Thursday, April 30, 2009

Telling Time Without A Watch

We were nearing the end of another busy day at the hospital. Dirty towels and surgical drapes were piled high in the laundry basket. Some instruments were soaking in the bucket of disinfectant and others were finishing up in the autoclave, getting sterilized for tomorrows procedures. Patient charts were seperated into different piles, some for the nurses to make follow up calls, others for me to complete writing my medical notes and plans for patinet care. But one of the tell-tale signs that the day was coming to a close was the presence of Noodles and Twitchi, our hopsital cats. Without fail, every evening starting around 4:30 or 5, they make there way out from where ever they had been hanging out, usually working pretty hard, sleeping on a cat post or in one of the receptionist's chairs. Then they oh so patiently just sit-and stare-and wait. It is kind of creepy, actually, like the gathering of the birds in Alfred Hitchcocks movie. There is no mistaking what they want-come on humans-don't forget us (as if we ever have!) It is dinner time!

Anyone who has ever had a pet knows that they can tell time-no watch or clock needed.
We can say they have a "biological clock" or an "internal clock." It actually is an anatomical site within the animal's hypothalamus, an area of the brain directly above the place where the optic nerves cross. Composed of about 20,000 neurons, this area is known as the suprachiasmatic (above the cross) nucleus. It takes in variations in the available light from the retina, (the structure at the back of the eye) then transmits this information to the pineal gland. The pineal gland is a small, cone-shaped organ in the brain of most vertebrates that secretes the hormone melatonin. It is also called epiphysis, or pineal body.

There is a complex process allowing this transmission. Genes are encoding proteins and these genes will then regulate the functions of the cells of the pinel gland. This is when the cells start secreting the melatonin hormone. Once in the bloodstream, melatonin peaks in the daylight hours and ebbs at night causing wakefulness and sleepiness.

The circadian system is the total of all these neurons, their cells and the proteins and hormones they secrete. The system is not dependent on light and dark cycles, however. That is why animals can re-set their internal clocks as long as the new pattern is fairly regular and sufficiently important. In the case of Noodles and Twitchi-putting food in their bowls is plenty important!

Dogs and cats aren't the only ones who have these internal clocks. Species as diverse as fruit flies, humans and birds have circadian rythyms, and they don't have to be exactly one day long. (In Latin, "circadian" means "approximately one day.") Two examples are the heat cycles of domestic dogs, which usually occur about twice a year, and the menstral cycles of human females occuring approximately every 28 days.

So tomorrow night when your critters start circling up in the kitchen or come over and lay down near their food dish-raising those expressive eyebrows at you (as if you really don't know what they could want-we are dumb humans after all) , remember how complex a thing this circadian rythym process really is-and why when Noodles and Twitchi get ready to "retire" from their very busy jobs here, they probably don't need that gold watch. They do just fine with their internal clocks.


Tuesday, April 21, 2009

Jesse is Being an Ass

If it isn't one thing, it's certainly another-that sure is true around my house, what with all the critters we have. From pulling Stella out from under the bed to give her asthma medications, to making sure Verbal gets her arthritis drugs and supplements every day, and more recently chasing a ticked-off rooster so I can dose him with some pain meds-gee, what more do I need to medicate? I shouldn't have asked that question. Can anyone say limping donkey?

Yep, Jesse, my very furry, long-eared donkey is very lame, barely putting any weight on his left hind leg. I am pretty sure it is due to an abscess in his hoof-he seems to get one every year. Donkeys or burros are supposed to have really tough, hardy feet. Well, I don't know if it is all the mud we have (really not too bad considering all the rain here) or the rocks, his particular conformation or what, but Jesse's feet are just prone to these infections that occur within the hoof.

A hoof abscess can be defined as a localized accumulation of purulent exudates (pus) located between the germinal and keratinized layers of the epithelium (hoof capsule), most commonly subsolar or submural. I have seen these occur in horses secondary to nails from shoeing, but Jesse has never had shoes on his feet, and the last trimming he had done was over a month ago. Of course, the same thing can happen if a horse is punctures by a nail or other sharp object. Other abscesses occur after a deep bruise to the sole, usually from a stone wedged in the sulcus or groove adjacent to the frog tissue. The frog is the softer triangular wedge of tissue that acts as a pump in an equine leg. Often referred to as an additional heart, the 4 frogs (one in each foot) help the circulatory system, literally pumping blood back up those long legs to the lungs so it will get oxygenated again. Breakdown at the junction between the sole and wall as happens in white line disease or a simple crack in a hoof wall can predispose a foot to abscessation.

