If you become a regular on Veterinary Nutrition Care’s blog, you’ll probably see more of Austin. Full disclosure: he’s my dog. I’m writing about him not because he’s my dog and he makes me smile every day, but because he’s been my most challenging and interesting nutrition patient. Sharing his story also gives you a bit more about who I am and how I approach my work. This post is longer than I’m planning for usual, but read on. It’s a good story.
Austin is a German Shorthaired Pointer, presumed to be mixed with a Lab. My husband, Nic, and I adopted him as a total goofball with no manners at about a year of age. With a lot of work and patience, he became a reasonable pet by the time he was five or so. Those of you with dogs who don’t have the “I want to be a good dog because it makes you happy” mentality can relate. He’s now about to be ten years old, and worth every bit of home-repair he’s caused.
In 2012, just before I completed my nutrition residency at UC Davis, we sold our house and moved to a rental. We checked the yard- no problems, enough cool, shady, spots. It seemed like a safe place for Austin to stay while we were at work. One night, a few months later, Austin was “off,” but not showing us what was wrong- not dehydrated, not painful, pink gums- it was hard to say. Until, that is, he began vomiting during the night. Not just vomiting, but vomiting grapes. A short time later, he was feeling terrible, and by then, he was getting dehydrated.
For those who don’t know already, grapes (and raisins) can be toxic to dogs. Exactly why this happens, and why it only happens in some dogs, is still not known.
Huh? He certainly wasn’t accidentally fed grapes, and he couldn’t have gotten any off
of the counter or out of the refrigerator. Not only was he not prone to do things like that, even with his favorite foods- we didn’t even have any grapes in the house. We investigated the yard. Uh-oh. In the time since we’d done our inspection, grape vines from the neighbor’s yard had grown over (and through) the fence and commenced with production. It wasn’t possible to know how much he’d eaten, but it could have been a lot.
So, then there was the trip to UC Davis’ Emergency Service. Some testing was started, and given his sky-high blood concentrations of blood urea nitrogen (BUN), creatinine, and phosphorus, which the kidneys are supposed to be getting rid of; among other things, a tentative diagnosis of acute kidney injury due to grape toxicity was made. In acute kidney injury, the kidneys are essentially shut down for a while; they can’t filter the blood, and they can’t make urine. The kidney does have some capacity to recover, but if it happens, it takes some time. And it doesn’t always happen.
Treatments, including IV fluids and anti-nausea medications were started. Time is the real medicine for acute kidney injury. The rest of the care is supportive, meaning that it brings relief from the (horrible) effects of kidney failure while the body’s repair mechanisms work. In theory, and maybe depending on his “dose” of the “mysterious grape toxin,” his kidney function may come back in the short window of time until he became too sick to go on. Treating these patients is tricky; because they need to receive fluids- they’re dehydrated. On the other hand, they can’t get rid of fluids, so they go very quickly from being dehydrated to being over-hydrated. Having worked with patients in the same scenario, I knew in my gut that when the morning came, we’d have to be talking about dialysis.
Dialysis can’t fix injured kidneys, but when the kidneys can’t do their job of filtering the blood, “bad stuff,” called uremic toxins, builds up. These uremic toxins were responsible for Austin’s feeling terrible, vomiting, and a lot of other, more subtle, issues. Dialysis removes the uremic toxins so that a pet can feel well enough to wait for the kidneys to repair themselves. It buys time. The other thing that dialysis can do is to correct over-hydration.
Sure enough, in the morning, the last day of my residency, despite the best supportive care under the sun, Austin hadn’t produced any urine overnight, he felt awful, and was now over-hydrated. The usual mischievous sparkle in his eyes was gone. There was no way to continue like this.
Even before meeting my colleagues from dialysis, I knew we’d have to make a big decision: either dialyze or euthanize. Just writing this now makes my stomach hurt.
I sat with him in his kennel and cried. I asked him to tell me what he needed. He could barely lift his head, but he put his warm and dry nose up to my cheek and sighed. I managed a small laugh. This was a weak attempt at a behavior that had always annoyed me. He’d never been one to lick your face, but given the opportunity, would shove his nose way too close to your face for a second and sniff. Almost, but not quite touching. I’d never realized before that he’d been trying to say “I love you.”
