Physical examination revealed general weakness, distended left flank, moderate dehydration, elevated rectal temperature (40°C), (reference range, 38.5 to 39.7°C), normal heart rate (74 beats/min), (reference range, 60 to 80 beats/min), normal respiratory rate (14 breaths/min) (normal reference range 10 to 30 breaths/min), and abnormally high rumen motility (5 contractions/2 min) (normal reference range, 2 to 3 contractions/2 min). Moderate tick infestation was observed on the animal. Hematological analysis revealed hemoglobin 104 g/L (reference range, 80 to 150 g/L), total leukocyte count 7.5 × 10⁹/L (reference range, 4.0 to 12.0 × 10⁹/L), packed cell volume 0.36 L/L (reference range, 0.24 to 0.46 L/L), neutrophils 1.8 × 10⁹/L (reference range, 0.6 to 4.0 × 10⁹/L), lymphocytes 5.1 × 10⁹/L (reference range, 2.5 to 7.5 × 10⁹/L), monocytes 0.15 × 10⁹/L (reference range, 0 to 0.8 × 10⁹/L), eosinophils 0.45 × 10⁹/L (reference range, 0 to 2.4 × 10⁹/L), and negative for blood parasites. No abnormality was detected on auscultation of the heart and lung areas.

On the basis of physical examination, reticuloruminal involvement was suspected and various differential diagnoses included traumatic reticulitis, reticular abscess, diaphragmatic abscess, or hernia. An ultrasonic diagnostic examination was planned, as it was noninvasive and a less stressfull procedure for the sick animal.

For ultrasonographic examination of the reticular region, the right lateral wall of the thorax from the 4th to 7th intercostal space was shaved and smeared with transmission gel for optimal transmission of ultrasonic waves. The reticulum was identified within the abdominal cavity by using an ultrasound scanner (Concept/MCV Veterinary Ultrasound Scanner; Dynamic Imaging, Livingston, Scotland), in real time B-mode with a 3.5 MHz microconvex transducer, as a smooth crescent-shaped structure with characteristic biphasic contractions when scanned at the right 6th and 7th intercostal spaces at the level of elbow. Ultrasonographic examination at the level of the right 4th and 5th intercostal spaces revealed a reticular wall-like structure (Figure 1a). Reticular motility was present but the amplitude of contractions was comparatively reduced. The reticular wall also appeared to undulate. Ultrasonographically, the presence of reticular motility at the level of the 4th and 5th intercostal spaces indicated reticular herniation into the thorax.

To confirm the ultrasonographic findings, plain and contrast radiographs of the reticulum were taken with the cow in right lateral recumbency. Plain radiographs revealed a fairly demarcated diaphragmatic line and the presence of metallic foreign bodies in a sac-like structure located cranial to the diaphragm. Contrast radiography showed the passage of contrast agent into the herniated reticulum located cranial to diaphragm (Figure 1b). Based upon the ultrasonographic and radiographic images, a final diagnosis of reticular diaphragmatic hernia was made.

Left flank exploratory laparorumenotomy was done under linear infiltration anesthesia with the cow in the standing position. The peritoneal cavity was observed to be normal except for increase in normal appearing peritoneal fluid. During the rumenotomy, frothy rumen contents were evacuated completely (up to 90%). Then the rumen and reticulum were explored, and the omasum and abomasum were palpated. Five sharp and many nonpenetrating metallic foreign bodies, cloths (about 2.5 kg), polythene plastic, coal tar balls (about 10 cm and 6 cm in diameter size), and a lot of sand were removed from the rumen. The size (10 cm in diameter), location (extreme right side of diaphragm) of the hernial ring, as well as the extent of herniation and perireticular adhesions, were recorded. Protozoa concentration in the ruminal fluid was 2–5 organisms/40× field. Two boluses of live yeast cells (Yeasac Boluses; Ranbaxy Labs, New Delhi, India) were put in the rumen before its routine closure. Postoperatively, normal saline (0.9%) sodium chloride solution (Claris NS; Claris Life Sciences, Ahmedabad, India), 40 mL/kg bodyweight (BW) was administered, IV, along with ampicillin and cloxacillin (AC Vet Fort; Unichem Lab, Mumbai, India), 10 mg/kg BW, IM, q12h for 7 d, gentamicin (Ranbamycin; Ranbaxy Fine Chemical, New Delhi, India), 2 mg/kg BW, IM, q24h for 3 d, meloxicam (Melonex; Intas Pharmaceutical Ahmedabad, India), 0.2 mg/kg BW, IM, q24h for 3 d, and 2 live yeast bolus (Yeasac), PO for 15 d.