Understanding how an abscess forms can help in the understanding of how to best treat the often very painful condition. Bacteria will enter at the puncture, bruise, nail hole or white line defect, usually at the sole-wall junction at any point around the foot. As the horse walks and puts weight on the foot, dirt and other foreign matter push into the tract made by the bacteria. Once inside the hoof, the body's defense mechanism sets off a reaction called inflammation-this is ultimately what causes the heat, swelling and pain. The bacteria continue to grow in this environment, and white blood cells migrate to the area to help fight the infection.

Enzymes are released from the bacteria and this causes the hoof tissue to melt or liquify, turning into the blackish/gray "goo" associated with abscesses. The body tries to wall this off with a thin capsule, forming the abscess capsule. It can get very tight as the bacteria continue to reproduce within, resulting in more inflammation and thus more pain. It usually only takes about 3 to 5 days from the initial "insult" for clinical signs to occur, so if your farrier accidentally misplaces a nail or your horse (or donkey) gets a puncture from some other cause, treating with an antiseptic for a few days might ward this off. Of course, we often never know about the puncture or bruise that caused the abscess, as in Jesse's case. If I had, I would have loved to have prevented this apparent excruciating pain-and my need to fight with yet another of my own own butthead patients.

Jesse lets me know he has an abscess by showing up extremely lame in the affected foot. The lameness can be pretty sudden as his tend to be, and can vary from subtle early on to non-weight bearing as the condition progresses. It is often possible to palpate a digital pulse near the fetlock, stronger on the side of the foot where the abscess is located. Overall, the affected foot is usually warmer due to the inflammation, and if long-standing, the entire pastern or fetlock may become swollen from the disease or from disuse. We often use hoof testers to locate exactly where the abscess is, although some horses are sensitive in the entire foot making you need to rule out laminitis or founder, a severe bruise or even a fracture of P-3, the coffin bone itself.

Treating hoof abscesses requires first and foremost good drainage. An opening should be made that is big enough to allow good drainage and won't heal closed too quickly, but also won't be so big that it causes more problems. Under no circumstances should an abscess be approached through the sole. Dirt and manure and other foreign matter will just pack into a solar drainage hole, making it ineffective or even worsen the condition.

When an abscess is localized with the hoof testers, a small tract is often found in the sole-wall (white line) junction. If it is not visible or has closed up already, a poultice can be applied in an attempt to soften the area and break it open again. Animalintex, available at feed stores or veterinary supply stores, is a great product, as are epsom salt soaked sponges. Full foot soaks, once the norm for so many foot conditions, are now discouraged as they can really soften and weaken the integrity of the hoof wall.

The drainage tract is followed within the white line using a thin small loop knife, a 2 mm bone curette or other suitable probe. Gray/black pus is the reached when the "belly" of the abscess is reached and this area is cored out carefully.

A small opening is all that is necessary to obtain proper drainage. This can be determined by placing thumb pressure on the solar side of the tract and observing more drainage being expressed or a bubble at the opening when pressure is applied. Care should be taken to avoid exposing any corium, as it will invariably prolapse through the opening, prevent closure of the tract and create an ongoing source of pain.

The draining tract should be kept soft and drainage promoted. The application of an Animalintex or epsom salt poultice that has been soaked in hot water can be applied for the first 24 to 48 hours. The whole foot, including the coronet band, should be incorporated into the poultice for best results.

The relief is usually pretty immediate. Once the pressure is relieved, most animals will bear weight again, and if the infection is controlled, all lameness should be resolved in just a few days. It is often best to keep the foot bandaged to prevent the introduction of more bacteria and debris into the newly opened drainage site, and antibacterial dressings can be applied to help speed up the healing. Betadine or iodine solutions are effective and inexpensive.

