Your Pet's Best Friend

First parasites of spring - fly-bites, mosquitoes and ticks.

Suddenly, it's warm.  Too bad I wrecked my motorcycle.  Even worse, the insects seem to have burgeoned almost instantaneously this spring.  It's made a week of firsts.

This wad of heartworms was removed from a Beagle who was only two years old  and dying because of them, sad to say.  Most dogs, even with no heartworm prevention at all (like this dog) would make it three or four years.  We just have so many mosquitoes here (which is how you get them), and they are coming out already.

Here we have the first case of fly-bite dermatitis this year.  Flys don't have the needle-like proboscis of the mosquito. When they bite, it's more like a knife and a sponge.  They make a little cut, then sop up the blood that runs out.  Get a few hundred tiny cuts, and you've got a big sore on the dog's ear.  On a floppy-eared dog, it will be the base of the ear like this guy.  If the ear is erect (like a German Shepherd or Chow), the tips of the ears will be the damaged area.  You need to put a first-aid cream with local anesthetic (like Neosporin Pain Relief, or a generic equivalent) on the spots, then cover with insect repellent, like VIP ointment.  Don't put the insecticide in the sore places - it burns and they won't leave it on.

And here's the first fully engorged tick of Spring.  She looks a little wrinkled here, because I killed her with insecticide spray after I removed her from her dog.  I guess I should't be so surprised, but gosh, it seems early to have this kind of problem already.  These bugs are not as pretty as the first flowers of spring, which are blooming everywhere around southeast Missouri now.

So, it's not too soon to crank up your Frontline, put your VIP ointment on the ears, and keep that heartworm preventive going (like you should have been year-round).

Heartworm preventive medicines may not be 100% effective.

This is the sort of "can of worms" one hates to open. Yet I feel the need to open a discussion. I am concerned that heartworms (at least in our area) are starting to become resistant to all the preventive medications that we have.

I have been practicing in a severely endemic area for heartworm disease since 1978. Starting in 2006, it seems as though "the rules have changed" with regard to the prevention and treatment of canine heartworm disease. The problems that I have encountered are mirrored by other veterinarians in my area. They are experiencing the same frustrations. My Novartis representative has been working from Missouri south to Louisiana. In an unofficial conversation, he indicated that he had heard it was primarily a problem in the Mississippi valley, with the problem being worse as one goes farther south.

We routinely test all dogs for both microfilariae (baby heartworms in the blood) and heartworm antigen (adult heartworm protein in the blood) at their annual examination. In years past, I always detected a small number of heartworm-positive dogs which had allegedly been on year-round prophylaxis (as we recommend). Some few of these would prove to have an obvious deficiency in compliance. When I asked, "Is it possible that he missed a dose?", the folks would start looking at the floor and shuffling their feet. "Well, you see, Aunt Tillie was sick, and the boy was on a traveling team with the baseball season, and the motor in our car blowed up and…". Which is to say, yes, it is possible that he missed a dose.

On the other hand, each year we had four or five patients whose owners had bought plenty of preventive medication. These were folks whom I believed perfectly honest in their report of administration, and competent in their administration. With this small number of apparent product failures each year, it was easy to attribute the failure to things like the dog clandestinely vomiting under a bush. Nobody watches his dog 24 hours a day. So even though the owner was 100% conscientious in giving the medicine, and the medicine near 100% effective, these rare failures were easy to attribute to the weak link in the chain: the dog.

In 2006 and 2007, we have gone from 4 or 5 apparent product failures per year to 4 or 5 per month. Almost all are large-breed, outside dogs. We have the same percentage of failure among all the different products that we use. Interceptor/Sentinel (which we use in the majority of our patients), Heartgard 30, and Revolution. With this ten-fold increase in incidence of the problem, I am very concerned that the parasites are becoming resistant to the avermectins (EVERY heartworm preventive on the market except for Sentinel and Interceptor) and to milbemycin oxime (the active ingredient in Sentinel and Interceptor).

