Korean Journal of
Veterinary Service

Despite the livestock industry has made great improvements in feeding, breeding, and herd management, proper prevention and treatment of calf diseases are still remained as a challenge (Kim et al, 2021). Globally, calves’ morbidity and mortality rates due to several diseases have been reported to be about 35% and 7%, respectively (Mee, 2013; Windeyer et al, 2014; Abuelo et al, 2019). Among several diseases of calves, calf diarrhea is a disease of the digestive system with watery feces and more frequent intestine movements, and has been a major cause of economic loss to the cattle farms due to cost of treatment, retarded growth, and death of calves (Lee et al, 2020). Of note, it has been reported that diarrhea is the main disease with the highest morbidity from newborns less than 1 month old to the preweaned calves; in accordance with published articles in Korea, 97.6% of calves had diarrhea during the suckling period and diarrhea was the cause of death in 53.4% of dairy calf deaths (Kim et al, 1990; Hur et al, 2013; Choe et al, 2017; Kim et al, 2021). The diarrheic calf presents several symptoms including dehydration by the loss of water, acidosis owing to electrolyte loss and imbalance, depression, lethargy, decrease of the suck reflex, and more severity such as recumbence, coma, and death (Lee et al, 2020). The main etiologic agents of diarrhea in calves are bacteria (Escherichia coli K99 and Salmonella), viruses (rotavirus and coronavirus), and protozoa (Cryptosporidium parvum), which were able to cause specific infections to attack the lining of the intestine causing water loss through the damaged wall and malabsorptive diarrhea due to enteritis (Todd et al, 2010). In recent days, non-infectious factors such as stress, herd size, stocking density, sheltered area, nutrition, and humidity are also focused as the other causes of the calf diarrhea (Kim et al, 2021).

The digestive system of cattle has the peculiarity of being made up of 4 different anatomical components consisting of the rumen, reticle, omasum, and abomasum; the abomasum or rumen plays a role in production of digestive enzymes or fermentation of fibrous plant material by the ruminal microorganisms that produce volatile fatty acids, respectively (Martin et al, 2021). However, the obstruction in orifice part of the rumen or abomasum by foreign body make aboral transport of food failed. In adult cattle, the abomasal obstruction is created by extremely fibrous feeding and ingestion of indigestible materials (Mushonga et al, 2015). In calves, although the primary causes of abomasal obstruction are volvulus, displacement, and adhesions, idiopathic abomasal obstruction can be occurred in cases of feeding with low quality milk replacers, eating bedding material, and ingestion of indigestible objects; these materials may lead to formation phytobezoars or trichobezoars (hair balls) which may cause a mechanical obstruction.

The clinical signs of obstruction in the digestive system include anorexia, reduced feces, variable dehydration, and abdominal distention and will be severer until the terminal stage. Regarding more detail clinical symptoms of foreign bodies in the abomasum of adult cattle, the early stage (1∼4 days) exhibits feed intake decrease, shorter rumination time, less omasum motility, and slightly enlarged but soft abomasum during manual palpation. The middle stage (5∼10 days) presents decreased appetite, increased water consumption, apparently enlarged abdominal circumference, large fluid-filled rumen, and absence or weakening of sound in the rumen and omasum. In the last stage of diarrheic cattle (longer than 10 days), severer symptoms for disease such as depression, lethargy, and sunken eyes due to dehydration, loss of appetite and rumination, and noticeably expanded and hard abdomen can be found; especially, discharging small amount of mushy feces or foul-smelling feces mixed with mucus/purple-black blood clots can be observable in middle stage or last stage, respectively (Yong et al, 2021). In addition, it is a small proportion but the diarrhea is also occurred in 5% of adult cattle with foreign bodies in the rumen and reticle (Roth and King, 1991). Therefore, it can be concluded that mushy feces, diarrhea or hemafecia is one of symptoms to diagnose foreign bodies in the digestive system of cattle.

