A REVIEW OF ABOMASAL DISPLACEMENT- CLINICAL AND LABORATORY EXPERIENCES

  AT OUR CLINIC IN LJUBLJANA

CONTENTS

1. Synopsis

2. Introduction

3. Definition and classification of DA

4. History of DA

5. Aetiology

6. Epidemiology

7. Materials and methods

8. Results and discussion

9. Conclusion

10. Epilogue

11. Summary

12. References

1. Synopsis

2. Introdution

The dairy cow has been selectively bred to produce considerably more milk that is required by any calf, and if management is good, she will produce it for three-quarters of her life in the dairy herd. This requires a much greater intake of nutrients than the traditional high-fibre diet of cattle, in particular at the beginning of lactation, so nutritionists are constantly trying to devise means of increasing the cow^,s nutrient intake while maintaining stability in her metabolism (1,2). 

Fig. 1. The cow "Arafela", Israel-Holstein, 19 years old; in 13 lactations, she gave 168.000 kg milk, 4.822 kg milk fat, 4.553 kg milk protein (Dr. Dan Kalay, Israel Journal of Veterinary Medicine 1997;52)

 How to get a high milk production?

-         good quality roughage

-         a high level of dry matter intake

-         the strict respect for daily routine management

What are the bovine practitioner^,s expectations with respect to the current dairy industry in relation to herd health management on dairy farms in the next 10 years?

  Restrictions:

-         only cattle (dairy cows) and replacements,

-         not a prophecy for a millenium but for the next 5 – 10 years

  Segregation in dairy farms (at least in the EU)

-        Industrial dairy farming: high-producing milking cows, large-scale operations, high technology, balancing between health and feeding and the management regime, public health hazard and environmental pollution.

-    Organic/bio farming: smaller scale operations, lower milk production, higher milk production, limited in feeding concentrates, no/less fertilizers and minerals.

High producing milking cows

-         in Europe: > 10.000 kg/cow/year

-         in the USA and Canada: milk production has to be 20 times the body weight = about 13,000 kg/cow/year

-         Most of the progress is because of: improvements in feeding, cow care, and genetic contribution (25 - 40%)

High milk production depends on the "critical six weeks" health status of cows

  -         The last 3 weeks before and the 3 first weeks after calving. (transition period)

-         dramatic change in nutrient requirements

-         metabolic adaptation

-         the key issue is the drop in dry matter intake

The challenge: providing energy for the periparturient period of the dairy cow

Dairy herd health and welfare problems

Too many dairy cows culled after only 1 to 4 lactations are chronically lame or skinny and appear to be "worn out" by sustained hard work. The main welfare problems for dairy cows can be attributed to the systems of feeding, housing, milking and management that are unfitted to the genotype of the high yielding cow. Increased incidence and epidemiological studies show that diseases that are associated during the six critical weeks period with "negative energy balance (NEB) - hepatic lipidosis -  hypocalcaemia" are:

-         Clinical and subclinical form of milk fever (28,29,34),

-         Retained placenta (28),

-         Toxaemia in recently calved cow – septic metritis (36)

      -    4 to 7 times greater risk  of developing abomasal displacement (29,31),

-         Impaired ruminal contractions (32),

-         Lethargy and inappetence in early lactaion (29),

-         Reduced uterine involution (28),

-         Prolapsed uteri (33),

-         Reproductive disorders (29,30)

-         Mastitis (67)

 3. The definition and classification of AD

AD is the result of positional changes of abdominal viscera during late pregnancy or abomasal atony resulting from various factors (3). In this disease the abomasum is displaced from its normal position on the abdominal floor either to the left or to the right or into an anterior position. Practitioners and literature divide AD in 4 types (4).

1. In left displacement (LDA), a sac of the abomasum comes to lie in a position behind the omasum and to the left of the rumen. The greater curvature, which passes under the rumen, is impounded between  the rumen and the left abdominal wall, and lies in the left lower flank.

Fig. 2. Left lateral aspect of the abdominal viscera of a cow with a left-side displacement of the abomasum (Sack 1968)

2. In anterior displacement (ADA), the clinical picture is very similar to that of left displacement but the abomasum, or the major  part  of it, is displaced anteriorly and comes to lie between the reticulum and the diaphragm.

