Diagnostic and prophylactic measures of Diaphragmatic hernia in Buffaloes

Introduction

Diseases of the digestive tract in ruminants comprises of major clinical problems and sometimes, these either remain undiagnosed or fail to respond to medicinal treatment which ultimately results in major economic loss for the farmers. One of the commonly seen conditions in field which remains undiagnosed is diaphragmatic hernia (DH). Among all ruminants, DH has been found to have higher occurrence in buffaloes. Buffalo is an important meat animal as well as the major dairy species in India which contributes over 50% of the total milk production in the country

The diaphragm is a dome-shaped musculo-tendinous barrier between the thoracic and abdominal cavity. It separates the thoracic organs like heart and lungs from abdominal organs like rumen, reticulum, intestines, liver and spleen etc. Diaphragmatic hernia occurs when one or more of abdominal organs enter into the thoracic cavity through a congenital or acquired defect in the diaphragm. Commonly the reticulum is herniated into thoracic cavity. It is more prevalent in buffalo than other ruminants due to their indiscriminate feeding behavior as well as the genetic predisposition due to a weak diaphragm. DH is common during pregnancy as the uterus is extended into the abdominal cavity causing a pressure on the visceral organs and ultimately, on the diaphragm.

Etiopathogenesis of Diaphragmatic hernia

  1. Buffaloes have comparatively small tendinous portion of the diaphragm resulting in innate weakness which predispose them to be most affected.
  2. Increased intra-abdominal pressure may be due to advanced pregnancy or at the time of parturition, tympany, chronic cough, violent fall etc.
  3. The main cause of diaphragmatic hernia in buffalo has been found to be Foreign Body Syndrome; presence of potential foreign bodies in the reticulum which leads to weakening and ultimately, rupture of the diaphragm as a sequelae of Traumatic reticuloperitonitis.
  4. Deficiency of minerals in diet leading to pica due to which animals may relish objects with a mineral or metallic taste thereby, ingesting foreign bodies like wire, nails etc.

Diagnosis

Diagnosis is based on both history and clinical signs. Mostly the animals have a history of recent parturition or in an advanced stage of pregnancy. Affected animal do not respond to medicinal treatment.

Clinical signs

  1. Recurrent tympany: Inhibition of rumen peristalsis due to reticular adhesions is considered as the main cause of tympany.
  2. Frothy bloat: Due to entrapment of reticulum in thoracic cavity. This leads to distortion of oesophageal groove, reticulo-omasal opening and produces hyper motility of rumen which in turn forms frothy ruminal content.
  3. Animal may show signs of regurgitation at times.
  4. Partial anorexia with dry faeces containing mucus shreds or no defecation.
  5. Dyspnoea with open mouth breathing.
  6. The lactating buffalo shows a significant and sudden fall in milk yield.
  7. Auscultation: Reticular sound is audible on auscultation of thoracic cavity, suggestive of diaphragmatic hernia.

Confirmatory diagnosis is made by

a) Ultrasonography

b) Plain or contrast radiography

c) Laparo-rumenotomy

Ultrasonography: Scanning of reticulum motility cranial to 5thintercostal space in standing position is considered confirmatory for diaphragmatic hernia in bovines. Ultrasonographically, normal reticulum appears as a half-moon shaped structure with biphasic contractions of one per minute and the first contraction being incomplete. Reticulum can be located in the thoracic cavity by placing the transducer in the 5th,4th and 3rdintercostal space at the level of elbow joint. The transducer is then moved ventrally and reticular contractions are assessed. Presence of biphasic motility in thoracic cavity on B+M mode ultrasonogram is confirmatory for Diaphragmatic hernia in bovines.

Fig.1 Ultrasonogram showing hyperechoic reticular wall (a) at 4th intercostal space

Radiography: Radiographs in right lateral recumbency with forward stretched forelimbs at the end of inspiration helps in diagnosis of diaphragmatic hernia. Following findings are present either solely or in combination with others:

  • Break in the continuity of diaphragmatic line.
  • A sac like structure cranial to diaphragm either with metallic foreign bodies or without it.

