Introduction
Surgical interventions in small ruminants, particularly procedures like rumenotomy, necessitate a careful balance of anesthesia, and analgesia to ensure the well-being of the animal during, and after the intervention [1]. Anesthesia protocols play a pivotal role in mitigating the stress and discomfort associated with surgical interventions, thus, influencing not only the success of the procedure but also the overall recovery of the animal [2]. In this context, understanding the hematological responses to different anesthetic agents and pre-medication becomes crucial for refining and optimizing the surgical process.
Anesthetic protocols often involve a combination of pre-medication and induction agents to achieve a balanced state of sedation, analgesia, and muscle relaxation [3]. Diazepam and xylazine are commonly employed pre-anesthetic medications, each with distinct pharmacological properties. Diazepam, a benzodiazepine, acts as a central nervous system depressant [4] while xylazine, an alpha-2 adrenergic agonist, provides sedation and muscle relaxation [5]. The choice of pre-medication, in combination with an induction agent like Propofol, can significantly impact the physiological responses of the animal during and after surgery [3,6].
West African Dwarf (WAD) goats, with their manageable size and resilient nature, serve as an ideal model for studying the impact of anesthetic protocols on surgical outcomes [7,8]. Previous studies have explored the influence of various anesthetic agents on hematological parameters in diverse animal models [9–11]. However, there is a paucity of data on the specific impact of Diazepam and xylazine pre-medication in combination with Propofol anesthesia on hematological responses in WAD goats undergoing rumenotomy. This study seeks to fill this gap by providing a comprehensive analysis of hematological parameters in the postoperative period. Hence, in this study, the hematological responses of WAD goats undergoing rumenotomy under different anesthetic protocols were investigated.
Materials and Methods
Location of study
The research was carried out in the College of Veterinary Medicine, University of Agriculture Makurdi, Benue State, Nigeria. The large animal surgery theater and the large animal pen were used for the surgery and housing of the animals, respectively.
Ethical approval
Approval for this study was obtained from the Federal University of Agriculture Makurdi Committee on Animal Care and Use with reference no FUAMCAUC/013.
Animals used for the study
A total of 12 WAD goats in the age category of 1–2 years were used for the study. The animals were obtained from reputable markets in Makurdi and its environs, Benue State, Nigeria. The animals were stabilized and acclimatized for a period of 2 weeks, during which routine examination was carried out for any sign of ill health. The animals were fed with groundnut hay, bean husks, and water were provided ad libitum.
Grouping of animals
The WAD goats were randomly allocated into three groups (A, B, and C) with four animals each as follows:
Group A: Pre-medicated with Diazepam (0.2 mg/kg intravenous) and anesthetized with Propofol (5 mg/kg intravenous), followed by rumenotomy.
Group B: Pre-medicated with xylazine (0.05 mg/kg intramuscular) and anesthetized with Propofol (5 mg/kg intravenous), followed by rumenotomy.
Group C: Served as control, and were subjected to rumenotomy under Propofol anesthesia only.
Surgical procedure
The goats were fasted for 12 hours for feed and 6 hours for water. The left paralumbar fossa was shaved and the area was prepared aseptically with 0.2% chlorhexidine gluconate (Savlon, Vervaadingdeur, Johnson and Johnson Ltd London).
A standard laparotomy incising was made on the upper paralumbar fossa of the flank. The rumen was gently exteriorized out of the incision and firmly anchored to the skin. A 10 cm incision was made over a less vascularized portion of the rumen with greater curvature and the rumen was explored and foreign materials mostly plastic bags were seen in some of the animals. The edges of the rumen incision were cleaned with 0.9% saline solution, and a double-layer Cushing suture pattern was used to invert the rumen edges with a number 2 chromic catgut (Lifecare, Anhui Kangning Industries Group Co, Ltd Tianchang City, Anhui, China). The skin was closed using size 2 nylon suture (Lifecare, Anhui Kangning Industries Group Co, Ltd Tianchang City, Anhui, China) using a ford interlocking suture pattern.
Blood sample collection
Blood (2 ml) was collected from each goat via jugular venipuncture at pre-, intra-, immediate, 24, 48, 72, and 96 hours post-rumentomy, into labeled tubes containing ethylenediaminetetraacetic acid as an anticoagulant. Thereafter, the blood was processed for hematological analyses.
Hematological analyses
The packed cell volume (PCV), hemoglobin concentration (Hb), total red blood cells (TRBCs) and white blood cells (TWBCs), and differential leukocyte counts were determined as described by Coles et al. [12].
Data analysis
Data were expressed as mean ± standard error of the mean, and subjected to one-way ANOVA followed by Tukey’s post-hoc test. The level of significance was set at p ≤ 0.05. Statistical Package for Social Sciences (IBM 23) was used for the analysis.
