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derm lec 11/2/98
parasitic dermatoses
Dan Morris


skin: 
most important organ of the body - more metabolic / detox function than 
liver, as important as heart for regulation of BP, regulates electrolytes 
like kidneys - and makes a lot of money for practicioners, if that is an 
interest of yours. 

at least 50% of all the skin disease you see will be 
covered today, in parasitic dermatoses, so pay attention!

Argasid (soft) 
ticks - not much to say. Dr Morris isn't from a tick endemic area - but 
you and I are. the spinous ear tick isn't seen in this area but is 
present in the SW and SE USA. this tick parasitizes ear canals and can 
cause otitis externa and also tick paralysis. dogs/cats can have a lot of 
these ticks in juvenile form lodged in ear canal, requiring surgical 
removal. be aware of them.

ixodid (hard) ticks - transmit viruses, 
rickettsia, protozoa, tick paralysis. some hypersensitivity reactions to 
the saliva occur. some overwhelming infestations of these do occur. 
Frontline is effective against them. these are common here.

Demodectic 
mange mites - perhaps the biggest problem beyond the flea. demodex mites 
are seen on all mammals from blue whale to kangaroo mouse, and each spp 
has its own mite spp so transpecies spread is not thought to be possible. 
mites live in hair follicle or sebaceous gland. most domestic spp have at 
least 2 or 3 spp of demodex which parasitize them. a few mammals have a 
short, stumpy spp of demodex living on stratum corneum. not usual, 
though.

slide: feline demodecosis - cigar shaped mites. a bit longer 
than canine mites.

canine demodecosis: dogs probably harbor three spp of 
demodex, but d. canis is only real important one. that's the one causing 
the disease we see. two other spp are reported - one resembling d. cati 
also living in follicles, and one living in stratum corneum , which 
usually is seen only in presence of other spp.

life cycle of demodex 
canis:
4 life stages present in follicle: eggs, larvae, nymphs, adults. 
eggs are pyriform or macaroni shaped, fairly translucent and easy to 
miss. larvae and nymphs - 8 immature legs for nymph, larva has 3 sets of 
legs. when you scrape, you count # adults, # juveniles, # eggs. then do 
repeat mite count after initial therapy.
transmission of demodex is 
thought to occur perinatally from dam to nursing neonate. this explains 
why localized demodecosis is on face, front feet in little puppies. we do 
not think d. canis is contagious between dogs. 40 years ago a study was 
done here where they took a dog with severe, generalized demodecosis and 
put it in a cage with immunosuppressed dogs and those dogs did get it - 
but that was only transient and they were immunosuppressed. 

slide: long 
form of canine demodex, short form of mite that lives superficially, 
classic form of d.canis. there is a larva emerging from an eggshell on 
this slide. cool.

pathophysiologically on normal dogs we should not see 
any mites on scraping. if you have inflammatory skin disease and you do 
skin scraping and you find one mite or one egg, you should probably 
consider it an infestation and treat it. some people try to split hairs 
over how many is too many. if there is inflammation, one is too many.


initial proliferation in young dogs is probably due to a heritable, as 
yet undefined, immunodeficiency.

in adults - exogenous immunosuppression 
like pred, chemo; or endogenous like neoplasia, allows proliferation. the 
mites then secrete some lymphocyte suppression factor. mite derived 
immunosuppressive factor is its big survival mechanism. 

localized 
demodecosis: young animals, 3-6 mos of age at onset. affects face and 
forelimbs in most. most resolve w/in 6-8 wks. some are destined to 
progress to generalized dz but you can't predict which will. most will 
resolve w/o tx. if they are destined to progress, it is genetic, you 
can't stop it, you can't predict it. treatment with "spot therapy" may 
not truly alter the course of disease - is often done for the sake of the 
client, who wants to do something, not for any good medical reason. 
always evaluate health status, look for nutritional deficiency, 
endoparasites, other problems. usually it's just a healthy puppy. some 
breeds more notorious - shar peis.  if you tx localized demodecosis with 
topical like benzoyl peroxide - always warn people that it will cause 
more hairloss and make lesion appear to expand. 


