Meet Captain SLO

Captain SLO is not Top Gear’s former Captain Slow. For one thing, James May has participated in one more race than Nick has. Rather Captain SLO take his nickname from the cause of Nick’s dodgy nails, symmetrical lupoid onychodistrophy. That’s a scary sounding mouthful. This post is about the onset of Nick’s disease in 2011 and what I’ve learned about managing it since.



Revision History

  1. 4/25/2016 initial draft
  2. 4/26/2016 added references 1 and 2 and dosage information taken from Reference 2.
  3. 12/26/2022 Replace deleted reference URLS.

In doing the research for this article, I discovered that I’d been giving Nick an excessive amount of fish oil and will recalculate his dosage and stick to it. I divide his dose between morning and evening meals to improve stool quality and have a more uniform therapeutic effect.

See your vet

If your hound is experiencing splitting or peeling nails do not attempt to treat the condition on your own. Splitting nails are a condition with several root causes including infections in the nail growth bed, SLO, and other systemic causes. A veterinary dermatologist will perform a differential diagnosis to determine the proper initial treatment and maintenance treatment. The information given in Reference 2 is typical and is included to indicate that SLO is easily treatable and inexpensive to treat.

It began with a split nail

One evening I came home, took the dogs out into the back garden for after work toilet, and let them in. After a bit, I noticed Nick exiting my bedroom with a limp and leaving a trail of red dots everywhere he stepped with one foot. I found a split nail and took him in to his vet’s after hours clinic to have the nail cleaned up. We’d both assumed he’d split it in the garden or in a clumsy attempt to mount my bed where he’d like to hang out. After initial treatment, we thought nothing of it until about the 3rd visit for split nails. My day vet had not encountered SLO before so she arranged a specialist consult with the local dermatology practice.

At the dermatologist

Doctor Cook took one look at Nick’s dodgy nails and immediately recognized the symptoms as indicative of SLO.


This fore-paw photo looks largely unremarkable. But to the trained eye, it says SLO. The primary indications are a nail grown in a J with the bend parallel to the ground when standing and the stubby nails that looks like a carpenters pencil sharpened with a dull knife and the dull rough feeling horny covering. And from above


Contrast this with healthy nails on Missy.


Confirming SLO

SLO is confirmed by biopsy. This involves removing the dew claw or another nail to examine the growth plates. Most dermatologists are sufficiently confident of diagnosis by appearance and will treat without a biopsy confirmation. If the condition does not respond to tetracycline and steroids, then a biopsy is indicated.

SLO is an autoimmune disorder

SLO is an autoimmune disorder of the nail growth plates. The nail is actually a specialized bone designed to help with traction and serve as a tool for digging, defense, etc. SLO causes inflammation of the growth plate and poor formation of the nail. The nail is crumbly and weak and the horny covering is poorly attached to the quick. In the early stages, this presents as the nail peeling like a shrimp. The horny covering separates from the quick yet is attached at the growth plate. The separation is very uncomfortable and will usually result in a limp and possibly some minor bleeding.

As the disease continues, the nail sheaths (skin from which the nail emerges) can become swollen and infected. Most owners notice something is amiss long before this point and seek treatment.

Initial Treatment

Doctor Cook started Nick on a course of oral steroids and tetracycline. He also prescribed topical steroid (Synotic) to apply to the nail growth area at the knuckle. Doctor Cook also started Nick on Vitamin E (400 IU), niacinamide, and fish oil. I was to give the fish oil 180 mg EPA per 10 pounds of greyhound.

Your dermatologist will prescribe the dosage rates for the niacinamide and fish oil and leave you to calculate the proper amounts for the products you are using. It is important to give the fish oil at the proper rate to get the dosage he recommends. Excessive fish oil adversely affects blood clotting. Do the math.

Your vet will prescribe initial treatment based on the assessment of the hound’s condition.


SLO is an autoimmune disorder. It is not cured, just managed. The initial treatment with tetracycline and steroids brings the inflammation under control quickly to restore comfort. Continued treatment with niacinamide, fish oil, and Vitamin E manages the condition long term.

One issue I encountered was that I had misplaced my vet’s instructions and treatment began to drift.

Reference 2 gives dosages for a typical 60 pound greyhound.

  • EPA 180 mg per 1o pounds of greyhound (5 kg)
  • 500 mg nicainamine every 8 hours
  • 400 IU Vitamin E every 12 hours

The combination is synergistic so both the fish oil and the niacinamide must be given to maintain relief. The Vitamin E replaces E lost to fish oil metabolism. Some fish oils are supplemented with Vitamin E so don’t double up if you give a fish oil with a stated Vitamin E potency.

Not all Vitamin B are equal

Niacinamide is one of the many forms of vitamin B manufactured. Get this one. Not niacin, nor the non-flushing alternative. The body converts each of the three into Vitamin B but the but each has different secondary effects. Only nicinamide has the correct internal therapeutic action though all 3 will prevent deficiency diseases.