Results
Erythrocytic parameters
The PCV showed no significant (p > 0.05) differences in all the groups at pre-, intra-, immediate, 48, 72, and 96 hours post-rumentomy. At 24 hours post-rumenotomy, PCV was significantly (p < 0.05) higher in group A (27.75% ± 1.60%) than in groups B (25.00% ± 0.58%) and C (25.50% ± 1.44%) (Fig. 1).
Figure 1.
PCV of WAD goats pre-medicated with xylazine or diazepam, and anesthesia induced with propofol followed by rumenotomy. Values with different superscript alphabets at the same time differ significantly at p < 0.05.
There were no significant (p > 0.05) differences in Hb and TRBC in all the groups throughout the study (Table 1).
Table 1.
Hb concentration and TRBCs of WAD goats pre-medicated with xylazine or diazepam, and anesthesia induced with propofol followed by rumenotomy.
| Post-surgery period | Hb concentration (g/dl) | TRBCs (× 1012/l) | ||||
|---|---|---|---|---|---|---|
| Group A | Group B | Group C | Group A | Group B | Group C | |
| Pre- | 9.05 ± 0.60 | 9.23 ± 0.70 | 9.30 ± 0.40 | 11.20 ± 0.72 | 11.43 ± 0.84 | 11.50 ± 0.46 |
| Intra- | 8.70 ± 0.76 | 8.90 ± 0.21 | 8.30 ± 0.50 | 10.78 ± 0.92 | 11.00 ± 0.25 | 10.30 ± 0.59 |
| Immediate post- | 8.20 ± 0.81 | 8.45 ± 0.09 | 8.45 ± 0.66 | 11.01 ± 1.01 | 10.50 ± 0.12 | 10.50 ± 0.81 |
| 24 hours | 8.20 ± 0.54 | 8.30 ± 0.17 | 8.45 ± 0.49 | 10.40 ± 0.64 | 10.30 ± 0.23 | 10.50 ± 0.58 |
| 48 hours | 8.78 ± 0.50 | 8.13 ± 0.72 | 8.40 ± 0.62 | 10.90 ± 0.60 | 10.08 ± 0.86 | 10.38 ± 0.76 |
| 72 hours | 8.58 ± 0.25 | 8.95 ± 0.36 | 8.78 ± 0.90 | 10.60 ± 0.30 | 11.10 ± 0.46 | 11.00 ± 1.11 |
| 96 hours | 8.20 ± 0.62 | 8.35 ± 0.48 | 8.55 ± 0.67 | 10.18 ± 0.76 | 10.40 ± 0.57 | 10.58 ± 0.81 |
Leukocytic parameters
There was no statistical (p > 0.05) difference in the total TWBC of all groups of goats pre-surgery. At intra-surgery, immediate and 24 hours post-surgery, the TLC was significantly (p < 0.05) increased in group A (13.95 ± 0.48; 15.05 ± 0.43; 14.50 ± 0.53 × 109/l) compared to groups B (12.91 ± 0.47; 12.81 ± 0.98; 12.72 ± 0.62 × 109/l) and C (13.08 ± 0.78; 13.29 ± 1.19; 12.78 ± 0.48 × 109/l). At 48 and up to 96 hours post-surgery, the TLC showed non-significant (p > 0.05) differences in all groups of goats (Fig. 2).
Figure 2.
TWBC count of WAD goats pre-medicated with xylazine or diazepam, and anesthesia induced with propofol followed by rumenotomy. Values with different superscript alphabets at the same time differ significantly at p < 0.05.
There was no statistical (p > 0.05) difference in the neutrophil count of all groups of goats, pre-surgery. At intra-surgery, immediate, 24, and 48 hours, post-rumenotomy, the neutrophil count of goats was significantly (p < 0.05) increased in group A (5.92 ± 0.54; 6.40 ± 0.71; 7.07 ± 0.73; 6.66 ± 0.61 × 109/l) compared to groups B (4.59 ± 0.42; 4.29 ± 0.44; 4.75 ± 1.27; 5.37 ± 0.35 × 109/l) and C (4.46 ± 0.74; 4.72 ± 0.73; 5.04 ± 0.53; 5.38 ± 1.18 × 109/l). At 72 and 96 hours, post-rumenotomy, the neutrophil count showed no statistical (p > 0.05) difference in all groups of goats (Fig. 3).
Figure 3.
Neutrophil count of WAD goats pre-medicated with xylazine or diazepam, and anesthesia induced with propofol followed by rumenotomy. Values with different superscript alphabets at the same time differ significantly at p < 0.05.
