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: Clinical Approach to Feather Plucking


ArtS
06-11-2007, 05:09 PM
Clinical Approach to Feather Plucking

Neil A Forbes BVetMed Dip ECAMS CBiol MIBiol FRCVS
Avian and Exotic Department, Lansdown Veterinary Surgeons, Clockhouse Veterinary Hospital, Wallbridge, Stroud, Glos. GL5 3JD, UK and University of Bristol, Langford House, Langford, N Somerset. BS40 5DU, UK


Feather picking is the most common dermatological disorder of caged psittacine birds (Rosskopf and Woerpol 1996) and is one of the commonest presenting complaints in avian practice (Welle 1999). Feather plucking cases are typically complex, multi-factorial (often mixed medical and psychological) and even in experienced hands some 30% will be refractory to therapy (Jenkins 1999). Medical causes of feather picking must be eliminated prior to psychological causes being considered. In the authors opinion it is impossible to address a psittacine plucking case without a complete understanding of psittacine behavioural disorders. A diagnostic work up of such a case starts with the collection of a detailed history. This is rarely diagnostic, however, clinical suspicion may be increased to allow the experienced clinician to order further tests to expedite a diagnosis. Sections of this paper have been shortened for publication. A full version may be seen at http://www.lansdown-vets.co.uk

BACKGROUND HISTORY COLLECTION


See http://www.lansdown-vets.co.uk

HISTORY COLLECTION STAGE II


The following notes in a simplified form are then discussed and annotated point by point with the owner, with the aspiration that by the time the clinician undertakes the clinical examination, he can focus his attention on certain areas.

Medical Causes


Allergies

Well documented - see Girling this issue

Ectoparasites


See Chitty this issue

Endoparasites


Frequently cause problems, particularly in cockatiels, but should be excluded in all species. Giardia spp. and ascarid worm infestation have been documented to cause hypersensitivity reactions and feather picking mainly affecting the ventral wing web. Examining a warm wet direct faecal smear (within ten minutes of collection)for the presence of motile trophozoites may be diagnostic. When making smears, saline or lactated ringers solution should be used as a diluent. Trophozoites are flat and have a smooth rolling motion. Smears can be dried and stained with trichrome to detect Giardia spp. cysts. Zinc floatation techniques can be used to increase accuracy (Greiner and Ritchie 1994). Repeated examination may be required to make a diagnosis. Giardia spp. are commonly found in asymptomatic individuals so treatment of in contact birds is warranted. Giardia spp are potentially zoonotic and are treated with 50 mg/kg dimetronidazole q12h for 3-5 days. Ascarid ova are most readily detected on faecal flotation using saturated salt or sugar solutions.

Environment

Excess tobacco smoke, aerosols, other sprays or building dust, too dry an environment (often triggered by central heating being turned on), can all lead to itching or poor quality feather growth resulting in brittle feathers, which break as the bird plucks them. Many psittacine species developed in equatorial (rain forest) areas and will benefit from daily water spraying and weekly bathing. A continually dry environment may lead to premature wear on the plumage resulting in tatty feathers prior to the subsequent moult. A parrot with poor or damaged (especially clipped) feathers will often attempt to remove them. Low light intensity, an inability to bathe, or inadequate rest (<12hrs) will also cause plucking. It is often best to cover a bird at night, only removing the cover in the morning when you get up. The bird’s cage should not be left in direct sunlight. A bird living in a house in which there is domestic conflict may often react by plucking.

Metabolic / Systemic Disorders

Hypothyroidism- see Girling this issue

Any form of liver disease may lead to itchy skin and hence plucking. Chlamydophilosis (psittacosis) is the commonest cause of psittacine liver disease also causing septicaemia, and air sacculitis any of which may lead to feather plucking.

Heavy metals


Lead, zinc, copper or iron toxicity can causes somnolence, ruffled feathers, altered feather colouration, depression, ataxia, brown haemorrhagic urates or nervous signs. The presence of a new cage or aviary, toys or unsupervised periods outside, would indicate further testing. Elevated blood lead and zinc concentrations are diagnostic. Rubber stoppers on glass blood collection vials and rubber plungers on syringes will lead to false zinc elevations whilst haemolysis will give rise to false positive results. Blood zinc levels are not universally reliable (Fudge and Speer 2001).

