Antibiotics resistance

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Alfie

Post   » Tue Feb 19, 2002 10:46 pm


Something has been playing on my mind. I have concerns about the overuse of antibiotics to treat livestock and humans alike, which as you know is believed to contribute to parasites and bacteria developing new strains that are resistant to existing antibiotics. (For this reason I only eat organic meat.)

Anyhow, I was thinking about this in relation to treatments of cavies with ivermectin and other drugs, and the fact that many breeders and pet owners routinely treat their pigs every few months.

I´ve looked around on the Net and found that there are a number of parasites with ivermectin-resistant strains, including:
haemonchus contortus (barber´s pole worm), which can kill sheep and goats;
cooperia curticei, which also affects sheep and goats;
"sheep scab"
trichostrongylus colubriformis, which causes diarrhoea and possibly death in a range of animals (including rabbits) and
parelaphostrongylus tenuis, which apparently affects llamas, alpacas, etc.

Apparently there are other antibiotics that can successfully treat these strains, and I´m not suggesting that the small number of treatments of domestic guinea pigs (or horses) would have anywhere near the impact that mass livestock dosing would.

Nonetheless, it rings a few bells of concern in my head, particularly in light of the fact that there are now ivermectin-resistant strains of nematodes which cause the tropical disease river blindness in humans (which affects 20 million people).

http://www.soton.ac.uk/~pubaffrs/01121.htm

Does anyone have any thoughts on this?

Barber´s pole worm:
http://www.agric.wa.gov.au/agency/Pubns/farmnote/1999/f08699.htm
http://www.vetmed.lsu.edu/ech/miller.htm

Parelaphostrongylus tenuis:
http://www.vet.ohio-state.edu/docs/ClinSci/camelid/parasites.html

Ivermectin resistance in horses and other livestock:
http://evrp.lsu.edu/07fungi.htm
http://agpublications.tamu.edu/pubs/as/l5093.pdf

Josephine
Little Jo Wheek

Post   » Tue Feb 19, 2002 11:55 pm


Yup. That´s why I don´t routinely treat the entire herd for anything. I find strict quarantine and good sanitation keep out a host of ills. I believe people (including veterinarians) contribute to the problem by finding "favorite" drugs and using them to death routinely on the same animals. It does create problems. I´m scared Baytril won´t work on some cavy and then it will die before it has the chance to get another drug. I suspect it has happened. I have personally had one pig with a Baytril-resistant microbe. Thankfully, there are other safe cavy drugs, but not enough to get sloppy with antibiotic or antiparasitic usage. For some reason, antiparasitics aren´t usually held in the same esteem as antibiotics. They are all drugs!

I haven´t had anything contagious affect more than a single pig (and only new ones in quarantine at that) for close to seven years now. I used to have outbreaks of URIs and lice prior to that (2-3 pigs at a time). I wasn´t a very knowledgeable kid and those were the days of showing and breeding. But then, I was not very old at all. Fifteen, sixteen. I didn´t know half as much about cavy care and medical physiology then.

User avatar
Lynx
RESIST

Post   » Wed Feb 20, 2002 7:34 am


That is very interesting. Ivermectin seems to work differently on different kinds of parasites. It isn´t very effective on ticks, for example.

The resistances being observed are in some nematodes and worms -- which I don´t think we treat cavies for.

Mites are arachnids. I didn´t notice any resistance being noted in mites.

Josephine
Little Jo Wheek

Post   » Wed Feb 20, 2002 11:43 am


So, you´re saying that arachnids don´t develop resistance to drugs? I don´t think the inference is that they have already, just that the potential exists.

User avatar
Lynx
RESIST

Post   » Wed Feb 20, 2002 12:04 pm


No. I don´t know if they would or not. I just mentioned that all the articles refer to other types of bugs -- not any types of mites. It could be (and I am hoping) that because of their structure they would be less likely to ever develop an immunity. But I don´t know.

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