Fig. 3. Specific high-pitched tinkling sounds were detected in caudoventral left and right lateral abdominal region just behind the limits of the percussible lung field

3. In right displacement, the abomasum (RDA) is displaced to the right and is found lying between the liver and the right abdominal wall, and in severe cases may extend as far backwards as the pelvic brim. 

 Fig. 4. Fluid accumulates in the obstructed viscus and severe shock and dehydration follow; in the dilatation and displacement phase, the degree of ratio is less and although only small amounts of ingesta can pass, there are scant faeces

4. Torsion (volvulus) of the abomasum (VA) causes a syndrome of alimentary tract obstruction and, in its acute form, is manifested by severe abdominal pain and rapid death. Torsion occurs in a vertical plane and around a horizontal axis passing transversally across the body in the vicinity of omaso-abomasal orfice; viewed from the right the torsion may be clockwise or anticlockwise.

Fig. 5. In acute torsion, the twist is usually of the order of 180 ^o to 270^o and the syndrome is one of acute obstruction due to complete blockage, faeces are usually scant, soft and dark in colour; the abdomen is visibily distended; depression and weakness are marked; dehydration is obvious, the heart rate is 100 – 120/min.

   4. History of AD

In 1898, Carougeau and Prestat (cit. 5) diagnosed the first case of abomasal torsion in a calf. In 1928 and 1930, Vink (6) described the first abomasal torsion in adult cows, and since then a gradually increasing number of abomasal torsions has been recorded. In 1943 and 1945 Emsbo (7,8) reported an increasing incidence of abomasal torsion in Denmark and gave a detailed description of the disease. Løje (9,10) with clinical laparotomy for the first time diagnosed right-sided displacement of the abomasum. The first case of left-sided displacement of the abomasum was published by Begg (11), Begg and Whiteford (12) in the UK and the USA by Moor et al (13). The end of the first period of history of abomasal displacement is marked by the detailed and comprehensive study of Dirksen (14,15). Since then an avalanche of papers on abomasal displacement has been  published. The first cases by abomasal displacement in former Yugoslavia were reported in 1962 by Blagojević and Novak (16), Horvat et al (17), Vulinec and Herceg (18). In 1965 Van de Watering et al (55) observed the anterior dislocation of the abomasum.

At our Clinic the first surgery of a displaced abomasum was done in 1969 (19). Until 1980 five more displacements were surgically treated. Until 1998 there were only 9 reports for Slovenia of abomasal displacements in cattle in the literature (19,20,21,22,23,24, 25,26,27). In 1981 Zadnik successfully diagnosed and caried out his first surgical treatment of right-sided displacement of the abomasum (21,22).

        Table 1: Presentation of abomasal displacements from 1981 – 2001 at the Clinic for Ruminants in Ljubljana

¹= Left displacement of abomasum; ²= Right displacement of abomasum; ³ = Abomasal  volvolus; ⁴ = Anterior displacement of abomasum; ⁵ = Abomasal displacement

Because since 1995 the incidence of the disease has significantly increased among patients at our Clinic and because in Slovenian literature from 1998 alone, there have been  9 reports (19,20,21,22,23,24,25,26,27), we have begun an extensive study of the problem.

5. Aetiology

Abomasal displacement (AD) has been observed in adult dairy cows  with increasing  frequency in recent years. This may be due to an increase in the surgical treatment of cases of chronic indigestion in cattle which has led to the more frequent observation  of the displaced abomasum through laparotomy incisions. On the other hand there is a general impression that the disease has increased in incidence. This may be related to heavy feeding with corn silage, grass silage and grain in late pregnancy of cows because the market prices have stimulated farmers to high milk-production. Clinicians are of the opinion that the cause of displaced abomasum in cattle is multifactorial. A prerequisite for the development of the displacement is hypomotility, reflux of abomasal fluid, and gaseous distension of the abomasum (35,36,37). The feeding of high levels of concentrates to dairy cattle causes a decrease in abomasal motility  and the increases accumulation of abomasal gas. Abomasal hypomotility and emptying disorders could be evoked by the increased enteric inhibitory neuronal activity and the reduced cholinergic muscle response (38). Some authors stated that endotoxins, prostoglandins and histamine had been shown experimentally to induce LDA (47).  