Because of the invisibility of ingested foreign bodies and the limitation of diagnostic facilities in the farm field, the foreign bodies in cattle’s stomachs are only then found during slaughtering or necropsy in dead animals in most cases. However, the diagnosis of foreign body in the digestive system has been investigated in the adult cattle by manual palpation, exploratory surgery, and ultrasonography (Roth and King, 1991; Semieka, 2010; Tschuor et al, 2010; Rezac et al, 2014; Mushonga et al, 2015; Braun et al, 2018; Carvalho et al, 2020; Yong et al, 2021). Unfortunately, there is still limited information for diagnosis, treatment, and prognosis of foreign bodies in the digestive system in calves, especially in Hanwoo (Korean native cattle). In addition, because calf diarrhea possibly provokes the overuse of antibiotics even if it is not caused by infectious pathogens, proper differential diagnosis and effective treatment of diarrhea-related stomach obstruction are required to be further studied for public health concerns (Kim et al, 2021). In this sense, the present study is aimed to reveal the morbidity of diarrhea-related stomach obstruction, mortality post laparotomy, expected cause diarrhea-related stomach obstruction in Hanwoo calf, based on the medical records for 6 months as a retrospective study.

Ethics statement

The present retrospective study was implemented in compliance with Guide for the Care and Use of Agricultural Animals in Research and Teaching, 4th edition (2020), published by the American Dairy Science Association^®, the American Society of Animal Science, and the Poultry Science Association.

Inclusion criteria of medical records

Data in the present study were obtained from medical records from a large animal hospital (Goryeo large animal hospital, Sangju-si, Gyeongsangbuk-do, Republic of Korea) during 2021 March to 2021 October as a retrospective study. From the pool of clinical cases of diarrheic cattle, the inclusion criteria for selecting the subjects in the present study were as follows: (1) diarrhea in preweaned Hanwoo calves; (2) cattle farms placed near Sangju-si (north latitudes 36°08′ and east longitudes 128°08′); (3) similar breeding environment to calves including free access to foods (mother’s milk and/or starter) and water ad libitum, staying on sawdust bedding, being nurtured by each mother in individual barns, and having chance to access to mother’s hay (rice straw); (4) negative in E. coli K99, rotavirus, coronavirus, C. parvum and Giardia using the rapid diagnostic kit (BoviD-5 Ag, BIONOTE, Korea) to feces; (5) macroscopic identification of enlarged abdominal circumference and manual palpation of unknown foreign bodies in the rumen through the left flank and/or abomasum after calves were fastened for 12 h, limited to drink water for 12 h, and administered for 10 mg metoclopramide (prokinetics; Macperan Inj, Dong Wha PHARM. Co., Ltd, Seoul, Korea); (6) conducting blood gas analysis during diagnosis step.

Comprehensive clinical signs and findings of diarrheic calves

After application of the inclusion criteria, the Hanwoo calves diagnosed diarrhea-related stomach obstruction in the present study (n=32) were 26 to 60-day-old with an average of 36.48, almost evenly distributed genders (male n=17 and female n=15). The clinical history of calves from farm owners consisted of diarrhea, anorexia, dehydration, having pica (eating feces on the bedding), retarded growth of gradual loss of body weight, trials for intaking starter, and frequently licking mother’s body near udder. During body examination, the calves presented discharges at the perianal area and dirty tail by watery/bloody diarrhea, anorexia, sunken eyes (dehydration), depression, head held down, droopy ear, and/or unsteady balance. Because the feces from calves were negative in E. coli K99, rotavirus, coronavirus, C. parvum, and Giardia using the rapid diagnostic kit, the infectious diarrhea by the main etiologic agents was ruled out.

Blood gas analysis

Approximately 10 mL blood was collected via the jugular vein with 21 G needle and taken into heparinized blood collection tube (BD, Franklin Lakes, NJ, USA). Samples were gently agitated by hands for several minutes, stored at room temperature, and analyzed within 5 min after sampling using a portable blood analyzer (i-STAT, Abbott Point of Care Inc., Chicago, IL, USA) under farm conditions. The blood parameters included pH, sodium (Na⁺, mmol/L), potassium (K⁺, mmol/L), chloride (Cl⁻, mmol/L), blood urea nitrogen (BUN, mg/dL), hematocrit (Hct, %), partial pressure of carbon dioxide (pCO₂, mmHg), bicarbonate (HCO₃⁻, mmol/L), and hemoglobin (Hb, g/dL). The normal reference ranges of all test variables were obtained from a manufacturer’s guide.

