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Ivermectin*
Pyrantel pamoate
(Nemex, Strongid)**
Fenbendazole
(Panacur™)***
Dichlorvos
Praziquantel
(Droncit™)
Drontal-Plus™
(prazi- & pyr.
pam.)
Milbemycin
(Interceptor™)
Praziquantel with
febantel
(Paracitide-10™) |
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*When packaged for cattle and sold in feed stores
without prescription. Ivermectin had long been sold “off-label” for
dogs; it has been considered dangerous in Collies, Shelties, and
crosses of these, if given in doses large enough for treating
intestinal worms.
**Pyrantel pamoate is also sold as a paste for horses, but dividing
doses of that form is difficult; the pleasant-tasting liquid sold
for dogs is easiest to administer, though tablets are also
available. For hookworm, which is hard to rid from the premises,
every other week for 6 weeks may be required. Better to switch to
Ivermectin after the first dose.
***Panacur is effective against only one type of tapeworm (Taenia,
not Dipylidium); it is administered for 5 days for the tapeworm and
3 days for other worms.
In all cases, it is wise to treat the dam 2-3
weeks after whelping, or after her pups start eating “solid” food in
the last stage of the weaning process. I have found that almost all
intestinal worm problems seen in North America can be prevented by
dosing pups when they are 2 weeks old with Nemex, effective against
canine roundworms and hookworms, and then start oral Ivermectin
another two weeks after that. My own procedure on that latter wormer
follows:
Worms, the tick problem and Ivermectin: For worms and/or
ticks, I use Ivomec (a brand name), purchased at feed stores in
50-ml bottles of 1% injectable Ivermectin (it’s the active
ingredient in Heartgard). Sold there for cattle & swine, the same
stuff takes care of various worms in the canine. One bottle will
possibly last most of a little dog’s life, but even with large
breeds, you won’t be spending the small fortune that others do. I
store mine in the refrigerator, even though there doesn’t appear to
be a shelf-life problem at room temperature. It’s up to you (and
maybe your vet, if you wish) what you choose, but I have had good
results with the following protocol.
Some people asked me, “Can I figure out the dosage from the label on
the bottle?” Yes, but is it necessary? You may have to do a lot of
converting of volume measurements, metric system designations, etc.
What others use (it already has been done for you) may be close
enough, as long as you feel comfortable with its use in your breed.
I have had many years of success, with never a sick dog because of
Ivermectin. I have treated my GSDs, Shibas, and Whippets with it.
I dose orally, not by injection, even though I buy the “injectable”
form from my local farm supply & feed store. You should understand
that less of almost any drug gets into the circulatory system if
ingested, than if injected. Keeping that in mind, the manufacturers’
suggested levels (designed for hypodermic injection) are usually a
good bit below what they probably would recommend for oral
administration.
The Heartgard dosage to prevent heartworm, as I once wrote down from
their old literature, is 6 micrograms per kilogram of body weight.
But buying the high-priced pills from the vet is too expensive for
my tastes, when I get the same results by shopping where the
livestock farmers shop. The insert in the package of 1% injectable
sterile solution Ivomec (labeled “for cattle and swine”) recommends
1 milliliter (ml) per 110 pounds of bovine, and 1 ml per 75 pounds of
swine. Anatomically and medically speaking, dogs are more similar to
pigs than to cows, so I chose the swine dosage as a starting point.
Equivalents in medical jargon are 200 and 300 micrograms per
kilogram of body weight in cattle and swine, respectively, both much
higher than what I use monthly.
The insert explains that Ivermectin’s “wide margin of safety [in
mammals] is attributable to the fact that... [the active
ingredients, lactones]... do not readily cross the blood-brain
barrier. In other words, the chemical/drug acts so much more on the
brainless parasite than on your smart, “brainy” dog. In cattle and
swine, the Ivomec insert says, Ivermectin is effective against
gastro-intestinal worms, lice, and mites.
For heartworm prevention, I aim for approximately 0.15 ml for
every 50 lbs. of dog body weight, 0.21 ml for 75 lbs., and 0.27 for
100 lbs. Naturally, you can’t be accurate to two decimal places,
even when you use a 1-ml “TB” syringe, but I don’t have to be
precise, as it is quite a safe drug for almost all breeds,
especially at this low preventive maintenance level. I dose once a
month, and I don’t worry about giving a little more than the above
amounts. I don’t even do stool checks any more; just use that dosage
as a prophylactic (preventive) approach. Almost any diabetic can get
a hypodermic syringe and needle for you.