generalized 
demodecosis: much more concerning problem.
juvenile onset - 3-18 mos of 
age; adult onset is >4 yrs. in between cases are hard to classify, but 
usually have had it for a long time and not resolved. take it case by 
case to classify those. several purebreds are at increased risk - perhaps 
autosomal recessive trait w/incomplete penetrance? polygenetic? breeds: 
shar pei, great dane, pug, cocker spaniel (american). recommend not 
breeding affecteds (impossible in shar peis, they'd die out.
definition 
of generalized: five or more localized lesions; regional disease (entire 
face, etc); complete involvement of two or more feet. 
pododemodecosis is 
scariest form - if it affects interdigital spaces, bottom of feet - it's 
generalized even if only one foot.

slide: 8 mo old harlequin great dane. 
very cute. entire limbs are affected - erythematous, some hairloss. 
patchy areas of erythema and alopecia over whole dog, including black 
areas.  close up images reveal folliculitis - hair follicles are plugged, 
generalized erythema, thinning alopecia.

clinical presentation of 
generalized demodecosis: most start with patchy alopecia and 
folliculitis. some have just pododemodecosis or more rarely just otitis 
externa (can find on ear mite preps)
squamous form: dry seborrhea, 
flakiness without gross folliculitis
secondary bacterial pyoderma occurs

lymphadenopathy is very common - mites are taken to regional LNs by 
lymphatic flow. may be seen on fine needle aspirate or biopsy.
most of 
these dogs need systemic antibiotics for about 4 weeks due to the 
pyoderma. may progress to deep cellulitis.

slide: accentuation of hair 
follicles - black spots, follicles full of debris. this is a preferred 
area for skin scraping
slide: pododemodecosis: expect to find mites on 
scrapings. if you do not, take a biopsy. usually though when fairly 
non-chronic, you will find mites
slide: pododemodecosis, chronic - foot 
hugely swollen, painful - mites are walled off so unlikely to find them 
on scraping - might find them at periphery of lesion. this is an english 
bulldog - these dogs often get interdigitial granulomatous lesions of 
other causes but are high on demodex list so you would bx this. let dr 
goldschmidt find the demodex for you :)

slide: secondary pyoderma in GSD 
with generalized demodex. bright red lesion, accentuated hair follicles, 
patchy areas that are kind of raised and very erythematous - secondary 
pyoderma (bacterial). this dog needs 4 wks of abx. it isn't deep - not 
nodular, no draining tracts. C&S not required.

slide: squamous form of 
demodecosis - hard to see. dry areas, fine scaling, thinning alopecia. 
it's not possible to appreciate any follicular accentuation. in 
australian terriers, yorkies, other little land shark dogs, this is the 
more common form - do skin scrapings. 
slide: dalmation with "short coat 
folliculitis" - looks motheaten (so he says, this slide sucks). 

ddx for 
demodecosis:
the big three differentials: demodex, 
ringworm/dermatophytes, staph intermedius. staph is most common cause of 
folliculitis but do a scraping anyway. and charge for doing it! don't 
just do it for free if it is negative. you are ruling out a very 
important differential by doing it.
in advanced cases complicated by 
self-trauma and secondary infection, ddx list can be extensive. usually 
you find mites on scraping, treat them, then see if there is another skin 
disease too.

skin scrapings: be aggressive!!
slide: nice friendly shar 
pei (a rarity). he had a relatively normal haircoat but was a bit itchy. 
these dogs have a lot of skin allergy. scraping didn't seem that 
important but they did it and found nothing. so they looked for allergy. 
this dog belonged to the neice of barbara bush. finally they biopsied the 
skin. he had demodex. now shar peis have very very very deep hair 
follicles and often you do not find demodex. you may have to do a biopsy 
to find it. usually though there will be alopecia. this dog didn't have 
that so actually he didn't scrape it, but if he did he might not have 
found it. oops. 

