Tia
Well-Known Member
How many of us on here are happy to worm their horses with a chemical that remains in the horse's fat cells (including those of the brain) for over 3 months?
13 Week Wormers - Poll
- Thread starter Tia
- Start date
druid
Well-Known Member
How is it any different bar the time scale than the 8 week wormers which "remain in the horse's fat cells (including those of the brain)" for over 2 months?
Chex
Well-Known Member
I use them, but have to admit that I know absolutely nothing about the effects of it, I'm very guilty of just believeing the manufacturers when they say it the best (or whatever).
josie_s
Well-Known Member
Oh dear, hadn't thought of it like that.
I feel bad now
I feel bad now
Tia
Well-Known Member
Ah but they don't. Those ones only remain in the body for a handful of days.
druid
Well-Known Member
All of them?
Marnie
Well-Known Member
The 13 week wormers are different in the way that they are stored in the fat cells of the body apparently - this is why you have to be careful giving them to horses that are underweight and foals - my vet advised me to steer well clear when Muppet was a baby as you can easily overdose and cause a toxic reaction.
Lucy_Ally
Well-Known Member
I am not sure there is any evidence that compounds such as moxidectin (the most effective 13 week wormer) resides in fat cells for 3 months, I would be interested to see the data. There is a research paper that shows moxidectin has a longer residency in the blood (17.5 days) and in the faeces (up to 8 days). 90% of the drug was excreted in the faeces by day 8. Pour on moxidectin treatment was seen for up to 35 days in the tissues of cattle (including fat) but this will be metoblised by the body very differently to oral adminstration.
I am happy that wormers such as Equest are safe to use in my horse (as it has been tested in humans with no adverse effects). However I am of the opinion to only worm when necessary (i.e. do worm counts etc) with tapeworm and bot management to reduce resistance.
Plus, I have to say in a normal healthy horse there shouldn't be any fat cells in the brain
I am happy that wormers such as Equest are safe to use in my horse (as it has been tested in humans with no adverse effects). However I am of the opinion to only worm when necessary (i.e. do worm counts etc) with tapeworm and bot management to reduce resistance.
Plus, I have to say in a normal healthy horse there shouldn't be any fat cells in the brain
Tia
Well-Known Member
[ QUOTE ]
I have to say in a normal healthy horse there shouldn't be any fat cells in the brain
[/ QUOTE ]
Lucy, I don't understand this comment? My understanding has always been that more than half of ALL brains within the Animal Kingdom are made up of fat cells.
I have to say in a normal healthy horse there shouldn't be any fat cells in the brain
[/ QUOTE ]
Lucy, I don't understand this comment? My understanding has always been that more than half of ALL brains within the Animal Kingdom are made up of fat cells.
TGM
Well-Known Member
I understand that about two-thirds of the human brain is composed of fats, but I think (but am not entirely certain) that this is different from fat cells being present in the brain. I think that the fats in the brain are a constituent of the specialised brain cells, rather than actually being contained in fat cells
.
But I may be talking absolute drivel
!
But I may be talking absolute drivel
Lucy_Ally
Well-Known Member
Healthy neural tissue is comprised of neurones (nerve cells) and the supporting cells called glial cells. "Fat" cells in the sense of the rest of the body are called adipocytes and are not found within the nervous system.
ETS. The axons of neurones are insulated by a fatty sheath made up by schwann cells which enable more efficient conduction of electrical signals. These are not fat cells though.
ETS. The axons of neurones are insulated by a fatty sheath made up by schwann cells which enable more efficient conduction of electrical signals. These are not fat cells though.
TGM
Well-Known Member
[ QUOTE ]
ETS. The axons of neurones are insulated by a fatty sheath made up by schwann cells which enable more efficient conduction of electrical signals. These are not fat cells though.
[/ QUOTE ] I think that was what I was struggling to say
.
ETS. The axons of neurones are insulated by a fatty sheath made up by schwann cells which enable more efficient conduction of electrical signals. These are not fat cells though.
