Organophosphate Toxicity

Recently we had a couple cases at the clinic involving puppies exhibiting signs of sickness and weakness.  The pups had been vomiting, having diarrhea, and showing signs of weakness and lack of coordination.  At first the signs and symptoms seemed to point towards Parvovirus, a common but very serious disease often seen in puppies.  After checking the puppies' records, it was brought to our attention that both were up to date on Parvovirus vaccinations.  The pups were tested anyway to be safe, and sure enough both were negative for Parvo.  The owners of one puppy said they had applied a topical flea medication and saw symptoms shortly after.  The owners of the second puppy had applied Seven dust in order to rid of a flea infestation.  The veterinarian dealing with the cases immediately knew what was the cause of the problem.  He diagnosed the pups with organophosphate toxicity or in other words, insecticide poisoning.  Organophosphate poisoning results from overexposure to organophosphates by inhalation, ingestion, or dermal contact.  These compounds are a diverse group of chemicals used in both domestic and industrial settings.  Examples include insecticides, herbicides, nerve gases, ophthalmic agents, and anthelmintics.  The most common form of organophosphates that pets are exposed to are found in lawn and garden treatments and flea and tick treatments.  Organophosphates work by inhibiting acetylcholinesterase, an enzyme critical for nerve function.  Inhibition of acetylcholinesterase causes an accumulation of acetylcholine, a neurotransmitter, in the body, which results in nerve and muscle overstimulation.  Some noticeable symptoms include fever, vomiting, diarrhea, anorexia, depression, seizures, muscle tremors, hypersalivation, constricted pupils, increased heart rate, lack of coordination, and respiratory failure.  Once diagnosed with organophosphate poisoning, the animal needs to be stabilized, decontaminated, and treated.  Treatment includes the following, bathing the animal to remove remaining chemical residue, inducing vomiting to flush out the stomach if poison was ingested, administering IV fluids, and administering drugs such as atropine to counteract the effect that organophosphates have on the nervous system.  Despite the large variety and widespread use of organophosphates, poisoning can be prevented.  Insecticides and other organophosphates should be researched and labels should be followed correctly before using in the home, on the lawn, in the garden, or on pets. 

A Lesson Lived Is A Lesson Learned

One thing I love about working at the clinic is hearing all about the veterinarians wild tales of things that have happened to them during their years of practice.  Recently one of the veterinarians was telling a story about drawing blood on a horse for a Coggins test.  It was nothing too exciting, just a quick stick and everyone would be on their way.  When he went outside the clinic, the owner had not yet unloaded the horse.  The veterinarian asked the owner to unload the horse, but he insisted that it would be much easier and quicker just to draw blood from inside the trailer.  The veterinarian stepped inside the trailer and slowly approached the horse.  The horse, seeing and unfamiliar person coming toward him, began to panic.  The vet and owner tried to calm the horse down, but it began to frantically pull against the trailer tie.  Suddenly the horse swung its head to one side and snapped the tie.  The horse's face collided with the side of the veterinarian's head and knocked him out cold.  He had to be dragged from the trailer to avoid being trampled.  He woke up outside the trailer with a swollen face, a pounding headache, and a concussion.  The vet said he learned the hard way never to get inside a trailer to mess with a horse.

Just this week a client brought in a horse for a Coggins test.  The veterinary technician was sent out to draw the blood and I went along to help.  It was pouring down rain outside and the owner had not unloaded the horse.  The veterinarian's story ran through my head.  The owner said that since it was raining we could draw blood from inside the trailer.  We stepped into the back of the trailer to get out of the rain, but the veterinary technician suggested that it would be safer to work outside even though it was raining.  The owner insisted that we would be fine and proceeded to untie the horse, but just as he loosened the rope the horse spooked and ran backwards.  The vet tech and I scurried to get out of the way just as the horse slipped and toppled backwards out of the trailer.  The horse regained its footing and luckily wasn't hurt, but the vet tech and I got quite a scare.  I think it's safe to say I learned my lesson and will never again get in an unfamiliar horse trailer again.

 

Cryptorchidism

I have seen plenty of spays and neuters at the clinic.  They are a routine, daily occurrence so it is always interesting when something out of the ordinary happens during one of these procedures.  The other day there were two neuters scheduled, a cat and a dog.  Nothing too exciting or out of the ordinary.  However, while the animals were being prepped for surgery it was noticeable that something was not quite right.  Both animals had only one testicle.  They were both exhibiting cryptorchidism, otherwise known as retained testicles.  Cryptorchidism is a condition in which a male's testicles have not descended into the scrotum.  During male fetal development, the testes develop high in the abdomen and move from the abdomen down through the inguinal canal and into the scrotum.  By the time an animal is at the right age to be neutered, the testes should be fully descended.  If they fail to descend, the testicles may remain in the abdomen or inguinal canal.  Cryptorchidism can be unilateral in which one testis is retained (like the two neuters scheduled for surgery at the clinic), or it can be bilateral in which both testes are retained.  Due to the need for thermal regulation during sperm production, bilateral cryptorchids are sterile while unilateral cryptorchids are still fertile.  Cryptorchidism is considered to be an X-linked, autosomal-recessive trait, or in other words a heritable defect, so it is highly advised that cryptorchid animals should not be used for breeding.  Surgical removal is the only treatment for cryptorchidism.  A cryptorchid surgery is more complicated than a normal neuter because it is more invasive (usually involves opening the abdomen) and the cryptorchid testicle may be difficult to locate.  Even animals that are unilateral cryptorchids should have both testicles removed because the retained testicle is prone to testicular torsion and testicular cancer.

Forms of External Coaptation

In the time that I have spent at the clinic, I have seen plenty of broken bones.  Splints are the "go-to" form of external coaptation that the clinic uses to fixate and immobilize limb injuries.  The two most common forms of splints I see used are the Robert Jones Bandage and the Schroeder-Thomas Splint.

