Foundered Horse with Inadequate Shoeing!

A 10 year-old Arabian cross gelding presented for shifting foot lameness and pounding digital pulses. There was no history of laminitis/founder. The horse was not willing to walk on concrete and was a grade 3/5 lame in both front feet on soft ground. Physical exam noted a prominent fat pad over the tail head and the development of a cresty neck! A radiographic exam was performed on both front feet to determine the severity of the gelding's condition.

Figure 1

Figures 1-3 correspond to the lateral projection of the right front limb. There is a clear explanation for the shifting leg lameness and pounding digital pulses. In Figure 2, the yellow dotted lines correspond to the dorsal hoof wall and the dorsal border of the coffin bone. In a normal horse, these two lines are parallel. However, in the case of laminitis/founder with coffin bone rotation the yellow lines are NOT parallel. The small blue triangles labelled A and B correspond to the angles of the yellow lines with the horizon (red line). In this horse, angle A does NOT equal angle B. These findings confirm the diagnosis of laminitis with coffin bone rotation. The difference between angle A and B corresponds to the degrees of coffin bone rotation and in this case that number was 10-12 degrees. The left front limb was similar.

Figure 2

In addition, the gelding's cranial to caudal balance is extremely poor. The yellow line in Figure 3 corresponds to the "center of rotation" and in a normal horse should divide the foot evenly in half. As such, there should be equal amount of ground contact (red lines) in front of the yellow line (cranial) and behind the yellow line (caudal). In this horse, the amount of ground contact behind the yellow line is nearly zero compared to that in front of the yellow line. This is due in part to the extremely long "toe" and the shoe placement. The extremely long toe and cranial shoe placement adds significant leverage on the toe which will aggravate the laminitis and increase the horse's level of pain!. Initial management of this case involved removing the shoes and significantly reducing the length of the toe. In addition, a blood sample was tested for insulin resistance and the horse was confirmed to be suffering from insulin resistance secondary to metabolic syndrome. The gelding was treated with the appropriate diet, stall confinement, pain medication, and medical management for insulin resistance. Stay tuned for follow-up.....

Figure 3

Pyloris of a Horse of course!!

The endoscopic images in the following figures are of a horse's pyloris. This is the portion of the stomach that creates a valve and allows gastric fluids and contents to enter the small intestines. The very first region of the small intestines is known as the duodenum. In Figure 1, the pyloric sphincter is open and a small amount of feed material is noted around the edges of the sphincter. In Figure 2, the pyloris is nearly completely closed. The movement of material through the pyloris is controlled via rhythmic contractions or peristalsis of the stomach's muscular wall.

Figure 1

Figure 2

In Figure 3-6, there are very important abnormalities noted around the pyloric sphincter. In Figure 3 and 4, there is evidence of active bleeding from ulcerations around the pyloric sphincter! These ulcerations are likely to be a source of significance discomfort in the horse and would contribute to signs of gastric ulcer disease. It is possible and common to examine a horse's stomach and miss these lesions if the horse is not properly fasted prior to the gastroscopy and the pyloric sphincter is not visualized. This can be quite difficult in some equine patients!! The pyloric sphincter essentially controls the rate of gastric emptying hence any inflammation in this area will likely SLOW the rate of gastric emptying and result in an abnormal build-up of gastric fluid/content within the stomach.

Figure 3

Figure 4

 In Figures 5-6, there is a significant amount of hyperemia around the pyloric sphincter which corresponds to active inflammation. The degree of clinical signs may vary significantly from horse to horse however it is highly likely that horses with these types of lesions will have clinical signs consistent with gastric ulceration and WILL require the proper medical management! These type of lesions may be caused by excessive use of non-steroidal anti-inflammatory agents such as banamine and phenylbutazone. Diagnosis is dependent on a COMPLETE gastroscopy and I typically recommend a follow-up gastroscopy after treatment to verify complete resolution of the pyloric sphincter ulcerations!!

Figure 5

Figure 6

Shoulder swelling in a Horse

The mare in Figure 1 presented for a complaint of sudden onset severe swelling at the point of the right shoulder and near non-weight bearing lameness of the same limb. The mare is normally kept with other horses and there is no history of a "equine dispute" or evidence of external trauma. On presentation, the swelling consists of significant edema and the mare is considerably "tender" to pressure and palpation of the swelling. Manipulation of the limb was limited due to the significant pain response that resulted. Radiographic exam of the horse's shoulder is a viable option however due to the pain on manipulation and significant soft tissue swelling, an ultrasound exam was more highly indicated.

Figure 1

The images in Figure 2 and 3 correspond to the soft tissue swelling noted in Figure 1. A large, fluid filled pocket was noted deep to the skin surface. The fluid had a mixed pattern of echogenicity suggesting that the fluid consisted of cellular debris mixed with blood/serum. These findings are most consistent with a large subcutaneous abscess. The two most likely causes for abscess formation in this area would be trauma induced or abscess formation from a bacteria called corynebacterium pseudotuberculosis. This condition is also known as "Pigeon's fever". Pigeon's fever is a serious condition due to the highly infectious nature of the bacteria AND the fact that once the bacteria is present on the premises, it is very difficult to remove from the environment. Correct diagnosis depends on collecting a sample of fluid from the abscess and submitting for laboratory evaluation. Treatment of either condition requires establishing drainage of the abscess and daily  lavage for 10-14 days after drainage. Microbiological identification in this case is pending and the horse is in quarantine on the farm! The abscess was opened and drainage established.

Figure 2

Figure 3

Interestingly, within 7 days of examining the mare above, a gelding presented for similar symptoms. He was found non-weight bearing lame in the pasture with severe swelling of the shoulder region. The referring veterinarian provided digital radiographs which did not identify the cause of the lameness/swelling. On ultrasound exam, a bright, bone-like structure (red dotted line) was noted extending into a fluid filled mass that appeared to be a hematoma (Figure 4 and 5). The bone-like structure was the humerus bone (red dotted line) and it was fractured plus displaced. This gelding was humanely  immediately euthanized!

Figure 4

Figure 5

Although these cases are quite different in outcome, they demonstrate the benefit of soft tissue ultrasound with regards to assessing "swellings". As demonstrated it is possible to evaluate soft tissue changes as well as bony changes.