Happy Holidays! All of this weekโs posts will be themed around the winter holiday season. Todayโs path rounds are on ๐ซ๐๐ ๐ง๐จ๐ฌ๐!
๐๐ก๐๐ญ ๐ข๐ฌ ๐ข๐ญ?
๐๐๐ ๐ง๐จ๐ฌ๐ is more scientifically known as ๐ข๐ง๐๐๐๐ญ๐ข๐จ๐ฎ๐ฌ ๐๐จ๐ฏ๐ข๐ง๐ ๐ซ๐ก๐ข๐ง๐จ๐ญ๐ซ๐๐๐ก๐๐ข๐ญ๐ข๐ฌ, and is a viral infection affecting the upper respiratory tract. As the name might suggest, affected cattle often have a ๐ก๐ฒ๐ฉ๐๐ซ๐๐ฆ๐ข๐ (red) nose!
๐๐ก๐จ ๐ ๐๐ญ๐ฌ ๐ข๐ญ?
This disease is typically found in feedlot cattle.
๐๐ก๐๐ญ ๐๐๐ฎ๐ฌ๐๐ฌ ๐ข๐ญ?
Red nose is caused by ๐๐จ๐ฏ๐ข๐ง๐ ๐ก๐๐ซ๐ฉ๐๐ฌ๐ฏ๐ข๐ซ๐ฎ๐ฌ-๐. Animals will inhale the virus through aerosols or direct contact with nasal secretions from infected cattle. From there, the virus covers the respiratory mucosa, and enters the ๐ญ๐ซ๐ข๐ ๐๐ฆ๐ข๐ง๐๐ฅ ๐ง๐๐ซ๐ฏ๐, where it makes itself a little home. The virus can become ๐ฅ๐๐ญ๐๐ง๐ญ (non-infectious but still present) here, and can cause repeated infections when the animal is stressed. This process is similar to cold sores in humans, which are also caused by a herpesvirus!
๐๐ก๐ฒ ๐ข๐ฌ ๐ญ๐ก๐ข๐ฌ ๐ ๐ฉ๐ซ๐จ๐๐ฅ๐๐ฆ?
In its disease-causing form, the virus destroys the ๐๐ฉ๐ข๐ญ๐ก๐๐ฅ๐ข๐๐ฅ ๐๐๐ฅ๐ฅ๐ฌ (surface cells) of the nasal passages and airways. This causes ๐๐ซ๐จ๐ฌ๐ข๐จ๐ง๐ฌ to form, where the mucosal surface is completely lost. Because these tissues often have a lot of vasculature, the vessels under the erosions will secrete ๐๐ข๐๐ซ๐ข๐ง, a major clotting protein, in order to try and fill in the defect. This fibrin ultimately combines with the dead epithelial cells producing a ๐๐ข๐๐ซ๐ข๐ง๐จ๐ง๐๐๐ซ๐จ๐ญ๐ข๐ ๐ฆ๐๐ฆ๐๐ซ๐๐ง๐, which is characteristic of the disease.
In some cases, affected cattle can also develop a pneumonia, because the epithelial cells of the trachea are compromised. These epithelial cells have long ๐๐ข๐ฅ๐ข๐ (finger-like projections) that help push bacteria, foreign materials, and mucus back up the throat to be coughed out. Without these cilia, anything that ends up in the trachea falls right into the lungs, and can cause pneumonia.
๐๐จ๐ฐ ๐ข๐ฌ ๐ข๐ญ ๐๐ข๐๐ ๐ง๐จ๐ฌ๐๐?
The veterinarian might suspect the disease based on a necropsy, or clinical signs of affected animals. From there, viral isolation can be conducted to confirm the presence of the virus.
๐๐จ๐ฐ ๐ข๐ฌ ๐ข๐ญ ๐ญ๐ซ๐๐๐ญ๐๐?
Because these cattle are predisposed to pneumonia, they often get a dose of antibiotics to either prevent a pneumonia, or treat an existing one. Eventually, the animal will likely recover with the virus going back to its latent state.
๐๐จ๐ฐ ๐ข๐ฌ ๐ข๐ญ ๐ฉ๐ซ๐๐ฏ๐๐ง๐ญ๐๐?
Thankfully, this virus can be easily prevented using vaccines! Other recommendations include low-stress handling, avoiding mixing groups of cattle from different locations, and ensuring the animals have access to feed and water to lower stress.
๐๐ก๐จ๐ญ๐จ๐ฌ
1) A cow with a red nose from IBR!
2-4) Examples of the fibrinonecrotic membrane in the trachea from IBR.
5) More fibrinonecrotic membranes, this time in the nasal passages!
๐๐จ๐ฎ๐ซ๐๐๐ฌ
Maxie, G. Jubb, Kennedy and Palmerโs Pathology of Domestic Animals, Volume 2. Sixth Edition.
Photos 1-5 ยฉ Noahโs Arkive contributors Jakowski, Doster, King, Williams licensed under CC BY-SA 4.0.