Laparotomy for the abomasotomy and rumenotomy

Once the unknown foreign bodies in the diarrheic calves (n=32) were palpated in the rumen through the left flank and/or abomasum as a whole at the ventral region, the laparotomy was conducted to 25 calves within 2 days (n=18) or after 2 days (n=7). But in the other animals (n=7), the owners did not consent for laparotomy in calves but only wanted to administer wide spectrum antibiotics (10 mg/kg enrofloxacin; Baytril 100, Bayer, Leverkusen, Germany). For the laparotomy, the calves were anesthetized with intramuscular injection of 0.5 mg/kg Xylazine (UNI XYALZINE, UNIBIOTECH, Anyang, Korea) and then placed at right lateral recumbent position. The surgical site was clipped and sterilized. After a vertical incision as 15∼20 cm at the skin on the left paralumbar fossa (just behind the last rib and about 3 cm from the transverse lumbar process) was made, the subcutaneous tissue, oblique abdominal muscles (external, internal and transverse), and peritoneum were opened to approach the abdominal cavity. Then if the foreign bodies in the digestive system were definitely diagnosed by a manual palpation, removal for the foreign bodies in the rumen (rumenotomy) and/or abomasum (abomasotomy) were followed. In the abomasotomy, the region of the greater curvature of the pyloric part of the abomasum was incised about 15 cm and then 2 stay sutures were made at the cranial and caudal parts of the incision. Through the incision entry, the indigestible foreign bodies were removed. After removing the foreign bodies and completing the abomasomal examination, the opened abomasum was closed with 2 layers of sutures using absorbable suture material by inverted. Cushing suture pattern or the inverted Lembert suture pattern. Once the abomasum was fully closed, it was thoroughly washed again and cleaned for any debris before it was allowed to return to the abdomen. The rumenotomy was additionally conducted when foreign bodies were palpated during the exploratory laparotomy. The removal of foreign bodies by rumenotomy was similarly performed with the abomasotomy, except that incision site was not greater curvature but less vascularized surface. The abdominal wall and skin were closed in a routine manner.

Postoperative care

Postoperatively, the calves were fasted for 24 h, limited to drink for 24 h, and treated with antibiotics (enrofloxacin). In addition, administrations of cimetidine (a histamine H2 receptor antagonist that inhibits stomach acid production) and intravenous fluid treatment with glucose and electrolytes were performed to correct acidosis and dehydration for 3 days. The calves were carefully observed and allowed to eat the mother’s milk after 24 h post operation as 3 times per day for a week; if necessary, additional fluid therapy was applied.

Statistical analysis

The Chi-squared tests were applied to determine statistically significant difference in contingency table between the several factors (age of calves, position of foreign bodies, laparotomy, laparotomy date after diagnosis, and blood parameters) and mortality (survival or death post operation). Pearson’s correlation test between herd size of calves in each farm and incidence of diarrheic calves with foreign bodies in stomach was conducted. Significance was determined as P<0.05.

Blood parameter values of diarrheic calves with foreign bodies

The means for concentration of pH, Na⁺, K⁺, Cl⁻, BUN, Hct, pCO₂, HCO₃⁻, and Hb are presented in Table 1. The mean values of parameters in diarrheic calves with foreign bodies in the digestive system presented metabolic acidosis (low pH), hyponatremia, and high BUN level (azotemia).

Table 1 . Blood parameter values of diarrheic calves with foreign bodies.