[/ QUOTE ] I think that was what I was struggling to say
Lucy_Ally
Well-Known Member
[ QUOTE ]
I think that was what I was struggling to say
.
[/ QUOTE ]
Lol! I thought so! If I am being pedantic the cells that insulate neuonal axons in the peripheral nervous system are schwann cells, those in the brain are oligodendrocytes. I am officially a geek
I think that was what I was struggling to say
[/ QUOTE ]
Lol! I thought so! If I am being pedantic the cells that insulate neuonal axons in the peripheral nervous system are schwann cells, those in the brain are oligodendrocytes. I am officially a geek
K_T
Well-Known Member
Good grief!! That hurt my head a bit
too early on a Sunday morning to be concentrating too hard!!
casey2312
Well-Known Member
A geek maybe, but I am totally in awe! Go Lucy.....
TGM
Well-Known Member
Have found an article here:
http://www.horse-previews.com/198articles/198vetcorner.html
by an American vet on the use of moxidectin wormers such as Equest. Here are some extracts:
"Quest need not, and should not, be used any more often than every three months. It lasts longer than other dewormers because it is stored in the fat cells and released into the body slowly. Because it is fat soluble, it can also be absorbed into the brain tissue, and when overdosed can cause incoordination and other signs of nervous system toxicity. It is important to use a weight tape on your horse to estimate the proper dose before administration. If you have a pony or miniature horse, have your veterinarian estimate its weight before giving the product."
"What sets Moxidectin apart from the other dewormers is that it kills encysted small blood worms in the large colon. These encysted worms are a leading cause of colic. There have been reports of severe colic and even death following administration of Moxidectin. This is probably not due to toxicity, but instead to an inflammatory reaction to a large kill-off of worms. For this reason it is probably ill-advised to give this product to debilitated horses or to those who may not have been on a good deworming program prior to treatment. Additionally, foals under four months of age should not be dewormed with Moxidectin, and it should not be used for a foal's first deworming."
http://www.horse-previews.com/198articles/198vetcorner.html
by an American vet on the use of moxidectin wormers such as Equest. Here are some extracts:
"Quest need not, and should not, be used any more often than every three months. It lasts longer than other dewormers because it is stored in the fat cells and released into the body slowly. Because it is fat soluble, it can also be absorbed into the brain tissue, and when overdosed can cause incoordination and other signs of nervous system toxicity. It is important to use a weight tape on your horse to estimate the proper dose before administration. If you have a pony or miniature horse, have your veterinarian estimate its weight before giving the product."
"What sets Moxidectin apart from the other dewormers is that it kills encysted small blood worms in the large colon. These encysted worms are a leading cause of colic. There have been reports of severe colic and even death following administration of Moxidectin. This is probably not due to toxicity, but instead to an inflammatory reaction to a large kill-off of worms. For this reason it is probably ill-advised to give this product to debilitated horses or to those who may not have been on a good deworming program prior to treatment. Additionally, foals under four months of age should not be dewormed with Moxidectin, and it should not be used for a foal's first deworming."