-drop of mineral oil on skin
-squeeze, scrape, squeeze, 
scrape
-must get capillary blood
-transfer to glass slide and use a cover 
slip, view at 10x with condenser turned down to get good contrast. 
coverslip is IMPORTANT
-histopath may be required in shar peis, and some 
cases of pododemodecosis.

ancillary diagnostics:
in old dogs > 4 yrs, we 
worry about underlying disease (b/w 18 mos and 4 yrs, up to you...even in 
young dogs, hypothyroidism is a predisposing cause, though, so always 
check for that). probably with dx of hypothyroidism is that lots of 
demodex cases have suppressed total T4 - a free T4 by equilibrium 
dialysis and a TSH should be done to prove hypothyroid, because the fT4 
by ed isn't affected by euthyroid sick syndrome. 
do culture/sensitivity 
of deep pyoderma
cbc/chem/ua
chest films/abd u/s when indicated
rule out 
iatrogenic immunosuppression - dogs on chemo, dogs on steroids
slide: 
cocker spaniel with Cushing's disease. easy dx. 
when you run your 
routine bloodwork and it is all normal, you feel good that it is just an 
idiopathic demodecosis - but then a few mos later someone else will find 
lymphoma...so, you may want to do chest films, rads, etc. to rule out 
neoplasia. at least make an effort to find a predisposing disease, to the 
limit of the client's ability to pay. few people will want to do 
abdominal u/s when there is just a skin disease. 

client education: 
people love their dogs but can't afford disease work ups and ask you 
"don't you love animals? why won't you help me without taking my money??" 
and this disease takes money to dx in adult dogs.
this disease is hard to 
treat in some dogs
-commit to ruling out underlying dz
-6 weeks to 6 mos 
or more for initial tx period - tell client this! dog may require weekly 
tx for life
-lifelong therapy in some cases
-give an estimate of cost for 
weekly Rx
-genetic counseling: if dog is young and has localized dz, 
maybe it is ok to breed. some evidence does say it is a different thing. 
but some progress to generalized form. so what do you tell people? 
probably shouldn't breed affected animals. with generalized demodex - you 
should never breed parents, littermate, or patient.

licensed therapy:

mitaban dips are the only approved therapy for demodecosis. the FDA is 
very conservative here, so we use a very low dose compared to other 
countries. mitaban is licensed for q 14 days, at 250 ppm- one vial per 2 
gallons of water - which will dip most animals fine. 
we always need to 
clip medium/long haired dogs down to very short hair. you have to do 
this, or you will not get a successful treatment. clients do not like 
this but you need to do it. then, prebathe with benzoyl peroxide shampoo. 
this gets down into follicles and extrudes follicular contents such as 
debris, mites, etc. lather really well. rinse. then towel dry. then 
sponge on the dip and massage it into skin for a minimum of 10 minutes 
prior to putting it in cage to drip dry. do not rinse. 
we also use 
mitaban in mineral oil 1:9 for local tx of feet or ear canals. this is an 
off-label treatment. this should be stable for about a month. this is 
argued a lot. some people say it isn't stable. no one has studied it. we 
mix it fresh every month. 

it is tempting in small dogs to use 1/2 a 
vial of mitaban and save the other 1/2 vial. but once mitaban is exposed 
to oxygen, it oxidizes and gets 8 times as toxic within two weeks. so do 
not do that.

alternative therapies:

"extra strength" mitaban weekly: 
one vial per gallon - 500 to 1000 ppm (off label) every week. in some 
countries, mitaban is labelled at 1000 ppm - that will cause some 
toxicity. he's gone up to 750 ppm

daily 1% ivermectin (ivomec, cattle 
type) - target dose 300-600 micrograms/kg - do that first week, if no 
toxicity, treat 2 more weeks - there is dose dependent toxicity. rescrape 
- if you've stopped reproduction, continue at 300 mcg/kg, if not 
improving, go up to 400 mcg/kg. 600 mcg/kg is pretty much the highest. if 
you give too much you can kill dogs with dose dependent toxicity. 
tx 
four weeks until first neg scraping, then two weeks for two additional 
negative scrapings, then you can stop but can relapse up to 18 mos later.