The drugs are far from useless, however. In fact, I believe that they are still preventing almost all of the heartworm infections from reaching maturity. In a previous post, I noted that a dog’s problem with heartworm treatment is pretty directly related to how many adult worms he has to deal with. These dogs who have been on year-round preventive (and turn up positive for heartworms anyway at their yearly physical) rarely show signs of thrombo-embolic complications after adulticide treatment. This would indicate that these dogs have very few adult worms present. For this reason, I believe that the preventives are largely effective, though no longer 100%.

Again, though the number of heartworm prevention failures has risen dramatically, it is still a very small percentage of our patients. Almost all have been large-breed, outside dogs, and our practice is in an area with a heavy mosquito population during the warmer months (and a few skeeters nearly all year). I certainly would not stop giving the preventive medications.

I certainly would give the medicine year-round, and I certainly would have my dog tested every year. When we can document the dog’s previous "clean" status, and document the preventive medicine purchases, the manufacturers have been very good about paying for the dog’s treatment under their guarantee programs.

Too fat to scratch

Tommy and Missy are housemates.  Missy weighs 12 pounds, which is pretty big for a female cat.  Tommy weighs 21 pounds which is too big for his frame.  In fact, his size makes it difficult for him to groom himself adequately.  So, despite the fact that their environment is the same, and that they both have fleas, Tommy's flea population is exponentially higher.

Here's Tommy next to the pile of dead undercoat I combed out of him in about five minutes.  I often say that I don't care how a pet looks in a bathing suit, but when their weight begins to affect their health, that's a different story.  You think that grooming is just about looks, but when there is this much dead hair hanging around, that's not good for the skin underneath.  Plus since he can't groom, he can't do much about his flea population.

Here's a close-up of some of that wad of hair.  All the little black specks are flea-droppings (aka nasty flea poo-poo mess). The white junk is dandruff.  There are probably some flea eggs in there, too, but they are much smaller and more difficult to see. Obviously, we need some flea control here, but we also need a little help with personal hygiene, i.e. brushing this guy once or twice a week.  That's pretty do-able (compared to getting his weight down, which is frequently not so easy, and certainly can't be done as quickly).  We like Revolution for flea control on our cat patients.  It's about the same trouble and expense as other products, but it also gives you ear-mite protection, de-worming for hookworms and roundworms, and heartworm prevention.

Note to self: I need to become much more lovable if I'm going to ask people to help with my personal hygiene.

Heartworms just keep on coming.

Old Yeller Alert

The weather is finally getting cold here in southeast Missouri.  Motorcycle riding will be reduced to the bi-weekly ride to "blow out the cobwebs"-- twenty minutes of freezing while wishing I was home already.  You'd think the mosquitoes would all be gone, but they are still flying around inside my house.  We live in a swamp... a drained swamp, yes; a reclaimed wet-land, even...  but still a swamp.

Back when the only heartworm preventive drug was DEC (diethylcarbamazine), it had to be given every single day, or it didn't work.  So you're going to feed the dog every day, you pet it every day -- just give it the pill  while you're at it (or the liquid, or the chewy treat).  That's fine for dogs that don't object to being medicated.  For those that do object, however, it was a real ordeal.  If your dog puts up a big fight every time you have to give that once-a-month heartworm preventive, you can feel real satisfaction about  a job well-done.  Sure, it wasn't easy, but you got it done: you did the best for your dog.  Once a month, it feels good.  Every single night of your life... not so good.  People don't get a dog so they can fight with it.  People who had to deal with that would talk themselves into the notion that they could stop their heartworm preventive when the weather cooled off.  It ain't so, at least it ain't so here in the swamp.

We have so many mosquitoes for so much of the year that we really have to give the preventive medicine year-round.  With large-breed outside dogs, sometimes they still get heartworms, even so.  You surely can't skip months here and there and expect the dog to stay free of these parasites.