Radiographic visualisation of heavy metal particles in the gastrointestinal tract along with clinical signs is highly suggestive. The absence of heavy metal particles on radiography does not rule out toxicosis, as particle size may be rapidly eroded. More over, the cause is typically “chronic” low-level exposure, which frequently does not involve particulate metal ingestion. Non-enteric metal will not result in toxicosis.

Medical treatment consists of fluid therapy, antibiosis and chelation therapy with calcium disodium versenate at 50-100 mg/kg IM q12h for 5 days. Supportive care, warmth and fluids are essential in critical patients. Prokinetics (cisapride at 0.5-1.5 mg/kg q 8-12h) and gastrointestinal bulking agents (pysillum or peanut butter) may be useful. Large non-progressive metal foreign bodies will require endoscopic, surgical or gavage removal. Control is achieved by identifying and removing the source from the bird’s environment. New galvanised aviary wire may be scrubbed with a five percent acetic acid solution to remove surface zinc. Cages may be powder coated.

Chlamydophilosis


(Psitticosis). May cause a wide range of clinical signs including poor plumage, emaciation, lethargy, fluffed appearance, conjunctivitis, dyspnoea, rales, sinusitis, diarrhoea, CNS signs, yellow to green droppings and “sudden” death or no clinical signs at all. Chlamydophilosis is the commonest cause of hepatitis in psittacine birds. Skin effects of Chlamydophila spp infection are often related to liver pathology. Dermatological signs include generalised pruritus and plucking of the abdomen. Many plucking birds test positive for the disease, whilst this does not confirm that this is the primary cause of the condition, all plucking birds should be tested and treated as indicated by results.

For methods of testing and treatment see http://www.lansdown-vets.co.uk

Folliculitis:

Bacterial

See Chitty this issue

Fungal

Dermatitis or folliculitis is rare but clinical signs may not be indicative. It may be caused by Candida spp (commonest in gallinaceous birds in the vent area and in some pet birds around the head), Aspergillus spp (seen as feather or skin lesions commonest in pigeons but may well be under diagnosed), dermatophytes (causing patchy feather loss especially on head neck and breast) or Rhizopus spp. (often seen as discolouration of the plumage). Typically there is follicular involvement in candidiasis with white crusting around the affected follicles.

Polyfolliculitis


Affects multiple feathers from one follicle. Common cause of self trauma specific to love birds and budgerigars (Perry 1991). Surgical removal of affected follicles is efficacious, although reformation and similar affliction of other follicles is likely.

Viral

See Chitty this issue

Genetic


Feather dusters and straw feather are two genetic abnormalities affecting budgerigars. The names are descriptive of the visual appearance of affected birds. Feather cysts are common in certain breed lines of canaries. A genetic susceptibility is postulated. Many other psittacines suffer feather cysts.

Malnutrition


See Girling this issue

Neoplasia

Feather plucking may occur over the site of a skin cancer or the trauma of repeated plucking may cause such a lesion (most associated with chronic ulcerative dermatitis - CUD). A wide range of cutaneous neoplasms has been documented in various species (Forbes et al 2001, Wilson et al 2000) together with suggested treatment regimes. Many tumour types have been identified including the following: fibrosarcoma, lymphoma, adenocarcinoma (affecting the preen gland), papilloma, squamous cell carcinoma, myxofibroma, fibroma, histiocytic sarcoma, leiomyoma, epidermoid carcinoma, haemangioma and mast cell tumours. Papilloma often affects the cloaca, choana (common in Amazons and macaws) or feet (cockatoos) and on occasions caused by herpes virus - may respond to systemic and or topical acyclovir therapy. Those affecting the cloaca or choana often progress to cause fatal bile duct carcinoma (Taylor and Smith 2001) For solid bodied tumours, chemotherapy regimes have been documented with carboplatin (Filippich 2000). This is given as a daily bolus at a dose of 5 mg/kg.

Once all medical causes have been excluded and management has been improved then behavioural causes must be considered.

PSYCHOLOGICAL CAUSES


The typical pet parrot has the mental age of a four year old child but never grows up. In considering the conditions listed below, doing so through the eyes of a four year old will enable greater understanding. Much information can be gained by finding when the bird plucks, who is present or absent at the time, the time of day, season of year and how it reacts when it is plucking (see initial history collection).

