WSU equine veterinarians deliver despite fatty liver

When Sue Morris sent her 17-year-old trail horse, Tracker, on a trailer bound for Washington State University’s Veterinary Teaching Hospital, she wasn’t sure he would survive the two-hour trip from Mead, Washington.

“His respirations increased, he was sweating, and of course it was a bad day; it was 99 degrees,” Morris said. “I honestly didn’t think he was going to make it. I actually made plans to have him cremated four days before he came to WSU.”

Tracker’s liver was close to failing; and with his red blood cell count gravely low, his body was struggling to provide oxygen to vital organs and tissues.

It was suspected the 1,250-pound Tennessee walking horse needed an emergency blood transfusion.

“Something made his liver stop working and without the liver you can’t make it,” said Macarena Sanz, the lead veterinarian on the case. “When we see liver disease this severe, its rare to see them recovering. I didn’t think he was going to make it; I think we all felt that way.”

Since Tracker didn’t eat much for a few days, his liver mobilized fat cells that were causing inflammation. This condition is severe and can cause liver failure and death if left untreated.

Upon arrival, WSU equine veterinarians had two initial priorities. First: support the patient. Second: identify a compatible blood donor in case an emergency blood transfusion was needed.

Fortunately, Tracker’s red blood cell count remained stable that initial night. The medicine team administered dextrose, a calorie-dense simple sugar, via an IV line to allow the liver to rest. This was key not only to prevent further liver damage but to minimize fat mobilization that occurred as a result of Tracker not eating.  

In addition to dextrose, Tracker received a powerful anti-inflammatory, which helped reduce the inflammation in Tracker’s liver and additional medication to reduce scar tissue which could limit  liver function later on.

Tracker’s abnormal fat deposition and muscle wasting was most telling for Dr. Sanz.

Due to his age and these signs Dr. Sanz suspected Tracker had pituitary pars intermedia dysfunction, also known as equine Cushing’s disease, although the equine condition is very different than that of other species. Horses with PPID produce many abnormal hormones which lead to different clinical signs (excessive sweating, increased urination and water intake, laminitis, lethargy among others). As this condition also exacerbates liver inflammation, the medicine team began administering medication to treat the condition immediately.

“He perked up a little bit,” Sanz said. “We decided to wait on the blood transfusion and see how he did overnight.”

WSU equine veterinarians and fourth-year veterinary students monitored Tracker’s health that night, and consistently for the next two weeks.

Tracker’s liver also began to shrink to a normal size as the inflammation subsided as a result of treatment. 

It took 10 days, but gradually Tracker began to eat again and go for short walks. His liver also resumed its normal size.

“We don’t usually see many cases like these where they pull through,” Dr. Sanz said.

Tracker is now back at home in the mountains near Mead, with Morris, a mare named Annie and another gelding, Hugo.

He’s even galloping again, when he wants.

Sanz said the referring veterinarian’s care and their prompt referral gave WSU’s equine veterinarians a critical head start.

“Saving a horse like this is the best part of what we do, and it is always reminds us why we love what we do,” she said.