SLO treatment options

[Jo CIMDA]

SLO   -   Taken from Bearded Collie SLO seminar notes by Jo Tucker
Treatment Options for Autoimmune Skin Disease
Fortunately, there are different treatment options for autoimmune skin diseases and as primary SLO is not life threatening, the most popular treatment seems to be a combination of Tetracycline or Doxycycline with Niacinamide (Vitamin B3).
Tetracycline and Doxycycline are antibiotics which also have anti-inflammatory effects and suppress antibody production. It is an immunomodulating drug, meaning that it has the ability to adjust the immune response to a desired level.
Note: Tetracycline (and Oxytetracycline) should be used with caution in dogs with renal impairment as it is eliminated from the body via the glomerula filtration and a build up of the drug can occur if used for prolonged periods. If it is necessary to give a dog with renal impairment Tetracycline or Oxytetracycline the dose should be lower than recommended but a lower dose may not address the problem of SLO, and also the treatment is likely to be for many months at least.  However, Doxycycline is excreted in the faeces and does not affect renal function and can be used in animals with renal insufficiency. (Plumb's Veterinary Drug Handbook)
Tetracycline or Doxycycline is commonly used in combination with Niacinamide (vitamin B3) for the treatment of immune mediated skin diseases.  Niacinamide works with Tetracycline or Doxycycline to further suppress antibody production.
Important:  Niacinamide is also known as nicotinamide but it must not be confused with, Nicotinic Acid, (Niacin). Although Niacin acts identically as a vitamin, it increases the blood flow and blood pressure, and should not be used.
It will take 1-3 months before any positive results are seen (although duration of treatment is much longer) but, in spite of this, it seems to be the treatment of choice for SLO as it is usually well tolerated and it avoids the use of steroids and other stronger drugs.  Many dogs do very well on this treatment regime. When good clinical improvement is seen the drugs can be gradually reduced and the dogs weaned off medication over a period of months. 
Dose:  Tetracycline & Niacinamide
Dogs less than 10kg : 250mg each Tetracycline and niacinamide every 8 hours
Dogs more than 10kg : 500mg each Tetracycline and niacinamide every 8 hours
Note:  Food can significantly reduce (up to 50% or more) the amount of Tetracycline or Oxytetracycline absorbed.   Avoid giving oral tetracycline within 1-2 hours of feeding or giving milk or dairy products
Doxycycline (5mg/kg/24 hrs) can be prescribed instead of Tetracycline and may be more convenient as it is given only once a day and, unlike tetracycline, food and dairy products do not affect its absorption.    (Plumb's Veterinary Drug Handbook)
Note:
Some authors recommend:
Dogs less than 10kg : 250mg each Tetracycline and niacinamide every 12 hours
Dogs more than 10kg : 500mg each Tetracycline and niacinamide every 12 hours
Michael J Day – Clinical Immunology of the Dog and Cat
Steroids
Steroids are life saving and can work like a miracle drug at times but, obviously unless you have no choice, as in a life threatening situation, it is always worth trying other treatment options before using high doses of steroids and other more potent and expensive drugs. If you and your vet choose steroids to treat your dog's SLO you may see quicker results, because the effect of steroids on the immune system is rapid.  However, the usual side effects of steroids can be expected. 
Steroids suppress the immune system in order to stop the destruction. The dose of steroids has to be `immunosuppressive', anything less and the treatment will not work and remission will not be achieved.   Over a period of months the dose is gradually reduced.
Immunosuppressive Protocols for Oral Prednisolone in the Dog.
Ref: Clinical Immunology of the Dog & Cat by Michael J Day  – Professor of Veterinary Pathology, University of Bristol, UK and WSAVA - Chairman of Scientific Advisory Committee.