6. Epidemiology

In general, AD occurs in 1.75% to 6.0% of dairy cows all over the world (40,41,42). The mean rate of occurrence in a cow population over a period of years in Denmark was 0.62% with a range of  0.2 to 1.6%. The lactational incidence risk of LDA for dairy herds in Ontario (Canada) is about 2% (39). In Norway, 88% of the abomasal displacements  are left-sided and 12% are right-sided (36).               

Risk factors

Parturition

Displacement of abomasum occurs most commonly in large-sized, high-producing adult dairy cows immediately after parturition. About 90% of displacements of the abomasum were diagnosed one week prepartum to three weeks postpartum. LDA occurs in about 75% of cases as the abomasum migrates from the lower right side of the cow to the left side of abdominal cavity.  RDA involves a twist or torsion on the right side which can restrict blood and abomasal flow and is more serious than  LDA (36,39,40,41,42).

High level of concentrate feeding

The disease is common in the EU and North America where dairy cattle are fed grain for high milk production and the animals are usually housed for part of the year or kept under confinement. The disease is uncommon in Australia and New Zealand where much fewer concentrates are fed to dairy cattle and the animals are usually on pasture for most of the year.

Breed and age

DA is predominatly seen in Black&White dairy herds with an above-average milk yield, and in cows between the age of 4 to 7 years.

Season of the year

Higher incidence rates were observed in the winter and early spring months (41,44).

Concurrent diseases

Concurrent diseases were present in 30% of AV cases and 54% of LDA cases (36). In general, cows are suffering from negative energy balance, hypocalcaemia, lipidosis and ketosis (31,41,45,46).

7. Matherials and methods

 Our report is based on a study of 161 cows which were clinically treated at our Clinic. Health data including history of the disease, results of clinical and laboratory examination, surgical treatment and postoperative therapy were analysezed.

Fig. 6. Percussions and simultaneous auscultation of left or right abdomen to elicit pings or pungs or fluid-splashing sounds, which indicate that fluid and gas are in the distended abomasum or loops of the intestine

Clinical examination

A routine general clinical examination of the cows (n=161) was performed prior to a close examination of the gastro-intestinal tract and abdomen (inspection of the contour, palpation, ballottement, simultaneous percussion and auscultation, and succussion). The body temperature (^oC), heart and pulse rates (beats/min), respiratory rates (breaths/min), and ruminal movements, especially peripheral circulation including venous circulation, and the state of hydration were examined.

The abdomen was examined by percussion with a flick of the finger or, most reliably, with a plexor while auscultating at the same time. The stethoscope was placed immediately adjacent to the area being percussed and the examiner listened for resonant sounds, which may vary from high-pitched bell-like sounds (pings) to a low-pitched bass drum sound (pungs). To elicite the diagnostic ping it is necessary to percuss and auscultate side by side, and to percuss with a quick, sharp, light and localized force.

  Fig. 7. Stippled regions represent typical areas of tympanitic resonance "ping effect" heard over the right side of abdominal wall of cow with conditions causing gas distension of intra-abdominal viscera (65)

All clinical  diagnoses were  later confirmed by right laparotomy. All types of AD were operated on standing cows in the right paralumbal fossa via the "Ljubljana method" for fixation of the abomasum – right percutaneous paralumbar fossa omentopexy (7,8). We used paravertebral and local infiltration anaesthesia with 2% lidocaine. We prefer not to use sedatives like Xylazine, because thise substance slows the intestinal motility for a long time after surgery (53). A 25 cm long incision is made, beginning one hand below the lateral spinous process of the lumbar vertebrae, running from craniodorsal to cavdoventral 5 fingers width distance from the last rib. The abdominal cavity must be carefully   opened to prevent injury to the distended and right sided abomasum, that lies directly under peritoneum. After placing a sterile cotton operating cuff, the highest point of the abomasum is punctured by a cannula that is attached to a sterile rubber tube. The abomasal wall should be punctured tangentially in order to produce a long punture wound that will seal itself, thereby preventing the leakage of abomasal contents. After puncture there is enough space in the abdominal cavity to perform manual exploration.