Attention seeking


Many pet birds are bored and feather plucking can be an excellent way of attracting their owners attention. The owner often gives positive reinforcement for the bad behaviour by 'telling the bird off'. The more the owner scolds the bird, the more attention it is receiving, the happier it will be and the more it will pluck. Such birds often vocalise to attract the owners attention prior to plucking. These birds should be ignored, or one can use a ‘time out method’ of behavioural modification. If the bird plucks, you go to the cage, do not address the bird, but cover it up. Initially for a three minute period, increasing to as much as 15 minutes if necessary. The bird must receive negative feed back for its bad behaviour rather than the positive encouragement it has received up until now (Wilson 2000).

Boredom


Boredom or lack of routine is a very common cause of feather picking. In comparison with the bird's natural life in the wild, life in a cage or a household, when owners are often absent for much of the day may be similar to solitary confinement for a human. A normal bird in the wild spends 50 % of the day flying to and from and searching for food. Thirty percent of the day is spent playing with the birds flock mates, and 20% is spent preening. A captive bird does not have to hunt for food, often has no flock mates to play with, and hence will fill more of the day with the preening which may then become compulsive. This should be addressed with environmental enrichment. If the bird can be kept occupied and active, these problems are less likely to arise.

Separation anxiety


Separation anxiety may be as important as boredom as a cause of feather picking. Although seen in cats and dogs, it is even more likely in parrots in view of their high intelligence. Keeping the bird busy will help, medication can be of value (clomipramine [0.5 - 1.0 mg/kg po bid] or fluoxetine (Prozac) [1-2mg/kg po bid]), but is not a solution unless combined with behavioural modification training. The training should be geared to break down the anxiety triggers and to increase the parrot’s confidence that it can cope for short periods alone. Separation anxiety exhibit plucking as soon as they are left alone. Giving them something to do to occupy them when they are first alone helps, although care must be taken that the activity does not become a signal of impending separation. The bird should not be able to predict when or whether you are going out, or even whether you have gone out. Separation anxiety may be over come but it requires considerable understanding, patience and time.

Stressors


May be many, varied and different to what a human would expect to be stressful. The avian response to fear or threat is to flee. If unable to escape it may redirect it’s energy to a ‘fear response’, which may include plucking or self mutilation. Causes of stress or fear should be identified and eliminated. Increasing confidence, (behavioural modification training) and facilitating controlled flight is beneficial. Haloperidol [0.02 - 0.20 mg/kg po bid], clomipramine and fluoxetine may be useful in the initial stages of retraining.

Over crowding


Overcrowding and social stress can lead to plucking. Overcrowding can lead to disputes between birds over territory rites. A dominant bird in a cage will sometimes pluck a subordinate bird in order to enforce his dominance (this can also happen between a breeding pair where one bird is particularly dominant).

Environmental change


Birds are accustomed to a variable life. If variety is provided, they will be stimulated and will enjoy it. If the bird is scared of the cage moving to a new room, coming out of the cage, or new toys in the cage, this is a certain indication that the bird has become 'institutionalised - i.e. acclimatised to solitary confinement, together with all the abnormal behaviour patterns that accompany it. Birds unaccustomed to change are unable to tolerate change. Recent change or a disorganised constantly changing household can lead to plucking. Additions or losses of any members of the household (including other pets) can trigger plucking. Domestic aggression within a household will often trigger plucking.

Excessive preening


This may start as normal preening (in particular at the start of a moult) and then become obsessive particularly if there is insufficient environmental enrichment.
Sexual aggression or frustration


Aggression is most common in cockatoos and love birds. In such cases the head and beak are frequently attacked, although wings, chest and legs may also be insulted. In the author’s opinion, frustration is responsible, at least in part, for many of the behavioural problems experienced in both cockatoos and greys. Parent reared birds mature at five to six years, but hand reared birds can become sexually active from the age of six months. Some birds will regurgitate to a family member, or present their cloacal region. These birds perceive they are human and on becoming sexually active they request sexual favours from their owners. Signals from the birds are misread and not reciprocated. Such cases require a multi faceted approach. The birds may be injected every two weeks on three occasions with leuprolide acetate (Leupron). This acts on the pituitary gland, switching off messages that stimulate the gonads to increase sex hormone production. At the same time the owner to whom the bird has been making advances must not interact with, handle or go near the bird for a period of at least six weeks. Exposure to daylight is reduced to 6-8 hours in the hope that the bird believes winter is coming and that it would be a bad time to breed anyway. Although these treatments will defuse the situation temporarily, a long term solution is required. Behavioural modification training must be used to gain a ‘parent : child’ or ‘leader: follower’ relationship, (rather than a partner: partner relationship) between the owner and the bird. This is achieved primarily by achieving a dominant relationship over the bird. This must comprise height advantage at all times, but also the bird must be prepared to obey commands without question at all times. If this is achieved, further sexual problems are unlikely. Having two birds in separate cages but within each other's view can also lead to sexual frustration and may trigger plucking.