Professor Michael DayBSc, BVMS(Hons), PhD, DSc, DiplECVP, FASM, FRCPath, FRCVS 

This example is base on a dog receiving an induction dose of 1.0mg/kg/q12hrs

Dose                Duration (based on clinical effect)

1.0mg/kg/q12h             10-28 days
0.75mg/kg/q12h            10-28 days
0.5mg/kg/q12h             10-28 days
0.25mg/kg/q12h          10-28 days
0.25mg/kg/q24h          10-28 days
0.25-0.5mg/kg/ Every other day      at least 21 days
0.25-0.5 mg/kg/ Every third day       at least 21 days
Note:  Steroids can cause an excess of stomach acid so, as a precaution, giving something to protect the stomach, such as Antepsin and/or Ranitidine alongside steroid treatment, is prudent.  Dogs treated with steroids without a gastroprotectant may develop stomach ulcers and all the problems associated with this avoidable complication.
The side effects of steroids should be considered when deciding on a treatment for SLO.  I am not going expand on what to expect when your dog is on immunosuppressive doses of steroids, or the side effects of using steroids, but if you do decide to go down the steroid route and would like to have more information or clarification, please contact me.
Regardless of which treatment you opt for, the damage already done to the nails within the nail bed will have to be dealt with in the usual way, and as the damaged nails emerge through the skin they may have to be surgically removed.  Sometimes, if the nails are only deformed, and not split or fractured, they can be managed by keeping them short. Hopefully within a few months the new nails will emerge looking much healthier or at least, not broken or fractured, and the dog will be free of pain.
Other drug options, if your initial choice doesn't work, can include:
(Chlorambocil, Gold salts, Pentoxifiline, Retinoids, Azathioprine, Atopica)
•   Pain Relief especially in the early stages or after surgery may be necessary, eg. Tramadol.
•   Essential Fatty Acids (EFA's) are given in therapeutic doses, regardless of which primary treatment regime is used.  High doses of EFA's also play an `active' role in the treatment of skin diseases and should be included in the treatment regime and in low maintenance doses after remission.  EFA's are known to be `steroid sparing' in high doses. This means that they may ultimately, lead to a lower dose of steroids being used and this is especially useful in dogs that have to remain on steroids.
EFA Ratio
Quote: "Research is being performed to determine the optimal ratio of omega-6 to omega-3 fatty acids that should be consumed. Previously, it was thought that the ratio should be approximately 15:1. Current recommendations are for ratios of 10:1 to 5:1." (Omega fatty Acids: sources, Effects, and Therapeutic uses in Dogs, Veterinary Services Department, Drs Foster & Smith, Inc.  Holly Nash, DVM, MS)
Example Therapeutic Dose: Essential Fatty Acids
"Effect appears to be dose related and optimum doses and the most effective combinations of these oils have not yet been determined. Daily doses of:
•   Evening Primrose oil 172mg/kg/day
•   Fish oil @ 44mg/kg/day
have been used in dogs over a one year period without ill effects."
(Ref: The Veterinary Formulary by Yolande M Bishop)
•   EFA dose should start at a high level until a response is seen.  This can take up to 12 weeks. EFA's can cause loose stools. If this occurs, start on a lower dose and build up to highest dose over a couple of weeks. Avoid Evening Primrose Oil in dogs with epilepsy.  Branded veterinary products are available. Follow manufacturer's dosing recommendations.
•   Natural Vitamin E (400-800iu/12hrs) encourages new cell growth.
(Ref: Clinical Immunology of the Dog and Cat by Michael J Day). 
•   Chinese herbs are also noted as being effective but the owner would have to go to a vet who practices in natural treatments.
•   Biotin (*5mg/kg/day) improves the quality of the nails but it can be difficult to obtain. Some dogs with SLO have shown to be deficient in biotin. This may be due to their diet.  Foods with a relatively, high biotin content include cooked eggs, liver, chicken livers, kidneys, some vegetables eg., boiled broad beans, raw or canned tomatoes, raw cauliflower, dried skimmed or whole milk, fresh milk, bran, yeast and raw egg yolk.  Do not give raw egg white as it contains a substance called avidin which binds to biotin and prevents its absorption. This does not apply to cooked egg whites as the cooking process deactivates avidin.