daily milbemycin oxime - much, much safer. but only available as 
Interceptor. give 0.5 to 1 mg/kg/day - that's about 500 bucks/mo for 60 
lbs dog - dose dependent sticker shock - but very safe.

mitaban 
toxicity: is an MAO inhibitor. monoamines: serotonin, dopamine, norepi - 
mite NTs. MAOs inhibit their breakdown. mitaban also has alpha2 
adrenergic properties - OD causes sedation, weakness, ataxia, 
bradycardia, etc - reverse those effects with yohimbine, the a2 blocker. 
sometimes we see skin irritation. do not split and save bottles of dip! 

never use with other MAO inhibitors (hydroxyzine, other antihistamines)


feline demodecosis: also important. cats have two spp of mites - d.cati 
is the big one, a follicular mite. unnamed "stumpy demodex" resides in 
stratum corneum. these cause fairly different clinical signs. 
little is 
known of d.cati immunopathology, probably similar to d.canis

immunosuppresion does predispose
in cats, facial and acral (leg) most 
common sites
follicular plugging, alopecia, erythema, crusting, 
ceruminous otitis externa (demodex otitis more common in cat than dog)


slides: host response is variable - one cat here has mild alopecia, non 
pruritic. other cat has big red bloody lesion.

stumpy mite - probably 
part of normal feline microflora. this spp is associated with a lot of 
pruritis and mimics allergic dz closely. can mimic any of the allergic 
patterns. almost all cases of stumpy demodex occur secondary to steroid 
administration, diabetes mellitus, hyperthyroidism...some are primary, 
though. this is the one spp of demodex that is contagious to normal 
housemates. always check housemates - some may be asymptomatic carriers. 

stumpy demodex causes cats to lick their hair off - "bald belly syndrome" 
or in allergic pattern. can cause eosinophilic plaques - seen here in the 
groin. can also cause papular rash, an uncommon presentation of feline 
inflammation. 

dx feline demodecosis: stumpy demodex - look for this 
with broad, superficial scrapings (no blood needed) or fecal flotation. 
single mite is enough to warrant tx. r/o FeLV, FIV, DM, neoplasia.

tx: 
lyme sulfur dip - 2%. smells bad, stains white cats yellow and pisses 
them off. 6 dips at 5-7 day intervals will usually do it, but do continue 
until scrapings are negative. sometimes half strength mitaban works, but 
may make cats sick.

--break---
bring parasit notes on friday!!

canine 
and feline scabies:

lifecycle:
21 days, egg to adult - incubation period 
unknown
caused by separate spp of times, but these can parasitize mammals 
other than their usual host species. so they are host adapted but not 
totally specific. sarcoptes scabei var canis, var humanis, etc. etc.
all 
sarcoptid mites burrow through the stratum corneum - very superficial 
dwelling which affects diagnostic techniques.

canine scabies:
-intense 
pruritus -itchiest of all diseases.
-classic pattern - starts with pinnal 
margins, elbows, hocks - then entire ventrum gets involved. mites prefer 
cooler skin to start with and then spread. you will see generalized 
cases. 
"scabies incognito" - hypersensitivity - occurs with hyper 
clients who constantly bathe animals and wash off mites, but dogs still 
have itchiness
"Norwegian scabies" - huge mite proliferation with no 
pruritus - usually seen with immunosuppression

slide: scabies ear - red, 
lichenified, alopecic ear margin. no other dz causes this regularly. 
erythema and alopecia right on the ear margin.

slide: elbows, hocks 
affected, progressing into axilla. progression is rapid.
slide: self 
trauma, excoriations over ears.
secondary bacterial infections are 
surprisingly rare.
lymphadenopathy occurs - scabies mites do not get into 
LNs, but the inflammatory cells do, causing "dermatopathic" 
lymphadenopathy.