TGM
Well-Known Member
And from here:
http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/hrs3718
a bit about the dosage problems of moxidectin:
"Quest® (moxidectin) is a new dewormer that is a cousin to ivermectin (Eqvalan®). The drug is less active against bots than ivermectin, so the paste formulation is twice the concentration as ivermectin. Moxidectin is distributed to body fat more than ivermectin. Since ivermectin is so safe, horse owners commonly administer an entire tube of the paste no matter what the size of the horse. Since its release as a dewormer, Quest® has been involved in a number of drug reactions. Despite the young foal on the package, Quest® is not labelled for use in foals under 4 months of age. Foals have very little body fat, allowing higher levels of moxidectin in the blood stream, which then crosses into the brain and causes staggering, weakness, coma and even death. Also, the tube of Quest® is labelled to treat 1150 lbs. Most horse owners overestimate their horse's weight and often give the whole tube no matter what the horse weighs. Weight tapes are readily available and should be used before dosing any horse with Quest®. However, it is very difficult for owners to get accurate weights on thin horses, miniature horses, donkey and mules, and these equines have been involved in a lot of the problems with Quest®. When dosed accurately, Quest is a very good dewormer. "
http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/hrs3718
a bit about the dosage problems of moxidectin:
"Quest® (moxidectin) is a new dewormer that is a cousin to ivermectin (Eqvalan®). The drug is less active against bots than ivermectin, so the paste formulation is twice the concentration as ivermectin. Moxidectin is distributed to body fat more than ivermectin. Since ivermectin is so safe, horse owners commonly administer an entire tube of the paste no matter what the size of the horse. Since its release as a dewormer, Quest® has been involved in a number of drug reactions. Despite the young foal on the package, Quest® is not labelled for use in foals under 4 months of age. Foals have very little body fat, allowing higher levels of moxidectin in the blood stream, which then crosses into the brain and causes staggering, weakness, coma and even death. Also, the tube of Quest® is labelled to treat 1150 lbs. Most horse owners overestimate their horse's weight and often give the whole tube no matter what the horse weighs. Weight tapes are readily available and should be used before dosing any horse with Quest®. However, it is very difficult for owners to get accurate weights on thin horses, miniature horses, donkey and mules, and these equines have been involved in a lot of the problems with Quest®. When dosed accurately, Quest is a very good dewormer. "
Lucy_Ally
Well-Known Member
Ok, what we know about Moxidectin is that the target tissue is primarily fat, it is readily absrbed and stored in fat tissue. We know it has a longer residence in the body than other wormers and we know that it can cause neurological problems if overdosed, especially in youngstock. This is fine, the original post however said that the drug was stored in the body for 3 months and was also stored in the brain - neither of which is mentioned in that article or in any relevant scientific research.
Whilst the side effects of Moxidectin are serious they are usually only an issue if the drug is overdosed, what people seem to forget is that any wormer is a pretty powerful drug and overdose can have serious consequences. Incidentally the amount at which a horse will suffer effects of Moxidectin overdose is usually 3-5 times the stated dose, so its quite hard to get it wrong in an adult horse. My case for only worming when necessary is strengthened by the fact that the majority of horses owners only have basic knowledge about wormers and worming routines which can quite easily lead to misuse of these drugs.
From Journal American Vet Med Assoc. 1999 Mar 1;214(5):678-80
Outcome and complications associated with administration of moxidectin gel to 3 foals < 4 months old are described. Two foals became comatose but survived following supportive treatment. One foal died following loss of consciousness associated with moxidectin administration. Risk of moxidectin overdose exists, because horse owners often fail to read or comprehend the package insert instructions pertaining to use of the syringe-locking mechanism. In addition, moxidectin should not be administered to foals < 4 months old, because it is likely that treated foals will become comatose.
Whilst the side effects of Moxidectin are serious they are usually only an issue if the drug is overdosed, what people seem to forget is that any wormer is a pretty powerful drug and overdose can have serious consequences. Incidentally the amount at which a horse will suffer effects of Moxidectin overdose is usually 3-5 times the stated dose, so its quite hard to get it wrong in an adult horse. My case for only worming when necessary is strengthened by the fact that the majority of horses owners only have basic knowledge about wormers and worming routines which can quite easily lead to misuse of these drugs.
From Journal American Vet Med Assoc. 1999 Mar 1;214(5):678-80
Outcome and complications associated with administration of moxidectin gel to 3 foals < 4 months old are described. Two foals became comatose but survived following supportive treatment. One foal died following loss of consciousness associated with moxidectin administration. Risk of moxidectin overdose exists, because horse owners often fail to read or comprehend the package insert instructions pertaining to use of the syringe-locking mechanism. In addition, moxidectin should not be administered to foals < 4 months old, because it is likely that treated foals will become comatose.
TGM
Well-Known Member
[ QUOTE ]
This is fine, the original post however said that the drug was stored in the body for 3 months and was also stored in the brain - neither of which is mentioned in that article or in any relevant scientific research.
[/ QUOTE ] Agree with you the original post wasn't accurate! Out of interest do you know how long moxidectin does actually remain in the body?
