Esophagostomy feeding in the early postoperative period in cats after ureterotomy for ureteral obstruction

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Introduction

Early feeding in the postoperative period in cats is one of the key factors affecting the quality and speed of recovery after surgery. Patients undergoing ureterotomy with creatinine levels exceeding 1000 µmol/L typically exhibit anorexia, vomiting, depression, and reduced activity [1, 2]. Prolonged absence of food intake increases the risk of hepatic lipidosis, whereas early nutritional support improves prognosis and accelerates recovery after surgery and discharge to outpatient care [3, 4]. Nutritional support is important for animals during recovery from disease or surgery. While many animals recover at home after mild illness or routine procedures, patients with more severe conditions require hospitalization. Early nutritional support improves prognosis and reduces hospitalization time in dogs [5]. Adequate intake of fluids, energy, and nutrients is critical during the first 14 days after trauma or disease onset [5]. It is important for an animal recovering from disease or surgery to receive nutrients to ensure optimal functioning of the gastrointestinal tract. Enteral nutrition is preferred over parenteral nutrition because intraluminal feeding stimulates gastrointestinal function [5].

It should be noted that after surgery and stabilization, acute renal failure often progresses to a chronic stage requiring lifelong therapy [6–10]. Standard protocols include infusion therapy (Sterofundin, Ringer’s solution, Ionosteril), antibiotics, and analgesia [11–13]. Nutritional support, alongside infusion therapy, requires further study and development of protocols for postoperative management because postoperative cats often lack appetite due to pain, stress, nausea, and vomiting associated with azotemia [14]. Compared to other animals, cats have unique metabolic adaptations affecting their ability to maintain homeostasis under stress, disease, and starvation [15], including higher protein and amino acid requirements.

Currently, there are no studies on cats with ureteral obstruction and creatinine levels above 1000 µmol/L evaluating preventive esophagostomy placement for improved recovery.

The aim of the study is to evaluate the effect of esophagostomy tube placement on postoperative recovery in cats undergoing ureterotomy for ureteral obstruction.

Materials and Methods

Between January 2, 2025, and June 13, 2025, 13 cats with acute renal failure due to ureteral obstruction were admitted to the veterinary clinic “Alisavet.” The animals were divided into two groups: a control group (8 patients) and an experimental group (5 patients). Cats in both groups had creatinine levels above 1000 µmol/L, indicating severe disease. In all cases, obstruction was caused by ureteral calculi leading to partial or complete blockage. All patients received antibiotic therapy during the first 7 postoperative days using amoxicillin with clavulanic acid at a dose of 20 mg/kg intravenously twice daily or subcutaneously once daily [15–18].

Cats received infusion therapy before and after surgery, using Sterofundin to correct dehydration and electrolyte imbalances [19–21].

At the same time, a deficient volume of circulating blood, ongoing losses and a maintenance volume of fluid were determined.

Fluid requirements were calculated as follows:

Deficit volume = % dehydration × body weight (kg) × 8,   (1)

where 8 is a constant value.

Ongoing losses was calculated in the presence of diarrhea and vomiting according to the formula

Ongoing losses = 1.5 × body weight (kg) × 24,      (2)

where 1.5 and 24 are constants.

The maintenance volume was determined by the formula

Maintenance volume = (30 × body weight (kg)) + 70,        (3)

where 30 and 70 are constants.

The total infusion volume was administered continuously over 24 hours, with daily recalculation.

In the experimental group, intravenous metoclopramide (1–2 mg/kg/day) was additionally administered to improve gastrointestinal motility during hospitalization.

All animals underwent ureterotomy: the affected ureter was exposed to visualize a calculus, a linear incision was made over the calculus, and after removal, a simple interrupted suture using non-absorbable polypropylene (USP 7/0) was applied. After that, the suture consistency was assessed and the surgical wound was closed in layers.