The Robert Jones bandage is a common external splint used to immobilize lower-limb injuries.  This bandage should not be used on upper-limb fractures/injuries because it cannot properly stabilize such injuries.  The Robert Jones bandage offers limb stability, tissue fluid absorption, and protects from trauma.  It promotes healing by immobilizing the injured area, thus reducing swelling and providing protection from secondary trauma.  The bandage consist of multiple layers of soft, compressible, and absorbent materials such as cotton wrap and conforming bandages.  These layers are supported by bandage tape stirrups, plastic splints, or a combination of both on either side of the leg.  The entire leg is then wrapped with vet wrap and once finished should keep the leg rigid and immobile.

The Schroeder-Thomas splint is another common external splint used to immobilize any fracture below the midfemur of midhumerus.  The splint is a traction device or traction splint.  This most commonly refers to a splinting device that uses straps attaching over the pelvis, hip, or shoulder as an anchor, metal rods to mimic normal bone stability and limb length, and a sling-like device to apply traction in order to reduce pain and realign the limb.  The splint is designed so that bandages and tape are used as slings on the metal frame to position and counteract muscle movement to help align and immobilize parts of the limb.

Although splints are a quick and easy way to set and immobilize fractures, casting is another common form of external coaptation.  Casts lie in contact with the skin and are made to conform to the injured area.  Plaster and fiberglass can be used for casting, but fiberglass is more commonly used because it is lighter, stronger, and dries quickly.  I had the pleasure of seeing a cast applied to a front limb fracture on a dog for the first time the other day.  The patient was anesthetized and the fracture was set.  Cotton cast padding and a stockingnette were applied to decrease pressure points that could cause skin ulceration.  Rolls of casting tape were dunked in warm water and applied up and down the leg.  Within minutes the cast was dry and hard as a rock.  The cast would be left on for 6-8 weeks in order to allow the fracture to form a callous and heal before being removed.

Peculiar Poultry

We had the pleasure of treating a rooster at the clinic just the other day.  He was a beautiful bird with shiny black feathers and a bright red comb, a show quality bird, but there was one peculiar thing about him.  He sat splay legged in his pen with his head tucked under his chest.  His neck was so weak and limp that he could barely lift it.  The owner explained that it was a perfectly healthy bird and had just started having problems a couple weeks ago, but had gotten progressively worse.  The vet examined the rooster and determined that an injury was not the cause of the problem.  He concluded that it must be due to a vitamin deficiency.  One common deficiency often seen with chickens is riboflavin deficiency.  It can be seen rarely in adult birds, but is most commonly seen in young, growing chicks and is often referred to as curled-toe paralysis due to paralysis and disfigurement of the extremities.  Sitting splay legged and hock-resting postures are also often seen.  The owner was sent home with some riboflavin suspension to give the bird by mouth for 7-10 days, in hopes that the bird would be well and 4-H fair ready within a couple weeks.

Help! It's stuck!

It seems like it never fails, just when we all think we can close the clinic on time clients walk in at the last minute with animals that need immediate attention and extensive treatment.  This always seems to happen on Friday evenings when everyone has plans and is itching to get off work.  Just this Friday we had a client call at the last minute to say he was bringing his dog to the clinic because he had a bone stuck in his mouth.  We all imagined that the dog had lodged a bone in the back of his mouth and was choking.  When the owner arrived with his dog we quickly realized that the dog was in a totally different predicament than we had imagined.  The owner had given the dog a stuffed shin bone to chew on.  The dog clearly enjoyed his treat a little too much.  He had worked so hard to lick the filling from the bone that he somehow worked the bone over his lower jaw and even over his lower canines.  The bone was really stuck.  The sight was quite hilarious, but the dog was clearly in distress.  He clawed frantically at the bone, but it wouldn't budge.  The dog was sedated and the veterinarian went to work on trying to remove the bone.  He slipped a strand of wire saw underneath the bone and proceeded to saw through.  The bone was so tight that the wire saw was starting to cut the dog's skin.  The veterinarian went to the clinic's storage room, rummaged around, and came back with a pair of bolt cutters.  He placed them at the end of the bone and clamped down.  With one cut, the bone snapped off and went flying across the room.  The vet laughed and said, "Nothing like an easy and humorous case to end the day."

Abnormal Eyelids

There were several interesting cases at the clinic this week.  One such case involved a young pitbull puppy about five to six months old who had been brought in to be spayed.  As I took the dog out of its kennel to be prepped for surgery, I noticed something was not quite right with her eyes.  They looked swollen and inflamed and a pus-like discharge was coming from the corners of the eyes.  After inspecting her eyes for a few moments I was confident that I knew what the problem was.  I had never seen a case in real life, but I remembered reading about the same eye problem in a James Herriot book.  I couldn't remember the name of the condition so I asked one of the veterinarians and he told me the dog was suffering from entropion.  Entropion is a genetic condition that occurs in a wide variety of dog breeds in which a portion of the eyelid is inverted or folded inward.  The inward folding may occur on the top or bottom lid or both.  This can cause the eyelashes to scratch and irritate the surface of the eye, resulting in a corneal ulceration.  In the long run, entropion can cause a decrease or loss of vision if not treated.  Entropion can be treated by using eye drops to alleviate some of the irritation.  A temporary surgery known as "tacking" can be performed by rolling the eyelids back and holding them in place with sutures.  This surgery is usually performed on young puppies in hopes that the dog will grow into the skin around the eyes.  Surprisingly enough, the condition can be permanently corrected by a simple surgery.  A small sliver of the affected eyelid or eyelids is removed and the remaining gap is stitched together, which in turn everts the eyelid away from the eyeball.