In some animals, a characteristic reticular honeycomb pattern cranial to diaphragm is also confirmatory to diaphragmatic hernia.

Fig. 2: Radiograph showing reticulum(R) herniated into thoracic cavity adjacent to heart (H) with some metallic foreign bodies. Arrows are showing broken diaphragmatic line.

Laparo-rumenotomy: Left flank rumenotomy under local anaesthesia in standing position is a confirmatory diagnostic procedure for diaphragmatic hernia.

Fig. 3: Left flank rumenotomy for diagnostic as well as for treatment purpose.

Treatment

The only treatment for diaphragmatic hernia is surgical intervention which is done in two steps. Apart from being a diagnostic method laparo-rumenotomy, is also a primary step for treatment of diaphragmatic hernia. In this procedure, penetrating foreign bodies are removed from reticulum as well as rumen and almost three-fourth or complete ruminal content is evacuated. Animal is kept off feed and off water for 24-48 hours prior to surgery and kept hydrated with fluid therapy.

In the second step, diaphragmatic herniorrhaphy is done in dorsal recumbency under general anaesthesia. In this procedure, adhesions between reticulum and diaphragm are bluntly dissected and reticulum is retracted to its normal anatomical position. Hernial ring is sutured with non-absorbable suture material mostly with no. 3 silk in lockstitch pattern.

Fig. 4: Diaphragmatic defect repaired with non-absorbable suture material (Diaphragmatic herniorrhaphy)

Negative pressure is important to maintain in thoracic cavity during the surgery. Which can be achieved by connecting a 6 inch long needle with a suction pump and placing it close to the point of elbow in thoracic cavity. These patients are unable to expand their lungs or thorax to a normal ability may need ventilation support. To provide this, Intermittent positive pressure ventilation (IPPV) should perform. Mechanical ventilator deliver a controlled pressure of gas to assist in ventilation or expansion of lungs. Positive inspiratory pressure, ventilation rate, or tidal volume of the ventilator will have to set up according to the patient’s need. After herniorrhaphy, muscles and skin are sutured in routine manner. It is important to re-establish the negative pressure in the thoracic cavity before complete closure of the surgical incision. Surgical intervention is necessary; if untreated, diaphragmatic hernia may induce mortality in buffaloes.

Postoperative care

  • Adequate intravenous fluid therapy upto a week should be done.
  • Parenteral antibiotic and analgesics should be given for about a week.
  • Antiseptic dressing of the skin wound at least twice a day till the date of suture removal.
  • An external support to incision site with soft padded pillow like material should be tied ventrally with cotton folding cot to prevent recurrence of hernia.
  • Feed should be given gradually to the operated animal.

Points to keep in mind for farmers

  • Prophylactic magnet feeding is an effective alternative to rumenotomy in traumatic reticuloperitonitis cases. All cattle and buffaloes over one year of age should be fed prophylactic magnet to immobilize the metallic foreign body in reticulum thus preventing its penetration through reticular wall. After oral administration, most magnets drop firstly into the rumen then move to the desired location in the reticulum following ruminoreticular contraction, where metallic foreign bodies gets trapped to magnet and prevent several complications like traumatic reticuloperitonitis, diaphragmatic hernia, reticular abscess.
  • Buffaloes should be kept away from construction sites and grazing fields should be monitored for metal debris.
  • Processed feed should always be passed over magnets to retrieve any iron containing foreign materials prior to being fed to the animals.
  • Animal should be given good quality mineral mixture in their daily ration.

Reference

1.   Al-Abbadi, O. S., Abu-Seida, A. M., & Al-Hussainy, S. M. (2014). Studies on rumen magnet usage to prevent hardware disease in buffaloesVeterinary World7(6).

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