I met with the dialysis team: Dr. Larry Cowgill, veterinary dialysis guru; Dr. Kayo Kanakubo, then the intern in dialysis; and Dr. Bing Zhu, then an internal medicine resident. They proposed a plan. An initial dialysis treatment, then repeat treatments as needed (when the uremic toxins build up high enough that he starts feeling poorly again) until his kidneys recover, with continued supportive care. He was guessing that this would be over a month or so, but he’s had patients require dialysis for six months to recover. In Dr. Cowgill’s experience, half of dogs in Austin’s position go home, and of those that do, half go home with chronic kidney disease.
I talked with my husband. We cried some more. Dialysis was an expensive proposition, and with both of us residents at UC Davis at the time, there wasn’t a big chunk of “dialysis money” set aside. We could manage it for a month, we thought, but may be in the same hard place a month down the road if Austin’s kidneys hadn’t come on-line yet. Before we had Austin, when we’d talked about our clients that were in similar do-or-die situations, we’d both thought that we’d try to be practical, and could make the hard decision to let our pet go when faced with odds that were not necessarily favorable. I realized then that we’d never considered whether we could live with ourselves if we’d made that decision. Standing in those shoes, with only a 25% chance of coming out really okay, we could only choose to go forward with giving Austin a chance.
I went back to check on Austin and promised him that if he came through this with us, I’d never get mad at him for sticking his nose in my face again. I stopped by the Nutrition Service’s office to give my colleagues an update. I was told that my few remaining loose ends could wait, and to take the day to take care of Austin. Veterinary nutritionists are nice people.
I called Dr. Cowgill back, and we got started. Austin would be anesthetized for placement of a dialysis catheter (a giant IV catheter in his jugular vein that attaches to the dialysis machine) and feeding tube, then would receive his first dialysis treatment immediately. Patients with acute kidney injury are usually hospitalized in the ICU, at least initially, because there’s a lot to do to keep them comfortable, hydrated, fed, and medicated and because there’s a lot of checking to do to make sure things stay on track. That said, equipment-wise, the needs are relatively simple- he wouldn’t be attached to a ventilator, EKG, or oxygen. Dr. Zhu had the crazy idea that since I’d just finished my residency, and wasn’t starting my graduate program for a few weeks, that we’d hospitalize him at home, with me and Nic doing round-the-clock care and monitoring, and bringing him back to the hospital mornings and evenings for her to examine. Basically, my house was an extension of the hospital, she was the attending clinician, and Nic and I were the nurses. This would allow us to reduce the cost of Austin’s nursing care to stretch our resources for further dialysis treatments. I told Austin’s doctors that I would be the most compliant pet owner they’ve ever given orders to, but, despite being a veterinarian, that I wanted no clinical input on Austin’s medical management. I wanted to make no decisions, other than for his nutrition.
Please note: this home-hospitalization plan could ONLY be possible with an unemployed (and maybe slightly insane) veterinarian as the pet’s owner. If your pet is ill and requires hospitalization, do not suggest to your veterinarian that you can do it at home. If you’re lucky, he/she will just smile and tell you it’s not a good idea. If not, you may get laughed at, which may be hard to take in the moment. While it’s do-able for a veterinarian, it takes many years of training. In the long run, hospitalizing your pet costs much less than vet school.
The first nutrition decision came right away. Dialysis patients have a waxing and waning appetite, since they eat when they feel good after dialysis takes away all of the uremic toxins, but the toxins build up again, and they won’t eat. That said, dialysis patients have extremely high energy requirements. The treatment literally takes a lot out of them, so they need to be fed, regardless of what their appetite is like.
I’d managed nutrition for Dr. Cowgill’s dialysis patients before, and knew that he had (at the time) a habit of using a particular long and narrow feeding tube in large dogs. In my experience, the veterinary students and nurses had a very hard time with these, since it was difficult to push the large volumes of pureed diets we fed to these dogs through. That wasn’t going to happen with my dog.
A few months prior, I was at the exhibit hall of the American College of Veterinary Internal Medicine’s annual conference and came across one of many medical device vendors. On display was a large variety of tubes, used for various purposes. I picked up a chest tube (designed to remove air from around the lungs in patients who’ve had open-chest surgery or trauma) with a nearly 1-cm diameter, waved it at Dr. Jennifer Larsen, one of my nutrition mentors, and said; only half-jokingly, “This is what we should be using for Cowgill’s big dogs.” We bought one on the spot, just in case. It was a little extreme, but it would at least make the point that what he’d been using wasn’t working very well. Little did I know that it would go into my dog.
