As in cattle, the issue of latency is important. This supports the concept that significant numbers of non-lethal infections occur. These negative results may reflect that the virus had been cleared from these animals or was not present at detectable levels in the examined tissues of healthy latently infected fallow deer. Circumstantial evidence suggests that there may be sources of virus other than sheep in SA-MCF as a number of outbreaks of cervid MCF have been observed in which no contact with sheep was reported. Treatment of affected animals is fairly futile.
Most affected deer die regardless of what measures are taken.
Preventing spread of the disease could prove difficult as the incubation period may be as long as 50 days, perhaps longer. MCF is thus very important to both the cattle and deer farm industry. The possibility of inaparent, chronic disease has important implications in terms of herd health and profitability. There is a need for more research in this area and a necessity of care in management to avoid mixing species susceptible to clinical MCF with species that may be MCFV carriers.