Owners of certain at-risk Collies, Shelties, Sheltie mixes such as
Silken Windhounds, perhaps Australian Shepherds, Kelpies, etc. might
want to check current knowledge on vet websites for information on
“the mdr1 mutation”. As the moderator of the VetMed list says,
“Mixes of unknown pedigree should be treated with caution at the
higher Ivermectin doses.” Which higher doses, you may ask? Well,
that’s a reference to using the drug for killing intestinal worms.
For actual round, hook, or whipworm presence, or high
exposure risk such as weekly exhibition on probably-contaminated dog
show grounds, I give my dogs 0.3 to 0.4 ml per 25 lbs., or 1 ml per
75 lbs. every 4 or 6 months instead of their regular low-dose level.
I also use the higher dose to combat ticks when they get especially
bothersome.
TICKS - While I still maintain that the best way to control
ticks is to go over your dog every day and pluck them off with a
tweezers and drown them in soapy water (or other detergent), you can
also get an additional measure of control by using Ivermectin.
Especially if you have an unusually bad tick year. Higher doses than
I use against worms are used in Australia in Aboriginal communities
(where the children and some of the adults sleep and otherwise are
in intimate contact with their dogs) to kill ticks and sarcoptic
mites on family dogs. In that country, the use of Ivermectin as a
public health measure has favorably affected mortality rates of both
man and dog, and greatly improved the health of both. When the dogs
are made tick-free and cleared of Sarcoptes, the children benefit
because they no longer contract these diseases from their furry
friends. There is much history elsewhere of using it for mites &
ticks. In much larger, more frequent doses, it has been used against
demodectic mange. My personal experience, verified by anecdotes from
others, is that Ivermectin has considerable action against ear mites
and ticks (which are non-insects) but not against fleas (insects).
The higher de-worming level I mentioned earlier is what I also use
(in alternate months, two to four times a year) when ticks get bad
(as in 2007 and 2008 when we in northern Alabama have seen the
third-worst tick problem in 30 years), or else I give the dogs an
extra mid-month (roundworm-control-size) dose, and that helps
control the ticks a great deal. The nasty little arthropods still
bite, but very few survive long enough to suck much blood. They tend
to “die and dry”. By the way, this “large dose” (as I call the one I
give for other than heartworm preventive), is the same that pigs get
by injection. And as I said, not as much gets absorbed through the
gut as would if injected subcutaneously.
Procedure: I stick a 1-ml “hypo” (the size sold to diabetics, and
what used to be called a “TB syringe”) into the rubber-stoppered
50-ml bottle and keep it in the refrigerator more for convenience
than any instability problem. The first of the month, I pull the
desired amount into the barrel, disconnect it so that the needle
stays in the bottle (stuck in the rubber seal), and squirt the
selected volume into the mouth of the dog.
The site
http://www.vin.com/proceedings/Proceedings.plx?CID=WALTHAMOSU2002&PID=2984
has more on efficacy of medications like this. I hope this
has been informative. The above information is not a medical
recommendation; by law in most states, you need to confer with your
veterinarian for that.
Ivermectin vs. other drugs: Here, as additional information,
is a collection of some of the statistics on adverse effects of the
various heartworm preventatives currently on the market. The data in
the following list was compiled from the Food and Drug
Administration listing of
Adverse
Drug Experience Reports. The number of deaths per year is
significant, although comparative percentages are not given.
Selected other adverse events are also reported.
Ivermectin, Oral, Dogs (Heartgard & other brands)
Year approved: 1987
Number of Adverse Drug Experience (ADE) Reports in FDA through
7/Jun/2007: 1,069 (per year: 53)
Total Deaths: 126 (6 per year since FDA approval); Anemia: 6;
Platelets low: 3; autoimmune hem: 3
Reports of ineffectiveness against heartworm: 10 per year
Ivermectin & Pyrantel combination, Oral, Dog (Heartgard Plus): Year
approved: 1993
Number of Adverse Drug (ADE) Reports in FDA through 7 June 2007:
9,871 (705/yr)
Total Deaths: 97 (7/yr); Selected other adverse events reported:
Convulsion(s): 197; Anemia: 25; Autoimmune hemolytic anemia: 20;
Platelets low: 9
Reports of ineffectiveness against heartworm: 156/yr
Milbemycin, Oral, Dog (Interceptor™ brand name) Year approved; 1995
ADE Reports in FDA through 7 June 2007: 4,745 (395/yr)
Total Deaths: 159 (13/yr); Convulsions: 268; Anemia: 29; autoimmune
hem: 15; Platelets low: 1
Reports of ineffectiveness against heartworm (total): 2757
Ineffective against heartworm reports per year: 230
Milbemycine oxide with Luferon [sp.?], Oral, Dogs (Sentinel™): Year
approved: 1995
ADE Reports in FDA through 7 June 2007: 1,777 (148/yr)
Total Deaths: 43 (5/yr); Convulsions: 109; Anemia: 10; autoimmune
hem.: 8; others: 4; Platelets low: 12
Total reports of ineffectiveness against heartworm: 775 (65/yr)
Selamectin, Topical, Dogs (Revolution™) Year approved: 1999
ADE Reports through 7 June 2007: 10,917 (1,365/yr)
Total Deaths: 217 (27/yr); Convulsions: 339; Anemia: 60; Autoimmune
hem: 16; Other anenmia: 37; Platelets low: 59
Total reports of ineffectiveness against heartworm: 3,855 (481/yr)
Selected other ineffectivness reports: fleas: 1,622; ticks: 501; ear
mites: 206; mites: 61; sarcoptes mites: 56; other ectoparasites: 11;
treating for hookworms: 11; hookworm prevention: 45.