The diaphragmatic herniorrhaphy was scheduled for 24 h after the rumenotomy. Preoperatively, the cow was administered normal saline (0.9%) solution (15 mg/kg BW, IV) and dexamethasone (Dexona; Sarabhai Zydus, Animal Health Ahmedabad, India), 0.5 mg//kg BW, IM, and then premedicated with midazolam (Mezolam; Neon Labs, Mumbai, India), 0.2 mg/kg BW, IV (1). Anesthesia was induced with 5% thiopental sodium (Thiosol; Neon Labs), 5 mg/kg BW, IV, with the animal in right lateral recumbency and maintained with 2% halothane.

With the cow in dorsal recumbency, the diaphragmatic hernia was repaired as described previously (2,3). Many thick adhesions of the herniated reticulum to the hernial ring and uniquely to the lung (Figure 2) were observed. The reticulum was retracted back into the abdominal cavity and the hernial ring, which was very close to the liver was then cleared of any remaining adhesions and closed by using no. 2 silk thread. Before placing the last suture, the lungs were hyperinflated to expel air from thoracic cavity. Positive pressure ventilation, using pure oxygen, was given during the operation for 45 min and continued postoperatively till the animal had effective spontaneous breathing. The muscles and skin were sutured as described earlier (2,4,5).

During recovery, the cow was supported in sternal recumbency until about 3 h after the operation, when she stood without support. Four hours postoperatively, she could stand and walk normally and took small amounts of grass and water. Milk yield in this cow started increasing in about 1 wk and reached 60% of peak production by 2 mo post surgery.

Diaphragmatic hernia is observed mostly in dairy cattle that have recently calved or are in advanced pregnancy (2,3,7,8,11,13) but occasionally in heifer (9) and ox (10). Cattle suffering from reticular diaphragmatic hernia generally show typical symptoms of traumatic reticulitis (13). In the present case, the rumen was hypermotile as has been reported earlier (6). The marginal eosinophilia in the present case might have been related to the tick infestation.

A diaphragmatic hernial ring can be present in the left, mid, or right hemisphere of the diaphragm (3,6,12,13), but it is more common in the right (13). Diaphragmatic hernia has been reported in the absence of reticular metallic foreign bodies (6). However, some reports consider metallic foreign bodies or traumatic reticuloperitonitis pathogenic for the disease (13).

Surgical repair of a diaphragmatic hernia is usually through the post xiphoid abdominal (2,3,5,13) or thoracic approach (9), although successful repair in the standing position under local anaesthesia through the thorax has been reported (12). Radiography has been used successfully for the diagnosis of diaphragmatic hernia (2–4,11,13) and reticuloperitonitis (15). In doubtful cases, contrast radiography can help to confirm a diaphragmatic hernia (4,5,16).

Recently, ultrasonography has been emerged as a reliable tool in diagnosis of forestomach and intestinal disorders in cattle (17,18) and it was a noninvasive means for the diagnosis of reticular diaphragmatic hernia in this case. Ultrasonography besides being noninvasive is less stressful to the animal compared with reticulography, which may involve putting the animal in lateral recumbency. The undulations in the reticular wall seen on ultrasonographs, could have been due to the adhesions (15).