Surgical correction and postoperative care of RDA and AV

Right-sided displacement with torsion requires immediate surgical interference. On the basis of the characteristic clinical signs (ping, pung, ileus, colics, dehydration, toxaemia, cardiac conditions) an accurate diagnosis is established. Before and during the surgery fluids and electrolytes are usually administered intravenously. The procedure is carried out on the standing animal. Laparotomy is performed on the right paralumbar fossa. A 25 cm skin incision is made 10 cm caudally behind the costal arch. The abdominal cavity is protected with sterile compresses against contamination by abomasal contents. By palpation the position of the abomasum, direction and degree of torsion are established. The abomasum is pulled into the wound, where the fixation is done by an assistant. On the abomasum a concentric suture is applied. Through the central part a small incision is made through which a sterile nasal tube is pushed (a Newmann^,s nasal sound). The suture is tightened, so that the slit between tube and the edge of abomasal wound is closed. Via the nasal tube the abomasal contents (gas, fluid) are removed, whereupon it is pulled out and the incision wound is tied using a concentric suture. The torsion, if present, is corrected and the abomasum replaced in its normal position. Postoperative care consists of the administration of fluids, electrolytes, glucose and antibiotics. Dietary measures (administration of linseed broth with digestives via a stomach tube) are taken over several days.

Surgical correction and postoperative care of LDA and ADA

With LDA and ADA the abdomen is opened at the right side, behind the costal arch. The left arm is stretched along greater omentum and craniodorsally across rumen to the left costal arch where the dislocated abomasum is palpated. Generally the abomasum is palpated as large inflated tube. The gas-filled abomasum is displaced under the rumen and becomes trapped between the left abdominal wall and rumen. A cannula of 2-3 mm in diameter affixed to a rubber tube (150 cm) is inserted into the abomasum. After the gas is released, the cannula is removed. The right hand is moved cranioventrally along the right abdominal wall to the omasum. The abomasum is drawn to the right side of the abdomen. The pylorus is drawn into the wound. Thereafter omentopexy is performed near sow,s ear in the greater omentum. The procedure is described under the heading (Omentopexy). In 20 cows the ADA was established during operation. Three cows were slaughtered immediately after the surgery because of perforated abomasal ulcers. Relapse ocurred after five days in one animal with LDA. It was again operated and it was established that omentum was torn away from the fixation suture. Severe postoperative peritonitis due to omentopexy was never established. 

Right percutaneous paralumbofossal omentopexy using the "Ljubljana method"

Omentopexy is performed with LDA, RDA, AV and ADA. Until 1993, omentopexy was not carried out with right-sided displacement and torsions. Because of numerous relapses, we began with fixation of all types of RDA. LDA began to be surgically corrected in the right paralumbar fossa  as reported by Dirksen (14,15,65).  After replacement of the abomasum the omentopexy is performed near to the pylorus. The omentum which (5 cm away from the pylorus area s.c. "sow,s ear" in the greater omentum) is attached to the pylorus is sutured to the right abdominal wall. Right percutaneous paralumbofossal omentopexy was done with a Gerlach needle and a silk ribbon. The abdominal wall is perforated two times ca. 5 – 10 cm beneath the incision

Fig. 8. Omentopexy is performed in the greater omentum about one hand^,s  width caudal to the pylorus. We recommend a Gerlach needle and a silk ribbon 50 cm long and 1 cm wide, usually used for of vaginal prolapse wound at the level of the knee joint. For omentopexy we used 50 cm long and 1 cm wide silk ribbon, usually used for of vaginal prolapse. The position of the omentum is well attached to the abdominal wall. Thereafter the both ends of ribbon are tightened and tied. The fixation suture is removed 8 – 10 days following the operation (26).

