Diseases of the gastrointestinal system. Sheep, Goat, and Cervid Medicine 2021. [PMCID: PMC7169351 DOI: 10.1016/b978-0-323-62463-3.00014-1]

Impact of concerning excipients on animal safety: insights for veterinary pharmacotherapy and regulatory considerations

OBJECTIVES

Veterinarians and pharmacists are familiar with the efficacy and safety aspects attributed to active pharmaceutical ingredients included in medicines, but they are rarely concerned with the safety of excipients present in medicines. Although generally recognized as safe, excipients are not chemically inert and may produce adverse events in certain animal populations. This review aims to present excipients of concern to these populations and highlight their relevance for rational veterinary pharmacotherapy.

EVIDENCE ACQUISITION

A comprehensive review of the literature about the existence of adverse reactions in animals caused by pharmaceutical excipients was carried out based on an exploratory study. An overview of the correct conditions of use and safety of these excipients has also been provided, with information about their function, the proportion in which they are included in the different pharmaceutical dosage forms and the usual routes of administration.

RESULTS

We identified 18 excipients considered of concern due to their potential to cause harm to the health of specific animal populations: bentonite, benzalkonium chloride, benzoic acid, benzyl alcohol, ethanol, lactose, mannitol, mineral oil, monosodium glutamate, polyethylene glycol, polysorbate, propylene glycol, sodium benzoate, sodium carboxymethylcellulose, sodium lauryl sulfate, sulfites, polyoxyethylene castor oil derivatives, and xylitol. Among the 135 manuscripts listed, only 24 referred to studies in which the substances were correctly evaluated as excipients.

CONCLUSIONS

Based on the information presented in this review, the authors hope to draw the attention of professionals involved in veterinary pharmacotherapy to the existence of excipients of concern in medicines. This information contributes to rational veterinary pharmacotherapy and supports veterinary pharmacovigilance actions. We hope to shed light on the subject and encourage studies and new manuscripts that address the safety of pharmaceutical excipients to the animal population.

Abomasal impaction in buffaloes: Risk factors, clinical indicators, necropsy findings, and histology studies

The present study aims to identify potential risk factors and most possible clinical indicators of abomasal impaction in buffaloes. Among the screened buffaloes (n = 636), the logistic model was fitted for 491 buffaloes because of the non-availability of parity-related data for 145 buffaloes. Third-trimester pregnancy, feeding paddy straw alone, and concurrent disorders were identified as the potential risk factors using multivariate regression analysis. The buffaloes reared by farmers devoid of land tended to have a higher incidence of abomasal impaction. Depressed demeanour, absence of rumination, abdominal guarding, scleral congestion, sunken eyeballs, anorexia, reduced dung output, abacus beads-like faeces, colic signs (straining to defecate, frequent lying down, and kicking at abdomen), tachypnea, and tachycardia were the most repeatedly noticed clinical signs in buffaloes diagnosed with abomasal impaction. Further, the principal component analysis revealed increased rumen fluid sedimentation time and chloride content, serum creatine phosphokinase, and blood neutrophil and eosinophil content along with decreased blood lymphocytes proportion, potassium, and chloride as the greatest indicators for abomasal impaction. Next to them, a higher rumen fluid methylene blue reduction time, serum urea nitrogen, and blood total leucocyte count, along with a lower serum albumin and blood haemoglobin were the best possible indicators for diagnosis. The necropsy findings of the buffaloes that died with abomasal disorders revealed an abomasum with increased dimensions and constant pitting on pressure. Furthermore, the histopathological studies showed degeneration and necrosis of the abomasal wall with infiltrated mononuclear cells. The results of the study help in designing a comprehensive evaluation mechanism for diagnosing abomasal impaction in buffaloes.

