From:
"Church, Robert Ray (UMC-Student)"
Date: 2002-07-12 18:31:44 UTC
Subject: Bob C: Vitamin A and CD:1
To: <ferrethealth@smartgroups.com>
Cc: "Church, Robert Ray (UMC-Student)" <rrc961@mizzou.edu>
Message-ID: <43C5FBB91EB9CC468627C2BCB23391D32B9C9E@TIG-MAIL2.tig.mizzou.edu>
Sorry about the late response to the Vitamin A discussion in ferrets, but I=
have just worked the 15 of the last 17 nights, I have been experiencing em=
ail problems of late...and I sort of =91lost=92 the group for a short while=
(if I was a paranoid type, I=92d suspect it was on purpose...Sukie?). I e=
agerly read your comments, as well as a quite a number privately emailed to=
me (some excellent ones I WISH had been made on the list). Rather than re=
sort to extensive quoting, I will paraphrase questions and remarks for resp=
onse. To help in reducing length, I shall answer and post each question se=
parately.
------------------
1. I was unaware that Vitamin A was recommended for use in children with me=
asles (rubeola).
A tremendous amount of peer-reviewed literature, published in respected sci=
entific publications, supports the use of Vitamin A in children with measle=
s to reduce mortality and morbidity (the condition or expression of disease=
; also defined as the sick rate--the ratio of ill to healthy individuals). =
Measles, while not necessarily recognized as a deadly disease in the Unite=
d States (only 90 children died in 25,000 cases), according to WHO and UNIC=
EF it causes up to 2,000,000 childhood deaths per year, worldwide (1992 fig=
ures). Just over a century ago, measles was known to kill up to 50% of its=
victims and was 11% of the total death rate. Modern death rates from meas=
les in undeveloped countries, even with medical treatment, hovers around 25=
-30%. Measles routinely causes pneumonia and severe diarrhea. It frequent=
ly causes vision problems, middle ear problems, and encephalomyelitis. It =
has recently been implicated as a contributing factor in the development of=
multiple sclerosis. Hypovitaminosis A (the condition caused by low blood =
levels of Vitamin A) is linked to measles, and has been tied to increased t=
umor growth in older individuals, increased susceptibility to parasitic inf=
ections, and is a leading cause of childhood blindness. Some may consider =
measles a childhood disease, but it is a nasty one.
People in the United States have forgotten many of the serious consequences=
of measles for the same reason we fail to remember the sound of the iron l=
ung: widespread and effective immunizations. In the USA and most Western c=
ountries, children are routinely immunized against measles in their first y=
ear of age with the MMR vaccination, with booster shots given afterwards (M=
easles [rubeola], Mumps, Rubella [German measles]). Proof of MMR is requir=
ed to attend most schools, as well as for most health care and teaching pro=
fessionals. The same is not the case in parts of South America, Asia, and =
Africa, where childhood case-fatality from measles reaches 30%, mostly from=
complications from pneumonia or diarrhea. The close association of measle=
s with low blood levels of Vitamin A (retinol) has been well documented fro=
m the late 1970s. The discovery that morbidity and mortality resulting fro=
m measles could be significantly reduced by dosing the victim with a single=
mega-dose of Vitamin A has been documented from the late 1980s (the first =
report dates to the 1860s!), and is still supported by research as recent a=
s 2001. However, because measles in the USA is relatively rare and has a l=
ow morbidity (given the immunization protocol and state of nutrition), it w=
ould not be unusual that many US health care professionals are unaware of t=
he use of Vitamin A in measles treatment. It would be even less likely tha=
t general veterinarians would know of Vitamin A in the treatment of measles=
, never enabling them to extrapolate such therapy to the care of ferrets.
The bottom line is that children with hypovitaminosis A contract measles at=
a higher rate than children with normal or higher than normal levels of Vi=
tamin A in their blood. Once they have measles, children deplete Vitamin A=
stores at a higher rate than normal, exacerbating the problem. The extrap=
olation of these findings to canine distemper in ferrets does not make me t=
hink ANY dose of Vitamin A will prevent a non-inoculated ferret from contra=
cting the disease. However, following standard and proven practice in chil=
dren, a dose of Vitamin A given at the same time as the distemper shots (an=
d boosters), as well as making sure ferret blood levels for retinol remain =
normal, MAY provide enough of a immune boost that marginal ferrets (older, =
sick) can resist unexpected mild exposure to canine distemper.
Personally, while I wouldn=92t presume ANY positive effect without strenuou=
s testing, there are enough other benefits from ferrets having normal blood=
levels of Vitamin A that I would consider giving it a win-win situation. =
Even if giving retinol at the same time as the canine distemper inoculation=
proved useless, other benefits (discussed later) MAY make it worthwhile. =
We can probably extrapolate a safe dose of Vitamin A for ferrets from amoun=
ts given to infants (based on dose/weight), assuming a primary, obligate ca=
rnivore has a higher tolerance for retinol than a carnivorous omnivore. We=
could then refine that amount using established guidelines for mink, assum=
ing ferret and mink Vitamin A requirements are similar (hard to say=97see t=
he beta-carotene discussion below). The requirements for growing mink kits=
have been investigated, but adult mink requirements are unknown. Accordin=
g to Fox and McLain (1998), there is no data on Vitamin A requirements in f=
errets.
Bob