Narongsak Chaiyabutr

• DVM MS PhD FRS(T)
• Professor Emeritus at Chulalongkorn University

Background Temperature regulation is essentially important for survival of poikilotherms such as snakes. Body temperature is regulated by snakes through behavioral and physiological responses. The global-warming crisis, combined with the need to house large population of snakes in limited spaces, increases the likelihood of exposing snakes to high...

This review aims to better understand the regulation of milk yield in response to the prolonged administration of recombinant bovine somatotropin (rbST) in 87.5% crossbred Holstein cattle in the tropics. Prolonged administration of rbST at different stages of lactation is associated with an increase in milk yield, which correlates with an increase...

Background and Aim In tropical regions, the intrusion of saline from seawater (SW) due to global warming and sea level rise in recent years is an important natural factor influencing goat well-being. This study aimed to determine the effects of diluted SW in drinking water on the physiological responses and eating and drinking patterns of crossbred...

The aims of this study were to determine adaptation mechanism of sheep to salinity in drinking water. A group of 10 male sheep were used in a 6‐week of experiment, with 1 week for pre‐treatment period (Week 1), 4 weeks for during treatment period (Week 2 to Week 5), and 1 week for posttreatment period (Week 6). During the pre‐ and posttreatment per...

The hooding behavior exhibited by cobras is a distinct defensive mechanism against predators, encompassing both visual and auditory displays. This behavior can be triggered by natural predators or humans. Considering that human provocation may potentially stimulate the hypothalamic-pituitary-adrenal (HPA) axis, the present study aimed to determine...

This study aimed to evaluate the effect of saline water (SW) on physiological responses, blood biochemical parameters and body weight changes in Bach Thao goats. The study was designed completely randomized with four treatments (n = 5 each), including a control as goats’ drinking fresh water (FW), goats’ drinking 0.5% SW (LSW, low SW), goats’ drink...

Background This study examines the direct nephrotoxic effects of Daboia siamensis venom (RVV) and venom fractions in in vivo and isolated perfused kidneys (IPK) to understand the role of inflammation pathways and susceptibility to oxidative stress in venom or fraction-induced acute renal failure. Methods We administered RVV and its venom fractions...

This experiment aimed to determine the effect of adaptive duration to saline water on behaviors, weight gain and blood biochemical parameters in growing goats. The experiment was arranged in a completely randomized design, which included four treatments with five animals per group. The goats were administered either fresh water (control) or seawate...

Background and Aim In our previous study, we observed that a high dietary cation and anion difference (DCAD) of 40 mEq/kg dry matter (DM) in the diets of lactating dairy goats increased heat dissipation. In the present study, we believe that the level of DCAD fed to non-lactating and non-pregnant goats was twice as high as that fed to lactating goa...

To date, the pharmacokinetics of fluoroquinolones in estuarine crocodiles (Crocodylus porosus) have been reported for enrofloxacin but not for marbofloxacin (MBF), which is a broad-spectrum antibiotic used only in veterinary medicine. This study investigated the pharmacokinetics of MBF after intramuscular administration at two difference dosages (2...

High ambient temperature (HTa) causes acid–base imbalance and systemic oxidative stress, and this may indirectly affect the mammary gland. Furthermore, HTa induces intracellular oxidative stress, which has been proposed to affect cell metabolism directly. We previously showed in dairy goats that the negative effect of HTa was compromised by enhanci...

Snakebite envenoming is a medical emergency requiring urgent and specific treatment. Unfortunately, snakebite diagnostics are scarce, time-consuming and lacking specificity. Hence, this study aimed to develop a simple, quick and specific snakebite diagnostic assay, using animal antibodies. Anti-venom horse immunoglobulin G (IgG) and chicken immunog...

Background and aim: The behavioral mechanism of stray dog occurrence is associated with domestication process. This study aimed to investigate the population and demographic relationship of stray dogs from our ecological habitat. We tested whether baited enclosure method could be used as an operant conditioning treat-ment to activate habituation b...

