Laminar inflammatory gene expression in the carbohydrate overload model of equine laminitis

Reasons for performing study: There is a need to assess the laminar inflammatory response in a laminitis model that more closely resembles clinical cases of sepsis‐related laminitis than the black walnut extract (BWE) model. Objectives: To determine if a similar pattern of laminar inflammation, characterised by proinflammatory cytokine expression, occurs in the CHO model of laminitis as has been previously reported for the BWE model. Methods: Sixteen horses administered 17.6 g of starch (85% corn starch/15% wood flour)/kg bwt via nasogastric (NG) tube were anaesthetised either after developing a temperature >38.9°C (DEV group, n = 8) or at onset of Obel grade 1 lameness (OG1 group, n = 8). Control horses (CON group, n = 8) were anaesthetised 24 h after NG administration of 6 l of deionised water. Laminar tissue was collected from horses while under anaesthesia, followed by humane euthanasia. Real time‐quantitative PCR was used to assess laminar mRNA concentrations of genes involved in inflammatory signalling. Results: Increased mRNA concentrations (P<0.05) for IL‐1β, IL‐6, IL‐12p35, COX‐2, E‐selectin and ICAM‐1 were present in laminae from horses with OG1 lameness but not at the DEV time, when compared to the CON horses. No differences between the groups were found for IL‐2, IL‐4, IL‐10, TNF‐α, IFN‐γ or COX‐1 at either the DEV or OG1 time points. Conclusions: There was a notable difference in the temporal pattern of inflammatory events between the BWE and CHO models, with the majority of laminar inflammatory events appearing to occur at or near the onset of lameness in the CHO model, whereas many of these events peak earlier in the developmental stages in the BWE model. This suggests that, in addition to circulating inflammatory molecules, there may be a local phenomenon in the CHO model resulting in the simultaneous onset of multiple laminar events including endothelial activation, leucocyte emigration and proinflammatory cytokine expression. Potential relevance: The similar (although somewhat delayed) inflammatory response in the CHO model of laminitis indicates that inflammatory signalling is a consistent entity in the pathophysiology of laminitis.     

Effects of ophthalmic disease on concentrations of plasma fibrinogen and serum amyloid A in the horse

Reasons for performing study: There is little scientific information available about the ability of ocular disease to cause a systemic inflammatory response. Horses are frequently affected with ocular disease and ensuring their systemic health prior to performing vision saving surgery under anaesthesia is essential for the successful treatment of ophthalmic disease. Hypothesis: Ocular disease will cause elevations in the concentration of the acute phase proteins fibrinogen and serum amyloid A in peripheral blood. Methods: Whole blood and serum samples were obtained from 38 mature horses with ulcerative keratitis or uveitis and no evidence of systemic disease, 9 mature horses with no evidence of ocular or systemic disease (negative controls) and 10 mature horses with systemic inflammatory disease and no evidence of ocular disease (positive controls). Blood samples were assayed for concentrations of the acute phase proteins fibrinogen and serum amyloid A. Results: Fibrinogen and serum amyloid A were significantly different in the positive control group compared to the negative control, corneal disease and uveitis groups (P<0.126). There was no significant difference between the negative control, corneal disease and uveitis groups (P<0.001). Conclusions: Ulcerative keratitis and anterior uveitis are not associated with elevated concentrations of the acute phase proteins fibrinogen and serum amyloid A in peripheral blood. Potential relevance: When the clinician is presented with a patient with ocular disease and elevated plasma fibrinogen or serum amyloid A concentrations, a nonocular inflammatory focus should be suspected.     

Pedal bone fractures

Fractures of the pedal bone are usually the result of direct trauma, and are relatively commonly encountered in equine practice. Either front or hind feet may be affected. Seven distinct fracture types are recognised. Type I fractures involve the palmar/plantar process and do not enter the distal interphalangeal (DIP) joint. Type II fractures are oblique or parasagittal fractures that are articular but are not on the midline. Type III fractures are midline articular fractures that bisect the pedal bone into 2 equal halves. Type IV fractures involve the extensor (pyramidal) process of the pedal bone. Type V fractures are comminuted and split the pedal bone into multiple fragments. Type VI fractures are solar margin fractures. Type VII fractures are exclusive to foals and are also fractures of the solar margin. In most cases the onset of clinical signs is acute. The diagnosis is usually achieved by radiography, although computed tomography or magnetic resonance imaging can be helpful in some cases. Treatment options include surgical and nonsurgical therapies. The prognosis for articular fractures (Types II and III) is worse than for nonarticular fractures (Types I, IV, VI and VII) because of the likelihood of osteoarthritis within the DIP joint. Nonarticular fractures carry a good prognosis if a long enough convalescence is undertaken. Comminuted fractures (Type V) carry a poor, but not hopeless, prognosis.     