No statistical (p > 0.05) difference existed for the lymphocyte count pre- and intra-surgery, and from 24 hours up to 96 hours post-surgery. But at immediate post-surgery, the lymphocyte count was significantly (p < 0.05) decreased in group A (5.23 ± 0.53 × 109/l) compared to groups B (7.87 ± 0.50 × 109/l) and C (7.88 ± 0.96 × 109/l) (Fig. 4).
Figure 4.
Lymphocyte count of WAD goats pre-medicated with xylazine or diazepam, and anesthesia induced with propofol followed by rumenotomy. Values with different superscript alphabets at the same time differ significantly at p < 0.05.
Discussion
The response of WAD goats to specific pre-anesthetic medications, such as Diazepam and xylazine, in combination with Propofol anesthesia, offers valuable insights into hematological variations post-rumenotomy. Thus, investigating the hematological changes in WAD goats subjected to rumenotomy under different anesthetic protocols involving these agents is essential for a better understanding of their effects on postoperative recovery. The study investigated the hematological responses of WAD goats undergoing rumenotomy under different anesthetic protocols (Groups A, B, and C). The PCV results revealed no significant differences among the groups at various time points, indicating overall stability in red blood cell volume post-rumenotomy. However, at 24 hours post-surgery, group A, pre-medicated with Diazepam and anesthetized with Propofol, exhibited a significantly higher PCV compared to groups B and C. This temporary increase could be associated with the anesthetic regimen used in group A, potentially influencing blood viscosity and fluid balance [13,14].
Hb and TRBC remained consistent across all groups throughout the study, suggesting that the anesthetic protocols did not significantly impact these parameters. Similar findings have been reported in studies involving small ruminants undergoing various surgical procedures, thus, emphasizing the stability of Hb and TRBC under different anesthesia regimens [2,15,16].
The significant increase in TWBC in group A compared to groups B and C could be influenced by several possible mechanisms. One potential mechanism could be the specific combination of Diazepam pre-medication and Propofol anesthesia used in group A, which might have triggered a more pronounced immune response compared to the other groups. Previous studies have highlighted how certain anesthetic agents can modulate immune reactions, potentially leading to variations in TWBCs [17–19].
Moreover, the stress response induced by the anesthetic regimen in group A, involving Diazepam and Propofol, could have contributed to the elevation in TWBC [20]. Stress responses can stimulate the release of certain hormones and cytokines that influence white blood cell production and mobilization, leading to an increase in TWBC levels [21,22]. Another possible mechanism could involve the inflammatory response triggered by the surgical procedure itself. Rumenotomy is a surgical intervention that can elicit an inflammatory reaction in the body, resulting in an increase in white blood cell counts as part of the immune response to tissue injury [1]. Group A may have exhibited a more robust inflammatory reaction post-surgery, leading to higher TWBC levels compared to groups B and C.
Furthermore, individual variations in how animals respond to anesthesia and surgery could also play a role in the observed differences in TWBC among the groups. Factors such as genetic predisposition, overall health status, and immune system resilience can influence how animals react to surgical interventions and anesthesia, potentially impacting their white blood cell counts post-operatively [23].
Neutrophil counts in group A were significantly elevated during intra-surgery, immediate, 24, and 48 hours post-rumenotomy compared to groups B and C. This heightened neutrophil response aligns with stress-induced leukocytosis during surgical interventions [24]. The elevated neutrophil counts may indicate a systemic response to the surgical procedure, potentially influenced by the specific anesthetic agents used [20].
Contrastingly, the lymphocyte count in group A was significantly decreased at immediate post-surgery compared to groups B and C. This unexpected result may be attributed to the immunomodulatory effects of Diazepam, a benzodiazepine used for pre-medication in group A, as these drugs were reported to influence lymphocyte function and numbers in certain contexts [25,26].
Conclusion
This study sheds light on the hematological changes in WAD goats undergoing rumenotomy under different anesthetic protocols. The observed variations in PCV, TWBC, neutrophil, and lymphocyte counts emphasize the need for careful consideration of anesthetic agents and pre-medication in surgical procedures involving small ruminants. Further investigations should explore the underlying mechanisms influencing these hematological responses so as to improve anesthetic practices and optimize the overall welfare of animals undergoing rumenotomy.
Acknowledgment
The authors wish to acknowledge the technical assistance rendered by Mr. Abor Moses to make this work a success.
Conflict of interest
The authors have no conflict of interest to declare.
Author contribution
NTO, UA: Design of the experiment, performance of the surgical procedure, and writing of the original draft.
OO, AJT: Were involved in the writing of the methodology, data analysis, and proof reading.
