Sunday, July 31, 2016

The Bicycle Bells of Amsterdam

Amsterdam is a biking city.   There are actually more bicycles than there are residents.  These bicycles all have bells on them, and there are nearly as many varieties of bell as there are bikes.  Solid pastels, floral patters, messages, animals, stars, logos... a little of everything. I took a few pictures of some that caught my eye.






















Thursday, July 28, 2016

Feline Body Parts – The Stomach

Body Parts – The Stomach
by Arnold Plotnick, MS, DVM, ACVIM



If you can’t stomach the thought of an article about the stomach, then this column may not be for you.  But have no fear, I will make this material easy to digest.

The stomach is an important part of the gastrointestinal tract.  Food that is swallowed is propelled by the esophagus into the stomach, where the digestion process begins.  The stomach is comprised of several distinct sections.  The fundus is the small part that lies just above the junction between the esophagus and the stomach.  The inlet or opening from the esophagus into the stomach is called the cardia.  The largest section is the body of the stomach.  This section mainly serves as a storage tank for undigested food.



The next part of the stomach is the antrum.  The antrum is very muscular and serves to grind up the food into smaller pieces.  The pylorus is a sphincter – a ring of muscle – that regulates the flow of stomach contents from the stomach into the duodenum, the first part of the small intestine.  The pylorus also serves as a one-way valve, preventing backflow of intestinal contents into the stomach.  The stomach is shaped like a lopsided kidney bean.  The longer outside margin, on the left side of the body, is called the greater curvature.  The shorter outside margin, on the right side of the body, is the lesser curvature.

The principal job of the stomach is to store, mix, and digest food, and to regulate the emptying of its contents into the small intestine, where digestion continues.  The stomach contains glands that produce acid and enzymes that digest the incoming food.  The acid also helps to kill bacteria that enter the stomach.  The stomach is also lined by glands that secrete mucus, which helps protect the stomach from being digested by its own acid and enzymes.  

The most common sign that something might be amiss with your cat’s stomach is vomiting.   Every cat vomits now and then, and most of the time there’s a harmless explanation for it, such as eating too fast, a sudden change in diet, or hairballs. 

When cats groom themselves, the barbs on their tongues remove the loose and dead hair. These hairs are swallowed. Most of the hair passes through the digestive tract, but some hair may accumulate in the stomach, where it can form into a hairball. Ultimately, cats will rid themselves of hairballs by vomiting them up.  Long-haired cats like Persians and Maine Coons are predisposed to hairball problems. Cat owners should be cautioned, however, from instinctively blaming all vomiting on harmless hairballs.  Certainly if you see a big hairball in the vomited material, and this occurs infrequently, then hairballs is the likely diagnosis.  But cats that vomit hairballs very frequently usually have an underlying disorder, and this should be investigated by a veterinarian.

Inflammatory bowel disease (IBD) is a disorder in which the immune system sends inflammatory cells into various segments of the gastrointestinal tract.  The stomach is commonly affected.  In fact, my own cat Mittens has IBD of the stomach.  Other signs, such as decreased appetite and weight loss may accompany the vomiting.  Most affected cats tend to be middle-aged or older, although any age cat can be affected.  To make a definite diagnosis, biopsy specimens from the stomach are required.  These can be obtained via surgery, or by endoscopy.   Endoscopy is a procedure where a long snake-like tube with a camera on the end is inserted down the esophagus and into the stomach, and biopsy samples are obtained.  This is how my cat’s IBD was diagnosed.  Treatment with anti-inflammatory medications often brings the vomiting under control.

Sadly, cancer of the stomach can occur in cats.  Although it can strike cats of any age, it is mostly seen in older cats.  Lymphoma is the most common stomach cancer, but other types such as gastric carcinoma and mast cell tumors can occur.  If the tumor involves a discrete area of the stomach, surgery to remove the cancerous part of the stomach may be feasible.  Lymphoma is considered to be a systemic disease, and chemotherapy is the treatment of choice.  I treated a cat named Beowulf with chemotherapy for high-grade stomach lymphoma.  He remained in remission after a year of treatment, so we stopped the chemotherapy.  Three years later, he appears to be cured of his cancer. 

Some of the medications we used to treat stomach disorders in cats are similar to the ones we use to treat people.  If excessive stomach acid is believed to be contributing to a cat’s symptoms, we prescribe drugs like cimetidine (Tagamet), ranitidine (Zantac) and famotidine (Pepcid).  Cats needing a stronger antacid can be given omeprazole (Prilosec).  However, cat owner should never administer any over-the-counter medications without consulting their veterinarian, because the dosages for cats will very different, of course.