I rarely put these patients on systemic antibiotics as it was mentioned above that these infections are usually walled off from the body and therefore inaccessible to the bloodstream. Pain relief medication such as phenylbutazone is very welcome, however. Jesse, of course, hates his bute, even the apple-flavored paste, and isn't making this process very easy. Be sure tetanus vaccinations are up to date as the tetanus organism thrives in soil and would love this type of wound.

Some people actually allow abscesses to "run their course," allowing the infections to follow the path of least resistance and eventually rupture up and out at the coronet band. This seems like a cruel thing to do, making an animal wait in extreme pain for this process to occur, and it can leave the hoof much weaker and prone to repeated abscesses in the future.

So, today after work, my terrific horse shoer, Fred, came over and helped me wrestle with my problem child. Jesse really does love most people, but he and Fred have always had a bit of a love/hate relationship. Fred doesn't take any of Jesse's shenanigans, one time even trimming his feet laying down when Jesse threw a fit and decided to fall down to the ground in protest. He has since learned it doesn't do a darned bit of good; Fred will win every time, darn it!

Jesse was in fine form tonight, though, and oh so quick with that sore hind foot. While Fred got ready with the hoof knife and nippers, I got out the drugs. It was no fun finding a vein in which to give his drug through all that winter hair of his, and he proved just as stubborn metabolically-his drug dose probably would have stopped an elephant but Jesse barely hung his head. It was enough for Fred to quickly cut into that hoof, find the abscess and provide some good drainage before Jesse decided he had enough and found his aim again. He could barely walk-he looked like quite the drunk donkey-but I wouldn't have trusted that back foot one iota. I snuck some bute between his lips much to his chagrin and let him stagger off to commiserate with Raquel. He's going to be just fine.

Prevention of hoof abscesses is achieved through proper hoof care and centers on promoting a strong, solid sole-wall junction (white line) that resists penetration by debris. Hoof abscesses are less likely to occur when a solid sole-wall junction (white line) is maintained.

Excessive toe length increases the bending force exerted on the toe, leading to a widening and weakening of the white line. Other conditions that cause mechanical breaks or weakness in the continuity of the white line are hoof capsule distortions (long toe-under run heels, excessive toe length, heels too high or a club foot, sheared heels), hoof wall separations (white line disease, seedy toe) and chronic laminitis. Excessive moisture or dryness, and the extreme back and forth from one season to the next, may also contribute to weakness in the white line. I really think this is Jesse's problem, as we do a pretty good job keeping his feet trimmed and he has never had white line disease, laminitis or any of the other hoof pathologies mentioned.

So, thanks to Fred, Jesse is all doctored up for the evening. I chased down Viggo and pulled off that last straggling bandaid from his surgical site. It is healing well and he is crowing and herding his ladies in the yard-I think he is doing well, too. Verbal got her dinner with her medications for arthritis mixed in. And I just popped Stella her prednisolone tablet to help calm her inflammed airways until her inhaler arrives later this week. Whew! It feels like a vet hospital around here. It's a darned good thing that Bill the emu is healthy-I better knock on wood!


Friday, April 17, 2009

Viggo Can't Help Being a Boy

Poor Viggo. He's just being a boy, and after all, that's what he is. But boy + chicken = ROOSTER, and when that is accompanied by an attitude that won't quit, well, something has to change. He is a handsome thing-and he certainly knows it. We have a whole slew of chickens, his little band of girls, and I'm not sure if he thinks he is protecting the ladies or if he is just being a butt head (much more likely) but he has started attacking us lately-and it hurts! Viggo hurls himself up and slams his 6+ pounds against your thigh or whever he can contact-and then he rakes his evil spurs against you. The spurs are actually bony appendages on the legs of roosters. They are very sharp, and yes, they sure can do some damage. I had a bruise that lasted for a week after his last unexpected attack. I'm getting pretty good about watching for him now, and (don't tell the animal cops!) he has received a few well placed kicks in the hind end when he was caught flying towards me. I even bring Verbal with me when I go to feed the chickens-she loves to chase them and her favorite sport is tumbling them head over heels (do chickens have heels?) as they squak and flutter. She has never attacked or hurt one-she just loves the chase and I'm sure she likes the noise they make. But Viggo doesn't back down, from me or from Verbal, and I'm afraid he is going to hurt her or maybe some unsuspecting visitor to my little farm one day.