slide: scabies incognito in dog who gets bathed a lot - 
hairless, and itchy, but not red.

slide: cocker spaniel with immune 
mediated thrombocytopenia. on pred. sits in waiting room next to a puppy 
with scabies - four mos later he had scabies. 

dx: broad, superficial 
scrapings of papular rash. avoid lichenified or traumatized skin. ear 
margins are a good place. look for mites, eggs, fecal pellets. mite and 
egg are similar size! often you only see egg - like hookworm egg, but 
larger. histopath isn't that helpful. if pathologist says changes are 
suggestive of scabies - ignore it. scabies is a clinical suggestion, not 
histopathological - unless of course pathologist sees mites.

therapeutic 
trial: since you only find scabies 50% of the time when it is there (some 
say to do 15-20 scrapings - who has time?), you should r/o food allergy, 
FAD, atopy w/2ary infections if there isn't classic presentation. dx by 
response to therapy.

slide: mite in section, in path specimen. kind of 
embarassing when pathologist makes dx for you.

tx: lyme sulfur dips work 
well in dogs - 4-6 dips q 7 days. don't forget to tell client to remove 
jewelry! 

mitaban dips work great too, but may be overkill. 

ivomec 300 
mcg/kg once weekly orally or subq, 4-6 wks. toxicity is a concern and you 
can't use it in herding breeds! collie, sheltie, OES, australian 
shepherd, etc. 

milbemycin oxime: interceptor, 2 mg/kg PO q 7d x 4-6 
doses. not as cheap as lyme sulfur, but >98% effective, and safe.


environmental cleanup is very important as scabies mites can survive in 
house dust, and even in upholstered furniture up to 3 weeks. use reliable 
flea spray. 
since scabies is zoonotic, refer to a physician. always ask 
if any family members have a papular rash or any rash. forearms, 
waistbands are most common sites. 

feline scabies: notoedres cati: 
usually starts on pinna, progresses to rest of head, dorsal neck. may 
affect feet and perineum from grooming. skin gets rugated, ridged in 
classical presentation. most cats very pruritic. ddx otodectes, 
allergies. commonly call cat scabies "head mange"

slide: tail tip 
alopecia/pruritus, scaling/lichenification on feet - atypical feline 
presentation.

dx feline scabies: small round mites on scraping; occult 
cases very rare unlike in dogs - in cats, usually find huge #s of mites. 

lyme sulfur = tx of choice 
1% ivomec 300 mcg/kg PO or SQ q7d.
no reports 
of milbemycin used in cats
one NFC got very toxic at this dose of 
ivermectin
environmental cleanup important
physician referral important.


cheyletiella:
much less common than scabies, but this is an endemic area. 
(philly-DC, chicago, houston/austin/san antonio, san francisco)
c.yasguri 
in dogs, c.blakei (cats), c. parasitovorax (rabbits)
form pseudotunnels 
in epidermal debris, feeding on interstitial fluids
not terribly spp 
specific
cement eggs to hairshafts
very contagious, zoonotic potential
Dr 
Gomez had a sad case of 3 cats with this - easily cured - but owner was 
tx for breast cancer with a stage I trial drug and kept getting papular 
rashes, so her Drs changed her chemo protocol 4 times - but she really 
had chyletiella. MDs often do not ask clients with rashes if their pets 
have skin problems.

pruritus highly variable.
mild scale/walking 
dandruff with no pruritus, to heavy scale with intense pruritus.
may 
mimic scabies in dogs
cause of miliary dermatitis in some cats
all 
rabbits assumed infested until proven otherwise - notorious subclinical 
carriers.

dx: scrapings, flea combing, acetate tape prep, fecal 
flotation of eggs. look at material in mineral oil at 10x

tx lyme sulfur 
or mitaban, ivermectin, milbemycin
-nasal sequestration can lead to tx 
failure in rare cases txd with topical therapy. 
-environmental cleanup 
required. 