Parameter	Unit	N	Mean±SD	Min∼max	Reference range
pH	-	25	7.28±0.15	7.04∼7.51	7.31∼7.53
Na+	mmol/L	25	128.04±8.79	114∼143	132∼152
K+	mmol/L	25	5.60±1.78	2∼9	3.9∼5.8
Cl−	mmol/L	25	96.57±5.63	84∼105	95∼107
BUN	-	25	50.67±42.95	6∼141	6∼27
Hct	-	25	34.78±6.61	25∼46	25∼46
pCO2	mmHg	25	35.70±8.75	17.3∼35.7	35∼44
HCO3−	mmol/L	25	20.57±7.45	4.6∼31.8	17∼29
Hb	g/dL	25	11.39±2.43	5.6∼15.3	8∼15

Distribution of diarrheic calves with foreign bodies according to the levels of blood parameters

The distribution of the 25 diarrheic calves with foreign bodies in the digestive system according to the levels of blood parameters is presented in Fig. 1 with different colors (within reference range for red color; high level or low level than reference range for green or blue color, respectively). Of note, more than half calves had a low pH (<7.31, 60%) or low NA⁺ level (<132 mmol/L, 68%) as metabolic acidosis or hyponatremia, respectively. Low level in Cl⁻ (<95 mmol/L, 40%), pCO₂ (<35 mmHg, 36%), and HCO₃⁻ (<17 mmol/L, 44%) were also identified in some of calves. Hct and Hb levels showed no considerable changes in the present subjects. In case of BUN, more than half of calves showed high level (>27, 56%). Because the distribution of pH, NA⁺, and BUN in diarrheic calves with foreign bodies was extremely drastic, contingency table between these values and mortality post operation were further analyzed.

Figure 1. Distribution of diarrheic calves with foreign bodies according to the levels of blood parameters. red color: within reference range, green color: high level than reference range, blue color: low level than reference range. Na⁺, sodium; K⁺, potassium; Cl⁻, chloride; BUN, blood urea nitrogen; Hct, hematocrit; pCO₂, partial pressure of carbon dioxide; HCO₃⁻, bicarbonate; Hb, hemoglobin.

Morbidity and mortality of diarrheic calves with foreign bodies

By means of calculation of the number of diarrheic calves diagnosed as foreign bodies in the digestive system per the total number of newborn calves during the present study period, the morbidity was determined as 3.03% (32/1054) (Fig. 2A). In addition, when the correlation between herd size and the number of incidences for diarrheic calves with foreign bodies in each farm was analyzed, non-significantly weak relationship (P>0.05, r=0.390) was identified, which meant herd size was not the main cause of diarrhea with foreign bodies in calves (Fig. 2B). As aforementioned, because 28 of calves were only conducted for laparotomy with rumenotomy and/or abomasotomy from the pool of diarrheic calves diagnosed as foreign bodies in the digestive system (n=35), we performed a follow-up survey for their mortality. A return to satisfactory health without diarrhea and general appetite occurred approximately 5∼7 days after surgery (data not shown). In addition, while the mortality of calves post operation was 28% (7/26), extremely high death ratio was observed in non-operated calves as 85.7% (6/7) (Fig. 2C). These data implied the importance of aggressive decision for laparotomy with rumenotomy and/or abomasotomy when the foreign bodies were determined in the digestive system in calves.

Figure 2. Morbidity and mortality of diarrheic calves with foreign bodies in the digestive system. (A) Morbidity of diarrheic calves diagnosed as foreign bodies in the digestive system by calculating the incidences per the total number of newborn calves, (B) correlation between herd size and the number of incidences for diarrheic calves with foreign bodies in each farm, (C) comparison of the mortality between laparotomy-operated and non-operated calves.

Occurrences of foreign bodies in the digestive system in calves

Several types of foreign bodies such as trichobezoar (hair ball), curdled milk, feed (starter), and hay (rice straw) were recovered from the rumen and/or abomasum in the diarrheic calves (Fig. 3A∼3C). Most of diarrheic calves possessed the foreign bodies in the abomasum (96%, 24/25) but not always in the rumen (36%, 9/25), which implied that foreign bodies in the abomasum was a trigger for the clinical symptoms (Fig. 3D). In addition, trichobezoars and hays were the main foreign bodies in the digestive system in diarrheic calves, which was thought to be indigestible and easy to make obstruction in the digestive system (Fig. 3E). The curdled milk and feed in the stomach was thought to be stagnant due to narrowed way of the digestive system; further study was necessary but it was considered that they were also problematic because they were putrefactive in the digestive system which might occur severe systemic symptoms in calves.