Development of equine post anaesthetic myelopathy: Thirty cases (1979–2010)

Post anaesthetic myelopathy is a rare but devastating complication of equine anaesthesia and there is a need for better understanding of the condition and to raise veterinary awareness. The aim of this study was to collect data on unreported cases and combine those with reported cases to better identify possible risk factors and early clinical signs and outcomes of horses developing post anaesthetic myelopathy (PAM). A survey was conducted to identify cases of equine PAM. Records were also requested via the American College of Veterinary Anaesthesiologists listserve. Additional cases of PAM were located through review of the literature. Eighteen new cases and 12 published cases were identified. Large‐framed breeds between 6–24 months of age were more commonly affected (23/30). The majority of horses were positioned in dorsal recumbency during anaesthesia. Lack of movement and deep pain of the rear limbs, loss of anal tone and lack of panniculus response from the mid to caudal thorax distally were the most common clinical findings. Reported treatments resulted in no improvement of clinical signs and all horses died or were subjected to euthanasia from a few hours to 8 days post operatively. Poliomyelomalacia of the caudal spinal cord is the most common histopathological finding. Although a rare complication it is a catastrophic risk that can be eliminated by performing a standing operation. Hopefully in the future better understanding of this condition will lead to prevention and treatment strategies.     

Neutrophilic myeloperoxidase index and mean light absorbance in neonatal septic and nonseptic foals

Background: Two neutrophilic indices reported by the ADVIA 120 Hematology Analyzer, neutrophilic myeloperoxidase index (MPXI), and mean light absorbance (neutrophil X mean [NXM]) have been proposed as indicators of systemic inflammatory disease in horses and of neutrophil activation in coronary ischemic syndromes in people. Objective: The aim of this study was to evaluate NXM and MPXI in healthy, sick nonseptic, and sick septic foals to determine whether conditions likely associated with neutrophil activation result in decreases in these variables. Methods: In this retrospective study, CBC data from 61 neonatal foals presented to the Equine Teaching Hospital of Barcelona were evaluated for correlations between MPXI, NXM, percentage of large unstained cells, neutrophil count, and percentage of band neutrophils. Results obtained in septic (n=32), sick nonseptic (n=22), and healthy foals (n=7) were compared. In addition, results recorded in septic/neutropenic (n=12), septic/non‐neutropenic (n=20), nonseptic/neutropenic (n=8), nonseptic/non‐neutropenic (n=14), and healthy foals (n=7) were also compared. Results: A weak negative correlation was found between MPXI and neutrophil count and between NXM and percentage of band neutrophils. Septic/neutropenic foals had significantly higher MPXI values (median 17.9, minimum–maximum 4.7–42.5) than did septic/non‐neutropenic (1.5, ?24.4 to 22.3), nonseptic/neutropenic (6.6, 0.6–17.9), and nonseptic/non‐neutropenic foals (8.8, ?10.1 to 16.8) but did not differ significantly from controls (12.8, ?8.5 to 20.4). Conclusions: Significant differences in NXM or MPXI were not found when disease groups were compared with controls; however, septic/neutropenic foals had significantly higher median MPXI than other groups of sick foals. Further prospective studies are needed to clarify if this finding is related to decreased neutrophil function or activation in septic/neutropenic foals.     

Laryngeal dysplasia: Computed tomographic findings in an Oldenburg mare

A 5-year-old Oldenburg mare presented for poor performance, head-tossing and bucking when ridden. An abnormal respiratory noise was audible during exercise. Computed tomography (CT) revealed right laryngeal dysplasia; an absent cricothyroid articulation, abnormally shaped thyroid cartilage, underdeveloped cricopharyngeus muscle, rostral displacement of the palatopharyngeal arch and an oesophageal air column. In this case, it was unlikely that the laryngeal pathology was related to the horse's clinical signs. This case report provides a reference CT examination of laryngeal dysplasia, corroborating previous findings using magnetic resonance imaging, radiography, ultrasonography and post-mortem examination.     