So today our hospital sounds like a barnyard at 4 am-a very perturbed rooster is crowing at the top of his lungs-and won't shut up! Clients this morning have a very puzzled look on their faces, and everyone has smiled when we told them yes, we treat roosters, too, not just cats and dogs at this hospital. Noodles and Twitchy, our hospital cats, are just fascinated with this giant bird. They know they are supposed to be the predators, but Viggo stands taller than them and that voice-wow. Twitchy, especially, is going to need some time to get used to this.

The plan for Viggo was simple. We were going to place a mask over his beak and administer a gas anesthetic and oxygen mixture. Birds usually fall asleep very quickly with little struggle due to their very rapid metabolism. They generally have large tracheas, so we should be able to place an endotracheal tube for better anesthetic safety. We'll monitor him as we do any patient, and maintaining body heat is particularly important. Then I'll basically amputate those spurs or extra "toes." I had asked an avian specialist about this procedure and he said there shouldn't be much bleeding, but I could place some light wraps for a day or so if there was. He told me meloxicam would be fine for post-op pain relief and gave me some doses appropriate for a mature rooster. I'm not looking forward to chasing down that darned bird every day to stuff meds down his throat, but I will if I have to. Oh joy.

Here is Viggo getting his pain meds. He was a good boy for his medications, so maybe it won't be such a chore after all.

Well, the procedure itself was pretty quick, but I don't know what the specialist was talking about-those spurs bled like a son of a gun! I had to place some pretty tight little wraps over the surgery sites to get the blood to stop. Viggo started to pick at the wraps when he woke up and was kind of dancing a bit-I felt like the pain medication wasn't enough for him, so gave him an extra dose. That seemed to do the trick-he stopped dancing in his kennel and left the wraps alone after that. Pain control is important for all of us, even roosters.

So, we'll see how this goes. Taking away his weapons should at least make us safer around the barn yard, but maybe it will humble that cock-o'-the-walk, too. I can hope!

One other funny thing happened as a result of Viggo being in the hospital today. A sweet patient named Roarie, here for her own surgery and recovering in the cage right next to Viggo, was barking and howling and basically calling back and forth to him all day. It really sounded like she was trying to crow just like he was! Her owners were great about it, laughing when they heard her as they came to pick her up. I sure hope they are still laughing when she starts crowing at the 4 am wake-up call!


Friday, April 10, 2009

No More Tears for Tucker

Tucker is a bouncy, happy Springer Spaniel puppy that didn't actually look very happy before his surgery yesterday. ( I didn't get a picture before surgery, darn it. I'll try to remember when he comes in for his suture removal.) He was constantly tearing or crying in one eye-and certainly not because he had anything to be sad about. This puppy has great owners and when we pointed out the tears during his physical exam last month, they promised to watch the eye and note any changes. I showed them how Tucker's lower eyelid was rolling inward, a painful condition called entropion, which causes the eyelashes along the border of the lid to constantly rub on the sensitive cornea of the eye.

Entropion can have a genetic cause, and Springers are one of the breeds predisposed to the condition. Other breeds commonly affected are Boxer, Bull Mastiff, Cavalier King Charles Spaniel, Chesapeake Bay Retriever, Cocker Spaniel, English bulldog, Golden Retriever, Great Dane, Irish Setter, Labrador Retriever, Poodle, Pug, and St. Bernard. Chow Chows and Shar Peis have all those extra wrinkles in the skin, so they can have very severe forms of the condition, and left untreated, entropion can cause painful ulcers and erosions on the cornea that results in scarring and affects vision. Those pets with the heritable form of entropion should not be used for breeding. Entropion can also occur as a secondary condition resulting from scarring of the eyelid, infection, corneal spasms and pain, trauma, or nerve damage. Sometimes it happens after the eyelids lose their normal neurologic function.

Tucker was fortunate because only one lower lid was affected-entropion can often affect both eyes and both upper and lower lids. When we examined his eye, we applied a stain called fluorescein on his cornea. If there had been any defect on his cornea such as an ulceration from chronic eyelash rubbing, the stain would have glowed bright green when a black light was shown on the eye. Tucker's cornea was fine so far, so correction of the eyelid malformation should prevent that damage and subsequent pain.