In the experimental group, an esophagostomy tube was placed during surgery. A Halsted hemostat was introduced into the esophagus via the oral cavity, the point of protrusion of the end of the instrument was palpated and externalized through a neck incision, by clamping the surgical Halstead through the wound opening, the end of the feeding tube was gripped and guided towards the oral cavity. After that, the end of the feeding tube was placed into the esophagus. Tube placement was confirmed radiographically and secured with a purse-­string suture.

The tube was removed one day after the return of spontaneous appetite. The procedure was performed without anesthesia by removing the fixing suture material and pulling out the tube. The wound healed by secondary intention with daily treatment using 0.05% chlorhexidine and betadine.

Patients were monitored on the day of surgery and on postoperative days 3, 5, 7, and 14. Serum urea and creatinine levels were measured as indicators of renal function. Self appetite recovery was also assessed. Analyses were performed using a DRI–CHEM NX500 biochemical analyzer.

Statistical analysis was conducted using Microsoft Excel (Analysis ToolPak).

Results and Discussion

Clinical observations showed that nutritional support via esophagostomy during infusion therapy in the experimental group lasted 3–4 days, after which the tube was removed due to return of spontaneous appetite. Feeding began 6–8 hours after surgery. In the control group, appetite returned only on days 4–5.

Both groups showed similar trends in urea and creatinine reduction, but the experimental group demonstrated greater efficiency. In these patients, an improvement in the general condition was noted within 14 days, which correlated with the positive dynamics of blood parameters (Table).

Biochemical parameters of blood serum of cats in the postoperative period

Indicators	Time after surgery	PhI	Animal groups M ± m
			1	2
Urea, mmol/L	Before surgery	3.28…10.24	51.8  ±  2.6	52.9 ± 2.5
	After surgery		47.5 ± 1.8	47.7 ± 1.1
	Day 3		40.9 ± 1.9	38.9 ± 1.1
	Day 5		38.0 ± 1.8	32.9 ± 0.6
	Day 7		27.3 ± 1.6	25.4 ± 0.7
	Day 14		13.1 ± 1.3	12.3 ± 1.1
Creatinine, µmol/L	Before surgery	35…124	1190.6 ± 50.9	1179.6 ± 51.9
	After surgery		684.4 ± 50.7	680.2 ± 66.6
	Day 3		492.5 ± 38.7	479.6 ± 31.4
	Day 5		388.6 ± 21.5	350.4 ± 10.4
	Day 7		260.4 ± 16.7	235.6 ± 8.6
	Day 14		186.3 ± 13.8	173.6 ± 15.5
The day after surgery when self-appetite appeared			4.8 ± 0.5	2.8 ± 0.4

Note. PhI is a physiological indicator; p < 0.05 relative to Ph I.
Source: compiled by V.A. Lyust, Yu.A. Vatnikov, V.I. Semenova, and E.V. Kulikov.

Urea levels decreased sharply after surgery: by 9% in the control group and 10.9% in the experimental group, which indicates the success of resolving unilateral obstruction of the ureter.

The urea concentration gradually decreased on the following day after surgery. The level of urea decreased: on the 3rd day in the control group by 17% and in the experimental group by 22%, on the 5th day — by 7 and 18%, and on the 7th day — by 39 and 29%, respectively. By day 14, a decrease in the urea was observed, but it did not reach the physiological norm. There is a faster trend towards a decrease in azotemia from the time after surgery to the 5th day of observation, but on the 7th day it accelerated. By the end of the study, on day 14, urea levels in the control group were 6.5% higher than in the experimental one.

Creatinine levels decreased by 73% in both groups immediately after surgery, which indicates the success of resolving unilateral obstruction of the ureter. Already on the 3rd day, the creatinine level decreased in the control group by 29% and in the experimental group by 41%, on the 5th day by 26 and 36%, respectively, and on the 7th day — by 49% in both groups. By day 14, levels approached but did not reach reference values By the end of the study, on day 14, the creatinine level in the first group was 7.5% higher than in the second one.