Figure 3. Occurrences of foreign bodies in the digestive system in calves. (A∼C) Several types of foreign bodies such as trichobezoar (hair ball), curdled milk, and hay (rice straw), (D) The frequency of foreign bodies in the abomasum and rumen, (E) The main foreign bodies in the digestive system in diarrheic calves (trichobezoars and hays).

Predicted prognosis by several factors of diarrheic calves with foreign bodies

As further analysis, contingency table between several factors and mortality (survived n=18, dead n=7) was assessed by Chi-squared test as shown in Table 2. First, the laparotomy-operated calves (n=25) were classified 2 groups depending on average age (less or more than 35.48 days) and the results suggested that the age were not related with mortality post operation. The calves having the foreign bodies in the abomasum exhibited more possibility to death than those in the rumen. Non-laparotomy in diarrheic calves due to foreign bodies in the digestive system were associated with mortality. The operated calves were divided into 2 groups who were operated for laparotomy within 2 days after the first diagnosis and more days; the latter was related with mortality. In addition, acidosis (lower blood pH) was correlated with death post operation but Na⁺ and BUN level did not. In diarrheic claves with foreign bodies, these results proposed that position of foreign body in stomach and blood pH could become indicators to expect the favorable prognosis after laparotomy operation as well as laparotomy within 2 days after the first diagnosis was important to reduce postoperative death.

Table 2 . Predicted prognosis by several factors of diarrheic calves with foreign bodies.

Chi-squared tests	N	Value	Df	P value
Age vs. mortality	25	2.968	1	0.085
Position of foreign body vs. mortality	25	5.469	1	0.019
Laparotomy vs. mortality	32	7.552	1	0.006
Laparotomy date vs. mortality	25	10.429	1	0.001
pH vs. mortality	25	4.407	1	0.036
Na vs. mortality	25	1.239	1	0.266
BUN vs. mortality	25	3.792	2	0.151

Because calf diarrhea has been a main cause of economic loss to the cattle farm due to high morbidity, cost of treatment, retarded growth, and possibility for death, the veterinarian should play an important role in the prevention and treatment in clinical practice (Meganck et al, 2014). Diarrhea in neonatal calves is commonly caused by different pathogens, but not always bacteria. Yet, antibiotics are routinely administered as the first treatment to an unknown extent and without a tentative diagnosis. In a global survey with 873 farms in Austria, Belgium, Portugal, and Scotland, 52.5% of the participants responded that they first use antibiotics when diarrhea was detected in neonatal calf; 27% of them always use antibiotics, and 45% thought that antibiotics was the highest priority (Eibl et al, 2021). The aim of the present retrospective study is therefore to introduce the clinical signs of the diarrheic calves with foreign bodies in the digestive system as a non-infectious etiology of calf’s diarrhea, to plan for diagnosis protocol with manual palpation and exploratory laparotomy, and to emphasize aggressive clinical approach and surgery to reduce its mortality as laparotomy is essential and better to conduct as prompt as possible. Because the present study reveals that several types of foreign bodies can also induce diarrhea in calves by obstruction of the stomach of calf, we suggest that together with animal caretakers and veterinarian should take more notice of the herd anamnesis addressing the young calf management for preparing a list with possible critical control points for diarrhea caused by foreign bodies in the digestive system. Of note, several gastrointestinal (GI) problems demand surgical approach and correction to save the animal’s life. For this reason, it is very important that the animal caretakers need to rapidly recognize clinical signs of GI obstruction such as decreases of feed intake, less rumination, depression, lethargy, noticeably expanded abdomen, and diarrhea (Yong et al, 2021). The veterinarian must diagnose cows presenting such clinical signs as prompt as possible. Along with the most probable diagnosis by physical examination for diarrheic calves with foreign bodies in the digestive system, the veterinarian should quickly decide whether the surgery can be performed at the farm or not (Nichols and Fecteau, 2018). Especially, the present retrospective study highly emphasized to quickly conduct laparotomy, which was followed by rumenotomy and/or abomasotomy allowing the emptying of the indigestible content; non-operated calves presented higher mortality than laparotomy-operated ones and time from the onset of the clinical signs to the laparotomy and/or surgery (within 2 days) is a key factor in the success of the procedure as shown in Table 2.