Cardiomyopathy in Dystrophin-Deficient Hypertrophic Feline Muscular Dystrophy

A colony of cats affected with hypertrophic feline muscular dystrophy was used to study the occurrence of cardiomyopathy associated with dystrophin deficiency. Affected male and female cats, obligate carrier females, and unaffected healthy littermates were followed from 12 weeks of age into adulthood. Thoracic radiography, 2-D echocardiography, and 2-D-derived M-mode echocardiography were performed at 3-month intervals until 12 months of age and regularly thereafter. From 9 months of age, all affected cats had larger hearts than normal and carrier animals. Left ventricular wall thickness in systole and in diastole and interventricular septal thickness in systole were greater in affected cats 12 months and older when compared with normal or heterozygous animals (P < .05). The myocardium of affected cats was diffusely hypoechoic and thickened. Multiple hyperechoic foci were in the myocardium and papillary musculature. Shortening fraction was normal in all cats. Changes seen in carrier females included enlargement and hyperechogenicity of the papillary musculature after the age of 2 years. Gross and light microscopic examination revealed left ventricular wall thickening with multiple foci of mineralization in 2 of 5 hearts from dystrophin-deficient cats. Although approximately 10% of the normal dystrophin amount was present in the skeletal muscle, dystrophin could not be detected in the myocardium. Early onset concentric myocardial hypertrophy was present in all adult cats. Lesions were mainly localized in the myocardium of the left ventricular free wall and interventricular septum, papillary musculature, and the endocardium. Clinical signs of heart failure developed only infrequently in cats with hypertrophic feline muscular dystrophy.     

Approaches to modeling intramammary infections in dairy cattle

In this paper, three approaches (Markov processes, discrete-event simulation, and differential equations) to modeling intramammary infections (IMI; focusing on the dynamic changes between uninfected, subclinical, and clinical udder-health states) are described. The objectives were to describe the various approaches to modeling intramammary infections, determine if simulations of the examples of the three approaches yield stable prevalences, and discuss the approaches' limitations. The literature review showed that there is no agreement on the proportion of animals that change health states. The approach of discrete-event simulation modeling included the most cow-level risk factors and udder-health states (hence, was judged to replicated best the dynamics of the infection process) and yielded stable prevalences for all udder-health states. However, there remain parts of the dynamics that need further research. These include the pathogen-specific probabilities and times of occurrence for: regression of clinical IMI to subclinical IMI, flare-up of subclinical IMI to clinical IMI, and incidence of subclinical IMI. Also, the assumption in all current approaches of homogenous mixing is violated because the primary contact structure for contagious pathogens during milking is either between cows through residual infectious milk in the milking machine or within a cow by vacuum fluctuations or teat-cup liner slips. Better contact structures should be incorporated so that the effects of control strategies can be better-estimated. Moreover, the three modeling approaches discussed assumed that all non-infected quarters are susceptible to infection—which might be denied by work in genetic resistance.     

Low‐density lipoproteins and milk serum proteins improve the quality of stallion sperm after vitrification in straws

Lipids and proteins can be used for sperm vitrification to preserve the integrity of sperm membranes or to increase the viscosity of the medium. This study evaluated the effect of low‐density lipoproteins (LDL) and milk serum proteins (Pronexcell) for stallion sperm vitrification. Hippex extender (Barex Biochemical Products, The Netherlands), plus 1% of bovine serum albumin and 100 mM of trehalose, was used as control for sperm vitrification. In experiment 1, different concentrations of LDL (L1 = 0.25, L2 = 0.5, L3 = 1%) and in experiment 2 of Pronexcell (P1 = 1, P2 = 5, P3 = 10%) were added to control extender. Vitrification was performed in 0.25‐ml straws directly plunged into liquid nitrogen. Total motility (TM, %) and progressive motility (PM, %) were analysed by CASA, and plasma membrane (IMS, %) and acrosome membrane integrity (AIS, %) were assessed under epifluorescence microscopy. Post‐warmed sperm parameters were compared between treatments by ANOVA. Results were expressed as mean ± SEM. In both experiments, the minimum concentration of LDL and Pronexcell obtained significantly higher values (p < 0.01) than the control extender for TM (L1 = 52.95 ± 4.4; P1 = 58.99 ± 4.6; C = 30.88 ± 3.0), PM (L1 = 36.79 ± 5.5; P1 = 47.25 ± 4.3; C = 19.20 ± 2.4), IMS (L1 = 68.88 ± 3.6; P1 = 47.25 ± 4.3; C = 52.81 ± 2.6) and AIS (L1 = 45.88 ± 3.6; P1 = 47.25 ± 4.3; C = 26.00 ± 2.1). No differences in sperm parameters were found among different concentrations of LDL or Pronexcell. In conclusion, the addition of 0.25% LDL and 1% Pronexcell to the vitrification extender is recommended to improve the quality of stallion sperm after vitrification.