07 | March | 2010

Archive for March 7, 2010

Tick Season Already?

With daytime temperatures rising into the 40′s, spring has been on my mind. There’s still more than a foot of snow on the ground but the creek is filled with meltwater and the birds’ spring migration is just beginning. Life was great — until this article from The Culpeper, Virginia Star-Exponent ruined my day…

Robins and many other songbirds are often the heralds of springtime and warmer weather just around the corner. Unfortunately, a new report is stating these welcome spring visitors are quite possibly spreading a serious disease of humans and pets … Lyme Disease.

Ticks are the primary vector for spreading Lyme Disease to people, dogs, and horses. Most ticks acquire the disease-causing bacteria by feeding on infected rodents. Deer also play an important role as expanding populations import large numbers of ticks into new areas of the country.

But now, researchers at Yale have found that robins, blue jays and other common birds are also reservoirs of this illness. Furthermore, the nymph and larval stages of the tick life cycle can be carried by the birds across distances and into the yards where pets and people often roam. What this means is that the heralded robin of spring could be leaving their parasite passengers and Lyme Disease in your backyard.

I hate ticks. I really hate ticks. If I could wave a magic wand and make every last one of the evil eight-legged bastards disappear – I’d say damn the environmental torpedoes, full speed ahead!

Sadly, I don’t have a magic wand. And – if robins and jays are dropping evil arachnid invaders into our midst, they could already be active during the day. Deer ticks typically become active at temperatures above 45° F.

This means it’s time to get off my duff and figure out what kind of preventative to use on the dogs this year. Here are the options:

Revolution/Stronghold (Pfizer)
These are monthly spot treatments typically applied between the shoulder blades. They enter your dog’s bloodstream through his skin and then are selectively distributed from the blood to the skin where they provide protection against a wide range of pests. The active ingredient in these products is selamectin.  Revolution and Stronghold are listed as being active against fleas, American dog ticks, ear mites, sarcoptic mange and heartworm in United States and fleas, ear mites, sarcoptic Mange, heartworm and roundworm in Europe.  Selamectin kills parasites by blocking nerve signal transmission. These products are absorbed through the skin and travel to the bloodstream and gastrointestinal tract where some of the pesticide action occurs. The products eventually migrate out to the hair and skin where they provide some external protection against fleas, mites and ticks. There have been scattered reports of adverse reactions to these products.

Frontline Top Spot (Merial)
Another monthly topical spot treatment with the active ingredient Fipronil. It is listed as being effective against fleas for 90 days and ticks for 30 days. Frontline used to be the treatment of choice here for ticks, but studies suggest that fleas and ticks are quickly becoming resistant to it. Frontline only protects against fleas, ticks and biting lice.  The fipronil is mixed with an oil carrier that allows it to collect in the sebaceous glands of the skin where it is released over time. This product offers some water resistance and it acts by blocking chlorine in the insect’s nervous system which causes paralysis and death. It doesn’t contain permethrins that are toxic to cats. There have been some reports of adverse reactions in dogs.

Frontline Plus (Merial)
Frontline Plus contains fipronil and methoprene, an insect growth regulator. Methoprene mimics juvenile growth hormones and keeps immature fleas from developing by preventing them from molting. The main advantage of this product over regular Frontline is that it provides extra protection against fleas.

K-9 Advantix (Bayer)
Advantix is a topical treatment marketed as preventing heartworm by repelling and killing mosquitoes before they bite your dog. Like Frontline, it collects in the sebaceous glands of the skin and is released over time. Active ingredients are the pyrethroids imidacloprid and permethrin. Imidacloprid acts by blocking insects’ nerve receptors. Imidacloprid kills fleas but doesn’t affect ticks so permethrin is added to provide protection against them. Pyrethroids may offer some environmental advantage because they are highly biodegradable, but permethrin is extremely toxic to cats, so you may not want to use this product if your household includes cats (or ferrets). There have been some reports of adverse effects related to Advantix.

Advantage Multi/Advocate (Bayer)
A  monthly topical treatment that protects against fleas, ear mites, sarcoptic mange, heartworm, roundworm, and hookworm. Advantage and Advocate provide NO TICK PROTECTION. The active ingredient in both products is imidacloprid. A poodle in Canada was reportedly glued to the bottom of his crate after application of Advantage. Benzyl alcohol, one of the inactive ingredients in the product, is a common organic solvent. Benzyl alcohol can be used to extract and dissolve many kinds of plastics. It is used as a preservative, solvent, anesthetic, and viscosity-decreasing agent in many products for human use. It is probably an ingredient in other topical antiparasitics as well. Be sure these products are fully dried and/or absorbed before putting your pet in a crate, car seat or other potentially adhesive environment.

Bio-Spot On (Farnam)
This monthly topical treatment contains imidacloprid and permethrin like Advantix and adds insect growth regulators and insect growth inhibitors. Insect growth regulators include methoprene, pyriproxyfen and fenoxycarb. Insect growth inhibitors include lufenuron and diflubenzuron. Bio-Spot On is listed as being active against fleas, ticks and mosquitoes and, like K-9 Advantix, should provide some repellent action. There are scattered reports of adverse reactions to this product. Like Frontline and Advantix it collects in the sebaceous glands where it is released over time.