It felt a little weird giving “the guru” orders, but I had to put my foot down. There was no way we were going to use the long, narrow tube to feed this dog. I was already on the edge, and being frustrated with not being able to feed my dog just wasn’t an option. We rifled through the hospital’s supply of feeding tubes, but didn’t find one I could agree to, so I went back to the nutrition office and brought out the big chest tube. “Here. We’re using this” I said. Dr. Cowgill was taken aback for a second. I’m not sure if it was my tone or the size of the tube, but either way, Dr. Cowgill is well-dressed, composed, and confident. He’s hard to rattle, so it was mildly amusing to see.
Placement of the dialysis catheter went fine, though there was a bit of work to devise a method to place such a big feeding tube. Once that was figured out, dialysis ensued. Dialysis treatments take several hours, and though Austin started his treatment anesthetized, he recovered on the warm and padded dialysis table. By the time he finished his treatment, he was brighter, wanted to be petted, and while not 100%, seemed much more like himself. Even though I knew this would be temporary, it still felt like relief.
Once he was liberated from the dialysis equipment, I grabbed a plastic bowl (wishful thinking that there would be urine to collect) and took him outside to see the sun for the first time that day. We walked down a path to a strip of grass outside the Center for Companion Animal Health. He stretched. Sniffed. Lifted his leg. And peed! I was so excited; I almost forgot that I was supposed to be collecting urine. I caught what I could and relaxed a bit, thankful for the good news.
There were cheers when I walked back into the dialysis room with a bowl half full of urine. It’s funny what veterinarians can get excited about. I left Austin with Dr. Kanakubo, and John Kirby and Sean Naylor, the dialysis service’s amazing technicians, and headed down to pharmacy and central service for drugs and supplies. I took the case of IV fluid bags (yes, case; the first of several), a bag of miscellaneous syringes, packages of bandaging material (for the wrap that protected the dialysis catheter and feeding tube placed in his neck), and what felt like a hundred medications out to my car, then went back to the nutrition office for the case of canned therapeutic diet that I’d be feeding through the tube. In the mean time, Dr. Zhu wrote my orders for his overnight care, and sent them to my email.
By then, Nic was done for the day. We picked Austin up from dialysis and thanked Sean and John for the care package of things I’d not thought to get from central service, but could immediately see the need for, and we headed out the door to set up our ICU. Just before the door closed, I heard Sean say something. We went back. “What was that?” we asked. Sean repeated. “Did Cowgill tell you his head is going to swell?” Great. It made sense: his fluid balance was better, but still fragile, plus the hole that was put into his jugular vein to accommodate the giant dialysis catheter meant that the wrap around his neck had to be snug, to say the least. Yeah, his head is going to swell.
Once home, we got IV fluids running, gave a round of medications, and I sat down to make Austin’s feeding plan using the canned diet I’d brought home. It was the best fit, but still needed to be modified a little. Austin’s diet plan was basically a lot of calories, enough protein (but not too much), not a lot of fat, low phosphorus, extra potassium, low sodium, and a double-dose of his usual fish oil. Our canine dialysis patients often develop pancreatitis, and one way to manage (and we thought maybe prevent, in Austin’s case) pancreatitis is by feeding a low-fat diet.
Please note: there is debate among the nutrition community about whether low-fat diets are useful to treat pancreatitis, and certainly using one to “prevent” pancreatitis was a stretch, but when it’s your dog, and it doesn’t cause another problem, you’ll try anything that makes even a little bit of sense.
I blended the canned diet I picked with the amounts of salt substitute and fish oil that my calculations told me I needed, and enough water to be able to draw it into the syringe. It looked like a chocolate milkshake, but smelled like, well, canned dog food and fish oil. Austin looked interested. I thought he might just eat it. He sniffed, but not quite. I’d calculated how much I intended to feed over the next day, as well as how much water this would provide. I started at less than half of what I’d determined his energy requirement to be, not because he didn’t need the nutrition, but because feeding too much, too rapidly, to a sick patient can make them feel poorly or have even more serious effects. As badly as I wanted to make sure Austin was getting everything he needed, a gradual increase up to the amount I wanted to feed was the way to go. His kidneys were making some urine, but we weren’t sure yet if that part of kidney function was completely back on line, so we still had to be careful about his fluid intake relative to his urine output.