That's why I was so surprised when taking the history on Max the Labrador Retriever three weeks ago.  It was our first time to meet Max.  He had suffered some bite wounds to the top of his head and his ears (ouch).  His owner told me that he had been treated to clear out adult heartworms in 2005, but had not been taking the preventive medicine since then.  WHOOPS!  The heartworm treatment clears out the adults, but has no effect on the development of new ones. More mosquito bites will mean more heartworms, unless you keep the guy on preventive medicine (Heartgard 30, Interceptor, Sentinel, Revolution, etc.). "As soon as he gets over these wounds, we need to get him up to speed on the heartworm situation.  He probably already has some new adult worms."  Truer words were never spoken.

Today they found Max by the back door, stone dead.  Post-mortem exam showed extensive hemorrhages throughout his lungs.  He had more than 50 worms in his heart, plus worms throughout his pulmonary arteries.  He didn't die of heart failure, but from the damage the worms did to the arteries in his lungs. He drowned in his own blood.  It was a sad day, and even sadder because it didn't have to happen.

When to De-worm

Has your pet been "wormed"?  And does that mean he's been covered with worms? If you've been "slimed", you've been covered with slime, right? [See "Ghost Busters"]

Most folks mean "de-wormed", or freed of worms when they say "wormed".  They mean that a vermifuge has been administered --  a drug that will cause those worms to flee.  Preferably, we're talking  a medicine that will just cause the worms to die peacefully, letting them drift gently away with the next regularly scheduled poop. [As opposed to just trying to blow them out, as with arecoline].

As part of your pet's annual physical examination, we ask you to bring a stool specimen, i.e. about a tablespoonful (use someone else's spoon) of fresh (less than 12 hours old) poop.  That's because most intestinal parasites, including worms and protozoa (microscopic one-celled animals), do not pass out where you can see them. They remain inside the intestine eating your pet's food, or even eating your pet.  Most of the time, when there are parasites inside, they are producing many, many offspring in form of eggs, larvae and oocysts.  These leave the old family homeplace in the intestine with the next bowel movement, going out into the wide world to seek their fortune.

The parasite eggs contaminate the soil wherever an infested animal eliminates. [I started to say, "goes to the bathroom", but if they went to the bathroom and used the toilet, we wouldn't be having this problem.] Your innocent and delicate pet (the one who likes to eat cat-poo) wanders over this contaminated soil and picks up these microscopic baby parasites.  Some enter the skin directly (like hookworm larvae), others are taken in by mouth.  Eventually, they wind up in the animal's intestine and set up housekeeping, and the circle of life begins anew [cue inspirational music by Elton John].

Since there's no one medication that's guaranteed to eliminate every kind of parasite from your pet with a single dose, we ask you to bring that specimen.  We examine it under the microscope to determine what sort of parasites may be present, thus allowing us to use the most appropriate medicine and use it on the most effective schedule.  The problem is, the parasites are not little precision machines, kicking out a certain number of eggs per minute round the clock.  In fact, one perfectly jolly specimen may contain no eggs at all, while the next reveals the presence of a travelling band of gypsy whipworms.

SO, if the odds suggest that parasites are likely to be present, we may recommend de-worming even when the microscopic examination reveals no evidence of parasites.  For instance, most puppies and kittens have a high likelihood of being infested with hookworms and roundworms.  These nasty things can cause a great deal of damage, even killing the youngster.  Thus, we recommend routine de-worming for puppies and kittens, starting at 3 weeks of age, and repeating at 2-week intervals.  And we haven't even considered the risk to human health, but you can check it out here.

Another time we may de-worm is when we have intestinal problems that aren't resolving readily.  It's worth trying a broad-spectrum de-worming drug just to rule out the parasites, even though you couldn't find them.

Remember Hunter?  He's been doing great since recovering from his surgery, that is until this week.  This week he's been having some diarrhea and occasional vomiting.  He's also gassing up, somewhat similar to his last episode. Fortunately, he's not acting nearly so sick, still eating and keeping most of it down.  Here's a dog who has had numerous negative stool examinations.  He mostly stays inside.  Yesterday he was hospitalized for observation, and the second exam of the day revealed the presence of whipworms.  So in addition to symptomatic treatment for colitis, he's getting a vermifuge (Panacur - fenbendazole). 