Preventic and ProMeris (Fort Dodge)
Preventic is a collar, ProMeris is a monthly topical treatment. Both products contain amitraz. ProMeris also contains metaflumizone which targets synaptic sodium channels and blocks nerve impulses resulting in the paralysis and death of fleas. Amitraz kills ticks by disrupting nerve function leading to reduced feeding and attachment, paralysis and death. ProMeris is listed as controlling fleas, ticks and mange. Preventic is a tick collar. There have been several reports of adverse affects related to ProMeris. Both products have a very strong, eucalyptus odor that many people (and pets) find offensive.

Program and Sentinel (Novartis)
Program and Sentinel are monthly oral treatments containing the insect development inhibitor lufenuron. Lufenuron is stored in the animal’s body fat and transferred to adult fleas through their bite. It acts by inhibiting chitin production in larval fleas and is NOT EFFECTIVE AGAINST TICKS OR ADULT FLEAS. Sentinel also contains milbemycin oxime, a microfilariacide which disrupts nerve transmission in parasites leading to their death. Milbemycin oxime is active against immature heartworm larvae and adult hookworms, roundworms and whipworms.  It is not listed for use against ticks.

Capstar (Novartis)
Capstar is an oral treatment containing nitenpyram. Nitenpyram blocks fleas’ nerve receptors. It enters your pet’s blood stream in about twenty minutes and when the fleas bite they’re killed very quickly. Capstar can reportedly be used as frequently as on a daily basis. It is listed for use on pregnant or nursing dogs and cats, and puppies and kittens 4 weeks and older. Capstar can wipe out an ugly infestation but it provides no long-term pest control because it passes through your pet’s system in just 24 hours. Capstar also provides NO TICK PROTECTION.

Comfortis (Elanco)
Comfortis is a monthly oral flea treatment. The active ingredient is spinosad, a tetracyclic macrolide that activates nicotinic acetylcholine receptors in the fleas’ nervous systems and makes it seize until it dies. FDA has warned that it has received adverse reaction reports on spinosad that are consistent with ivermectin toxicity, so use caution in treating dogs with known or potential ivermectin sensitivity. Because Comfortis acts by triggering lethal seizures in the flea, I would not use this product on an epileptic dog.  Comfortis is NOT EFFECTIVE AGAINST TICKS.

Vectra 3D (Summit)
Vectra 3D is a quick-acting monthly topical treatment that repels and kills fleas, ticks, mosquitoes, lice, sand flies and mites. The active ingredients in Vectra 3D are dinotefuran, pyriproxyfen and permethrin. Dinotefuran is based on acetycholine, other flea control products are based on nicotine.The manufacturer states that the differing lead compound makes it less problematic with respect to . Dinotefuran also binds to different nerve synapse receptor sites than other products and it kills pests by contact, not ingestion. Unlike other products, it is reportedly spread through a dog’s hair. Because it contains permethrin, it is highly toxic to cats.

TriForce (Agri Laboratories Ltd.)
TriForce is a fast-acting monthly topical flea and tick treatment for dogs. The manufacturer states that it also repels ticks and mosquitoes. The active ingredients are etofenprox and pyriproxyfen. Etofenprox is a pyrethroid, so it cannot be used on cats. Pyriproxyfen prevents larvae from developing into adulthood and reproducing.

We don’t have a significant problem with fleas, ticks are our primary concern. So Program, Sentinel, Capstar, Advantage, Comfortis and Advocate are easy to eliminate. Like many other people, I’ve noticed that Frontline doesn’t seem to be as effective as it used to be, so I’ll nix Frontline and Frontline Plus as well. I’m not comfortable with the number of reports of adverse effects I’ve seen with ProMeris so it’s off the list too.

That leaves me with Advantix, Bio-Spot On, Revolution and Preventic. Since we don’t have cats, I’m more comfortable with pyrethroids than growth inhibitors and regulators (on a purely subjective level, neurotoxins don’t seem as nasty to me as compounds that interfere with the growth and development of organisms). So the current plan is to use Preventic collars (we’ll try them on top of bandannas) when we’re out hiking in the brush and have some Advantix on hand for any infestations the collars don’t prevent. The dogs are already on Heartguard, so they don’t need the extra protection (and chemicals) in Revolution. If we have significant tick problems this year, I may try Revolution next summer.

Pyrethroids are toxic to fish and other aquatic organisms at part per trillion concentrations, so I’ll make sure I apply Advantix on a day when the dogs aren’t going to be in or near the water. Because it’s safe to assume that benzyl alcohol or other organic solvents are probably a part of all topical formulas, I’ll make sure they’re completely absorbed before I put the beasties in crates or let them wrestle on the rubber mats in the training room. And because there is some risk of adverse reactions to all drugs and treatments, I’ll treat the dogs when I’ll be home with them for a least a few hours after applying the product.

The usual caveats apply: I’m not a veterinarian, your experience may be different than mine and your pets may have sensitivities and problems not mentioned here. This information is incomplete and simply represents the process I went through to decide what products to use for my own dogs. In other words – your mileage may vary.

Ideas? Opinions? Anecdotes? – Put them in the comments!

March 7, 2010 at 7:48 pm 36 comments