Niacinamide plus tetracycline is as effective as oral steroids in the initial treatment of several inflammatory diseases and its low toxicity and lack of side effects makes naicinamide preferred for maintenance. I give Nick 500 mg once or twice a day with peanut butter. Based on my reading today, I need to be careful to give 2 or 3 doses a day. It has a strong taste and is uncoated so pill with peanut butter.

Niacinamide is available over the counter in the US by special order from Target and CVS. A bottle of 90 or 100 tablets is about $5 so I buy in lots of 5 bottles to make it worth while. This usually lasts about a year. It can also be ordered from Amazon. Be careful that your supplier doesn’t don’t substitute on you.

The first year

If you give the fish oil at the proper dosage, the nails should show improvement over the first three months of treatment. It took me a good bit of fiddling around to begin to use bulk oil and to give an adequate amount.

Initial treatment brought improved comfort for Nick but his nails continued to peel while I learned to get the Synotic in the right place and tried various forms of oil. I had been getting capsules from the vet and giving 4 grams of oil a day. That was too little. We continued to treat a peeled nail every month or two.

After a bit, the vet decided that it was easy to get oil out in town and stopped carrying the oil capsules. I picked up some Verus coat supplement from my food dealer and began giving it. Over a couple of months, the splitting decreased while continuing the Synotic, E, and B with the oil.

The Verus oil was derived from Flax seed and was low in EPA and DHA relative to fish oil so I looked for a cold water fish oil to give in its place. I found two that are available in the US, Sea Pet and Alaska Natural. The oil that you give should have a statement like

  • provides 775 mg of EPA, 520 mg DHA and 200 IUs (134mg) of natural form vitamin E with each teaspoon.

that allows you to calculate the proper amount of oil to give. For 70 pound Nick, the dosage of this product works out to 1.6 teaspoons or 2 teaspoons. I’ve used both but tend to buy the Alaska Natural which is about $32/quart from my pet food dealer. The product comes in a thick hard plastic bottle with a 1/2 teaspoon pump. The Sea Pet product comes in a lighter soda plastic bottle without a pump. Both should be refrigerated once you start to use them to retard oxidation.

Sea Pet offers the cold water fish oil in three grades, regular oil, and two oils that have elevated levels of EPA and DHA. These sell at a significant premium proportional to the increased DHA/EPA level but the dosage is lower so they work out similarly cost wise per treatment. If you are experiencing sloppy stools, the more concentrated oil will help with that while still providing adequate levels of EPA and DHA. The Sea Pet products are available locally in the Virginia Tidewater and are easily mail ordered from the usual suspects.

After switching from fish oil capsules

Several months after I began giving bulk oil in the chow Nick experienced a reduced rate of nail splitting. The initial improvement occurred with the flax based oil but the best improvement came with the switch to salmon oil. For the two years that I’ve been giving salmon oil, the split nail rate showed a big drop. Nick is getting about 1 teaspoon of oil per 10 pounds of Nick, maybe a bit more. I had been putting 8 pumps or 4 tsp on a ration. Over time, the amount crept up. Having found Reference 2 and doing the math, I can reduce this to 3 pumps per ration.

Nick likes the salmon oil and won’t eat until I’ve put oil in his ration. He goes to the fridge and barks when time to be fed. He associated the oil with dinner and barks at the fridge rather than at the coat close where the food bin is. So I guess he likes it. It’s definitely a better deal than gelcap in peanut butter.

Four years on

Nick still has SLO. It’s an autoimmune disorder, but his is managed and he is comfortable. Peeled nails are rare but his nails are still dodgy as indicated by the crumbly ends. But the horny covering is smoother and is well attached to the quick. Splitting or peeling is rare because they are short and nail quality is improved. Nick is not not reactive to having his nails wiggled and prodded but he’s a grump about it and will tell me off if I’m overly poky about it.

One nail refuses to grow straight and has a rough porous feeling covering. the others are straight with blunt ends. Normal nails are like a machine sharpened pencil with a slick covering. So his are not normal but he is comfortable and his disease is well controlled.

Fish Oil and Clotting

Nick was due for dentistry about a year ago. In preparation, the vet ran a clotting time as part of Nick’s annual blood work. And found it slow. She prescribed Vitamin K treatment and did another draw. Nick was in spec. We scheduled surgery. They did a draw that morning and he was out of spec. So we did a second round of K and did the surgery immediately at the end of the course of K. Success. And he needed no extractions. Go figure.

I was reading another blog about SLO and discovered that fish oil (DHA and EPA) adversely affects clotting time. Nothing to be concerned about regarding every day nicks and scrapes but of concern when surgery is scheduled. The long and short of it is to consult with the dermatologist whenever surgery is planned as the fish oil is an important factor in the ongoing management of SLO. And to alert the vet when emergency care is needed.

Reference [1] mentions the clotting problem also and cautions against exceeding the recommended dosage for that reason.

By davehamby

A modern Merlin, hell bent for glory, he shot the works and nothing worked.