Since the diarrheic calves in the present retrospective study were negative for infectious pathogens including E. coli K99, rotavirus, coronavirus, C. parvum, and Giardia using the rapid diagnostic kit, we further focused on non-infectious factors, especially diarrhea caused by obstruction of the digestive system by unknown foreign bodies. The present study introduced that several types of materials (trichobezoar, curdled milk, feed, and hay) could make obstruction of the digestive system (Fig. 3). Further study is still required but several causes are possibly related with formation of foreign bodies in the digestive system, resulted in diarrhea in Hanwoo calves. First, although the body size of Hanwoo including adults as well as calves has been increased as a result of continuous breeding strategy in Korea for several decades, their daily milk yield is still on the small side than other cattle breeds (Hwang et al, 2008). In Hanwoo, the mean of daily milk yield of nursing mother was 3.74±0.96 kg, 3.26±1.15 kg, and 3.64±0.97 kg at 1, 2 and 3 month after delivery, respectively; peak milk yield was 3.75kg on 29.03 day after delivery (Hwang et al, 2002). Another study measured that peak milk yield was 2.73 kg on 37.1 day after caving in Hanwoo but other breeds recorded more values as 3.611 kg in Hereford cow, 4.9 kg in Woaklup cow, and 8.10 kg in Angus cow (Hwang et al, 2008). Meanwhile, it was reported that body weight at birth and 3-month-old in Hanwoo calf was 24.5 kg and 81.9 kg, respectively (Kwon et al, 2007). Therefore, although traditional recommendation to feed milk to calves is an amount of approximately 10 % of their body weight per day (Lorenz, 2021), daily milk yield of mother in Hanwoo becomes far from enough to calf from 2-month-old (3.26±1.15 kg vs. 5.32 kg as 10% value of approximately 53.2 kg calf) (Hwang et al, 2002; Kwon et al, 2007). This scarcity between daily milk yield and amount needed to calf might make them hunger, which can be resulted in repeated trials to lick mother’s empty teat and udder with more chance to swallow mother’s hair, as well as excessively eating indigestible feed to calf (hay); these hairs and hays were the main component of foreign bodies in the present study (Fig. 3). In particular, it has been noted that swallowed hairs in cattle are formed into oval shaped bodies (trichobezoar) as a result of churning and rolling movements of the stomach and these trichobezoars may cause obstruction of the pylorus in the stomach in calves (Abutarbush and Radostits, 2004). Second, curdled milk and feed in the stomach in the present study (Fig. 3) are putrefactive if they are stagnant for a long time in the digestive system. Once they are putrefactive, saprogenic bacteria extensively proliferate and then general etiology of infectious diarrhea may be occurred. In infectious diarrhea (e.g. Enterotoxigenic E. coli), the pathogens produces the enterotoxin that makes villous atrophy and absorptive surface destruction, resulted in malabsorption of water and electrolytes, and finally osmotic diarrhea. In addition, malabsorbed nutrients may stay within the GI tract, leading to bacterial overgrowth particularly in the small and large intestine. Furthermore, some of overgrown pathogens can induce endotoxemia, bacteremia, and/or septicemia, which is critical for calf’s life (Penati et al, 2021). Lastly, it is possible that calf management for feeding is wrongly scheduled. In accordance with Korean Feeding Standard for Hanwoo (KFSH) from National Institute of Animal Science, it is recommended that solid feed is supplied to calf from 3-week-old in order to fill up energy shortage only from mother’s milk and develop rumen papillae (NIAS, 2007). Especially, KFSH guides that a small amount starter (10∼100 g) is initiated to feed to 10-day-old calf. However, in a survey, Hanwoo farms in Korea supplies starter from 6-day-old calf (50.6%), give excessive starter (ad libitum), and feed starter together with hay (31.5%) (Yeo et al, 2012). Because developing stomach in calf is not ready to digest all kind of these foods, too early and excessive supplies of solid feed can be formed to the indigestible materials in the digestive system.