Goats can suffer from intermittent heat stress in high ambient temperature (HTa) conditions, which causes sporadic respiratory hypocapnia. Obstructive urolithiasis is a common urological problem in goats. Sandy uroliths can be partially relieved by urine acidification with short-term ammonium chloride (NH4Cl) treatment. However, the outcome of urin...

Background and Aim: Activation of breathing, the hypothalamic-pituitary-adrenal (HPA) axis, and plasma antioxidant defense are adaptive mechanisms in lactating dairy goats fed during the summer season. However, an excess of these responses can interfere with the gas exchange. This study aimed to investigate the effect of natural high ambient temper...

Background and aim: African horse sickness (AHS) is a non-contagious, high mortality, and insect-borne disease caused by a double-stranded RNA virus from the genus Orbivirus. The study aimed to develop inactivated vaccines serotype 1 inactivated AHS vaccine (IAV) and to compare the effect of IAV on antibody responses in young naïve horses and adul...

Snakebite, classified by World Health Organization as a neglected tropical disease, causes more than 100,000 deaths and 2 million injuries per year. Currently, available antivenoms do not bind with strong specificity to target toxins, which means that severe complications can still occur despite treatment. Moreover, the cost of antivenom is expensi...

The study evaluated the pharmacokinetic features of azithromycin (AZM) in 15 freshwater crocodiles (Crocodylus siamensis) in Thailand. The crocodiles were administered a single intramuscular (i.m.) injection of AZM at three different dosages of 2.5, 5, and 10 mg/kg body weight (b.w.). Blood samples were collected at pre‐assigned times up to 168 h....

The present study evaluated the pharmacokinetic profiles of danofloxacin (DNX) in freshwater crocodiles (Crocodylus siamensis), following single intramuscular (i.m.) administrations at two different dosages of 6 and 12 mg/kg body weight (b.w.). Blood samples were collected at assigned times up to 168 h. DNX in the harvested crocodile plasma was ext...

Milk protein is well accepted for nutritional value compared with other sources of protein. Detailed understanding of the natural factors that can determine milk protein subcomponent (i.e., casein) not only fulfill the knowledge of protein synthesis but also provide the potential idea to improve milk quality. The variation in milk protein content f...

ABSTRACT. – Total body water and the water turnover were studied in Naja kaouthia Lesson, 1831 and Malayopython reticulatus (Schneider, 1801) snakes by tritiated water dilution techniques. Both snakes species were injected intramuscularly with an aqueous solution carrier-free tritiated water (3H2O) at a single dose of 10 Ci/kg body mass. The equil...

Background: A new pit viper, Protobothrops kelomohy, has been recently discovered in northern and northwestern Thailand. Envenoming by the other Protobothrops species across several Asian countries has been a serious health problem since their venom is highly hematotoxic. However, the management of P. kelomohy bites is required as no specific anti...

Background: Eastern Russell’s viper (Daboia siamensis) is one of the most medically significant snakes responsible for the development of acute renal failure. However, variation of the clinical picture and renal pathophysiology following bites by young and adult D. siamensis have not been elucidated. Methods: In this study, we analyzed the venomic...

This study focuses on comprehensive characterization of the venom proteome of the beaked sea snake (Hydrophis schistosus) from Songkhla Lake, Thailand. H. schistosus can be considered as the deadliest sea snake commonly found in the Pacific and Indian oceans. Their envenomation causes muscular paralysis and rhabdomyolysis. To develop effective trea...

The venomic profile of Asian mountain pit viper Ovophis monticola is clarified in the present study. Using mass spectrometry-based proteomics, 247 different proteins were identified in crude venom of O. monticola found in Thailand. The most abundant proteins were snake venom metalloproteases (SVMP) (36.8%), snake venom serine proteases (SVSP) (31.1...