Surgery is the only way entropion can be permanently corrected-essentially plastic surgery for dogs, although it is not an elective or cosmetic procedure. The hair is surgically clipped around the eye and the skin is scrubbed, protecting the delicate eye tissue. Then the excess skin is "pinched" between several hemostats, taking gradually bigger bites until the eyelid everts or rolls outward to a more normal position. We don't want to incorporate too much skin in the hemostats or we can cause ectropion, the opposite condition in which the eyelid is rolled outward. I really like the pinch technique because it allows me to see how the the anatomy of the lid will change after removing the incorporated tissue. After removing the hemostats, the pinched skin stays standing up; this is trimmed away (called a blepharoplasty) and the resulting skin incision is sutured closed with very tiny, silk sutures. Most dogs need to wear an e-collar or satellite dish on their heads to prevent rubbing the surgery site as it heals. Stitches are usually removed in 10 - 14 days and once the hair grows back, you usually can't see much of a scar at all.

There isn't much problem with recurrence of the entropion except for in the very wrinkled, extra-skinned dogs like Shar Peis. Some surgeons may take a conservative approach to the initial surgery, only taking a small amount of skin during the blepharoplasty. They believe they can always go back to take more skin at a later date if the lid needs to roll out more, but it wouldn't be possible to put it back if too much was removed the first time. Some dogs require systemic or topical antibiotics and all should have pain relief medications for at least a few days post op.

Tucker's surgery went very well. I believe the repair resulted in a more comfortable eye for him, and I know his owners will be watching him for any signs of problems. He also got neutered that day, so he definitely got some pain relief medications and a nice big e-collar. When he recovers he can go back to looking as happy as he actually is-no more crying by Tucker!


Friday, April 3, 2009

A Horse is a Horse, Of Course, Of Course

I've been preoccupied with some extra-curricular things lately so have been very neglectful of my blog. I just put a nice deposit on a beautiful saddle for my gorgeous horse, Raquel. Michael, my husband, had been making some noises like he wanted to start riding her, so I wanted to do all I could to encourage him. He wouldn't feel comfortable riding in my "funny" little English all-purpose saddle. I like that one because it is MUCH lighter, and lifting a heavy saddle way up on her back isn't fun. My old roper saddle I use when other people ride her is, well, old. I have tried to take care of it, but the leather is cracked (I have newer leather for the latigos and cinch so it is safe, just not very pretty....) and it kind of lists to one side on those longer rides, so you constantly need to shift your weight over to balance things out. It was just time to retire it.

I found quite a few Western saddles that would work just fine-but boy are they expensive! I'm generally not one for buying new things for myself at all, shopping for most of my clothes and all at stores like Value Village or Goodwill-thrift and second hand stores. Don't get me wrong, I usually find pretty nice, brand name clothes there. I just hate to pay full price for anything. I'm wearing my work dresses around jumping, slobbery, muddy, shedding dogs and cats, so I just don't want to spend tons of money on things that could easily get ripped or pooped or peed on. Well, I decided to splurge and get Raquel a nice new saddle this time-she's worth it, and so am I! But I wanted to be smart about it, especially with this crummy economy right now. So no credit for us. Lay-away would work just fine.

Even though she is a pretty big horse, Raquel isn't too difficult to fit for a saddle. But since I was planning to spend so much, (for me, that is-I know other people can spend many thousands of dollars on much fancier saddles!) I wanted to be certain of that fit. I arranged with a local tack store to take a few saddles home to try on her, being very careful not to get them muddy or hairy-quite the feat in this Spring season. She isn't anything BUT mud and shedding hair right now! I wrapped some plastic grocery bags over my feet and put saddle blankets on her and we took a few short rides around the neighborhood. Now I sure didn't want or need anything too fancy-we aren't going to be showing any time soon. No silver or lots of tooling (carved designs in the leather.) I was looking for something that fit her, fit me and Michael, was comfortable to sit in, and also looked nice.