Obsessive compulsive disorders


If a bird suddenly stops in the middle of its favourite activity just to pluck, it is either very itchy or is suffering from obsessive compulsive disorder. Such behaviour is akin to stereotypic behaviour, which is seen in certain badly housed zoo exhibits. Medical therapy is oftenrequired to break the disorder (clomipramine, fluoxetine or haloperidol), whilst serious environmental enrichment is implemented. In truth, a major life style make over is required. Other causes of severe itch should be eliminated before assuming this diagnosis.

Feather clipping


A poorly or unevenly clipped wing can stimulate a bird to start plucking, perhaps in an attempt to do a neater job. If the cut ends of the primaries or secondaries are left at 30 - 50% of their full length, when the wing is closed against the body they may irritate the abdominal wall. Imping of the short, sharp or tatty feather ends may be palliative, imping back a complete set of feathers is better (Welle 1998a). A wing clip should not be performed to prevent flight. A bilateral clip should always be performed. Depending on the species either the tip of each wing (taking a diagonal line from the tip of the 4th primary to a point 1/3rd from the tip of the first primary, or leaving the outer 3-4 primaries then removing the next 4-5 primaries at the level of the covert feathers) may be clipped if essential.

Trauma


Any bird which has had any traumatic injury (recent or historic), or internal pain (including rickettic deviations of the ulna and radius), may pluck over the focus of pain.
PHYSICAL EXAMINATION AND COLLECTION OF DIAGNOSTIC SAMPLES

A systematic examination of the beak, cere, feet, ears, preen gland, skin and cloaca should be made. In particular, body condition, colour and nature of plumage, durability of feathers, stage of, or interval, since last moult (check all feather types). The feathers should be checked for 'fret' lines or bars (lines of weakness), which indicate that the bird was stressed by some concurrent disease, nutritional deficiency, trauma or other episode at the time of the previous moult. Check skin (face, apteria, inguinal, under wing, legs and feet, cloaca). Following a detailed history and clinical examination, a minimum database for all feather picking cases should include a complete biochemistry panel and haematology profile, lateral and ventrodorsal whole body high detail radiographs, faecal floatation and direct warm faecal smears, zinc and lead testing and Chlamydophila spp. diagnostics. If indicated on history taking, the following diagnostic tests should be considered. Feather pulp cytology with bacterial culture and sensitivity testing or fungal culture, follicular biopsy and histology, polyoma and circo virus (Psittacine beak and feather disease 'PBFD') testing; intradermal allergy testing, thyroid stimulation tests, impression smears, fine needle aspirates, skin scrapes and abdominal endoscopy with biopsy.

Blood collection is a commonly used diagnostic technique in avian dermatology. A sample of up to 1% of the bird’s body weight can be collected. For small volumes a toenail can be clipped and blood collected directly into a blood tube with an anticoagulant, although contamination (e.g. with uric acid) may occur. With the exception of very small patients, the authors preferred method is venous sampling as it enables more reproducible results. The use of a 25-gauge needle is recommended since smaller needles can result in significant collection haemolysis.

Different authors debate the necessity of general anaesthesia for jugular puncture. Cost, anaesthetic risk, risk of post sampling haemorrhage, age and health status of patient, the desires of client and risk of phlebitis should all be considered. The right jugular vein is accessible in most species. For raptors and Columbiformes the basilic vein is convenient and of a significant size. This location can also be used with patients in sternal recumbency when lateral recumbency poses a risk of regurgitation. The medial tarsal vein, proximal to the tarsal joint on the medial surface of the tarsus is readily accessible in Galliformes and Anseriformes. This vein also has a reptile like skin covering, a decreased chance of haematoma formation and the area is rarely covered by feathers.