Whipworms get their name from the fact that (provided you use some imagination) they look sort of like Indiana Jones's bullwhip.  Here's Max Mobley cracking an 8-foot bullwhip.  Look at the next picture to see the resemblance.   You can't see it?  What?

Whipworms "sew" themselves into the intestinal lining and suck blood.  They also can cause a lot of inflammation, producing diarrhea and vomiting.  Could they have had anything to do with Hunter's problem in June?  I don't know...maybe so.

Sometimes your veterinarian may include de-worming as part of your treatment plan, even though no positive diagnosis of parasites has been made.  Go ahead and do it: it's safe and doesn't cost much, and it just might help a whole lot.

Problems with Heartworm Treatment

The perfect treatment for a disease needs to satisfy several requirements:  the treatment should be 100% effective and it should be completely safe for the patient.  If it were also easy to do, and inexpensive, that would be perfect.  When the standard treatment for a disease fails to satisfy all four of those requirements, people begin to look for alternatives.  Sometimes this results in better treatments.  Sometimes it results in the patient receiving no effective treatment because he's busy getting some quack remedy that does nothing at all (or kills him.  Remember Laetrile?).

Treating a dog to clear him of heartworms is a situation where the state of the art is not perfect.  Prevention of the disease with monthly preventive medicine has been effective most of the time.  Treating the dog who has adult, foot-long worms in his heart -- that's a different story.

The conventional view is that the worms are in the right ventricle of the heart, and the big pulmonary artery trunk.  If you do a post-mortem on a dog who has died from heartworms, you'll find a lot of them there.  In a dog with a lower worm burden, there are not so many worms in the heart.

Most of the worms will actually be in the pulmonary arteries (taking blood from the right side of the heart to the lungs to get oxygen).  There may not be any worms in the heart.  If you open this dog at post-mortem, even though there may not be huge numbers of worms, you can cut the lung way out at the edge and find worms in the blood vessels.

The worms don't eat the heart or arteries, they just float.  When there are so many worms present that they clog the outflow from the heart (like roots in a pipe), the heart wears out (prematurely) from the constant overwork of pushing blood through the clog. 

Actually the worms don't just float -- they swim upstream. If they just floated, the pressure in the artery would force them downstream until they hit a branch too small to pass.  This would clog the artery either partially or completely, resulting in poor circulation to the downstream area of lung.  The dog might get a secondary pneumonia in this damaged area.  If he ran hard, increasing heart rate and blood pressure, the damaged artery could blow out, hemorrhaging into the lungs.  Indeed this does happen in some dogs, though most infected dogs develop the less dramatic signs of congestive heart failure: weight loss, coughing (especially after exercise), labored breathing, fainting spells and so forth.

This is ALWAYS what happens when the dog is treated to kill the heartworms.  Worms who have been swimming upstream, keeping the artery open, float downstream and clog up the works.  Unlike an intestinal worm infection (hookworms, roundworms, tapeworms, etc.), there's no exit here.  With intestinal worms, you kill the worms and they leave the body with the next bowel movement.  With heartworms, they clog up the works like a blood clot would (except that few blood clots are a foot long).  You've heard that you shouldn't get an air-bubble injected -- how about a handful of foot-long worms?  The only way to get rid of them is to let the body's microscopic white blood cell defenders eat them.  They'll do it, but it's a slow process, like termites eating your house.  It takes weeks after the death of the worms before the body dissolves them out of the circulation and opens all those clogs.

This is the unsatisfactory part of the heartworm treatment.  It's why dogs feel bad a week or so after they are treated.  That's when the worms die and shift position.  The dog may have a fever, cough, lose appetite, have trouble breathing, or cough up blood.  Sometimes you don't see any of those things, but you can just tell that your dog doesn't feel good.  You know your dog, and even though he may not have specific signs, you can tell when he doesn't feel well.  This is the reason we ask you to restrict the dog's activity for several weeks after treatment -- no hard running for a while.