these mites have long legs, little hairs around them. eggs 
also different from scabies.

otodectes cynotis: ear mites. a psoroptid 
mite of dogs/cats. has been reported in a few people. lives on surface of 
skin, prefers the ear canals. feeds on epidermal debris and interstitial 
fluid. most common in puppies and kittens; 21 day life cycle. in cats, 
may go to perineum and feet perhaps due to grooming behavior.

signs: 
dogs: otic pruritis with minimal d/c, mites on rump/trunk may mimic FAD.

kitten: ear canal fills with cerumen, blood, and mite exudate looking 
like coffee grounds, +/- pruritus.
cat: hypersensitivity response - 
chronic otitis externa w/o mites seen - therapeutic trial required. 
miliary dermatitis of neck/trunk may occur.
with cats, always tx whole 
body in case they are harboring mites on trunk - so dip the cat with lyme 
sulfur.
cats may also get hyperplastic grapelike grey nodules - 
hypertrophied ceruminous glands - in adult cats with longstanding ear 
mite hypersensitivity.
horses get psoroptes equi
rabbits get psoroptes 
caniculi
presentations like dog

dx: swab ear, mix with mineral oil, 10 x 
objective (coverslip required)
tx: clean ears, apply otic miticide 
(tresaderm), whole body tx with flea product. catteries and kennels with 
endemic problem - ivermectin. can also use ivermectin for therapeutic 
trials. 

human pubic louse - reproduces similarly to otodectes, hatches 
by passing gas. pthiris pubis.

dermanyssus gallinae - not common. 
bird/poultry mite. parasite by night, hider by day. causes eruptive 
dermatitis/itching in dog/cat/man. dx skin scraping, big round sucker. tx 
flea dip/spray/ivermectin, tx environment. leave  it up to poultry people 
to get rid of it on birds. cats that hunt birds may get it.

lynxacarus 
radovsky: cat fur mite - endemic to tropical climates, TX, FL, HI. long, 
slender mites grabbing hairshaft - salt and pepper look, diry look to 
coat. not pruritic. dx acetate tape prep or pluck hair. tx flea spray, 
mousse, lyme sulfur dip. not zoonotic.
long mite.

trombiculiasis - 
chiggers.  make small red itchy dot on skin. larvae are parasitic, 
adults/nymphs live free. summer/fall seasonal problem. pruritic, papular 
rash of contact areas. dx: microscopic exam, tx: flea dips, sprays, otic 
mite preps.

pneumonyssoides caninum: nasal mites
rhinitis, sinusitis, 
sneezing, catarrhal dc OR totally asymptomatic. may mimic allergic 
rhinitis. dx: nasal flush, rhinoscopy, use of gas anesthetic - capture a 
mite for micro. you see a little white thing RUN fast across its nose. 

tx ivermectin.

pediculosis: lice.
dorsoventrally flattened, wingless 
insects - basically a nonproblem unless you are in a rural area with poor 
flea control. flea products kill lice and people now use frontline, 
advantage, or other antiflea things. lice spend entire life cycle on host 
and are very spp specific. eggs are attached to hair shaft. sucking lice 
may cause anemia. any louse can cause pruritus and a dirty appearing, 
unkempt haircoat. 
dx: microscopy, eggs loosely attached to hair and 
larger than chyeletiella.

--
Flea biology and control:

fleas are your 
friend, not your enemy.
they are a practice builder. 
there is no perfect 
flea preventive or treatment.
a lot of OTC products are not that 
effective or safe, either. you must be an expert on flea biology and 
control. 

fleas are very responsive to genetic mutation. it seems the 
new products are seeing resistance form against them (advantage, 
frontline). 

wingless insects, laterally compressed bodies, 2000 spp 
worldwide, $9 million spent annually on flea control in US. 

spp seen in 
dog/cat here: ctenocephalides felis felis; c. canis in ireland, pulex 
irritans is human flea but prefers dog/cat, echidnophaga gallinacea is 
poultry flea. 
fleas aren't spp specific.