A blood film should be made at the time of collection. This can be achieved using a variety of methods aimed at reducing the number of smudge cells. A commonly discussed technique is to place a drop of blood between two cover slips and to glide them past each other before the blood spreads out (Fudge 1994). This technique requires practice. Lipaemic samples may result in false elevations of bile acids, calcium and plasma proteins when determined with non-temperature compensated refractometers. AST will be elevated with severe lipaemia. Haemolysis results in false elevations of bile acids, LDH and potassium. Bacterial contamination of samples results in decrease glucose, CPK and elevated calcium (Fudge 1994).

Feather pulp cytological examination


Should be conducted on cases when other testing has failed to determine an aetiological agent or when significant folliculitis is present. This involves plucking a blood feather and squashing it to expose the pulp using two sterile glass slides or a sterile scalpel blade. It is useful to have at least two preparations. A gram stain allows assessment of bacteria and yeast and a Diff Quik or Wright’s stain is used to assess inflammatory cells, inclusion bodies or yeast. The absolute number of bacteria and the type of inflammatory cells present will indicate where necessary the need for follicular bacterial culture and sensitivity testing. Other relevant samples are collected (feather pulp and blood) for PBFD and polyomavirus.

If feather cytology is suggestive of fungal disease, fungal culture should be undertaken. Black discolouration of feather tips with an oily appearance was documented in captive flamingos with saprophytic dermatophytosis (Robinson 1996). This author has also experienced this in psittacines with Rhizopus infections. Treatment includes improving hygiene, reducing moisture and the use of topical antifungal solutions. Normal feather structure is typically not regained until the subsequent moult. Malassezia infection demonstrated on histopathology or impression smears is considered a significant cause of pruritus by some authors. Although yeast may be seen, it may not be possible to culture the organism (Van Sant 1999). Fungal infections require treatment with ketoconazole 20 to 30 mg/kg q12h for 3 weeks, or topical weekly washes with miconazole or similar topical antifungal preparation for at least 4 weeks.

When collecting follicular samples for bacterial culture and sensitivitythe surrounding skin (but not the feathers) should be aseptically prepared with iodine or chlorhexidine scrub. The selected feather is plucked and the shaft bisected (in a sterile manner), to separate the calamus and rachis. The calamus can then be submitted for culture and sensitivity testing. Whenever a significant folliculitis is present, diagnosis and treatment of secondary infection is warranted.

A feather biopsy and histological examination is indicated in cases of feather dystrophy, to aid in the diagnosis of PBFD or Avian Polyomavirus (APV) (Schmidt 1993), to exclude feather cysts or to support a suggestion of hypothyroidism. Both PBFD and APV are associated with inclusion bodies in epidermal cells. Feather cysts are elongated follicles with a cystic structure containing yellow-white keratin. Norwich and Yorkshire canaries are predisposed to this condition suggesting a hereditary susceptibility. Treatment involves surgical excision of the entire cyst structure. Diagnosis is on histopathology. Further cysts are likely to form.

Pruritus caused by polyfolliculitis (multiple feather quills in a single follicle) has been documented in budgerigars and lovebirds (Perry 1991). The pathophysiology of these lesions is unclear and polyfolliculitis maybe a primary aetiology or secondary to pruritus. In lovebirds feather tracts of the rump, tail and mid upper neck are affected. These can be sampled for follicular cytology, biopsy and bacterial isolation, culture and sensitivity. A significant number of these cases are polyoma positive (Cornelissen et al 2000). Treatment is via surgical resection of the follicle. Recurrence at other sites is common.

Internal conditions such as preen gland infection, neoplasia, arthritis secondary to thoracic limb metabolic bone disease, may lead to localised feather loss or mutilation in response to pain associated inflammation of adjacent tissues. Diagnosis may require detailed examination, full body (in two dimensions) high definition radiographs, haematology, biochemistry, endoscopy and biopsy.

Action to be taken by the owner.


· If the parrot is alone by itself all day whilst everyone else is out at work, consider re-homing the bird.
· Improve the diet
· If possible, put the bird outside in a flight.
· Improve the bird’s environment, (no smoking, not too dry, no direct sunshine, no excessive day light etc.). Spray the bird lightly each day with warm water, preferably allow access to a bath, most parrots appreciate this. Take the bird out of the cage as much as possible.