Friday, July 22, 2016

Feline Body Parts – The Kidneys

Body Parts – The Kidneys
by Arnold Plotnick, MS, DVM, ACVIM


    Like all mammals, cats have two kidneys, one on the left, and one on the right.  They are shaped like…kidney beans, of course.  Blood flows into the kidney through the renal artery, and leaves via the renal vein.  As blood passes through the kidney, toxins are filtered from the bloodstream.  These toxins go into the urine, where they are excreted from the body.   The kidney also produces hormones.  One of these hormones, called erythropoietin, is responsible for the production of red blood cells from the bone marrow.  Other hormones produced by the kidneys help regulate blood pressure.

    As most cats age, kidney function gradually declines.  Eventually a point is reached where the kidneys can no longer maintain their normal function, and the toxins in the bloodstream accumulate.  This condition used to be called chronic renal failure, but these days, veterinarians prefer the term chronic kidney disease (CKD).  Unless the underlying cause can be discovered and treated, CKD invariably progresses.  In most cases, an underlying cause cannot be found.  Why most cats eventually develop CKD remains one of veterinary medicine’s biggest (and most frustrating) mysteries.

 





The primary clinical signs of CKD in cats are excessive thirst (polydipsia) and urination (polyuria), decreased appetite (anorexia), weight loss, and occasional vomiting.  Because these signs are also often seen in other illnesses, several tests are required to confirm a diagnosis of CKD.  These include a complete blood count, serum chemistry panel, and urinalysis.  The finding of dilute urine, coupled with an elevated level of kidney toxins in the blood, indicates that kidney function is compromised.  The two primary renal toxins that we monitor are “blood urea nitrogen” (often abbreviated BUN) and creatinine.  Other abnormalities, such as elevated phosphorus, low potassium, and anemia (decreased amount of red blood cells) may also be detected.  Although CKD is incurable, a variety of diet and drug interventions are now available that may slow the progression of the disorder, improve the cat’s quality of life, and extend a cat’s survival time.  Cats who are suitable candidates may be eligible for a kidney transplant.  This is a major endeavor requiring the expertise of a skilled surgical team at a university or referral center.  The procedure, as you might expect, is very expensive, and post-operatively, the cat will require long-term administration of drugs to prevent rejection of the transplanted kidney.



    Although chronic kidney disease is by far the most commonly seen feline kidney disorder, other kidney ailments are occasionally encountered in cats.  Acute renal failure (the currently preferred term is acute kidney injury, abbreviated AKI) is a disorder characterized by a sudden, dramatic decrease in kidney function.   This is a serious condition that, if not recognized and addressed quickly, can lead to rapid decline and possible death.  Unfortunately, the clinical signs of AKI – poor appetite, vomiting, extreme lethargy, weakness, decreased urine production – are nonspecific and may result in delayed recognition that the cat is ill.  The most common causes of AKI in cats are ingestion of ethylene glycol (antifreeze) and ingestion of lilies.  Many people are unaware that all parts of the lily plant – even the pollen – are toxic to cats if ingested. Other possible causes include unintentional administration of toxic drugs (for example, giving ibuprofen to a cat), and any situation that results in decreased blood flow to the kidneys (for example, anesthesia).

    Bacterial infection of the kidney, called pyelonephritis, is occasionally seen in cats.  In this disorder, one or both kidneys become enlarged and tender, and the cat usually develops a fever, high white blood cell count, and poor appetite.  Elevated BUN and creatinine levels may occur if kidney function becomes impaired.  Pyelonephritis usually requires hospitalization and treatment with intravenous fluids and antibiotics.

    Kidney stones (nephrolithiasis) are uncommon in cats and are usually of minimal clinical consequence. However, if a small stone leaves the kidney and becomes lodged in the ureter (the tube that connects the kidney to the bladder), the obstruction of urine flow causes a pressure buildup in the kidney that can lead to functional impairment and, if not relieved, ultimate destruction of the kidney.  Fortunately, this is an uncommon occurrence.

    Feline infectious peritonitis (FIP) is a viral infection that may affect cats of all ages, although it has a predilection for young cats.  There are two forms of the infection, the “wet” form, in which fluid accumulates in the abdomen (and sometimes the chest cavity), and the “dry” form, in which clusters of inflammatory cells infiltrate various solid organs in the body.  The liver and kidney are the favorite target organs for the FIP virus.  When FIP affects the kidneys, their function eventually becomes impaired as the viral infection progresses.  At present, there is no treatment for FIP, and all cats eventually succumb to this disease.  Treatment of FIP, however, is a very active area of research, and veterinarians are more optimistic than ever that an effective treatment will soon be discovered.