Clinical utility of abdominal multidetector CT in 85 goats with suspected abdominal disease

Diagnosing the cause of abdominal disease in goats can be challenging. Clinical history, physical investigation, and laboratory findings do not always allow definitive identification of intra-abdominal disease or the underlying cause. Multidetector CT (MDCT) has become more readily available and now often replaces or augments other abdominal imaging techniques. The objective of this retrospective, observational, descriptive study was to investigate the clinical utility of MDCT for evaluation of the abdomen in goats with suspected abdominal disease involving the urinary, gastrointestinal, reproductive tracts and abdominal wall. Medical records (1/2009-12/2017) were reviewed for all goats undergoing an abdominal MDCT. Signalment, clinical history, examination and MDCT findings and outcome were recorded and categorized by abdominal organ system and wall lesion. Clinical problems and MDCT findings were compared in the various abdominal categories. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic odds ratio (OR) were calculated for MDCT, using clinical examination findings as the reference standard. A total of 85 goats underwent an abdominal MDCT examination. The sensitivity of MDCT for detecting urinary, gastrointestinal, reproductive tract, and abdominal wall abnormalities in goats with clinical problems related to these body systems was high at 94.7 %, 78.3%, 94.1%, and 100%, and the specificity was high at 95.6%, 96.7%, 93.9%, and 100%, respectively. The PPV was 94.7%, 90.0 %, 80.0%, and 100.0%, the NPV was 95.6%, 92.1%, 98.4%, and 100%, and the OR were 387.0, 104.4, 248.0, and infinite. In conclusion, findings supported the use of MDCT as an adjunct diagnostic test for assessing goats with abdominal disease.

Bacteriophages: A possible solution to combat enteropathogenic Escherichia coli infections in neonatal goats

Due to awareness and benefits of goat rearing in developing economies, goats' significance is increasing. Unfortunately, these ruminants are threatened via multiple bacterial pathogens such as Enteropathogenic Escherichia coli (EPEC). In goat kids and lambs, EPEC causes gastrointestinal disease leading to substantial economic losses for farmers and may also pose a threat to public health via the spread of zoonotic diseases. Management of infection is primarily based on antibiotics, but the need for new therapeutic measures as an alternative to antibiotics is becoming vital because of the advent of antimicrobial resistance (AMR). The prevalence of EPEC was established using bfpA gene, uspA gene, and Stx1 gene, followed by phylogenetic analysis using Stx1 gene. The lytic activity of the isolated putative coliphages was tested on multi-drug resistant strains of EPEC. It was observed that a PCR based approach is more effective and rapid as compared to phenotypic tests of Escherichia coli virulence. It was also established that the isolated bacteriophages exhibited potent antibacterial efficacy in-vitro, with some of the isolates (16%) detected as T4 and T4-like phages based on gp23 gene. Hence, bacteriophages as therapeutic agents may be explored as an alternative to antibiotics in managing public, livestock and environmental health in this era of AMR.

Comparative Genomics of Clostridium baratii Reveals Strain-Level Diversity in Toxin Abundance

Clostridium baratii strains are rare opportunistic pathogens associated with botulism intoxication. They have been isolated from foods, soil and be carried asymptomatically or cause botulism outbreaks. Is not taxonomically related to Clostridium botulinum, but some strains are equipped with BoNT/F7 cluster. Despite their relationship with diseases, our knowledge regarding the genomic features and phylogenetic characteristics is limited. We analyzed the pangenome of C. baratii to understand the diversity and genomic features of this species. We compared existing genomes in public databases, metagenomes, and one newly sequenced strain isolated from an asymptomatic subject. The pangenome was open, indicating it comprises genetically diverse organisms. The core genome contained 28.49% of the total genes of the pangenome. Profiling virulence factors confirmed the presence of phospholipase C in some strains, a toxin capable of disrupting eukaryotic cell membranes. Furthermore, the genomic analysis indicated significant horizontal gene transfer (HGT) events as defined by the presence of prophage genomes. Seven strains were equipped with BoNT/F7 cluster. The active site was conserved in all strains, identifying a missing 7-aa region upstream of the active site in C. baratii genomes. This analysis could be important to advance our knowledge regarding opportunistic clostridia and better understand their contribution to disease.

