ofonorow wrote:It is interesting that wild animals don't need vaccines...
This is a huge can of worms (probably be way more detail than anyone cares about, but what the heck...).
One reason wild animals survive without vaccines is that their population density is far lower than that of domesticated pets. Felis sylvestris (wildcat) will tolerate 1 male and up to 6 females on a dozen sq. km territory, meaning there's not a lot of opportunity for disease transmission. On the other hand, domesticated cat population density is whatever people make it - sometimes 3000 cats per square km
. Disease spreads like wildfire under those conditions.
Another issue is, as you said, wild animals seem to make more C than domesticates. But wild animals are still infected by and die from the same diseases our pets are vaccinated for. Canine distemper causes fatal epidemics
in wild carnivore populations every year. The feline leukemia virus and feline immunodeficiency virus (FIV) are both widespread among feline populations, including bobcats, cougars, lions, tigers, cheetahs, etc (although the strain of FIV in lions, for example, seems to have become less virulent). So why do these pathogens kill wild C-makers, when C can prevent or cure the illnesses? Dunno. Maybe man-made toxins/stressors are eating up too much of their endogenous ascorbate.
Now, when it comes to rabies, some wild animals actually do get vaccinated. State governments have been distributing oral vaccines
to wildlife for 20 years. It supposedly helps keep the rate of infection in wildlife down, so pets and people won't be exposed to the virus as often.
And finally, a fun fact: opossums are almost totally immune to rabies infection. No one has found a rabid opossum in nature, and in labs it takes extraordinarily massive doses of virus to infect them. They are also extremely resistant to snakebite. The traditional explanation for these resistances is their "low body temperature and metabolic rate". Hmmm. Seems I've heard of another substance that is an excellent antivirus and antivenom - and no one, to my knowledge, has measured how much of it opossums make...