I think I found a really nice one-I couldn't believe how comfortable it was! It has a gel seat and a flex-tree, so it should be just as comfortable for Raquel as it is for me. I'll be sure to get pictures when I actually get the see, my thrift store nature came out after all. I took the manufacturer and model number and went searching on the web. I found the exact saddle, only it was a black one-perfect for my solid black horse!-for sale on Craigslist. The seller said she had only used it 3 times, so it was essentially new, and would save me over $800! How could I pass up such a deal? I felt bad about not buying it from the local tack store as I do like to spend my money locally, but I assured them I would be in frequently for all the miscellaneous things you always seem to need or just plain "have to have" when you are a horsey person. The saddle is in the mail as I type this, coming from New Hampshire!...I am very excited and this saddle is so nice that I might be converted to riding in the Western saddle more often! I just don't buy big things for myself very often, can you tell? I wonder if everyone gets this excited when they buy big toys? I hope so!

Speaking of Raquel, I have been trying to get her out riding more often lately. I joined a meet-up group of fellow horse lovers and we are actually going on a camping trip next month to the Oregon coast. It is a dream come true mixing two of my favorite things-horses and beaches! I sure hope we have some nice weather. It will probably be the first time my friend Kristen and I will be able to ride together-can you believe that? Neither of us has a trailer, so even though we live fairly close, we can't get our horses together-bummer. This camping trip will be a great thing since I hardly ever take time off work. I think everyone is saying "it is about time!" So, I am riding my big girl around the neighborhood a couple times a week and I just signed up for some riding lessons to work on better communication with her. I am really the only one who has ever ridden her regularly, starting her as a baby and all. It sure won't hurt to have that extra help to better both of our skills and to get us both into shape after a much too long winter.

I really like the folks in the meet-up group. It is the largest and most active equestrian meet-up in the world-right here in Snohomish/King counties! So far I haven't been able to ride with others, but we have frequent meet-ups where we have potlucks, sell our used tack and swap information. I'm the "animal health coordinator" so feel it is important to educate the group on all things veterinary-first aid, normal and abnormal vital signs, how to wrap leg bandages, etc. We are even putting together a binder of handouts on these topics for future use. I'm working with my staff at the hospital to put together an equine first aid kit, complete with bandaging materials, a stethoscope and thermometer and other things important for a horse owner to have on hand in case of an emergency.

So this blog will have at least a little bit of a veterinary topic today, here are the horse vital signs it is important to be familiar with. If your horse's numbers are significantly out of range, CALL YOUR VET!

Body Temp: 99.5 - 101.3 degrees F
Pulse rate: 28 - 45 beats per minute
Respiration rate: 10 - 14 breaths per minute

Take the temperature

  • Lubricate the thermometer with petroleum jelly, K-Y jelly or just spit on the end. It must be wet for good contact with the rectal mucosa.
  • Attach a string to the end of your thermometer. (They have been known to fall into bedding or even get "sucked" into the rectum.)
  • Tie a clothespin to the other end of the string so you can attach it to your horse’s tail while you’re taking his temperature.
  • Approach the horse from the side, and do not stand directly behind him.
  • Raise your horse’s tail and insert the thermometer into his rectum.
  • Wait at least 1 minute, then read the thermometer.
  • Digital thermometers are often very quick and accurate.

Find the Pulse

  • Use your fingers or a stethoscope to find your horse’s pulse under his chin or on the left side of his barrel, just behind his left elbow. It can also be located at the temple.
  • Each “lub-dub” is considered one beat.
  • Record the rate for 15 seconds and multiply by four to get your horse’s heart rate.

Check Breaths

  • Watch your horse’s chest move in and out, or cup your hand over his nostril and feel the air come out.
  • Use your stethoscope to listen to the breaths as the air travels across the trachea when he inhales and exhales. It should sound clear and consistent.
  • Note the characteristics of your horse’s breathing. Are the breaths shallow or deep? Are there any abnormal sounds like squeaking or roaring?

A horse’s daily water requirement varies from 5 to 20 gallons, depending on environmental temperature, workload, production state and feed intake. Providing clean, fresh water is a top priority for horse owners, especially if you are traveling.

The vital signs listed are for RESTING horses. If they are nervous or excited or just finished exercising, these will vary. Even just the sight of a thermometer or stethoscope can freak out some horses, so take this into consideration.

Happy trails, everyone!