Clinical, haemato-biochemical, and ultrasonographic findings of abomasal impaction and abomasal ulcers in buffaloes

The current study evaluated the clinical, ruminal, haemato-biochemical, and ultrasonographic findings of abomasal disorders' affected buffaloes grouped as abomasal impaction (n = 18) and abomasal ulcers (n = 15). The abomasal disorders' screening was based on clinical examination and confirmed by ultrasonography. The most common clinical findings of the buffaloes affected with abomasal disorders include depressed demeanour (96.97%), absence of rumination (87.88%), abdominal guarding (87.88%), sunken eye balls (81.82%), tachycardia (78.79%), tachypnea (72.73%), and kyphosis (63.64%). The average rumen motility, respiratory rate, and pulse rate for abomasal impaction and abomasal ulcers were 0.28, 33.37, and 83.44, and 0.33, 35.87, and 92.60, respectively. The faecal occult blood test (benzidine test) revealed the presence of melena in all the buffaloes diagnosed with abomasal ulcers (100%). The ultrasonographic examination of the abomasal impaction group revealed increased abomasal size with no movement of the abomasal contents. The ultrasonographic imaging of abomasal ulcer-affected buffaloes showed irregularity in the abomasal wall-outline with moderately echogenic abomasal contents and a layer of fibrin at the affected area. Nine buffaloes had ultrasonographic evidence of peritonitis. The abomasal contents of buffaloes with positive benzidine test (n = 15) were screened for Clostridium perfringens by a polymerase chain reaction and were found positive for cpa toxin yielding 900-bp length. The rumen protozoal count was higher in healthy buffaloes, while the sedimentation test, (time) methylene blue reduction test, (time) and chloride levels were higher (P < 0.01) in the buffaloes affected with abomasal disorders. Haematological findings revealed a higher haematocrit, total leucocyte count, neutrophils, and eosinophil proportion and lower haemoglobin, total erythrocyte count, and lymphocyte proportion without affecting the fractions of monocytes and basophils. Furthermore, the buffaloes affected with abomasal disorders showed lower albumin, phosphorus, and potassium and higher aspartate transaminase, blood urea nitrogen, creatinine kinase, creatinine, and chloride concentrations. The present study projects clinical signs, ruminal parameters, and haemato-biochemical parameters as better indicators of abomasal disorders; however, ultrasonography is the sole diagnostic aid for the confirmation of abomasal disorders in buffaloes.

Laparoscopic Retrieval of Abdominal Cysts in Sheep and Goat

The study was planned to evaluate the use of laparoscopy for the diagnosis and retrieval of abdominal cysts in sheep and goats. The abdominal cysts were located in 10 of 135 adult, healthy small ruminants by using ultrasonography (USG). Percutaneous Puncture-Aspiration-Injection-Reaspiration (PAIR) technique was used for six animals. Thirty animals, including four diagnosed with abdominal cysts by USG, were subsequently subjected to laparoscopy under diazepam sedation (0.1 mg/kg, IV) and lumbosacral epidural regional anesthesia using 2% lignocaine hydrochloride (1.0 ml/5 kg). The animals were restrained in dorsal recumbency and two-port paramedian laparoscopy was performed. Abdominal cysts were located in seven animals (one cyst/animal). The cysts were grasped carefully, lifted close to the abdominal wall, and evacuated percutaneously under laparoscopic vision. The collapsed cysts were then retrieved. In two animals enlarged ports were sutured, treated with an antibiotic and an analgesic, resulting in uneventful healing. Five cysts were nonparasitic, two were parasitic, one extracted from a sheep, and one from a goat. In conclusion, laparoscopy has higher diagnostic accuracy in detecting unattached abdominal cysts in sheep and goats compared to USG. It is also a reliable, minimally invasive, and safe procedure for cyst retrieval. However, a larger-scale study is necessary for ascertaining long-term complications and the recurrence rate.