As respected researcher John Cargill says,
Moxidectin (in Proheart tablets) is given once a month to prevent
heartworm disease. [Several] products contain macrocyclic lactones
which kill the tissue stages of heartworms larvae and are given once
a month. They are generally very safe, but should not be used in
young pups as they can enter the brain and cause nervous system
symptoms such as depression and signs of stupor. Collie-type dogs
are more sensitive to nervous-system effects than other dogs, but
even in these breeds, the products are safe at recommended doses.
http://www.petshed.com/articles/preventative-dog-heartworm-meds.html
other comments: Bonnie Dalzell, Borzoi breeder, says: The dose I got
from a vet working for Merck: 1% liquid “horse Ivomec”: dose for
dogs who do NOT have the MDR1 gene: 1 cc orally for 135 lbs of dog;
heartworm prevention dose, safe for MDR1 dogs: 0.1 cc orally for 135
lbs of dog. In general, I would not try to get an accurately low
(heartworm) dose for a 10-lb. dog — I would use the Heartgard or
Interceptor instead. Breeds that have been shown to have around 30%
individuals with the MDR1 gene include Silken Windhounds (Whippet
cross, probably with Sheltie), Shetland Sheepdogs, Rough Collies,
and Australian Shepherds. If you are in doubt, there is now a PCR
test for this gene. Since you can test to find carriers, you could
even eliminate it from a lineage of dogs. Here are two abstracts:
http://www.blackwell-synergy.com/doi/abs/10.1111/j.1365-2885.2005.00692.x
http://www.blackwell-synergy.com/doi/abs/10.1111/j.1476-4431.2006.00196.x
Oct. 2007 news item: A MYSTERY OF DRUG SENSITIVITY IN DOGS CAN BE
PUT TO REST! When given a high dosage of the Ivermectin
heartworm medication, many Collies developed severe neurological
signs that often resulted in death due to respiratory arrest.
Statistical data on drug sensitivity included Collies, Australian
Shepherds, Bearded Collies, Border Collies, Shetland Sheepdogs, etc.
and drugs ranging from an over-the-counter anti-diarrhea medication
(Loperamide) and pain controller Butorphanol to some chemotherapy
drugs. The mystery has finally been solved. A recent study by Dr.
Katrina Mealey has identified that the problem of drug sensitivity
relates to a genetic mutation in the multidrug-resistance gene
(MDR1). One of the responsibilities of the gene MDR1 is the
production of a protein called P-glycoprotein (P-gp). This protein
allows many toxins and drugs to be removed from the brain. An
affected dog lacks functional P-glycoprotein that leads to toxins
not being pumped out of the brain and, as a consequence, to an
abnormal neurological reaction. The mutation has an autosomal
recessive way of inheritance which means that, in order to be
affected (super sensitive to drugs), a dog has to have both genes
mutated. However, even the presence of a single mutation increases
drug sensitivity in a dog. A new DNA test for the presence of the
mutation MDR1 gene allows for the detection of affected dogs as well
as dogs carrying a single mutation. Knowing the dog’s status will
help veterinarians to properly administer treatment and will help
breeders to eliminate this disease in their bloodlines. To learn
more about ordering the test, please visit:
www.healthgene.com/canine/C142.asp
I hope this has been helpful to you in the management of your dog’s
health. For much more on caring for your dog, whatever breed, I
suggest you order the following: “Canine
HD and Other Orthopedics Disorders” ISBN 0-9764685-0-6 Copyright
2005. Now in its second printing, this book covers every
aspect of HD and most other disorders, and includes genetics,
diagnostic methods, treatment options, and the role that environment
plays.
Links