•   Gelatine – *10 grains (one capsule) every 12 hours.   (*Ref: Muller, Kirks Small Animal Dermatology).  Some owners give 1-2 cubes of jelly every day.
•   Good quality high protein diet in case of deficiencies.
•   Antibiotics if secondary infection is present.
•   Topical acrylic nail cement applied externally to permanent nail deformities, which suffer from re infection, could be strengthened and protected by this application.
I haven't known a dog to have external acrylic nail cement treatment but reference to this can be found in Muller, Kirks Small Animal Dermatology.
•   Removal of loose nails Loose nails may have to be removed, usually under anaesthesia. As you can imagine, recovery from this procedure is likely to be very painful.  Clipping, cleansing, removal of the fractured portion of claws may be necessary even after treatment is well under way. I would personally avoid having all the dog's nails on every foot removed, as walking and recovery is difficult.
•   Topical shampoos, Antiseptic soaks (Salt or Epsom Salt foot baths, Hibiscrub etc). Initially it may be necessary to bathe your dog's feet to keep them clean and to wash off the blood etc., but once they are dry and healing it seems better practice to try to keep their feet dry.  Antiseptic soaks or salt soaks will help to soothe and clean.  Epsom salt soaks are supposed to be very soothing when the dog has pain. When the feet are sore and weeping, you can use socks and boots (or strong plastic bags tied with string) when out walking.  This will keep the feet clean, but do remove the boots when indoors otherwise the feet may become warm and sweaty which could set up more secondary infection and prolong the healing time. New nails should be kept short.
Recovery
Tetracycline or Doxycycline/Niacinamide
Recovery is slow especially if the treatment is Tetracycline or Doxycycline and Niacinamide.  It takes at least 6 weeks before real improvement is seen. Although some owners have said that they have seen positive results within 4 weeks.  Dogs appear to tolerate this treatment very well, without any obvious side effects.  However, if adverse effects become a problem reduce the Niacinamide first, as this is more likely to cause an adverse reaction than the Doxycycline or Tetracycline. (Plumb's Veterinary Drug Handbook). 
Relapses
Relapses are not uncommon. If the dog is in remission when a relapse occurs, then it is most likely that he has encountered another trigger factor.  Treatment must start again at the original dose.
If a relapse occurs whilst still on treatment, then it is possible that the dose of the drug had been lowered too quickly or the initial dose was not high enough to achieve remission.  The treatment regime must be reviewed, or changed. Consider the possibility of an unidentified, underlying cause.
Autoimmune Disease - Working with your vet
It must always be a consideration that some vets in general practice may not have the experience to recognise autoimmune diseases, or even know the correct treatment. Autoimmune disease can mimic other more common conditions such as: infection, organ failure and even cancer. It is unreasonable to expect vets in general practice to know all of the diseases different breeds are predisposed to. It should be the owner's responsibility to be aware of the potential health problems within their dog's breed.  Don't forget that you and your vet are your dog's best friends and if your dog is showing signs of illness, obviously the vet is the first place to go. Working together with your vet is essential and your `breed specific' knowledge may assist the vet in reaching a correct diagnosis with the minimum of delay, and that may just make the difference!  If your dog is not improving and you don't feel happy with the way your vet is dealing with the problem – consult another vet or ask your vet for a referral to a specialist.
References
Plumb's Veterinary Drug Handbook.   
Clinical Immunology of the Dog and Cat by Michael J Day: The Veterinary Formulary by Yolande M Bishop. 
Muller, Kirks Small Animal Dermatology, UK Vet Publications.
       All information is provided for assistance and reference purposes only and is not meant in any way to substitute advice or treatment from your veterinary surgeon.