Effect of Intensification Practices, Lambing Period and Environmental Parameters on Animal Health, and Milk Yield and Quality in Dairy Sheep Production Systems on Crete

Due to increasing demand, many traditional, grazing-based Mediterranean sheep production systems have introduced intensified feeding regimes, increased investments in infrastructure and drug use to increase milk yields. However, compared to bovine milk production systems, there is limited knowledge about the impact of these intensification practices on animal welfare and health and on the quality of dairy products. The aim of this study was therefore to quantify the effects of management practices and environmental conditions background on udder health, parasitism and milk quantity and quality in Cretan traditional production systems. Milk yields were higher in semi-intensive production systems while concentrations of several nutritionally desirable compounds such as omega-3 fatty acids were found to be higher in milk from extensive systems. Antibiotic and anthelmintic use was relatively low in both extensive and semi-intensive production systems. There was no substantial difference in parasitic burden, somatic cell counts, and microbiological parameters assessed in milk. Recording of flock health parameters showed that animal health and welfare was high in both extensive and semi-intensively managed flocks, and that overall, the health status of extensively managed ewes was slightly better. In contrast, environmental conditions (temperature and rainfall) had a substantial effect on parasitism and milk quality.

Concentration of 2,3 bisphosphoglycerate in cattle affected with acute ruminal acidosis

The main objective of the study conducted here was to estimate the concentration of 2,3‐Bisphosphoglycerate (2,3‐BPG), 1,3‐Bisphosphoglycerate (1,3‐BPG), bisphospho‐glycerate mutase (BPGM) and 3‐phosphoglycerate (3PG) in cattle clinically diagnosed with acute ruminal acidosis. A secondary objective was to examine the physical and chemical characteristics of the ruminal fluid in affected cattle. A total of 20 cattle clinically diagnosed with acute ruminal acidosis and eight clinically normal cattle were included in this study. The results showed that decrease of ruminal pH changed the ruminal fluid colour, odour and consistency, as well as decreased the sedimentation time, increased the methylene blue reduction time, and decreased ruminal microflora motility. The study indicated that the concentration of 2,3‐BPG, BPGM and BPGP decreased with the decrease of ruminal pH, while 3‐PG concentration was not affected with the decrease of ruminal pH. In conclusion, 2,3‐BPG could play a role in the pathogenesis of ruminal acidosis, and thus, the intravenous administration of sodium bicarbonate is important, particularly in severe cases, to correct any systemic acidosis that can decrease 2,3‐BPG concentration and results in tissue hypoxia.

Long-Term Recording of Reticulo-Rumen Myoelectrical Activity in Sheep by a Telemetry Method

The reticulum and rumen are considered a single functional unit (the reticulo-rumen) with regards to myoelectrical and contractile activities. The specialized contractions of the reticulo-rumen provide constant mixing of partially digested material (cycle A), its flow into the omasum during eructation (cycle B), and regurgitation-rumination (cycle C). This study aimed to investigate the feasibility of electromyography (EMG) registered by a long-term telemetry method for assessment of the basic reticulo-rumen myoelectrical activity in sheep, to develop the effective recognition of the reticulo-rumen cycles at rest with no food stimulation, and to investigate the relationship between cycles A, B, and C in such basic conditions. The experiment was carried out on nine ewes. Myoelectric activity of the rumen, reticulum, and abomasum was recorded by the combination of three silver bipolar electrodes and a 3-channel transmitter implant. The myoelectrical activity registered successfully in the reticulum and rumen was determined as three characteristic patterns of cycles A, B, and C. The percentage of each type of cycle changed at different intervals from equally cycles A (43-50%) and B (50-56%), occurring when cycle C was not observed to the domination of cycle C (57-73%) with a decrease of cycles A (6-14%) and B (20-28%). The long-term EMG telemetry registration is feasible in the assessment of the reticulo-rumen myoelectrical activity in sheep.