h) secretion rates were not affected by nutrient infusion. There were SH x casein interactions for all pancreatic enzyme secretions (U/h; alpha-amylase, P < 0.03; trypsin, P < 0.08; and chymotrypsin, P < 0.03) and plasma insulin concentration (P < 0.10). Secretion of pancreatic enzymes was increased by SH (trypsin) and casein (alpha-amylase, trypsin, and chymotrypsin) but not when SH + casein were infused together. Glucose (P < 0.10) and cholecystokinin octapeptide concentrations (CCK-8; P < 0.05) were increased by SH, but glucagon was decreased (P < 0.10). Casein decreased (P < 0.10) plasma CCK-8 concentrations. These data indicate that positive effects of postruminal casein on enzyme secretion were inhibited by SH, emphasizing the complexity of the regulatory mechanisms involved in dietary adaptation of pancreatic exocrine secretion. Changes in hormone concentration may not relate directly to changes in enzyme secretion.     

Recurrence of thoracolumbar intervertebral disk extrusion in chondrodystrophic dogs after surgical decompression with or without prophylactic fenestration: 265 cases (1995-1999)

OBJECTIVES: To evaluate a population of chondrodystrophic dogs treated for Hansen type 1 intervertebral disk (IVD) disease by surgical decompression with or without prophylactic fenestration and determine the rate and location of surgically confirmed recurrence of intervertebral disk extrusion. ANIMALS: 265 dogs. STUDY DESIGN: Retrospective study. PROCEDURES: Medical records of dogs that underwent spinal decompression between 1995 and 1999 were reviewed. RESULTS: 3 (4.9%) dogs were euthanatized or died prior to discharge. Fenestration was performed in 252 dogs, including 37 (14.7%) at the site of decompression only, 48 (19%) at 3 to 4 disk spaces, and 167 (66%) at 5 to 7 disk spaces. There were 12 instances of recurrent disk extrusion confirmed by removal of disk at a second surgery 3.5 to 33 months after the first surgery. Recurrence was always at a new disk space, and rates did not significantly differ between dogs that underwent single or multiple fenestrations. Two recurrences were at a previously fenestrated disk space. Seven recurrences were at a site immediately adjacent to a fenestrated disk space, and 5 recurrences were at L4-5. CONCLUSIONS AND CLINICAL RELEVANCE: Prophylactic fenestration is generally successful in preventing future disk extrusions at fenestrated disk spaces. Prospective evaluation is still required to determine whether fenestration decreases the overall rate of recurrence. Prophylactic fenestration could promote disk extrusion at adjacent, nonfenestrated disk spaces. This could have a substantial clinical impact if recurrence develops at L4-5.     

Multifocal cutaneous histiocytic sarcoma in a young dog and review of histiocytic cell immunophenotyping

A 9‐month‐old male Great Dane had progressive generalized nodular dermatopathy for several months. There were > 100 raised, alopecic, firm, painful nodules throughout the skin. Aspirates from several lesions yielded moderate numbers of irregularly round or polygonal to spindle‐shaped cells with mild to moderate anisocytosis and few inflammatory cells, and the cytologic interpretation was proliferation of mesenchymal or histiocytic cells. On histopathologic examination, nodules were composed of densely packed sheets of round to spindle‐shaped cells with mild anisokaryosis and low mitotic activity. Multifocal histiocytic sarcoma with a spindle‐cell pattern was diagnosed based on morphologic features and intense expression of CD18. Additional immunophenotypic analysis on frozen sections of tissue confirmed the diagnosis of histiocytic sarcoma; expression of CD18, CD45, CD1a, CD11b, and CD11c, limited expression of Thy‐1 (CD90) and CD80, and lack of expression of CD4, CD11d, and CD86 indicated that the cells were likely interstitial dendritic cells; a review of reactive and neoplastic dendritic cells is provided. Based on staging, internal organs were not affected. Sequential treatment with lomustine and doxorubicin failed to prevent progression of the cutaneous lesions, and the dog died 3 months after initial diagnosis. At necropsy, a focus of neoplastic cells was present in one lymph node, but except for skin other organs were not involved. The clinical presentation of histiocytic sarcoma may be unusual, and neoplastic cells may lack overt features of malignancy on cytologic and histopathologic examination. In some instances, immunophenotyping is required to differentiate histiocytic sarcoma from other histiocytic disorders.     