Blood samples

We carried out  a haematological analysis (E, Hb, Ht, MCV, WBC, diff WBC) with Coulter Counter ZF₆ and biochemical sera analysis (Ca, iP, Mg, Na, K, Cl, AST, LDH, GLDH, GGT, total Bilirubin, Cholesterol, Glucose, Urea, BHB, FFA) with Cobas Mira analyser. Statistical evaluation: The data obtained were statistically processed by SPSS programme (5).  

8. Results  and Discussion   

During the period form 1991 to 2001 we surgically treated 161 cases of  AD. Table 2 shows that the incidence of the AD in our Clinic has been constantly on the increase. From the results it is further evident that a 12.4% incidence of ADA was with respect to other  types of DA rather high. This information is important especially for less  experienced  practitioners who must during the periparturient period consider also the possibility of ADA formation besides stubborn indigestion. Via the  data analysis and owners' reports it was established that  the cows gave the expected quantity of milk only after the surgery. Undiagnosed cases of ADA usually reach a certain level of inanition and may remain at an equlibrium for several months. Milk production decreases to a small volumen and the animal becomes thin with the abdomen greatly reduced in size. Reduction in the bulk of faeces, decrease in feed intake and permanent mild ketosis are great clinical pointers.     

 Table 2. Presentation of AD incidence from 1991 to 2001 at the Clinic for Ruminants in Ljubljana

Table 3. Presentation of some data on AD history

¹Winter months from November till June; 1 = 0 to 7 d postpartum (pp); 2 = 8 to 21 d pp; 3 = 22 to 90 d pp; 4 = >90 d pp; 5 = 7 to 9 months of pregnancy; 6 = heifers

Table 3 shows that the ratio of LDA+RDA+AV to ADA cases was 7,1 to 1. Black&White cows were at a higer risk of developing all types of AD than  other breeds. In our environment the incidence of AD, especially for ADA was highest in the winter season. Although parturition appears to be the most common precipitating factor, the disease occurs throughout the year independently of the incidence of parturition. On the basis of our findings, it is assumed that proportionately fewer cases of ADA occurred during late pregnancy. Other types of AD occurred  during the first three weeks after parturition – 53%, 56.3%, 40% and 20%.        

The risk of developing all types of AD increased with age, with the greatest risk at 4.0 to 5.5 years of age. The youngest cows had a higher risk of developing ADA (Table 4). ADA showed the longest period  (10.5 ± 13.5 days) from first signs to the recognized illness. In ADA the clinical findings are more or less similar to those described above except that the characteristic LDA pings cannot be elicited over an area between the upper third of the 9th and 12th ribs of the abdominal wall. In our study we detected a combination of "ping and pung" effects in 55.6% cases of ADA in caudoventral left and right lateral abdominal region just behind the limits of percussible heart and lung area. Of our 25 cows with AV  40% died. In cows with ADA there were statistically significantly fewer deaths (15%). Our cases have shown that the diseases of the wall of the abomasum (secundary ulcer) and fatty liver are commonly concurrent diseases in cows with ADA. 

Table 4: Mean age of cows, mean time from first signs of the disease to surgical treatment, frequency of ping effect, and percentage of successful treatments in cows with AD

¹Mean time/days from first signs of DA to surgical treatment ; ***P<0,001

 It was established, that Ca, K, Na, Cl, b-hydroxybutyrate, FFA and serum AST, GGT, GLDH activity were not convincing preoperative laboratory diagnostic indicators in cows with ADA.  In ADA cases there was no interference with blood supply to the trapped portion of the abomasum, so that the effects of the displacement were entirely those of interference with digestion and movement of the ingesta, leading to a state of stubborn indigestion, ketosis and lipomatosis. The high diagnostic value of total sera bilirubin in cows with ADA is the result of partial bile duct obstruction. On the basis of our findings relatively high but statistically significant low activity of AST, GGT and GLDH in cows with ADA was established with respect to cows with other types of DA which was associated with mildly increased degrees of

  Table 5: Some important and statistically significant mean values and ± SD in blood parameters in our cows with AD

*P<0,05; ***P<0,001

liver lipidosis. Ketosis and fatty liver were the most common complication of ADA. We detected increased but not significantly high levels of FFA and BHB in cows with ADA.   

