Friday, November 15, 2013

Gastric Ulceration causing poor performance in a horse!!


A 12 year-old event horse presented for poor performance that was best described as unwilling to "go forward". The gelding was evaluated for lameness and was described as sound. The gelding maintained a good appetite and there were no signs of colic behavior reported. A gastroscopy was scheduled and the owner was instructed to fast the horse for 18 hours. When the gastroscope was passed into the stomach a large volume of fluid was present mixed with feed material. Approximately 3 liters of fluid was removed from the stomach in order to visualize the non-glandular compartment. The remaining fluid was filled with feed material and was not removed. However, a clear pattern of non-glandular ulceration was noted throughout the exposed stomach wall (Figures 1-3).

  
Figure 1
 These ulcers appear full thickness thru the layer coating the inside of the stomach and are evenly spread through out the stomach. We were not able to visualize the glandular stomach or the pyloric region which may be abnormal in this horse. The fact that the gelding's stomach was filled with fluid and some feed after 18 hrs of fasting would suggest a delay in gastric emptying which may be associated with inflammation of the pyloric region. As such, this gelding will be treated with omeprazole for the appropriate period of time. In addition, the horse will be treated with a stomach coating medicine for the first 48 hrs to alleviate any immediate discomfort due to the ulcerations.

Figure 2
 This case presents yet another example of the types of clinical signs that may be associated with gastric ulcers. Classically we consider horses that have sings of colic, weight loss, poor appetite or failure to thrive. However, in my expereince, horses with gastric ulcers may present in many ways and this condition should be considered on our lists of differentials!!

Figure 3

Friday, November 8, 2013

Rattle box (Crotalaria spp) in full bloom in Florida!!

The images below (Figure 1-2)  are of a plant known as "Rattle box". This plant is commonly found throughout Florida and the southeastern USA however is usually only found to be blooming during the spring and fall months (Figure 3) . There are several varieties of this plant that are all in the Crotalaria spp family. The plant produces a toxin known as a pyrrolizidine alkaloid which causes pulmonary hypertension and liver fibrosis. Interestingly, horses develop a taste for these plants and will consume them during the months that they are present in the pasture; however, clinical signs typically don't develop for 2-4 months.

Figure 1

Figure 2
Figure 3


The effect that the toxin has on horse's liver is remarkable. In the image below, there is a normal sample of liver (top) next to a fibrotic sample of liver (below). The fibrosis is so severe that there is minimal blood filtration through the liver, rendering the liver useless. As such, toxins that are normally detoxified by the liver accumulate within the horse and result in depression, anorexia, neurologic disease and ultimately death!  Once the horse develops clinical signs for liver fibrosis, the prognosis is very poor. It is strongly recommend that all pastures and fence lines be screened for the presence of this plant species, especially during the fall and spring ( that means now!!). The plant must be removed by physically pulling the plant out of the ground. Mowing will only spread the plant by disseminating the seeds that are present within the "rattle box" pods!! If your horse has been exposed to this plant, I would recommend a simple chemistry analysis of their blood to determine if they have early signs of liver disease.

Figure4

Friday, November 1, 2013

Urinary Bladder Stone in a Horse

A 10 year-old gelding presented for a history of frequent urination and blood-tinged urine. The referring veterinarian had analyzed the urine and confirmed the presence of blood. In addition, a CBC and Chemistry was performed on blood collected from the gelding and all parameters were within normal limits. During my initial exam, I sedated the gelding and performed a rectal exam. A plumb-size structure was palpated within the urinary bladder and the gelding became increasingly agitated as the structure was manipulated. Trans-rectal ultrasound noted a 4cm, hyperechoic (bright white) structure within the lumen of the urinary bladder (Figure 1).

Figure 1
Subsequently, a cystoscopy was performed to identify the abnormal structure within the urinary bladder. Once visualized, the structure was identified as a urinary bladder calculi or stone (Figures 2-4). The stone was circular in dimension and the surface was very spiculated which was contributing to irritation of the urinary bladder wall and intermittent hemorrhage from the urinary bladder wall.

Figure 2

Figure 3

Figure 4
Following the cystoscopy, a trans-abdominal ultrasound was performed on the left and right kidneys. Unfortunately, a 5cm stone was visualized within the renal pelvis of the left kidney (Figure 5). Surrounding the hyperechoic (bright white) line is black fluid which most likely consists of urine and a dilated renal pelvis. It is quite likely that this kidney is not filtering blood as it should and nearly non-functional. Fortunately, the right kidney was normal and the horse will be okay as long as the right kidney does not develop a problem!!

Figure 5
The gelding was referred to a surgical facility and the urinary bladder stone was removed successfully. However, the gelding will need regular monitoring for changes in renal function and the presence of new bladder/kidney stones!! The development of kidney/bladder stones in horses is random however horses that consume a diet rich in calcium may be at higher risk.