Index selection in terminal sires improves early lamb growth

The use of terminal sires (TS) for crossbreeding is integral to the UK sheep industry where approximately 71% of market lambs are sired by TS rams. Early growth of these crossbred lambs affects profitability. The objectives of this study were i) to evaluate the effectiveness of index selection among TS on BW and ADG of their crossbred offspring; and ii) to compare the efficacy of that selection within TS breeds. The most widely used TS breeds in the United Kingdom are Charollais, Suffolk, and Texel. These participated in sire referencing schemes in which they were evaluated on a lean growth index designed to increase carcass lean weight at a given age. From 1999 to 2002, approximately 15 high and 15 low lean growth index rams per breed (93 in total, differing in index on average by 4.6 SD) were selected from within their sire referencing schemes and mated to Welsh and Scottish Mule ewes. Their crossbred offspring were reared commercially on 3 experimental farms in England, Scotland, and Wales. A total of 6,515 lambs were born between 2000 and 2003. Lambs were weighed at birth (BWT), 5 wk (5WT), and 10 wk (10WT), and their ADG from birth to 10 wk was calculated. Lambs sired by high index rams were on average, across breeds, heavier at all ages (P < 0.01) with 0.07 ± 0.03, 0.3 ± 0.1, and 0.4 ± 0.1 kg greater BWT, 5WT, and 10WT, respectively. Their ADG was 5.1 ± 1.9 g/d greater than low-index-sired lambs (P < 0.01). Suffolk-sired lambs were on average heavier at all ages, with greater ADG, whereas Charollais-sired lambs were lightest with smallest ADG. Overall, there was no significant interaction between sire index and sire breed (P > 0.10). Within Suffolk-sired lambs, there was little difference between high and low index sires for the traits studied (P > 0.3). High and low index Charollais-sired lambs differed in BWT (0.09 ± 0.04 kg) and 5WT (0.3 ± 0.1 kg), and Texel-sired lambs differed in 5WT (0.5 ± 0.1 kg), 10WT (0.9 ± 0.2 kg), and ADG (10.2 ± 3.3 g/d; P < 0.01). Lambs from Scottish Mule dams were heavier, with greater ADG, than lambs born to Welsh Mules (P < 0.01). Lambs reared in Scotland were heavier at all ages (P < 0.01). The results suggest that using index selection in TS can improve the growth of their commercial offspring reared on grass.     

The molecular epidemiology of equine influenza in Ireland from 2007-2010 and its international significance

Reasons for performing the study: Antigenic and genetic drift of equine influenza (EI) virus is monitored annually by the Expert Surveillance Panel (ESP), which make recommendations on the need to update vaccines. Surveillance programmes are essential for this process to operate effectively and to decrease the risk of disease spread through the international movement of subclinically infected vaccinated horses. Not only is surveillance necessary to inform vaccine companies which strains are in circulation, but it serves as an early warning system for horse owners, trainers and veterinary clinicians, facilitating the implementation of appropriate prophylactic and control measures. Objective: To summarise the genetic analysis of EI viruses detected in Ireland from June 2007 to January 2010. Methods: The HA1 gene of 18 viruses was sequenced and phylogenetic analysis undertaken. Results: All viruses belonged to the Florida sublineage of the American lineage. Clade 2 viruses predominated up to 2009. The viruses identified on 4 premises in 2007 displayed 100% nucleotide identity to A/eq/Richmond/1/07, the current clade 2 prototype. The first clade 1 virus was identified in November 2009 and, thereafter, clade 1 viruses were responsible for all the outbreaks identified. The Irish clade 1 viruses differ from the clade 1 virus responsible for the EI outbreaks in Japan and Australia in 2007. No virus of the Eurasian lineage was isolated during this surveillance period. Conclusions: In 2010 the ESP recommended that the vaccines should not include a H7N7 virus or a H3N8 virus of the Eurasian lineage but that they should contain both a clade 1 and clade 2 virus of the Florida sublineage. The surveillance data presented here support these recommendations and indicate that they are epidemiologically relevant. Potential relevance: These data also serve as a scientific basis for investigating the source of epizootics and outbreaks both nationally and internationally.     

Morphology and Neurochemical Expression of Neurons Immunoreactive for the Calcitonin Gene-Related Peptide (CGRP-IR) in the Lamb Ileum

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