Geishauser et al (62) stated and concluded that AST and BHB in the first and second week p.p. might be used as tests for subsequent LDA. Glucose, Ca and urea were not significantly associated with LDA or significantly associated only in the second week p.p.; this may limit their use as test for LDA.  Itoh et al (63) observed an increase in AST GGT, VFA and BHB in

cows^, blood with LDA.

The "ping effect" was established in 89.1% of cases. As very accurate, near by 100%, the simultaneous  auscultation and percussion proved in RDA, but less so (55.6%) in ADA. The characteristic ping sound in LDA or RDA was due to a quick course of dislocation. The pitch, intensity and range of ping effect varied with regard to the kind and degree of dislocation. The greatest range (35 cm in diameter and more) of ping effect was established in RDA with torsion and LDA. In the area of ping the characteristic tinkling abomasal sounds were heard 93.3% of cases, most frequently in RDA and LDA and least in ADA at irregular intervals. We found auscultation and a combination of percussion (flicking) with auscultation reliable and effective examination methods in cows affected  with RDA and LDA. Both techiques are non-invasive, requiring no special and expensive equipment. The method, however, requires that clinicians need to be experienced and painstaking in their examination. The use of invasive methods can be associated with complications, as e.g. infection of the abdominal wall. The diagnosis of all types of DA needs further development of efficient methods, as e.g. pepsinogen determination in blood or faecal blood as an indicator of affected abomasal mucosa (48, 65).

Mean values of pulse rate, respiration, with the exception of temperature, deviated from normal values. Table 6 shows that the mean value of T was the most constant. Slightly increased T values were found with LDA.

  Table 6. Mean values of temperature (T), pulse rate (P), respiration rate (R) and number of ruminal movements (Ru)

The increased T values could be due to accompanying septicaemia around concurrent parturition diseases, such as metritis, mastitis, peritonitis. The mean value of the respiration rate – with the exception of ADA, and probably due to the increased pressure of the dilated abomasum on the diaphragm – are within normal range. In all displacements the mean P value was  above normal values; it was highest in AV due to disturbed circulation and metabolic alkalosis. On the other hand, is the finding that ruminal contractions were, with regard to frequency in RDA, within the normal range. Compared to other dislocations these were less frequent and weak.  

9. CONCLUSION

For an accurate diagnosis of DA, the establishment of the "ping and pung effect" is of great importance. A definitive interpretation of the ping effect is possible, however, only in combination with the other examination methods described and laboratory blood, urine, and milk tests. The established ping effect, presence of ketones, and the occurrence of the disease within the postpartum period provide good diagnostic data for surgical interference.

Our findings revealed that 12.4% incidence of ADA was high with respect to other types of DA. According to our experiences, ADA may be characterized as a special type of abomasal displacement. Early and accurate diagnosis of ADA is very important for the production and good health of dairy cows. Practitioners should be careful when making the diagnosis because cows which show during the periparturient period stubborn indigestion, ketosis and fatty liver may suffer from ADA.  It has been established that quite a lot of our colleaques are not very well acquainted with the diagnosis, treatment and prevention of AD. Many make a wrong diagnosis and sometimes the disease is misinterpreted as stubborn ketosis and other postparturient diseases. In all displacements of the abomasum after the reposition the omentopexy was done via our own modified method, 5 cm away from pylorus. The "Ljubljana method" used for fixation of the abomasum is simple, reliable, and cost effective.

10. EPILOGUE

Characterizing the dry period as a resting phase between lactations and emphasizing it as a period of the lowest nutritional requirements for the cows has given presented the wrong impression of the critical role of the dry cow. The most important period in the milk production period is the transition between late pregnancy and early lactation (the critical six weeks). In this period an enormous metabolic challenge to the high-yielding dairy cows occurs. Proper management of the late pregnant dry cow period should be portrayed to dairy producers as an investment in the future. At this time not enough is understood about the effects of feed intake during the dry period on subsequent milk yield and the incidence of displacement of abomasum, milk fever, fatty liver, and udder oedema. These relationships are still under investigation at the time of this lecture.

SUMMARY

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