The Lake Isle of Innisfree
I will arise and go now, and go to Innisfree,
And a small cabin build there, of clay and wattles made;
Nine bean-rows will I have there, a hive for the honey-bee,
And live alone in the bee loud glade
And I shall have some peace there, for peace comes dropping slow,
Dropping from the veils of the morning to where the cricket sings;
There midnight’s all a glimmer, and noon a purple glow,
And evening full of the linnet’s wings.
I will arise and go now, for always night and day
I hear lake water lapping with low sounds by the shore;
While I stand on the roadway, or on the pavements grey,
I hear it in the deep heart’s core.
— William Butler Yeats, 1888, “The Spirit of Man: An Anthology, London, New York: Longmans, Green and Co, 1916.
This is a mysterious case history that started with a very observant owner, included a television show about a dog rescue, and ended with a surprise diagnosis that no one was expecting.
Denise Hearst is an expert horsewoman as well as publisher of this magazine. Recently, she noticed that her horse, Jay, was showing some unusual symptoms. “Looking back, there were a series of subtle signs, all of which could be rationalized,” Denise said. “But they added up to something. We’d had a week of heavy rain. J.J.’s one acre pasture was now swollen with runoff from the surrounding hills and there was a lot of standing water. J.J. also has access to bedded stalls that he is free to use at will. Was he using them more frequently than usual, I wondered? Understandable, I thought.”
“On this particular weekend, I noticed that he was more often covered with shavings than his preferred mud. I explained it away by telling myself that he had been drenched and the fluffy shavings were more enticing to him now. On Sunday morning, after a stormy night, I went to the barn to feed and found J.J. standing in the stall doorway, looking out at the light rain. I put a flake of hay in the manger and he didn’t even turn and look at me. I talked and cajoled him and at last he turned and came on over for a scratch and breakfast.”
“I went back up to the house and mentioned to my houseguest that J.J. seemed tired from last night’s storm. When I went to check on him at midday, he was out in the pasture grazing. He had left most of his grass hay uneaten, as he had done on several days recently, but I thought, that’s normal for him when the new grass is coming up.”
However, the next evening, things were different. “He was in his stall when I arrived at twilight, and it was clear that he was not right. He was standing stiffly and seemed a little depressed. I immediately called my veterinarian, ‘Dr. John,’ who arrived within 10 minutes, and agreed: ‘not right.’
Dr. John Bigley picks up the story from here: “I went out to examine Jay, a horse I know well, and I agreed with Denise — he was what we call ADR, or ‘ain’t doing right!’ He just seemed mildly “off.” Jay is a very straightforward horse. You know when he is not feeling well. He was standing in the back of the stall, and one of the first things I noticed was that he was jaundiced. His membranes — even the snip on his nose was yellow in color. Horses that haven’t eaten in several days can become jaundiced.”
Dr. Bigley continued, “I treated Jay with the basic approach for a gas colic, took blood samples to run for infection and inflammation, and did a blood chemistry panel to look at enzyme levels. Jay responded well to the treatment. The jaundice indicated a possible compromise of the liver system. With Jay being off food for several days, this might have had an effect. When I got the blood results, they were normal for liver enzymes, but the bilirubin level was quite high. This, combined with signs of infection, indicated that Jay may have an infection of his biliary tract. I started him on antibiotics and Jay’s attitude and appetite returned to normal. When I rechecked him several days later, the signs of infection had gone down dramatically on the antibiotics and his bilirubin levels had returned to normal.”
Another possibility that was raised by Denise was the chance that Jay could have ingested some sort of toxic plant that may not normally be part of the landscape, but had grown due to the high amount of rainfall. “We did talk about that possibility,” Dr. John replied, “but with a toxic plant you would expect the liver to be damaged, and the blood results showed that there was an infection as opposed to a toxin, and that the infection involved the biliary system, not the liver tissue itself.”
What Does the Liver and Biliary System Do?
In brief, the liver is important in blood storage and filtration, detoxification, protein synthesis, metabolism of carbohydrates and sugars, and the production of bile, which helps in metabolizing fats.
The biliary tract are the ducts that make and transport bile. Because horses don’t have a gall bladder, their liver continuously secretes bile through the biliary tract.
The Story Continues …
During this episode, I got a call from Denise. “Hey Cindy,” she said, “My horse has been showing some strange symptoms and I wondered if you had ever seen anything like this?” She went on to explain the symptoms. I was aware that California was experiencing unprecedented rainfall and that Denise lived in an area that was full of wildlife. Immediately, a lightbulb went off in my head — not because I am a good diagnostician, but because I had recently watched a television program about a dog rescue. A dog who had been confined in a small area in California was exposed to a great deal of standing water. The dog was quite ill, and when it was rescued, it was found to have Leptospirosis. This can be a debilitating disease and even fatal, but the dog was ultimately successfully treated. “Is Jay in an area with a lot of standing water?” I asked. “As a matter of fact, he is,” Denise replied. I asked her, “Have you thought of testing him for Leptospirosis?” While on the phone with Denise, I immediately looked up the signs of Leptospirosis in horses and many of the symptoms had occurred in Jay’s case. “It certainly wouldn’t hurt to test him in any case,” I said, “given the highly unusual amount of water that is happening in your area.” Denise called Dr. John to ask about Leptospirosis and he said he had not had a case in that central California area, but that it certainly would not hurt to test for it, so it could be ruled out, at least.