Environmental enrichment


Remember that the average parrot has a mental age of a four-year-old child. You would no more shut a four-year-old child into asmall cage and ignore it all day, than you should a parrot. Any child so treated would inevitably grow up a psychological wreck. Mentally stimulate the bird, use 12 toys, but only four at time and change them weekly. Toys may be divided into climbing, chewing, foot and puzzle toys.

Climbing toy - plastic chains, ladders, swings and the cage itself.

Chewing - many psittacines like chewing especially cockatoos and greys. They may be provided with wood, branches with the bark left on (non toxic woods which have not been treated with herbicide / fungicide), pasta, raw hide etc.. Empty paper towel rolls, with paper tucked in them, or paper threaded through the bars of the cage. Encourage the bird to be destructive.

Foot toys - stimulate manual dexterity, and may include fir cones, pieces of corn on the cob, nuts left in whole shells to manipulate and break open.

Puzzle toys - one the most important and least used groups. These may include parrot style music boxes and puzzle boxes that contain food, which they can access if they complete a task.

A bird's environments is not naturally quiet, lack of noise in a jungle situation would usually be an indication of danger. Keep the radio or TV on if you are out. Let the bird out of the cage as much as possible, but beware the household dangers, in particular the risk of chewing electrical wires and the ingestion of heavy metals (zinc or lead).

Prevent plucking by use of a collar or neck support, whilst therapy is on going. The bird may need to be hospitalised initially whilst it becomes accustomed to the collar. Collaring (as with medication) is a means to an end not a solution.

Behavioural Modification Training


Most young wild psittacines remain with their parents for a considerable period. During this time most of the bad behavioural problems would arise and be dealt with by the parents e.g. phobias, excessive territoriality, biting, screaming and feather picking. Since it is the parental guidance, which is lacking in these captive-bred parrots, then increased alternative training must be supplied. It is important that the bird knows his position within the domestic flock. The owner should exert dominance, as in time should all members of the family. The bird must be maintained at or below adult chest height. Each day the bird should be taken into a room it is unaccustomed to, and trained using basic commands. Using a 'T perch', do basic 'UP', 'DOWN', 'NO', 'OK' commands. Up and down refer from perch to arm and back, no is simple, ok denotes the owners decision to allow the bird to do something, ie it can only do it after your allowance. Birds soon quieten down and become less erratic and irritable once training commences. Such training can often assist in reducing the daily stress of the plucking bird, as the bird feels secure being part of a hierarchical group. Make all aspects of it's life, e.g. finding food, exercise, entertainment, thinking etc more exciting and varied (Blanchard 1999, Weiss Murad 2001, Martin 2001, Davis 2000, Smith and Orosz 1998).

Therapy for feather loss or plucking


Apart from the behavioural, husbandry and nutritional changes recommended above, medication is also on occasions required. If a specific pathogen is indicated then relevant systemic antibiotics or antifungals should be administered. If ecto parasites are incriminated then fipronil may be applied, the environment cleaned and treated with permethrin and pyripoxiphen. Ifmites are present systemic avermectins should be administered and metronidazole for giardia.

Psychotrophic drugs may also be administered (Welle 1998b, Tully 1997, Lennox 1999), not as a solution but as a way of giving an opportunity for training or other techniques to be used to over come the problems.

REFERENCES

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Welle KR (1998b). A review of psychotropic drug therapy. Proceedings. Association of Avian Vets Annual Conference. AAV. Lake Worth, Florida, 121-124.

Welle KR (1999). Clinical approach to feather plucking. Proceedings. Association of Avian Vets Annual Conference.AAV. Lake Worth, Florida, 119-124.

Wilson H, Graham J, Roberts R, Greenacre C, Ritchie B (2000). Integumentary neoplasms in Psittacine birds: treatment strategies. Proceedings. Association of Avian Vets Annual Conference.AAV. Lake Worth, Florida, 211-214

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lily
06-11-2007, 05:37 PM
Super article, Art! Thanks! Were you able to read the long version at the website stated?

ArtS
06-11-2007, 08:03 PM
Lily,

i haven't finished the short version ;).

I hope to read everything tonight.

Regards,

Art S.