High ambient temperature (HTa) is an important environmental factor influencing food intake (FI). We previously demonstrated that low-degree HTa exposure decreased FI earlier than activated physiological responses, and this effect was related to the median preoptic nucleus (MnPO) and arcuate nucleus (Arc) connection. The present study refines the c...

Clarithromycin (CLA) is a new β‐lactamase‐resistant macrolide antibiotic with potent activity against gram‐positive and some gram‐negative bacteria. To the authors’ best knowledge, limited pharmacokinetic information to establish suitable therapeutic plans is available for freshwater crocodiles. To assess the prudent use of antibiotic in reptiles,...

Background and aim: Metabolism and environment are closely related. Under high ambient temperature (HTa), dairy cows may have different energy metabolism during summer and winter. The present study was carried out to investigate the effect of HTa on the milk yield and blood concentration of beta-hydroxybutyrate (BHBA) and glucose at the herd level...

Background and Objective: Sacubitril/valsartan (SV) is an angiotensin receptor-neprilysin inhibitor that works by inhibiting the neprilysin enzyme as well as blocking angiotensin receptors. The benefits of using SV in congestive heart failure patients has been demonstrated in several clinical trials; however, limited data are available for dogs wit...

Acute kidney injury (AKI) following Eastern Russell’s viper (Daboia siamensis) envenoming is a significant symptom in systemically envenomed victims. A number of venom components have been identified as causing the nephrotoxicity which leads to AKI. However, the precise mechanism of nephrotoxicity caused by these toxins is still unclear. In the pre...

Background and aim: Milk synthesis by the mammary gland is negatively influenced in part by high ambient temperature (AT). This study aimed to clarify the pathway of intramammary glucose utilization involved in mediating lactose synthesis during treatment with somatotropin under housing with misters and fans. Materials and methods: A single subc...

To date, the necessary pharmacokinetic information has been limited to establish suitable therapeutic plans for freshwater crocodiles. Therefore, this study was conducted to evaluate the pharmacokinetic profile of the oxytetracycline long-acting formulation (OTC-LA) in the freshwater crocodile, Crocodylus siamensis, following a single intramuscular...

The pathophysiological effects of Russell's viper venom (RVV) and its fractions, including phospholipase A2 (RvPLA2), metalloprotease (RvMP), L-amino acid oxidase (RvLAAO), and phosphodiesterase (RvPDE) on renal functions were investigated using the isolated perfused rabbit kidney (IPK) model. Moreover, whether their effects on renal alterations we...

The aim of the present study was to elucidate the pharmacokinetic profiles of amoxicillin trihydrate (AMX) in Siamese freshwater crocodiles (Crocodylus siamensis). Crocodiles were administered a single intramuscular injection of AMX, at a dose of either 5 or 10 mg/kg body weight (b.w.). Blood samples were collected at preassigned times up to 120 hr...

The two venomous pit vipers, Trimeresurus macrops and T. hageni, are distributed throughout Thailand, although their abundance varies among different areas. No species-specific antivenom is available for their bite victims, and the only recorded treatment method is a horse antivenom raised against T. albolabris crude venom. To facilitate assessment...

Background Daboia siamensis (Eastern Russell’s viper) is a medically important snake species found widely distributed across Southeast Asia. Envenomings by this species can result in systemic coagulopathy, local tissue injury and/or renal failure. While administration of specific antivenom is an effective treatment for Russell’s viper envenomings,...

Objectives: The aim of the present study was to investigate the beneficial effects of dietary supplementation with oil palm frond (leaf) (OPF) with and without oil palm meal (OPM) on nutrient intake and digestibility, ruminal fermentation and growth performance in goats. Methods: Six female crossbred goats were fed for 28 days of 3 diet treatmen...

