Patient History Report: Sinwaan - 10/24/13

For those of you who are interested and have been following Sinwaan's story lately, he went back in to see the specialist Dr Dora Ferris on 10/24. Here is her write up of that visit;

Misc Medical Procedures - Ultrasound - hind suspensory ligaments
Sinwaan presented today for re-examination and ultrasound of his hind limb proximal suspensory ligaments.

Examination: He does not have significant back pain today and there is no withdrawal response when the tuber sacrale are compressed. At the walk both hind fetlocks drop/hyperextend when in the weight bearing phase of stride. At the trot, his lameness has not improved despite the 3 months of rest. The left hind foot continues to have a club footed appearance due to the short worn toe.

Sinwaan's heart was ascultated and was within normal limits. He was sedated with 4mg of detomidine and 60mg of xylazine IV. Both metatarsal regions were clipped and prepped for ultrasound examination. The left hind suspensory ligament was ultrasounded and compared to the right hind suspensory ligament. There was mild thickening of the plantar fascia of the left hind limb compared to the right. The suspensory ligament of the left hind was mildly enlarged, especially laterally compared to  the right hind evidenced by a reduction in the space between the suspensory and the metatarsus. Hypoechoic areas consistent with muscle and fat within the ligament were symmetrical from right to left. There was a mild  bone irregularity at the distal portion of the attachment of the suspensory ligament on the left hind. A brief  non-weight bearing exam was performed as well which did not show additional lesions.

Assessment:
The ultrasound did not reveal significant disruption or damage to the suspensory ligament at this time. My biggest concern is that there could be a slow, chronic degenerative process in play, causing mild breakdown of the suspensory ligament. Some have suggested this can be linked to metabolic syndrome in some horses. Sinwaan is slightly overweight, and resting will only make this more difficult to manage. This could be linked to a metabolic syndrome.

It is also thought, that in horses with a similar presentation there is nerve impingement of the deep  branch of the lateral plantar nerve beneath the plantar fascia due to the swollen suspensory ligament.

Plan:
We can discuss further treatments, and I am  happy to talk about these at any time. Treatments I would recommend pursuing:
Testing for equine metabolic syndrome, including insulin and cortisol (ACTH, Dex suppression testing). These cost around $100. Unfortunately in the fall and winter horses can come back falsely negative, so it is best to wait for this testing until spring. Some management changes could be undertaken prior to testing in an effort to minimize his weight changes. Changes include grass only hay, minimal concentrates or grains, or substituting with a low starch grain, minimizing or eliminating grass pasture turnout, etc.

Platelet rich plasma - While there is not visible disruption of the ligament, these horses often have a degenerative process occurring and PRP could potentially provide growth factors that can slow or decrease this process.

Radiograph - Radiographs of the hock/proximal suspensory region of the left hind limb could be helpful for two reasons, they could show if there is sclerosis (increased bone density at the proximal suspensory region) and could outline any hock changes as well. He may still have a portion of hock pain that is contributing to his lameness. If there is sclerosis at the origin of the suspensory ligament origin (consistent with the bone change seen on ultrasound) it would be consistent with a chronic issue.

In the interum time, I would like to start the following therapy for Sinwaan.
Lateral weight shifting - Stand to the side of his hip, facing him. Grasp his tail up as high as you can on the tail bone, then gently lean back, pulling him towards you. Watch for the  contraction of the quadriceps muscles on the side you are facing and slight dropping of the fetlock. You want him to resist the drop, and hold himself up without pushing and moving away from  you. This will improve his control of his hindlimb and muscle activation. Ask him to hold the contraction for as long as he is able, currently about 3-4 seconds, ideally he will improve several seconds per week until he can hold the activation for 20 seconds. Repeat this exercise for both hind limbs 5 times a day.

Aquatic therapy can be very helpful for these horses. While taking Sinwaan to a rehab facility is not really an option for him, exercising him in a pond, lake, or creek might be beneficial as long as the bottom of the lake is not deep and muddy, and the weather is not too cold. Please let me know if you have anything along those lines available to you and we can discuss a protocol.

I would like Sinwaan to have low impact exercise if possible. Walking in hand or ponied from another horse initially on a straight line on firm footing would be ideal. Start with 5 minutes 1-2 times daily, increasing by 5 minutes each week, until he is walking for 20 minutes up to twice daily in 8 weeks if possible. As he progresses, we can begin to add weight to his back.

Please apply the DMSO/Bute mixture to his proximal suspensory regions up to 1 time daily for 14 days. Please wear gloves and do not allow this to touch your skin. Don't touch his leg after you have applied it. This will help reduce the inflammation that may be occurring, and may help for any nerve pain he may be experiencing.

Shoeing changes - Research has shown that a high foot angle (tall heels) puts increased strain on the suspensory ligament. Since his heels have become so tall, I would like to have them trimmed to more closely match his opposite foot. Care needs to be taken that they are not shortened too much and cause a broken back hoof-pastern axis. Sinwaan may also benefit from heel extensions to bring support back under his fetlock further. In the past that has helped horses with similar conformation. I'm not sure who you have used in the past, but let us know if you need recommendations for therapeutic shoes.

If these therapies are started, I would like to recheck him next month if possible. Otherwise we can discuss his progress on the phone.

Dora Ferris