I set up everything I’d need for the first tube-feeding: syringes filled with diet slurry, syringes filled with water, paper towels for wiping up drips, a big towel because it just seemed like it would come in handy. I crushed the medications he was due for, mixed them with water, and drew each suspension into smaller syringes. I laid those out next to the food syringes. When it came time to feed, I first flushed the feeding tube with water. No problem. I switched syringes to one with food and started pushing. This was kind of a “moment of truth” instance for me, since I’d never gotten the chance to actually “test” this tube by pushing food through it when it wasn’t already a patient. The tube was fantastic! The only resistance to feeding came from the syringe itself. I breathed a sigh of relief for the second time that day. I’d have hated to have to tell Dr. Cowgill that the tube I demanded he use wasn’t such a good idea after all.
Overnight, there were some kinks to work out, but things mostly went okay. And yes, his head swelled. Not freakishly, but definitely swollen. At least it wasn’t a surprise, and I knew it didn’t hurt. Austin was a little brighter as we headed back to the hospital to check in with Dr. Zhu. She rechecked some labwork and was happy with how things were going. She reminded me that him feeling this well would be temporary; as the uremic toxins that had been removed by the dialysis treatment built back up, he’d start feeling more and more poorly until his next treatment. Dr. Zhu liked that I was able to tell her, between IV fluids and what I’d fed through his tube, Austin’s exact fluid intake, as well as his urine output, which I’d been collecting and measuring using a (now dedicated) Nalgene bottle. With this information, we were able to match his fluid intake to match his urine output to maintain his hydration. Having more information allowed us to customize Austin’s care. Dr Zhu agreed with my plan to begin increasing the amounts he was being fed to give him as much support as possible.
This continued for a few more days, and, as expected, each day he was a bit dumpier, the morning of his next dialysis treatment, he vomited. In hindsight, it was probably because I’d been palpating his abdomen (feeling around to make sure he was comfortable and that everything seemed normal) before I gave his anti-nausea medication, but there was also nothing to prove that this wasn’t the beginning of pancreatitis. Pancreatitis can be severe, painful, and life threatening. There was no contraindication to changing his diet (meaning that there was no good reason not to), so I formulated a balanced home-prepared mixture of eggs and egg whites, rice, and a vitamin and mineral supplement. Still not so appetizing by the time it was prepared, but it was much lower in fat, and it did everything else I needed it to do for Austin’s nutrition. I again figured out how much water it would take to get the slurry through into the syringe and through the feeding tube, and then how much water per calorie that would be delivering.
By this time, Austin’s urine production had increased to be just about normal (2-3 mL/kg/hr), though it was expected to continue increasing, since the next phase of the kidneys coming back to functioning normally is a period of post-obstructive diuresis, where they allow way too much urine to be made.
We’d weighed Austin each time he returned to the hospital, and he was generally trending downward with respect to weight. At first this is expected, since he was over-hydrated and getting rid of excess water, but once he is normally hydrated, the weight loss is real. In dialysis patients, the weight loss is muscle, it can be profound, and it can happen really quickly.
The second round of dialysis was uneventful. Austin’s urine production kept climbing, so in addition to IV fluids, he was receiving syringe after syringe of water, on top of a nearly-liquid diet. For every bit of urine output over “normal,” there’s an increase in the number of times a dog has to go outside to pee. When that urine output climbs to, say 17 mL/kg/hr (keeping in mind I said that normal is closer to 2 mL/kg/hr), you have to make some changes.
First, you have to move your bed into the living room next to the sliding door to the backyard, because otherwise you can’t get the dog outside fast enough.
Second, when your dog is producing that much urine, you’re out in the yard every hour, day and night, you get a little batty (not to mention irritable). When you need to collect and measure that urine so you can determine how much more water you need to give (in addition to that from the slurry and IV fluids) to match the urine output at 3 am, it’s way too easy to make a mistake. I’d been trying to let Nic sleep, since he was still in his residency, with early mornings and late nights, but in order to not make some kind of scary middle-of-the-night mistake, I had to admit that even though this phase would be temporary, I couldn’t do hourly 24-hour care by myself. Nic’s much more of a morning person, so he started doing the routine between about 2 and 6 am so I could get some sleep.
