Sesamoid Disease

Patty Khuly

Summary

Sesamoid disease is an orthopedic condition of large breed dogs in which the tiny sesamoid bones in the wrist (carpus) or ankle (tarsus) degenerate, typically sub-clinically. In some cases, however, severe pain may result.

The condition used to be considered one where trauma to the feet (especially the kind of repetitive injury seen in racing Greyhounds) caused tiny fractures in these small bones. Yet more recent evidence now suggests that the two conditions (fracture and degeneration) are two distinct disease entities––hence the nomenclature that refers to the degenerative (non-traumatic) form of the condition as “sesamoid disease.”

Unfortunately, sesamoid disease is not yet well understood.

Why do some dogs experience this change and never appear to feel discomfort while others become painfully symptomatic? Is trauma ever a factor? Given that larger breeds are affected, is it likely related to bearing greater weight and the chronic stress on these bones in big dogs? Is the canine disease related to the equine version in which a poor blood supply leads to bone death? Are the ligaments and tendons in this area too loose or too tight? Are there one or more genetic factors at play?

Currently, all these are open questions.

Symptoms and Identification

The most common symptom of sesamoid disease can be listed as “none.” Most dogs do not experience lameness (limping) or even pain when the joint is manipulated. Some, however, will suffer mild to marked lameness, pain on palpation/manipulation and swelling in the joint. Over time, a poor range of motion and a visible thickening of the entire joint may result from osteoarthritis (arthritis) secondary to the condition.

In many cases, more than one joint is involved. According to one study, the front feet are more commonly afflicted by a two to one margin.

X-rays are the mainstay of diagnosis, though anesthesia is strongly recommended for best visualization of the sesamoid bones in “stress” positions.

Affected Breeds

Breed predilection has not yet been reliably established. Though the literature suggests Rottweilers account for many more cases than other breeds, their large size and popularity may account for their over-representation in the current research. One study even suggests that smaller breeds might be more frequently afflicted, but that due to the dearth of symptoms and the expense of screening in the absence of a problem, the true incidence of this disease among dog breeds will remain a mystery.

Treatment

Treatment of sesamoid disease is a controversial subject among veterinary surgeons. Though some advocate removal of the diseased sesamoid bone(s), a poor range of motion and insignificant pain relief post-operatively (for some dogs) makes this expensive option questionably advisable only for our most severely affected patients. A board-certified surgeon is most definitely in order for these procedures.

Pain relievers (like NSAIDs and opiates) and nutraceuticals (like glucosamine) are offered for those who suffer any discomfort secondary to the disease.

No treatment is ever considered for asymptomatic cases beyond the use of cartilage-supporting nutraceuticals.

Veterinary Cost

Diagnosis for painful cases is typically relatively inexpensive (several hundred dollars), since sophisticated bone scans are usually not necessary. The cost of advanced treatment options like surgery, however, can be sizable. $2,000 to $4,000 is a reasonable ballpark figure for surgical cases.

Pain relief adds up, too, especially for severely affected large dogs who may require multiple medications daily for long-term comfort. Expect to pay $50 to $100 monthly to effectively dose a large Rottweiler, for example.

Prevention

This is an open question for those who study sesamoid disease. Some genetic influence is suspected, so removal of severely diseased dogs from any breeding programs is highly advisable. Because the incidence of the subclinical form is high (some studies report up to 40% in Rottweilers) and the connection of painful symptoms to the disease is still a simple correlation, most breeders do not take heed of veterinary warnings advising against reproduction.



References

1. Bennet D, Kelly DF: Sesamoid disease as a cause of lameness in young dogs. J. Small Anim. Prac. 1985; 26:567.

2. Vaughan LC and France C: Abnormalities of the volar and plantar sesamoid bones in Rottweilers. J. Small Anim. Prac. 1986; 27:551.

3. Robins GM: Sesamoid disease and metatarsal rotation. Aust. Vet Pract. 1986; 16:200.

4. Robins GM, Read RA: Diseases of the sesamoid bones. In Bojrab, MJ (ed): Disease Mechanisms in Small Animal Surgery, 2nd edition, p 1094. Philadelphia, Lea and Febiger, 1993.

5. Read RA, Black AP, Armstrong SJ et al: Incidence and clinical significance of sesamoid disease in Rottweilers. Vet Rec 1992; 130:533.

6. Robins GM and Read RA: Diseases of the sesamoid bones. In Bloomberg, Dee and Taylor (ed): Canine Sports Medicine and Surgery. Chapter 29. Saunders, Philadelphia, 1998.