Spontaneous feeding resumed earlier in the experimental group (2.8 ± 0.4 days) compared to the control group (4.8 ± 0.5 days).

In the experimental group, immediately after the operation, nutrition was performed through esophagostomy, and to improve peristalsis, patients received metoclopramide at a dose of 1–2 mg/kg/day intravenously. The early onset of self-feeding can be explained by the fact that food was supplied, which indirectly affected the work of peristalsis, and patients received prokinetics that contributed to the movement of chyme. In critically ill cats, metabolic changes include decreased insulin and increased glucose, lactate, cortisol, glucagon, norepinephrine, and free fatty acids [22, 23]. Glycogen stores are quickly depleted, especially given that cats have limited glycogen stores. It leads to increased proteolysis. Cats have high rates of protein metabolism and limited ability to suppress gluconeogenesis during protein deficiency [24, 25]. With continued food shortage, energy is obtained almost entirely through accelerated proteolysis, which in itself is an energy-­intensive process. The consequences of the ongoing loss of muscle mass include a negative impact on wound healing, immune response, general condition and, ultimately, on the overall prognosis [26].

However, it is worth noting that cats in the experimental group showed a lower rate of decrease in creatinine by 2.69% on the 3rd day and by 10.5% on the 5th and 7th days compared to the control one. Although subsequently, on the 14th day of the study, urea and creatinine levels began to converge again. With prolonged anorexia or starvation, the body begins to break down muscle protein to get energy. Creatinine is a breakdown product of creatine from muscle tissue, therefore, with active catabolism, its formation increases. With early postoperative feeding, energy needs are covered, catabolism slows down, for this reason, the creatinine level decreases not only due to improved filtration, but also due to a decrease in its production [26].

Conclusion

The study demonstrated that cats receiving esophagostomy feeding showed faster reductions in creatinine levels — on average 11% faster during the first 5 postoperative days. Although the rate equalized by day 7, by day 14 urea and creatinine levels remained about 7% lower in the experimental group. This is associated with earlier return of appetite due to esophagostomy feeding and metoclopramide administration. The control group began to consume food on average on the period of 4.8 days, in the experimental — 2.8 days. Early postoperative feeding via esophagostomy, combined with prokinetics, is therefore an important therapeutic component that accelerates the reduction of azotemia and promotes earlier voluntary food intake.

About the authors

Vladislav A. Lust

RUDN University; “Alisavet” veterinary clinics network

Author for correspondence.
Email: 1142220008@rudn.ru
ORCID iD: 0009-0003-7605-120X
SPIN-code: 4691-2786

postgraduate student, RUDN University; veterinary surgeon, “Alisavet” veterinary clinics network

6 Miklukho-Maklaya st., Moscow, 117198, Russian Federation; 17 Chobotovskaya st., bldg. 1, Moscow, 119634, Russian Federation

Yuri A. Vatnikov

RUDN University

Email: vatnikov@yandex.ru
ORCID iD: 0000-0003-0036-3402
SPIN-code: 2726-8270

Doctor of Veterinary Sciences, Professor, Director of the Department of Veterinary Medicine, Agrarian and Technological Institute

6 Miklukho-Maklaya st., Moscow, 117198, Russian Federation

Valentina I. Semenova

RUDN University

Email: semenova-vi@rudn.ru
ORCID iD: 0000-0002-1610-1637
SPIN-code: 2152-5318

Candidate of Veterinary Sciences, Associate Professor, Department of Veterinary Medicine, Agrarian and Technological Institute

6 Miklukho-Maklaya st., Moscow, 117198, Russian Federation

Evgeny V. Kulikov

RUDN University

Email: kulikov-ev@rudn.ru
ORCID iD: 0000-0001-6936-2163
SPIN-code: 6199-2479

Candidate of Biological Sciences, Associate Professor, Department of Veterinary Medicine, Agrarian and Technological Institute

6 Miklukho-Maklaya st., Moscow, 117198, Russian Federation

References

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