Evaluation of serum concentration of acute-phase proteins (haptoglobin and serum amyloid A) in the affected Arabian foals with rhodococcosis

BACKGROUND

Early detection of Rhodococcus equi pneumonia in foals is essential for horse health and for veterinarians.

OBJECTIVES

This study aimed to demonstrate the usefulness of assessing the serum concentration of acute-phase proteins (APPs) in the early diagnosis of pneumonia.

METHODS

The study evaluated APPs in 19 Arabian foals with R. equi pneumonia and compared them with 18 normal Arabian foals in equestrian clubs in Tabriz, Iran. Affected foals were identified through history, clinical findings and bacterial culture of tracheal washing. Biochemical methods and polymerase chain reaction tests were performed by examining the 16S rRNA and vapA genes to confirm the diagnosis of bacterial isolates. Blood samples were taken from all sick and healthy horses, and their serum was isolated. APPs in the serum were measured in all the samples.

RESULTS

Rhodococcosis increased the serum concentration of haptoglobin (Hp) and serum amyloid A (SAA) (p < 0.001). The relationship between SAA and Hp was meaningful in the infected group (r = 0.933) but not in the healthy group. In cases where there are clinical findings of R. equi pneumonia, the concentration of SAA and Hp can help the effectiveness of treatment.

- CONCLUSIONS

Serum concentration analysis of APPs can be helpful in early diagnosis and successfully treating foals with R. equi pneumonia.

Assessment of Standing and Recumbent Restraint Positions and the Significance of Rumenotomy Techniques Based on the Profiles of Serum Amyloid a in Kano Brown Goats

Standing and lateral recumbency positions have been used as a standard approach for most surgical procedures for large and small ruminants, respectively, without appropriate attention to the associated surgical stress. The study aimed to assess the level of surgical stress in Kano Brown goats (KBGs) based on their serum amyloid A (SAA) profiles by undergoing rumenotomy in lateral recumbency (Rumen Skin Clamp Fixation-RSCF and Stay Suture Rumenotomy-SSR) and a standing position restraint. A total of 24 KBGs were equally allocated by number and sex in groups A, B, C, and D. Groups A and B underwent RSCF and SSR in lateral recumbency, respectively, while group D underwent a rumenotomy in a standing position performed in a custom made mobile small ruminant surgical chute. Animals in groups A, B, and D were diagnosed with rumen foreign bodies, whereas group C was used as a control with a negative diagnosis. At 48 h post-rumenotomy, the mean SAA concentration in group B (137.88±66.87 g/L) was significantly higher (P<0.05) than the value in group C (34.59±0.57 g/L). The females in group B had a significantly higher (P<0.05) mean concentration of SAA at 48 hours (210.15±123.73 g/L) than groups C (35.18±0.08 g/L) and D (48.35±12.15 g/L). In group A, at 24 hours, SAA concentration (115.61±20.96 µg/L) was significantly higher (P<0.05) than that of group B (31.51±2.59 µg/L) and group C (34.86±3.21 µg/L) in males. Rumenotomy in the standing restraint position was associated with minimal surgical stress, hence it’s recommended over the conventional lateral recumbent position techniques.

Serum Amyloid A as a Promising Biomarker in Domestic Animals’ Reproduction: Current Knowledge and Future Perspective

Simple Summary

Acute phase proteins (APPs) are useful markers which can be evaluated in animals to assess health status and characterize inflammation, infection, and trauma. Among APPs, serum amyloid A (SAA) has been widely investigated in pets and food-producing species as a possible biomarker of inflammatory and infective conditions, especially in the field of animal reproduction. The aims of this paper are to review the literature available on the use of SAA for the diagnosis and monitoring of inflammatory reproductive disease in animals, critically appraising the usefulness of such marker and summarizing the current state of knowledge.

Abstract

The investigation of acute phase proteins in veterinary medicine has opened the doors towards the identification and use of new markers for a timely assessment of health status in both companion and food-producing animals. The aim of this paper is to review the literature available on the use of serum amyloid A (SAA), an acute phase protein, for the diagnosis and monitoring of reproductive disorders in animals. This review critically appraises the usefulness of such marker in clinical practice and summarizes the current state of knowledge. Recent advances in the diagnosis and monitoring of reproductive diseases are presented, highlighting where SAA evaluation may enhance early diagnostic tools for dogs, cats, cattle, and equines.