    Sadly, cancer of the kidney is a well-documented illness in cats.  The cancer can be primary, i.e. arising from the kidney itself.  An example would be a renal carcinoma. In primary kidney cancer, usually only one kidney is affected.  Cancer can also spread from other organs to the kidneys.  The most common type of cancer occurring in feline kidneys is lymphoma, in which both kidneys are infiltrated with cancerous lymphocytes.  Renal carcinomas, being unilateral, may be amenable to surgical removal.  Lymphoma of the kidneys, however, is almost always bilateral, and must be treated with chemotherapy. 

   
For more on feline kidneys, check out my articles:

     "Long Term Management of Chronic Renal Failure in Cats"
     "New Test for Renal Disease"
     "High Blood Pressure"
     "Polycystic Kidney Disease"

Saturday, July 16, 2016

The Effect of Music on Kitty Anesthesia: Vivaldi vs. Van Halen

The most recent issue of the Journal of Feline Medicine and Surgery contained a pretty interesting article about the effect of various genres of music on a few parameters of feline anesthesia.  Being a big music fan myself, I was intrigued.

The aim of the study was to determine if cats were able to process auditory stimuli even though they were anesthetized.   They evaluated two parameters, respiratory rate and pupil diameter.  These parameters are affected by the depth of anesthesia; as you come out of anesthesia, your respiratory rate increases and your pupils get larger.  Deeply anesthetized animals have a slower respiratory rate and smaller, constricted pupils.

Twelve cats that were scheduled to be spayed were fitted with little kitty cat headphones that completely covered their ears, and were exposed to 2 minute excerpts of music representing three different genres - classical, pop, and heavy metal at three different times during their surgery.  A medical monitor measured the heart rate.  and digital calipers measured the pupil diameter.

The results weren't surprising, really.  Cats showed nice low respiratory rates and small pupils when played classical music.  The values were intermediate for pop music.  Heavy metal caused a faster respiratory rate and larger pupils.

The conclusion:  cats under general anesthesia do indeed process auditory stimuli.  So, depending on the type of music being played in the surgery room, the anesthesiologist may be able to administer a reduced anesthesia dose, minimizing undesirable side effects.

I checked the "materials and methods" section to see exactly what the researchers used as representative of the genres.  Their classical choice was Samuel Barber's Adagio for Strings (Opus 11).  The pop sample was "Torn" by Natalie Imbruglia.  For heavy metal, they used "Thunderstruck" by AC/DC.

I'm trying to envision a cat, under anesthesia, with over-the-ear headphones, being forced to listen to Natalie Imbruglia.  Doesn't this violate animal cruelty laws?




Wednesday, July 13, 2016

Intestinal Intussusception in the Cat

Intestinal Intussusception in the Cat

This big medical term describes an intestinal condition that, if not recognized and treated promptly with surgery, could have dire consequences for your cat.



            A few months ago, a client brought her 4 month-old female kitten, Squeegee, to my feline-only veterinary hospital for an exam.  The kitten had been doing great, eating well, growing nicely, and playing like a maniac, until two days before when she began to vomit.  She became lethargic, the vomiting progressed, and her appetite abruptly disappeared.

            My physical examination revealed a markedly subdued, dehydrated little orange tabby.  Her body temperature was normal, and she was an appropriate weight for her age.    The exam was fairly unremarkable, until I got to the abdomen.  As I gently pressed on her belly with my fingers, I could feel a tubular, sausage-like structure.  She squirmed and tried to get away.  I gave her a little break, and then I softly pressed again to be sure of my findings.  It was unmistakable; there was something seriously amiss in Squeegee’s belly.  She was too young for cancer or inflammatory bowel disease.  A discreetly thickened loop of bowel in a kitten was highly suspicious for a condition called intestinal intussusception.   I recommended abdominal ultrasound to corroborate the diagnosis, and the owner agreed.  My suspicions were quickly confirmed, and preparations for immediate surgery were begun.