life cycle: occurs via 3 
larval stages, with molt b/w each, and one pupal stage. if you add up the 
time b/w all of these, they can go from egg to adult as fast as 11 days 
(rare) or up to 6 mos. avg life cycle is 3-4 weeks, though. that affects 
how we tx environment. 

important things to know about flea biology so 
you can justify why you tx the way you do and also so you can choose 
combination protocols:

larva which live in carpet feed on feces, dry 
blood, organic debris.
adults live on host until they die - do not jump 
off host, then jump back on.
clients claim fleas are jumping off dog onto 
them but they are hatching from carpet and getting onto client. 
eggs are 
laid on host, but fall onto ground
pupal stage: pupae stay pupated as 
long as needed to have easy access to blood meal. require stimulus to 
emerge. people may have summer homes, close them up in winter with a lot 
of pupated larvae in there, then when they go in and set up vibration/air 
currents/etc hundreds of fleas emerge within 10 minutes. 

for every 5 
fleas you find on a dog, there are 95 juveniles in the house. 
fleas 
spend whole adult life on host and must feed within 12 days of emergence 
- although really within 3-4 hours, 12 days is lab test value.
lifespan 
is about 100 days
females lay up to 50 eggs/day with avg 25/day
fleas 
vector several infectious dzs, can cause anemia, and FAD flea allergy 
dermatitis. 

on pet control:
adulticides
insect growth regulators

development inhibitors
new products in the works

environmental control: 
indoor and outdoor!

on pet delivery systems: many options:
collars, 
shampoos, dips, powders, foams, mousses, sprays, spot ons, systemics.

collars and shampoos basically are worthless. the collars impregnated 
with IGRs (ovitrol and knockout) are the only ones useful, best in cats. 
adulticide collars are pretty useless in most pets. shampoos are good for 
quick knockdown but have no residual activity. dips are not much better - 
residual activity on label is 3-4 wks but really about 3 days. 
powder/foam/spray - better residual activity - cats prefer foams in 
general. powder mainly for pocket pets, ferrets, kittens. spot ons - two 
different types. old world type - far too risky for use and should be 
taken off market. new type : advantage and frontline - safe and 
effective. systemics like program - or proban.

adulticides:


organophosphates:
we have better products now so these are hard to 
justify using. they are cholinesterase inhibitors, toxicity is a real 
clinical concern esp in cats. most of the OPs we use today are in lawn 
treatment products, not on pets or in pets or in the house. 

carbamates: 
(carbaryl) - also cholinesterase inhib but less toxic than OP. still used 
commonly in shampoos and powders. rabbits, pocket pets. avoid cumulative 
toxicity. if you use in kitten, only every other week unless you bathe in 
between. 

pyrethrins - safer adulticide. derived from chrysanthemums, 
which appeals to crunchy birkenstock Berkeley types. of course, cyanide 
is also a natural product. anyway, thes ehave fast knockdown, fairly low 
toxicity, ok in puppy, kitten, etc. however, short acting. good 
knockdown, rapidly inactivated by sun, short acting. can synergize with 
piperonyl butoxide which inhibits flea metabolism of it by P450 - but can 
also increase mammalian toxicity.

pyrethroids: man made pyrethrins. 
permethrin, allethrin, etc. longer residual action, slower flushing 
action. greater toxicity esp in cats. permetrhin has repellent activity, 
probably dose dependent. some products combine a pyrethrin with a 
pyrethroid. pyrethroids are available as on-pet and environmental sprays. 
permethrin is the ONLY preventive repellent available. ** advantage is 
not a repellent. frontline isn't a repellent. permetrhin is the ONLY ONE 
but we can't use it at a high enough concentration in cats to work w/o 
making them sick. 

rotenone: derived from derris plant. highly toxic to 
fish, bad for water supply, not used much anymore. active ingredient in 
Goodwinol ointment used for localized demodex. not that efective. rapidly 
decomposes when exposed to light, air.



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