Interrelationship between reproductive hormones and acute phase proteins during estrous cycle and pregnancy in Spanish purebred broodmares

In some species, female steroid hormones modify the profile of acute phase proteins (APPs) during the estrous cycle and pregnancy, according to the ovulation, embryonic implantation and placental development; however, nowadays there's no experimental evidence for equine species. Objectives of this study were: to compare the serum amyloid A (SAA), haptoglobin (Hp) and C-reactive protein (CRP) concentrations between cyclic and pregnant mares, and to analyze the influence of estradiol-17β (E2) during estrous cycle or estrone sulfate (E1) during pregnancy, and progesterone (P4) on these proteins to assess their potential role to identify the cyclicity or pregnancy in Spanish mares. Blood samples were taken from 20 Purebred Spanish mares on the day of ovulation (day 0), on days +5 and +16 post-ovulation, and then, monthly during the whole pregnancy. SAA, Hp and CRP did not change between day 0, +5 and +16 post-ovulation days. P4 concentrations were significantly higher on day +16 than on days +5 and 0; and E2 concentrations were significantly higher on day 0 than day +5. On the other hand, pregnancy was characterized by a progressive increase in the Hp, variable modifications of E1 and P4 concentrations, without changes in SAA and CRP. The absence of significant differences in the APPs between days 0, +5 and +16, suggested that these proteins cannot be used as biomarkers of diagnosis of heat or pregnancy in Spanish mares, at least early, since the Hp later increases during the gestation. Nevertheless, it is possible to use them for comparative purposes with other equine breeds, as supervisor instrument of health status in breeding females as diagnostic tools to monitor pregnancy's development and/or subclinical reproductive inflammations, that could lead to the early embryonic death.

The Accuracy of Serum Amyloid A in Determining Early Inflammation in Horses After Long-Distance Transportation by Air

Transportation of sporthorses increases their susceptibility to infectious diseases. Before, caretakers relied on rectal temperature together with their clinical impression to detect travel-associated infections. This study's aim was to assess and compare serum amyloid A (SAA) to rectal temperature as an indicator of early inflammation in sporthorses after air transportation. One hundred and twenty-two Warmblood horses were followed during the Longines Global Champions Tour 2016 to three destinations where the horses flew to compete. Clinical health checks and SAA measurements were performed before flying, upon arrival (0 hours), and 24 hours postarrival. Serum amyloid A was tested using a stall-side lateral flow immunoassay. Rectal temperature was measured twice a day using a commercially available digital thermometer. An SAA cutoff value of 23 μg/mL measured 24 hours postarrival was able to correctly distinguish between a healthy and sick horse with a sensitivity and specificity of 93.3% and 91.3%, respectively. Conversely, elevated rectal temperature had a sensitivity of only 3% to distinguish between the two horse groups. Monitoring SAA in traveling sporthorses is a more sensitive indicator of clinical health than monitoring body temperature and may aid in early identification of inflammatory processes.

Survey of Serum Amyloid A and Bacterial and Viral Frequency Using qPCR Levels in Recently Captured Feral Donkeys from Death Valley National Park (California)

Feral donkey removal from state land has raised concerns in terms of disease transmission between equine species. Disease outbreaks may occur as a result of the relocation of animals to new environments. Virus and bacteria DNA load and serum amyloid A derived from the pathogenic processes that they involve were measured in recently captured donkeys. Blood and nasal swabs were collected from 85 donkeys (Death Valley National Park, Shoshone, California); 24 were retested after 30/60 days in the Scenic (Arizona) long-term holding facility co-mingled with feral donkeys from Arizona and Utah. Quantitative Real-Time PCR (qPCR) was performed to detect viral and bacterial genomic material (equine influenza A [EIV], equine rhinitis A and B viruses, AHV-2, AHV-3, AHV-5 and EHV-1, EHV-4, Streptococcus equi subspecies equi and zooepidemicus,). Significant relations between behavior, body condition score, nasal discharge, and coughing were found in donkeys for which AHV-2 and Streptococcus zooepidemicus DNA was detected. Higher SAA concentrations were found in foals. AHV-2 and Streptococcus zooepidemicus DNA concentrations significantly differed between sampling moments (p < 0.05). In conclusion, donkeys do not appear to be a substantial risk for disease transmission to horses but could be if they carried strangles or other processes in which AHV-2 and Streptococcus zooepidemicus were involved.

The Effect of Sedation, Oral Examination, and Odontoplasty on Systemic Inflammation as Measured by Serum Amyloid A in the Adult Performance Horse

Serum amyloid A (SAA) is one of the major acute phase proteins in horses. It serves as a marker for systemic inflammation and infection, as the concentration can increase 100- to even 1000-fold during systemic disease processes. The objective of this study was to evaluate the effect of sedation, oral examination, and odontoplasty on systemic inflammation as measured by SAA in the adult performance horse. This study included 32 clinically healthy adult performance horses. Blood samples were collected immediately prior to sedation, oral examination, and odontoplasty and 48 and 72 hours afterward. Serum amyloid A levels were measured directly after venipuncture using a commercially available stall-side lateral flow immunoassay test developed and validated for equine SAA levels. Serum amyloid A values were within normal limits for each of the time periods and there were no significant differences in SAA values between the time periods. The results of this study suggest that sedation, oral examination, and odontoplasty have no systemic inflammatory effects as measured by SAA.

