Symmetric Lupoid Onychodystrophy In Sighthounds

Have  you heard of Symmetric Lupoid Onychodystrophy (SLO)?  Chances are you  haven’t as it’s a very rare auto-immune disease amongst dogs but one  that we’ve seen an increase in in recent years.

This  may be because of increased awareness, or through pure chance, but  we’ve seen it quite a few times now, and in a couple of cases it has  been in older hounds who have struggled for years without the vet  diagnosing the cause.

Poor nail  health can often be as a result of other conditions such as nail bed  infections, skin disorders, allergies, diet and nutritional  deficiencies, all of which are more common and cause similar symptoms  such as brittle, flaky nails.  It makes sense that vets may want to rule  out alternative diagnosis before jumping to SLO, given its rarity…but a  quick diagnosis is important to start treatment to manage the condition  as it is very painful.

SLO is a  perplexing autoimmune disorder which presents with the gradual  destruction of a dog's nails between 3-8 years old.  Unlike typical nail  disorders, SLO affects multiple nails simultaneously, often in a  symmetrical pattern, hence its name. While SLO can occur in various dog  breeds, most commonly Shepherds, Setters and Rotties, it does seem to be  a higher incidence within greyhounds than previously thought.

The  exact cause of SLO remains elusive, though while considered an  immune-mediated disease there are thoughts that there are genetic links,  as well as it being related to food intolerances and trauma.  But,  given that no one really knows, most SLO cases are referred to as  idiopathic, which means there is no known cause.

In  dogs affected by SLO, the immune system mistakenly identifies the nail  structures as a foreign invader which must be removed.  The body  launches an inflammatory response aimed at their destruction and it is  this immune-mediated attack that leads to the gradual deterioration of  the nails, resulting in pain, discomfort, and opens a hound up to  secondary infections.

The  condition presents with brittle, easily broken and sloughing nails that  regularly fall off entirely or just have the outer protective shell  break off, leaving the highly sensitive inner nail exposed.  The nails  that drop or are broken may or may not grow back, and if they do grow  back, they are often misshapen or lacking a properly formed hard outer  shell.  There are also cases in which new nails will start to grow into  the existing nail causing them to split, while causing a great deal of  pain.

There is no rhyme or reason  as to the development of SLO, and it can seemly appear and escalate out  of nowhere.  Spreading to all four feet within weeks or months of its  first presentation.

Thankfully,  vets are now allowed to provide a diagnosis and treatment plan based on  the disease’s presentation and symptoms alone.  It used to be that they  had to amputate a toe and send it away for a nail biopsy!  You’d think  they would just take a nail…but no, they needed to take the toe!  We’re  rather glad that we’ve moved on from such practices!

Unfortunately,  SLO is a life-long condition, but it can be managed very successfully  and put into long-term periods of remission using long-course steroids,  pain killers, antibiotics, and dietary changes.  Once put into  remission, you may never need further treatment again, but care will  still need to be taken.  Should they have a flare, or get secondary  infections, they will need to go back onto their treatment plan.

If  managed appropriately, over time the nails will grow in correctly.   Providing a good quality diet, supplemented with niacinamide, the  omegas, evening primrose and biotin can make the world of difference!

The  prognosis for hounds with SLO is typically very good if an effective  treatment plan is put in place, it is a very manageable condition!   However, there are always caveats to things like this, because it does  also depend on various factors such as the severity of the disease, its  response to treatment and your hound’s overall health.  

While  affected hounds experience great improvement with appropriate  management, it is important to understand that SLO often necessitates  lifelong management.