Objective: This study was carried out to determine the effects of elevated dietary cation and anion difference (DCAD) on dry matter intake (DMI) and ruminal fermentation pattern in lactating dairy goats under tropical conditions. Methods: Ten dairy goats were divided into two groups of five animals each. The groups received diets at different DC...

One of the major obstacles to the successful treatment of infectious disease in freshwater crocodile species is incorrect dosing of antibiotics. There are few reports on pharmacokinetics and dosage regimens of antimicrobial drugs in crocodiles. The purpose of the present study was to clarify the pharmacokinetic characteristics of ceftriaxone (CEF)...

To the best of the authors’ knowledge, pharmacokinetic information to establish suitable therapeutic plans for freshwater crocodiles is limited. Therefore, the purpose of this study was to clarify the pharmacokinetic characteristics of enrofloxacin (ENR) in freshwater crocodiles, Crocodylus siamensis, following single intravenous and intramuscular...

Background: Daboia siamensis (Eastern Russell’s viper) is a medically important snake species found widely distributed across Southeast Asia. Envenomings by this species can result in systemic coagulopathy, local tissue injury and/or renal failure. While administration of specific antivenom is an effective treatment for Russell’s viper envenomings,...

PATHOPHYSIOLOGY OF RENAL INJURY IN SNAKEBITE Narongsak Chaiyabutr. Queen Soavabha Memorial Institute, Bangkok 10330, Thailand Abstract : Envenoming following snakebite is a health problem in the tropical regions of the world. Acute kidney injury (AKI) is one of the most important causes of death in patients bitten by snakes of the class Viperida...

Objective: The present study was carried out to evaluate the effect of high dietary cation and anion difference (DCAD) rations on diurnal variations in eating and meal patterns, water intake and urination patterns in dairy goats fed under high ambient temperature (HTa). Methods: Ten crossbred dairy goats during peri-parturition period were selec...

Eating behavior is influenced by various external stimuli, including food and ambient temperature (Ta). In dairy animals, high ambient temperature (HTa) decreases eating and subsequently reduces milk production. Eight crossbred non-lactating Saanen goats in late pregnancy fed under HTa condition were used to investigate the normal eating behavior b...

Klotho protein is recognized as having a renoprotective effect and is used as a biomarker for kidney injury. We investigated the level of Klotho protein in hyperoxaluria-induced kidney injury and the effects of vitamin E (Vit E) and vitamin C (Vit C) supplementation. Hyperoxaluria was induced by feeding 2% (w/v) Hydroxy-L-proline (HLP) in the drink...

This study aimed to determine the effect of dietary cation and anion difference (DCAD) on milk production and body fluid distribution in lactating dairy goats. Ten dairy goats were selected and divided into two groups, five animals each. Animals received either control DCAD (control, 22.81 mEq/100 g dry matter (DM)) or high DCAD (DCAD, 39.08 mEq/10...

High ambient temperature (HTa) activates both behavioral and autonomic responses. Decreased food intake (FI) is a well-known behavioral response under HTa. In general, this behavioral response seems to be mediated under the activation of the stress axis. The present study, however, revealed that decreased FI after a low degree of HTa appeared to be...

Estradiol (E2) inhibits eating behavior in females via activating estrogen receptors (ERs) within the brain. Activation of hindbrain ERαs has been shown to be sufficient to inhibit eating behavioral pattern. To investigate the involvement of hindbrain ERαs in estrogenic control of eating behavior, intracerebroventricular infusion (4th i.c.v.) of an...

Hyperoxaluria and oxidative stress are risk factors in calcium oxalate (CaOx) stone formation. Supplement with antioxidant could be effective in prevention of recurrent stone formation. The present study aims to evaluate the protective effects of vitamin E and vitamin C in hyperoxaluric rat. The experiment was performed in rats for 21 days. Rats we...

Scientific literature on buffaloes (Bubalus bubalis) has skyrocketed in the last two decades, ranging from production to reproduction issues. Buffaloes have played an instrumental role in so-called emerging countries of the Asian continent, especially thanks to their intrinsic ability to convert poor quality forages and crop residues of marginal ar...