The Level of Prolactin, Serum Amyloid A, and Selected Biochemical Markers in Mares Before and After Parturition and Foal Heat

The aim of the study was to determine the level of prolactin (PRL), serum amyloid A (SAA), and selected biochemical markers (T-Chol, AST, TP, Mg²⁺, P⁺, and Ca²⁺) in the blood of mares during the perinatal period. The study involved 14 mares of the Polish Coldblood Horse breed, which were in the third trimester of pregnancy. Blood was collected for testing 2 weeks before parturition and then 24 hours after delivery and in the foal heat (9 days) and 9 days after ovulation and breeding. The research revealed significant differences in the level of PRL and SAA before and after delivery. The highest PRL level was found 24 hours after delivery, lowest in foal heat and 9 days after ovulation. Serum amyloid A concentration was within the accepted norms; however, on day 9 after foaling, a significant increase of this protein was observed. All biochemical markers were within physiological limits. However, significant increases in T-Chol, AST, and TP levels was observed 24 hours after the delivery, whereas in foal heat and after ovulation levels of T-Chol and TP significantly decreased and the AST level remained at a similar level. There were no significant changes in electrolyte levels such as Mg²⁺, P⁺, and Ca²⁺. The pregnancy rate in the foal heat was at 43%. Collectively, the results of this study in conjunction with clinical observations demonstrated that when the perinatal period was normal, no disturbances in health related to pregnancy, parturition, lactation, and reproductive status during the postpartum period were found.

Determining factors and interspecific modeling for serum amyloid a concentrations in working horses, donkeys, and mules

Serum amyloid A (SAA) is an acute phase protein and α-globulin that is produced in the liver in response to inflammatory cytokines. Considered a major acute phase protein in most domestic species, its concentrations rapidly decrease after resolution of inflammation, making SAA measurement a useful tool for monitoring the course of inflammation in an individual animal. The objective of this study was to compare SAA values in working equids including mules, donkeys and horses as well as values for different diseases at various times of the year. Samples were collected from 77 equids; 13 mules, 17 donkeys and 47 horses from sick or injured animals who presented to the clinic. Twenty-eight disease clinical diagnoses were compared with most cases being acute colitis. A highly significant differences between species was found when comparing SAA concentrations of mules to horses (P < .001) using Dunn comparison pairwise test. A difference (P < .05) was found between donkeys and horses, but not donkeys to mules (P > .05). The study suggests that SAA can be a helpful tool for disease diagnosis in mules and donkeys and suggests that the inflammatory response of mules maybe less than that of horses and donkeys but future studies evaluating SAA in healthy mules compared to diseased should be conducted.

Lactate-guided conditioning program using variable exercise intensities improves fitness and alters muscle enzyme activity but not inflammatory response in horses

Blood lactate concentration ([LA]) response to exercise challenges can be used to assess fitness in horses. Most equine conditioning programs (CP) that have been studied are based on regular bouts of exercise of similar to increasing levels of intensity. We hypothesised that a lactate-guided CP implementing 2× weekly short-duration high-intensity exercise bouts and 1× weekly low-intensity longer-duration exercise bout effectively increases fitness in horses. Six untrained adult horses followed a 12 week CP that consisted of 2× weekly exercise on an equine treadmill (6% incline) for 25 min at a velocity at which [LA] was 4.0 mmol/l (VLA4.0) and 1× weekly for 45 min at a velocity at which [LA] was 2.5 mmol/l (VLA2.5). VLA2.5 and VLA4.0 were determined by incremental-step standardised-exercisetest (SET) before the CP and adjusted every 3 weeks. Blood was collected for [LA], creatine kinase (CK), aspartate aminotransferase (AST), serum amyloid A (SAA), and fibrinogen (Fb) before each speed increase and 30 min, 2, 4, and 24 h after termination of the SET, when [LA] was ≥4.0 mmol/l. Repeated-measures ANOVA was used for analysis. During each SET horses showed increases in heart rate (P<0.0001), packed cell volume (P=0.003), and [LA] (P=0.002). Throughout the CP, VLA2.5 increased from 5.6±0.2 to 6.7±0.3 m/s (P<0.05) and VLA4.0 increased from 6.0±0.2 to 7.4±0.3 m/s (P<0.01). CK, AST, SAA, and Fb did not increase following submaximal exercise. CK and AST activity were attenuated throughout the 12 week CP (P<0.05). This lactate-guided CP was effective at increasing fitness based on achieving higher speeds during the SETs and did not appear to have deleterious effects on the horses’ muscular system or inflammatory state.