Most complications of treatment are minor and very treatable.  Severe problems like blood-vessel  rupture or allergic-shock-like reactions are extremely rare.  It could happen, but most dogs have years added to their lifespan when the heartworms are destroyed.

Here's the crux of the matter, and the reason I'm writing today.  Ill effects during the heartworm treatment are related almost exclusively to the dead worms clogging up the pulmonary arteries.  The drug that's used (Immiticide TM - melarsomine dihydrochloride) is unlikely to cause anything worse than some temporary soreness at the injection site.  It takes those little worms five days to die and they're taking a  bath in it.  There just isn't enough drug to bother the dog (unless he has some pre-existing severe liver disease).  That's why it doesn't matter whether your alternative remedy is a better chemical, a cheaper chemical, organic, holistic, homeopathic, herbal or black magic.  If it kills the worms, the arterial blood pressure is going to shoot them downstream and clog up the works.   

I've seen people use D-con rat poison, gunpowder, and levamisole (a sheep-wormer that is VERY hard on the dog's liver).  Today a client brought in some misinformation he'd downloaded from some "Natural" website (with many products for sale).  Their nostrum is alleged to be superior because "There seems to be no risks of the parasites dislodging and creating vessel blockage."  Yeah?  Do the worms die or don't they?  If they die, they're going to move.  You may not have seen an artery pumping, but a two-millimeter artery will shoot three feet in the air if your clamp slips off before you get it tied.  Dead worms don't swim - they go scooting downstream.

I wish that our standard heartworm treatment was 100% effective, safe, easy and inexpensive.  It doesn't totally satisfy any of those criteria.  It is usually effective in eliminating all the worms, most dogs have no complications (or very minor and easily treatable ones), and it just takes two injections, 24 hours apart.  But, it's not cheap.  And you have to let the body deal with those dead worms.  There's just no way around that, no matter how you kill them.

P.S. Don't forget to give your dog his heartworm preventive.

Ectoral Time Capsule

Some time ago, I posted on demodectic mange and mentioned that the treatment when I graduated in 1978 consisted of daily dipping with a stinky, poisonous insecticide.  Today I found some in a cabinet.  I guess I hadn't really forgotten it was there (though the expiration date is  1986).  It's one of those things that you quit using because something better comes along, and then it just sits there.  It's too good to throw away, not to mention too toxic.  On the other hand, you're not using it for anything, either.  So it just sits there. 

Ectoral was Pittman Moore's tradename for Ronnel, a potent organophosphate insecticide.  We just don't use stuff like that much anymore, as we have safer and more effective alternatives.  It does stink, too.  When we used it to treat demodex cases, you diluted it with propylene glycol, which helped it penetrate the hair follicles to kill the mites.  The whole building would stink for hours when you mixed up a bottle under the vent hood.  That was "Scott's Solution of Ectoral", and it was the state of the art.  It was so toxic that you could only dip a third of the dog at a time, but it worked so poorly that you had to dip them daily.  Monday, you'd sponge the dog's head and front legs; Tuesday, the trunk; Wednesday, the hindquarters;  Thursday, start over.  Continue for months.

It was dismal.  Not very many dogs got cured, though some might have if it hadn't been so nasty.  A lot of people gave up early in the treatment because it was so unpleasant. 

The upside of being a geezer is that you can really appreciate how much better things are now, as in "these are the good old days".  The downside is that I have really got to clean out those cabinets.

Advantage washes off.

Here is a flea emerging from its cocoon.  I'd go through the whole flea life cycle, but these folks have done a lovely job for you.  The point is that most of the flea's life cycle takes place OFF the animal in the environment.  Each flea lays hundreds of eggs each weak, and they fall off into the environment.  Once they develop into a new flea, they can remain dormant for months in your yard, carpet, upholstery, etcetera.  This is why having a flea-control product that stays on the pet for one month is so great.  When they return to the flea-cocoon-infested area, and pick up new fleas (within seconds), the new fleas die before they start the cycle over again.

