Hardware disease

Cows eat all sorts of stuff. Due to its role in sorting food particles by size, any foreign bodies usually end up in the reticulum. This includes nails, wire, ropes, etc. The sharp objects can be pushed through the reticular wall, creating a hole in the reticulum that leaks ingesta. The reticulum and heart are separated only by the diaphragm. A nail or similar object will often puncture the diaphragm and sometimes the pericardial sac. Cows with hardware disease may have peritonitis, abscesses from consolidated peritonitis, pleuritis, and/or pericarditis.

Signalment

Traumatic reticuloperitonitis secondary to hardware is more common in the postpartum period, often related to the straining of parturition. As the cow strains, the metal is pushed out of the reticulum.

Clinical Signs

• Anorexia
• Fever (although they can also be normothermic)
• Dramatic decrease in milk production
• Signs of abdominal pain: bruxism, grunting, hunched stance with abducted elbows

Clinical presentation

• Distended rumen
• Lifts up when pressure is applied at the xiphoid using a board or the hand pressure test
• Does not scootch with withers pinch

Diagnosis

Confirmation is more easily performed with ultrasonography rather than radiographically. Diagnosis on ultrasound is based on signs of peritonitis/pleuritis, abscess formation or other related changes. Sometimes the foreign object can be seen but it depends on how much gas is around it.

Ruptured abomasal ulcers and liver abscesses can present similarly to TRP from hardware disease.

Exploratory surgery is often used as a diagnostic test. The reticulum can be palpated from either the right or left side. A right flank exploratory is best if you don’t know the cause of the cow’s issues. If hardware disease is high on the list, a left flank approach provides an option for treatment as well as diagnosis.

Prognosis is guarded due to the challenges in effective treatment. Prognosis is grave if the object has penetrated the diaphragm.

Treatment

• Conservative – treat medically with antibiotics and rest; allow the infection to wall off. Add a magnet to the reticulum if she doesn’t have one; the goal is to stabilize the wire in the reticulum so it doesn’t penetrate through into the chest or abdomen. Magnets can be fed to cows and they should end up in the reticulum but this is not guaranteed. Or a magnet can be placed at the time of rumenotomy.  Transfaunate to improve the microbial flora. Flora can be “fed” to the cow, delivered via stomach tube or dumped into the rumen during a rumenotomy.
• Surgery – Rumenotomy to remove the object and/or drain the abscess. It is important to not make things worse. Start with an abdominal exploratory, leaving the reticular area to last. Do not explore the abdomen after contamination is encountered or rumenotomy performed. Tacking the rumen up or using a rumen board or shroud is needed to minimize the risk of peritonitis from leaking rumen contents. Remove any sharp objects found. Abscesses must be cranial to be worth draining (an ventral abscess won’t drain up into the rumen; drainage of an abscess on the medial aspect risks damaging the vagal nerve.) Ensure one magnet and transfaunate.
  • See How to – Rumenotomy
• Cull – not a bad idea for some cows

Prevention

As much foreign material should be kept out of feed troughs as possible. Cows may be pretreated with a magnet to catch metallic objects as they move into the reticulum.

Videos

rumenotomy in a buffalo

Resources

Braun et al. Aetiology, diagnosis, treatment and outcome of traumatic reticuloperitonitis in cattle. The Veterinary Journal 255 (2020) 105424.