Alterations of the distribution of body fluid were studied in Reticulated Python, Broghammerus reticulatus, (Schneider, 1801), which were subcutaneously injected with 20 ml per kg body weight of Ringer's acetate (RA) solution. The distribution of body fluid was observed by monitoring plasma volume (PV), blood volume (BV), extracellular fluid (ECF)...

In safety pharmacological and toxicological studies, all new chemical entities should be investigated for the possibility of slow atrioventricular (AV) conduction especially at the infranodal of AV node. The objective of this study was to compare two locations of His bundle electrogram (HBE) recording, the right side (right atrium) and the left sid...

The low milk production of both exotic and crossbred cattle is still the main problem in dairy farming in the tropics. A shorter persistency of lactation of crossbred cattle has been shown to relate to a rapid decrease in the plasma bovine somatotropin as lactation progressed to mid and late lactation. However, the mechanisms relating to high envir...

A simple latex agglutination test (LAT) has been developed for determining rabies virus (RABV) antibodies in human and equine sera. The test is based on the capability of specific antibodies to agglutinate antigen- sensitized polystyrene latex beads. The LAT for determination of RABV antibodies can be performed using inactivated whole RABV, glycopr...

A simple and rapid latex agglutination test (LAT) has been developed for detecting rabies virus (RABV) antigens in saliva. Latex particles are coated with anti-rabies antibody. The antibody-coated particles are specifically agglutinated by RABV, and the agglutination is evident macroscopically within minutes. Because the antigens can be visualized...

An immunochromatographic strip test is designed for fast and easy detection of rabies virus (RABV) antigens in clinical samples. In the field, saliva is a preferred clinical sample in the living patient because quick detection in such samples may be ideal for allowing management to be implemented in real time. Although the absolute RABV concentrati...

Background: The common complication in cases of poisoning by Russell’s viper (Daboia siamensis) venom (RVV) is acute renal failure, but the pathogenesis involved in the alteration of kidney function is still not well understood. Objective: To clarify the role of RVV in the pathogenesis of renal damage, the present study examines the functional shor...

Heart rate variability (HRV) and echocardiography were performed in 14 dogs with mitral regurgitation (MR) before and after 14 days of 0.5 mg/kg/day of enalapril treatment. All dogs were in heart failure stages B1 and B2. After enalapril treatment, left ventricular end diastolic diameter (LVEDd), left ventricular end diastolic diameter normalized f...

This study was conducted to determine the effects of rapid ventricular pacing on cardiac function and hemodynamics, and to determine the most suitable QTc formula for the effects of alterations in the RR interval on the QT interval of conscious dog with heart failure (HF). Electrocardiograms were acquired from dogs (n=18) at baseline and after rapi...

The objective of this study was to investigate the effect of supplementary betaine in diet on milk secretion, milk composition, mammary extraction of nutrients and relevant parameters in late lactating cross-bred Saanen goats. Ten, multiparous, non-pregnant cross-bred Saanen goats of approximately 10 weeks postpartum were used for the study. The an...

The evaluation of proarrhythmic and hemodynamic liabilities for new compounds remains a major concern of preclinical safety assessment paradigms. Contrastingly, albeit functional liabilities can also translate to clinical morbidity and mortality, lesser preclinical efforts are focused on the evaluation of drug-induced changes in inotrope and lusitr...

Several enzymes in Russell's viper (Daboia siamensis) venom are involved in the venom effects and renal injury. The effects of fractional components of Russell's viper venom, phospholipase A(2) and metalloprotease fractions, were examined in two groups of four experimental dogs each. Animals received an intravenous injection of 140 μg/kg of each ve...