Unfortunately, this only works if the product really stays on the pet for the whole month, if that's what you're expecting it to do.  Today we had a lady who felt that her dog must have multiple allergy problems requiring lots of cortisone, because she had the fleas under control -- she was using Advantage every month.  Examination revealed that the dog had many fleas present. "How often do you bathe him?  Bathing removes the Advantage pretty quickly you know."  Turns out, this dog likes to roll in nasty things (imagine that!) and sometimes is bathed more than once in a single day.  He certainly gets several baths per month.  This is one of those times that points up why it is so important to take a complete history when looking at the dog's problem.  You need to examine that patient's entire lifestyle.

Now Adantage (Bayer's imidocloprid) is a good product.  It spreads over the entire body when you squirt the little tube on the back.  The chemical forms tiny crystals that stick to the hair and skin and kill fleas (and their eggs) on contact.  A simple wetting, like getting caught in the rain, does not remove them.  It does last for a month, unless...  Scrubbing with soap and water takes it right off.  The first bath will take half of the product and the next bath takes the rest.  The dog is now "Advantage-free" and unprotected as far as fleas go.  If you're bathing three times per month (much less three times per day), this is not a good product for you to use once per month.

The over-the-counter products you can buy at Wal-Mart are either pyrethrin or permethrin.  They are also water-soluble, so a bath eliminates the product.  Worse, though they say you can use them once per month, they don't mention that these particular chemicals degrade rapidly in the open air and sunlight.  If you use these products, you probably need to use them once per  week, not once per month.  Now they don't seem like quite so much of a bargain. [Note: the permethrin-containing products say "do not use on cats"; this is no joke -- it will kill them.]

At KVC, we've had better luck with Frontline Plus (Merial's fipronil).  Like the aforementioned products, you apply the contents of one pre-measured tube to the pet's skin, putting it under the hair. Unlike the aforementioned products, it really lasts a month for most pets, and it survives bathing.  Fipronil is oil-soluble, not water-soluble.  When you apply it, it distributes through the skin oil, spreading over the entire body.  The excess wicks down into the oil glands in the hair follicles.  Certainly you can scrub it off with soap and water.  You know how dry your own skin feels when you get out of the shower in the wintertime -- you've stripped off the oil layer and there's nothing to hold the moisture in  your skin.   Even without lotion, the skin will put out another layer of oil from the little glands in the hair follicles.  If the pet has had Frontline applied, that skin oil will contain the flea-killing chemicals.  Even bathing once weekly, you should still have pretty good flea-control for a month.

Localized Demodecosis

This is Star.  She was just about to head out on the dog-show circuit with a professional handler when her owners noticed a small spot of hair loss on her lip. She surely looks great otherwise and really ready for the show ring.  Unfortunately, those folks are really competitive and there is no point sending a dog out to compete with even a small and inconsequential blemish.

This is localized demodecosis, not to be confused with generalized Demodectic mange.  True, they are caused by the same species of mite, but localized cases generally do not progress much, and resolve spontaneously.  They most often occur in a young dog who has undergone a bit of stress.  [Star had just finished her first estrous cycle, or heat cycle, two weeks earlier.]  You can do virtually anything for these dogs and they will get well anyhow.  Prescribe your favorite cream or vitamin, or try a simple laying on of hands, accompanied by some impressive mumbo-jumbo (my favorite), and you can receive credit for the cure.

If there are secondary infections in the hair follicles, oral antibiotics would certainly be helpful.  If the spot is persistent (unlike most), topical treatment with amitraz in propylene glycol will usually speed things along.  These dogs are most definitely not candidates for whole-body dipping.