Several types of indigestible materials including grass, hair, gravel, wool balls, placenta, plastic bag, string, almond shell, nail, wire, and pineapple pulp can be foreign bodies in cattle (Mushonga et al, 2015; Bwatota et al, 2018; Yong et al, 2021). Old cattle had more prevalent to have foreign bodies than younger ones, and cattle with poor body condition were determined to more contain foreign bodies in the digestive system than those with good body condition; in this study, it was concluded that presence of foreign bodies in the digestive system reduced the volume of the stomachs which was supposed to be filled with feed (Bwatota et al, 2018). An article reported that all of the foreign bodies in the abomasum was trichobezoar (n=28) (Mushonga et al, 2015). In addition, foreign bodies (hardware) can induce the secondary disease such as traumatic reticuloperitonitis, a critical case in cattle (Braun et al, 2018). In the diarrheic calves of the present study, indigestible materials in the digestive system were more prevalently placed in the abomasum (96%) than rumen (36%), and most of them were trichobezoar and hay (Fig. 3). Similar with the present study, other articles also reported abomasal obstruction by phytobezoar (almond shells and distillers’ grain), trichobezoar, nylon, and sand; the foreign bodies were successfully removed by the exploratory laparotomy and abomasotomy in adult cattle and calves (Tschuor et al, 2010; Conceição et al, 2021; Yong et al, 2021). Therefore, given that clinical cases of foreign bodies can be appeared at any time, occur even in the newborn ages, and have a favorable prognosis after operation, results of the present retrospective study indicate an aggressive laparotomy for rumenotomy and/or abomasotomy can be effective in treating diarrhea or relieving complications secondary to stomach disorders in diarrheic calves diagnosed as foreign body obstruction in the digestive system.

Consequences of diarrhea in calves commonly are resulted to electrolyte disturbance, dehydration, and metabolic acidosis (Naylor, 1987). In the clinical setting to animals, accurate diagnosis of diarrhea is made through comprehensive results from clinical signs and laboratory tests. However, in large animal practice including cattle, conducting laboratory tests on the farm is not easy. Therefore, it is necessary to develop a standard for predicting the prognosis based on acid-base and electrolyte imbalance with a portable laboratory instruments. Therefore, a study was designed to determine blood gas, electrolyte, hematological, and biochemical values using a portable clinical blood gas analyzer as the introduction of the point-of-care test in Hanwoo calves with diarrhea (Lee et al, 2020). In this study, the mean values of parameters in the calves with diarrhea showed metabolic acidosis, hyponatremia, and azotemia (high BUN). Moreover, both pH and BUN level showed the highest association with the physical deterioration status and dehydration. Similar with these results, the diarrheic calves with foreign bodies in the digestive system also presented acidosis, hyponatremia, upper limit of potassium level, and azotemia (Table 1). Metabolic acidosis in the diarrheic calves was induced to intestinal HCO₃⁻ loss and a decrease in the glomerular filtration rate due to severe dehydration (Klein et al, 2008; Lee et al, 2020). The hyponatremia is mainly originated from acute diarrhea, which loses Na⁺ via secretion through the intestine, and azotemia (high BUN level) showed the highest correlation with the dehydration status (Lee et al, 2020). High potassium levels are closely correlated to dehydration (Meganck et al, 2014). Among several values, because the distribution of pH, NA⁺, and BUN in diarrheic calves with foreign bodies was extremely drastic, we further analyzed to reveal the correlation between mortality post operation and each blood gas parameter. As shown Table 2, pH (acidosis) level was the only significant indicator for survival post operation.

The calf diarrhea is a complex disease with a high morbidity and mortality in the cattle farms. This retrospective study showed that surgical therapy with laparotomy for rumenotomy and/or abomasotomy is the first choice of treatment for non-infectious diarrheic calves by foreign bodies. Upon obstruction of the digestive system by foreign bodies is tentatively diagnosed in the calf, we believe that prompt and compete surgical procedure will guarantee a favorable prognosis. In addition, when differential diagnosis list is made to calf’s diarrhea, foreign body-derived diarrhea is necessary to be included.

This work was supported by a grant from the National Research Foundation (NRF) of Korea and funded by the government of the Republic of Korea (NRF-2020R1F1A1076723).

The authors declare no conflict of interest.