 intussusceptum (“inta-suh-SEP-tum). The outer portion that receives the piece of intestine is called the intussuscipiens (“inta-suh-SIP-ee-enz”). (When studying this in veterinary school, my trick for distinguishing between the two parts was to remember that the intussuscipiens is the recipient.) Intussusceptions are named by first citing the intussusceptum, and then citing the intussuscipiens.  For example, a “gastroesophageal” intussusception is one where a piece of the stomach (“gastro”) pushes itself into the esophagus.  An “enterocolic” intussusception is one in which a portion of the small intestine (“entero”) pushes into the colon.  In cats, the most common type is intestinal, where both the intussusceptum (the piece that pushes) and the intusscipiens (the piece that receives) are portions of small intestine.   
           Warning:  big words ahead.  An intussusception (pronounced “inta-suh-SEP-shun”) is a condition in which a piece of intestine telescopes or invaginates into another piece of intestine.  (See drawing.)  The piece of intestine that pushes into the other piece is called the

            Intussusceptions have been well-described in dogs.  They are most common in young dogs, with German Shepherds being the most commonly reported breed, although whether there is a true breed predisposition is debatable.   Less information is available regarding intussusceptions in cats.   In 1994, a series consisting of 12 cases was reported in cats.  Similar to dogs, the majority occurred in cats that were under 1 year of age.  Most cases involved the domestic shorthaired breed, although Siamese and Burmese cats were overrepresented, suggesting that these breeds might be more susceptible.  This was a small study. A few years ago (2009), a larger case series was published (20 cats) that shed additional light on the subject.

            In the more recent study, there was a bi-modal age distribution:  10 of the 20 cats were under a year of age when the intussusception occurred.  Interestingly, nine of the cats were older than 6 years of age.  (The remaining cat was 2 years old.) The most common clinical signs reported were the same signs that I saw in little Squeegee:  poor appetite, lethargy, and vomiting.   Weight loss and diarrhea were also commonly reported.  Most (13) of the cats examined had some degree of dehydration.  Nearly all of the cats had some abdominal abnormality that could be discerned during the physical exam, including abdominal pain, an abdominal mass, or a discreetly thickened segment of intestine. 

            Once there’s a suspicion of intussusception, a diagnosis needs to be confirmed.  X-rays usually reveal some abnormality of the intestinal tract, however, a definitive diagnosis cannot usually be made on x-rays alone.  Ultrasound is a better test for making the diagnosis.   In the study from 2009, seven cats underwent abdominal ultrasound, and in all seven cats, a definite diagnosis was made based on the ultrasound findings.  It was ultrasound that confirmed the diagnosis in Squeegee as well. 

            Intussusception is a surgical disease.  Without surgery, cats will invariably succumb to the disorder.   Once the cat is taken to surgery, an attempt is made to “reduce” the intussusception, i.e. separate the intussusceptum from the intussuscipiens.  While it might seem intuitive to do this by applying traction on the intussusceptum and pulling it out from the intussuscipiens, the proper technique actually involves grasping the intussuscipiens and gently “milking” the intussusceptum from within the intussuscipiens, carefully pushing it out.  In some cases, however adhesions have formed between the two pieces, and they cannot be separated from each other.  In these cases, the entire intussusception needs to be surgically cut from the intestine, and the two normal ends of the intestine reattached to each other. 

            Recurrence of intussusception after surgery has been reported in dogs.  Interestingly, in dogs and people, if recurrence occurs, it is usually in an anatomic location other than the original site.   In an attempt to reduce recurrence, a surgeon may elect to perform a procedure at surgery called “enteroplication”.  This technique creates permanent attachments between adjacent loops of intestine.   Although this procedure is said to reduce the incidence of recurrence, it sometimes leads to complications.   Thus, the decision whether or not to perform enteroplication is at the discretion of the individual surgeon.  Recurrence of intussusception appears to be less of a problem in cats, although data to confirm the actual incidence are lacking.   In the study from 2009, 13 cats underwent surgery.  One cat was euthanized at the time of surgery.  Three of the 12 cats that underwent surgery had enteroplication performed.   Two of those three cats experienced significant complications from the enteroplication; one cat died and one had to be euthanized.  The other 10 cats were discharged from the hospital.  Five of them were lost to follow-up, but the other five did well and never experienced a recurrence of intussusception.  Owing to the small number of cats in the 2009 study that underwent enteroplication, we aren’t able to draw any conclusions as to whether this technique is beneficial or not in preventing recurrence, compared to the potential risks.

            Squeegee’s intussusception was easily reduced at the time of surgery, and enteroplication was not performed.  She was spayed at the same time.   I spoke to her owner a few days ago, as they were preparing to celebrate her first birthday.  She is doing well and she weighs approximately twice as much as when she came in to my hospital feeling sick.  Because recurrence is a possibility, we will always remain on our guard, but for now it seems that she’s made a total recovery.

           
Related Posts Plugin for WordPress, Blogger...