One caveat: if you see this in an older dog, look for some underlying disease process that would be undermining the dog's body defenses.  Sometimes skin problems are just skin problems, and sometimes they are the tip of a whole-body problem iceberg.  A dime-sized area of hair loss could tip you off to an early cancer.  Don't lose sleep over that.  Just remember that when your veterinarian looks at the whole pet when he "just has a skin problem", he's being an animal doctor, not a "spot doctor".

Demodectic Mange

This is the "before" picture I took today.  I have high hopes that I'll be showing you some much nicer "after" pictures in the coming weeks.   "Lucky" is a stray dog who showed up about six weeks ago.  The extremely nice man who adopted him tells me that he actually looks a little better after the treatments they've been doing, but it seemed to him like the progress was a little slow with the dipping treatment their previous doctor prescribed.  What, you're not happy with the whole body as a running sore?

You'll hear a lot of folks refer to any dog with hair loss as "having the mange".  Mange properly refers only to the skin diseases caused by an infestation of microscopic bugs from the mite family.  One of the more common kinds is that caused by Demodex canis.  These tiny bugs live deep in the hair follicles.  Parasitologists tell us that a small number can be found on almost any dog, apparently causing no problems.  When they over-multiply, they damage the hair follicle, causing the hair to fall out.  If they continue out of control, they do enough damage that bacteria living on the skin take advantage of the "open door" and set up shop to cause a severe skin infection.  In Lucky's case, he now has deep pyoderma (pus in the skin that goes all the way to the lowest layers of skin).  This is a pretty severe complication and is responsible for most of the discomfort experienced by the dog.

Here is a less severe case.  She has lots of hair loss, but no deep infections.  She's a pretty good illustration as to why this is sometimes known as "red mange".

Dogs that are stressed by illness, pregnancy or simply rapid growth as puppies may experience transient bouts of localized demodecosis.  This manifests as a small hairless spot or spots. The skin is smooth and it doesn't seem to itch.   The vast majority of these individuals will heal spontaneously as their own body defenses crank up and get the mites in check.  They do not require treatment of any kind as a general rule, though persistent cases may benefit from topical treatment of the spots.  Whole-body dipping is NOT indicated for these patients.

When the dog is more severely compromised, generalized demodecosis may result. Sometimes this happens with chronic illness in a young dog.  If it happens in an older dog, you really need to search for some serious underlying disease.  There are some dogs whose immune system simply does not recognize the mite as being a problem.  These dogs mount no defense at all against the mites and they run rampant, with much secondary damage as well.  Lucky could be one of these dogs, but we hope not.  If the dog's body defenses do not participate in the treatment, cure is unlikely.

Most dogs can be cured with today's treatments.  Thirty years ago the only treatment was daily dipping with a very toxic (and stinky) insecticide.  It seldom worked.  People tried everything from rubbing the dog with raw meat to burnt cylinder oil.  They didn't work.  Then came amitraz, first in an orchard spray chemical, then the currently approved form called Mitaban.  You bathe the dog in medicated shampoo to flush the debris from the hair follicles so the dip can get in.  You dry the dog thoroughly for a few hours so that the follicles aren't full of water.  Then you soak him in the amitraz dip.  If he soaks up enough to work, he feels a little bad or "drunk".  Once per week seems to be the most effective regimen. 

Daily oral treatments with high doses of ivermectin or milbemycin oxime are much less nasty to perform and (with ivermectin) actually cheaper than the dipping process.  In many dogs this systemic treatment is more effective at killing the mites, as well. 

In any case, prolonged treatment is needed to eliminate the problem. Treatment generally takes two to four months in a severe case like Lucky's.  One also needs to treat the secondary problem.  In a severe case like this, dipping alone is unlikely to be successful.   Lucky will need to take antibiotics for the skin infection for at least three weeks (the length of time needed to grow a new layer of skin).  Nutritional supplements to boost his immune system are needed.   We also need to get rid of any other debilitating problems (like the hookworm infestation that had not been treated yet).  Medicated shampoos help clear the debris from his skin and hair follicles, depriving the parasites and bacteria of their support.

Look for Lucky's first "after" picture in about two weeks.