[ QUOTE ]
Whilst the side effects of Moxidectin are serious they are usually only an issue if the drug is overdosed, what people seem to forget is that any wormer is a pretty powerful drug and overdose can have serious consequences.
[/ QUOTE ] True - but I understand that it is much easier to overdose Moxidectin than any of the other worming drugs. I have heard, for example, that Ivermectin can be given in doses up to 60 times the standard dose without causing harm to your horse, whilst Pyrantel is safe up to 20 times the standard dose. I think this lulls owners into a false sense of security with wormers, so it is important that their attention is drawn to the fact that they DO have to be much more careful in calculating correct bodyweight when using Moxidectin and that it is important to heed the advice about using it on foals.
On the other hand you have to balance the "dangers" against its proved effectiveness against encysted small strongyle larvae. I understand that the only other wormer that counters them is Panacur which has well-documented resistance problems.
[ QUOTE ]
My case for only worming when necessary is strengthened by the fact that the majority of horses owners only have basic knowledge about wormers and worming routines which can quite easily lead to misuse of these drugs.
[/ QUOTE ] Agreed!
This is fine, the original post however said that the drug was stored in the body for 3 months and was also stored in the brain - neither of which is mentioned in that article or in any relevant scientific research.
[/ QUOTE ] Agree with you the original post wasn't accurate! Out of interest do you know how long moxidectin does actually remain in the body?
[ QUOTE ]
Whilst the side effects of Moxidectin are serious they are usually only an issue if the drug is overdosed, what people seem to forget is that any wormer is a pretty powerful drug and overdose can have serious consequences.
[/ QUOTE ] True - but I understand that it is much easier to overdose Moxidectin than any of the other worming drugs. I have heard, for example, that Ivermectin can be given in doses up to 60 times the standard dose without causing harm to your horse, whilst Pyrantel is safe up to 20 times the standard dose. I think this lulls owners into a false sense of security with wormers, so it is important that their attention is drawn to the fact that they DO have to be much more careful in calculating correct bodyweight when using Moxidectin and that it is important to heed the advice about using it on foals.
On the other hand you have to balance the "dangers" against its proved effectiveness against encysted small strongyle larvae. I understand that the only other wormer that counters them is Panacur which has well-documented resistance problems.
[ QUOTE ]
My case for only worming when necessary is strengthened by the fact that the majority of horses owners only have basic knowledge about wormers and worming routines which can quite easily lead to misuse of these drugs.
[/ QUOTE ] Agreed!
Lucy_Ally
Well-Known Member
This paper states an average residence time of 17.5 days.
Plasma pharmacokinetics and faecal excretion of ivermectin, doramectin and moxidectin following oral administration in horses.
Equine Vet J. 2001 Sep;33(5):494-8.
Gokbulut C, Nolan AM, McKellar QA.
Division of Veterinary Pharmacology, University of Glasgow, UK.
This one states that 90% of the drug is excreted by 8 days after adminstration.
Faecal excretion profile of moxidectin and ivermectin after oral administration in horses.
Vet J. 2001 Jan;161(1):85-92
Perez R, Cabezas I, Sutra JF, Galtier P, Alvinerie M.
Some papers have suggested that detectable levels are present up to 75 days post administration but this is the longest time point I can find and the levels are only just detectable.
Plasma pharmacokinetics and faecal excretion of ivermectin, doramectin and moxidectin following oral administration in horses.
Equine Vet J. 2001 Sep;33(5):494-8.
Gokbulut C, Nolan AM, McKellar QA.
Division of Veterinary Pharmacology, University of Glasgow, UK.
This one states that 90% of the drug is excreted by 8 days after adminstration.
Faecal excretion profile of moxidectin and ivermectin after oral administration in horses.
Vet J. 2001 Jan;161(1):85-92
Perez R, Cabezas I, Sutra JF, Galtier P, Alvinerie M.
Some papers have suggested that detectable levels are present up to 75 days post administration but this is the longest time point I can find and the levels are only just detectable.
TGM
Well-Known Member
Very interesting - thanks for that
.