At the same time, Dr. John was beginning to hear rumors from small animal veterinarians in the area who were seeing positive Leptospirosis cases in dogs. Up to this time, he would normally not have considered Leptospirosis a possibility. “I checked Jay’s blood titer for Leptospirosis and it came back strongly positive.”
What is Leptospirosis?
It is a bacterial disease carried by wildlife that is excreted in their urine. It can be transmitted to horses, dogs, livestock, and even humans. The disease is caused by leptospires, which are mobile bacteria. Animals become infected when they come in contact with infected urine. When there is a lot of rain in areas with wildlife, it washes the urine out and can infect standing water. The horse may drink the water, or get splashed with it, so that it enters the mucous membranes, or it may eat hay or feed contaminated by infected water. In any case, once the horse has been infected, the leptospires often congregate in certain areas of the horse, including the liver, kidney, and eyes.
Some of the clinical signs of Leptospirosis include depression, loss of appetite, fever, abortion in pregnant mares, swelling of the eyes and light sensitivity of the eyes. Jaundice can be another symptom of Leptospirosis. However, many of these signs are common to other diseases, so in an area where Leptospirosis had never been diagnosed in horses, it is easy to see how it would not be the first conclusion a veterinarian would come to when presented with Jay’s signs. A vaccine for horses specific to Leptospirosis was only recently developed and has been available since 2015.
The Diagnosis is Made
Dr. John reported that once he got the confirmation that Jay was positive for Leptospirosis, it still required investigation. “The fact that he was positive means he had been exposed to the bacteria, but because kidney disease is a common result of Leptospirosis, so we also checked Jay’s kidney enzymes and they were excellent when we ran his third series of blood tests. We will continue to monitor his eyes periodically for several months, as recurrent uveitis (moonblindness) is also caused by Leptospirosis. The leptospires tend to congregate in the fluid of the eye and die, and then the horse’s immune system responds to that, which causes the uveitis.”
Based on what he knows now, if Dr. John had known the horse was positive for Leptospirosis in the beginning, would he have treated Jay differently? “The only thing I would have changed would have been the antibiotic I used initially,” Dr. John responded. “Because Leptospirosis was not on our radar before, we are going to start testing for it if we suspect that it could be Leptospirosis. I always say, “If you don’t look, you don’t find.” When I saw Jay’s jaundice initially, it didn’t really send me in the direction of Leptospirosis, but now when we see it, we will be looking at all possibilities.”
What can horse owners do if they suspect the presence Leptospirosis? “First of all breeding farms need to be very aware,” says Dr. John. “Vaccinating broodmares might be a good place to start, because Leptospirosis causes abortion in mares. If the horses are in an area with a lot of wildlife and standing water or are in an at-risk environment, vaccination might be indicated.”
Based on this experience, what is Dr. John telling his clients? “That this is something we haven’t seen or talked about before, but we are talking about it now. If you think your horse may have Leptospirosis or has been exposed to the bacteria, we can run a blood titer to make sure. The strength of the blood titer is important. A low response may mean the horse was exposed at some point in its life, but does not have an active infection. With an at-risk environment (high wildlife concentration, standing water, etc.) consider vaccinating your horses.”
Meanwhile, J.J. is now doing fine, but will continue to have his eyes monitored by Dr. John. Fortunately for him, his owner, who was able to recognize subtle signs early, got her veterinarian involved early on. Dr. John, who when faced with a disease that had not occurred in his practice before, was not adverse to testing for it anyway, and in doing so, is changing the course of testing and treatment for the horses in his practice and beyond. It was a long shot — the combination of unheard of rain and a fortunate television episode of a dog rescue that held the answer to Jay’s diagnosis. Denise adds an important reminder: “If something doesn’t seem quite right, it probably isn’t. So pay attention to what your horse is telling you.”
As a postscript, as this was going to press, Denise emailed me to report that “Jay and I went for a ride in the hills today … it was sunny and green and breezy and he was positively bursting with vitality. Happy horse!”
March can be a cruel month in terms of weather. If you have early foals, hopefully the weather is kind where you are. Our first foals are due at the end of the month and that is a good thing. The heavy rains here continue and the fields are still muddy and damp. Hopefully they will be dry by the time the foals start to arrive. Meanwhile the foaling kit is ready by the stalls and the foaling mares come up to the barn today. Let the season begin!
Dr. John Bigley has his equine practice in Cambria, California. He graduated from Colorado State University and has been serving his equine clients for more than 30 years.