I designed an Excel sheet to keep the many things to do straight. I set it up to convert amounts fed to amounts of water this provided, and keep track of the total amount of fluid intake over the day, then compare that to the total urine output for the day. For each hour, it would determine how much additional water was needed to match “ins” to “outs.” It would also allow us to know if medications had already been given to avoid missing, or repeating, treatments.
At the time, my family was eager to have a next generation, and they were eyeing Nic and I. “This is great training for having a baby” my mom said. “If you can handle this, the baby will be no problem.” Thanks, mom. We were irritable, and literally in “survival mode.” Definitely not the time to be talking about a baby.
Now that our son is a year old, I can say that I see what Ma was getting at: being up all night and day caring for a helpless creature that you’re crazy about. But it’s different. My son was (is) healthy, and while being up all hours of the night with him was hard, I wasn’t worried about the same things with my healthy baby as I was with my very sick dog. It’s hard to find people who really understand that feeling.
Austin’s weight was still trending slightly downward, but he wasn’t showing the dramatic muscle atrophy that we sometimes see with dialysis. He seemed to take everything in stride, though after another four days or so, he was feeling bad and needed another dialysis treatment. The good news though, was that his BUN and creatinine weren’t going as high as they had before, and were staying lower for a bit longer. Hopefully this meant that the kidneys were starting to do a better job of filtering the uremic toxins out of the blood.
If all goes well, the kidneys regain their ability to concentrate urine (keep water from being lost as urine and retain it for the body), but it’s hidden because we’re busy giving extra fluids to match the recent output. Even kidneys that work really well will produce huge volumes of urine if your intake is huge. When this happens, it’s the end of the post-obstructive diuresis period. This means that there is a time when you stop matching “ins” to “outs” and instead match only, say, 90% of the output to see if the kidneys can handle it, and Dr. Zhu said that the time had come. I reconfigured my Excel sheet, and Austin stayed normally hydrated, despite getting less fluid. The next day, we matched 80%, and so on.
Gradually, very gradually, Austin began returning to normal. He started drinking water and eating on his own. He required less nursing care and fewer trips outside. I still measured his food and water intake and supplemented with the tube, but this was real progress. We were able to stop giving IV fluids altogether, and gradually tapered off of some of his medications. Since I wasn’t worried about pancreatitis anymore (false alarm), I went back to the canned therapeutic diet to make life a little simpler. There was a first time we “slept through the night” (back to that baby-prep talk) without having to take the dog outside. When the day arrived that I wasn’t giving any additional fluids with the tube, I was nervous. We’d been checking his bloodwork and urine concentration daily or every other day since this started, but this was a real test of whether his kidneys were able to hold their own.
He did it. His concentrations of BUN and creatinine were close to normal, and his urine concentration was reasonable. A few days later, things looked even better. It’s hard to describe how relieved I was. Shortly after, we removed Austin’s feeding tube, and he went on about life as a normal dog. He’d made it. Not only was he one of the 50% that get to go home, he was one of the 25% that go home without chronic kidney disease.
Months later, I ordered routine screening bloodwork, in addition to a parathyroid hormone (PTH) concentration. It’s is an early indicator of chronic kidney disease. It goes up long before other changes show up. Not only were the screening tests normal, but so was the PTH. Not even “high-normal.” Just normal. I eventually got brave enough to change his diet back to a non-therapeutic adult maintenance diet. Since then, I’ve repeated these tests several times and they’ve remained normal.
Austin is back to being the fastest dog at the dog park. I assume that the “grape incident” as it has come to be known, did some permanent damage to Austin’s kidneys that we can’t yet detect. Our labwork isn’t perfect, and each kidney function test has a “threshold” for how much damage has to exist before the test result becomes abnormal. So far, if that’s the case, he hasn’t reached any of those thresholds. If/when Austin does show a decline in kidney function, you’ll see another entry about how I manage his changing needs. Until then, I’m grateful for the care that Austin received, and the care with which Nic and I were treated by Austin’s team.
There are many technical details that I’ve left out of the story; details about estimating energy and protein requirements, formulating diets, adjusting electrolyte intake, slurry preparation and administration, measuring body composition, and so much nutrition minutiae it would make your head spin. Those could each be their own very long blog post. I’ll just say that whether we talk about the big picture or the details of nutrition, Austin’s taught me a lot.