Todayโs path rounds are on ๐ฆ๐๐ฅ๐ข๐ ๐ง๐๐ง๐ญ ๐๐๐ญ๐๐ซ๐ซ๐ก๐๐ฅ ๐๐๐ฏ๐๐ซ (MCF)!
๐๐ก๐๐ญ ๐ข๐ฌ ๐ข๐ญ?
๐๐๐ฅ๐ข๐ ๐ง๐๐ง๐ญ ๐๐๐ญ๐๐ซ๐ซ๐ก๐๐ฅ ๐๐๐ฏ๐๐ซ is a serious infectious disease found worldwide, that has up to a 100% lethality rate in susceptible species.
๐๐ก๐จ ๐ ๐๐ญ๐ฌ ๐ข๐ญ?
Any member of the family Bovidae (cattle), Cervidae (deer) and Giraffidae (giraffes) can technically get this, but we usually think of it in our cattle species!
๐๐จ๐ฐ ๐๐จ ๐๐ง๐ข๐ฆ๐๐ฅ๐ฌ ๐ ๐๐ญ ๐ข๐ง๐๐๐๐ญ๐๐?
This disease is kind of cool because it can be caused by multiple different herpesviruses. The main ones are ๐จ๐ฏ๐ข๐ง๐ ๐ก๐๐ซ๐ฉ๐๐ฌ๐ฏ๐ข๐ซ๐ฎ๐ฌ-๐, which is naturally found in sheep, and ๐๐ฅ๐๐๐ฅ๐๐ฉ๐ก๐ข๐ง๐ ๐ก๐๐ซ๐ฉ๐๐ฌ๐ฏ๐ข๐ซ๐ฎ๐ฌ-๐, naturally found in wildebeest.
The carrier sheep or wildebeest sheds the virus in their nasal secretions, which is then picked up by a cow going about its cow life. From there, the virus enters the upper respiratory tract and infects the tonsils, which then allows it to enter the bloodstream of the poor cow.
๐๐ก๐ฒ ๐ข๐ฌ ๐ญ๐ก๐ข๐ฌ ๐ ๐ฉ๐ซ๐จ๐๐ฅ๐๐ฆ?
MCF classically causes a ๐ฏ๐๐ฌ๐๐ฎ๐ฅ๐ข๐ญ๐ข๐ฌ, inflammation of vessels, in multiple vessels within the body. This vasculitis leads to ๐ฆ๐ฎ๐๐จ๐ฌ๐๐ฅ ๐ฎ๐ฅ๐๐๐ซ๐๐ญ๐ข๐จ๐ง on the mouth, bladder and intestines, due to decreased blood flow causing tissues to die off. It can also affect the nose and skin. Vasculitis can also cause ๐๐จ๐ซ๐ง๐๐๐ฅ ๐๐๐๐ฆ๐ in the eye, making the eye look cloudy. The brain and ๐ฆ๐๐ง๐ข๐ง๐ ๐๐ฌ (protective cover of the brain) can also be affected, causing neurologic signs.
The disease also causes ๐ฅ๐ฒ๐ฆ๐ฉ๐ก๐จ๐ฉ๐ซ๐จ๐ฅ๐ข๐๐๐ซ๐๐ญ๐ข๐จ๐ง, or an immune system that is ramped up like crazy! This can lead to enlarged lymph nodes and deposits of immune cells in places we wouldnโt normally expect to find them. One of these places of lymphocyte accumulation is the kidney, which can produce a mottled appearance where the aggregates are found.
๐๐จ๐ฐ ๐ข๐ฌ ๐ข๐ญ ๐๐ข๐๐ ๐ง๐จ๐ฌ๐๐?
Since this disease can basically affect anywhere in the body, the clinical presentation depends on the organs affected. In cattle, swollen lymph nodes and cloudy eyes are most common, which can be good signs that the disease is occurring. Often the affected animals also have copious amounts of nasal discharge and excessive salivation, which can also be a good clue! A history of contact with sheep or wildebeest is also a strong clue to start suspecting MCF. Once the disease is suspected, ๐๐๐ is used to specifically detect the viral DNA, and confirm the diagnosis.
๐๐จ๐ฐ ๐ข๐ฌ ๐ข๐ญ ๐ญ๐ซ๐๐๐ญ๐๐? ๐๐จ๐ฐ ๐ข๐ฌ ๐ข๐ญ ๐ฉ๐ซ๐๐ฏ๐๐ง๐ญ๐๐?
Unfortunately, there is no real treatment for this disease, and no vaccine available. The best method of prevention is separating carrier animals, like sheep and wildebeest, from cattle.
๐๐ก๐จ๐ญ๐จ๐ฌ
1) A poor cow nosey with severe ulceration from vasculitis.
2) Oral ulcers from MCF.
3) A super cloudy eye wth corneal edema.
4) A spleen with distinct nodules from aggregates of lymphocytes.
5) A piece of very ulcerated intestine from MCF.
6) A sad vessel on histology that looks very tattered, with lots of cells invading its wall. This is what vasculitis actually looks like!
๐๐จ๐ฎ๐ซ๐๐๐ฌ
Maxie, G. Jubb, Kennedy and Palmerโs Pathology of Domestic Animals, Volume 2. Sixth Edition.
Callan, R.J. Malignant catarrhal fever. Merck Veterinary Manual, 2015.
Photos 1-6 courtesy of Noahโs Arkive.