Background Black cumin (Nigella sativa) is an ancient herbal medicine recommended by the World Health Organization. The antioxidant and antihyperglycemic effects of black cumin are well established. Amelioration of renal dysfunction in nephrotoxic rats with black cumin treatment has also been noted. However, the effect of black cumin treatment on r...

The effect of supplementary administration of recombinant bovine somatotrophin (rbST) on the renal tubular handling of sodium in crossbred 87.5% Holstein cattle housed in normal shade (NS) or mist-fan cooled (MF) barns was evaluated. The cows were injected with 500 mg rbST at three different stages of lactation. The MF barn housed cows showed a sli...

The objective of this study was to investigate the effect of supplemental recombinant bovine somatotropin and cooling management on changes in oxidative stress index in the plasma of crossbred Holstein cattle at different stages of lactation. Tenpnmiparous crossbred 87.5% Holstein cattle were randomly divided into 2 groups of five animals each whic...

The aim of this study was to investigate the influence of long-term administration of recombinant bovine somatotropin (rbST) on the acid-base homeostasis of lactating crossbred cows under hot and humid condition of Thailand. Two groups of five animals each of primiparous crossbred dairy cattle were supplemented either with rbST or with control vehi...

Background: Envenoming by snakebite is an important public health problem in rural tropics. Venomous snake families such as Elapidae and Viperidae frequently produce severe poisoning. Anti-venoms are not available for all venomous snakes of Thailand and there is need for more development in this field. Objective: We characterized the important veno...

In 2000 the Queen Saovabha Memorial Institute (QSMI) entered into an agreement with the School of Conservation (funded by DANIDA) in order to conduct research on the biology of sea snakes with primary reference to serum production. From February 2001 to January 2002, 23 specimens of Enhydrina schistosa (16 females, 7 males) and 23 Hydrophis brookii...

Background: Oxidative stress induces renal dysfunction in diabetes, in which renal mitochondrial disturbance was implicated. Vitamin C (VC) supplementation may ameliorate the renal dysfunction in diabetics. However, it is not clear whether VC supplementation is effective for renal mitochondrial disturbances in diabetes. Objective: Investigate wheth...

Effects of cooling and supplemental recombinant bovine somatotropin (rbST) on hemato-biochemical characteristics were studied at different stages of lactation of crossbred Holstein Friesian cows in a tropical environment. Ten primiparous cows were divided into two groups of five animals each. The first group was housed as the non-cooled animals in...

In this study, 16 pregnant crossbred Holstein Friesian (HF) heifers, consisting of eight animals of two breed types, 87.5%HF and 50%HF were selected and each breed was randomly allocated into two groups. Each group, consisting four animals from the same breed, was fed either 5% urea treated rice straw or pangola ( Digitaria decumbens ) hay as the s...

Noninvasive hormone assays provide a way to determine an animal's health or reproductive status without the need for physical or chemical restraint, both of which create unnecessary stress for the animal, and can potentially alter the hormones being measured. Because hormone metabolism is highly species-specific, each assay must be validated for us...

The objective was to measure the effects of cooling techniques (shade cloth vs. normal roof) on performance and physiology of 16 Friesian crossbred cows (87.5% Holstein Friesian × 12.5% Brahman) located at Sakol Nakhon Livestock Research and Testing Station, Department of Livestock Development, Ministry of Agriculture and Cooperatives (Sakol Nakhon...

Background: Many studies have reported the occurrence of lethal acute renal failure after snakebites. Bungarus candidus (Malayan krait) is a medically important venomous snake distributed widely throughout Southeast Asia. The best known features of systemic envenoming by B. candidus are neurotoxic. Objective: Obtain more information on effects of B...

Two groups of five crossbred 87.5% Holstein cattle were housed in normal shade only (NS) as non-cooled cows and in shaded with misty-fan cooling (MFC) as cooled cows. The cows were treated with recombinant bovine somatotropin (rbST) in early, mid and late lactation with three consecutive injections of rbST 500 mg of rbST (POSILAC) in every 14 days....