Wednesday, July 12, 2017

Cat Man Adieu

It’s been a little over a month since I retired.  I’m still finding it hard to get used to.  I overhear other people say, “I’m not working the rest of this week” or “I’m off for the rest of this month”, and I realize that hey, I’m off for the rest of my life. 

There are many things to adjust to.  I suppose the most noticeable thing for me is the silence.  As a veterinarian, I used to spend my day talking to clients during appointments.  If I wasn’t in an appointment, I was likely talking to a client on the phone.   If there were surgeries or procedures to perform, I’d be chatting with my staff in the treatment room before, during, and after the procedure.  My entire day was spent in some type of conversation.  In retirement now, I go through the day barely speaking a word to anyone.  Most days, the extent of my conversation is, “I’ll have the chicken salad club and an iced tea”, or “Can I have the venti green tea frappuccino?” (I’ve been saying that one a lot lately) I’m a social, outgoing person, and the curtailment of my conversation is the most striking difference in my day.

The lack of a set routine is probably the next most noticeable change.   My day was used to be pretty much the same: wake up, shave, shower, feed the cats, have breakfast, do a few household chores (laundry, dishes, litter box), and then descend into the hellish subway to work (thankfully only 5 stops), and then see appointments all day.  That routine is now gone, but being a creature of habit, a new pattern is starting to emerge to my mornings.  Sadly, I’m still getting up very early, because Mark (the hubby) still has to wake up at the ungodly hour of 5:20 a.m.   While he hops in the shower, I feed the cats and make breakfast for us both. (I’m getting very skillful and creative with omelets.) I complete a few more chores, and then I accompany him out the door at 6:30.  He walks to 14th Street to catch the van that takes him to work, and I peel away when we approach 27th Street and hit Planet Fitness.  Yes, I’m going to the gym for nearly 2 hours every single morning. 

Twice a week, I do a little grocery shopping at Fairway after the gym.  Otherwise, I come home, do a few more chores, shave and shower, read the New York Times headlines (delivered to my inbox every morning.  I’ve figured out how to work around their ten-article-a-month firewall), answer a few e-mails, and then confront the agonizing decision about where I’m going to have lunch.   As for my afternoons, they’re open.  Some days, I go to the mid-Manhattan library and either borrow some books, browse their books, or read a book that I’ve brought with me.  At least once a week, and sometimes twice, I catch the 1:30 movie at MoMA.  I’m a member, and so the movies are free for me.  These are usually old movies from the 30’s, 40’s, and 50’s, being shown as part of some actor/actress/director retrospective.  After the movie, I usually hang around and read in the sculpture garden.  Most of my afternoons are spent reading (and occasionally napping) in a park.   Some days (usually if I’m feeling a bit lonely or isolated) it’s Bryant Park.  Other days, it’s Madison Square Park (usually on days when I eat lunch at Eisenberg’s Sandwich Shop, because it’s close by).  Mostly, I head down to Tompkins Square Park.  It’s a little out of the way, but on weekdays it’s really peaceful and quiet, and I have a particular bench in a perfect, shady spot that is ideal for people-watching.  Rough life I lead, eh? 

I suppose the other major change since retirement is a so-called “lack of sense of purpose” that I’ve been warned about.  Two retirement books that I’ve read have mentioned this potential issue.   And yes, I can see how this can be an issue, and may end up being one for me in the future, given how strong a sense of purpose my career as a veterinarian had given me.   It so happens, this lack of a sense of “purpose” that I’m currently experiencing has actually turned out to be the most liberating and calming part of my retirement.  For 29 years, my purpose was to help sick animals become well, and help clients deal with all issues regarding their pets’ health, while mentoring students, interns and technicians along the way.  It was a huge responsibility (more on that in a future post).  Being free of all of that, for the moment, is a huge (we’re talking ginormous) weight off my shoulders.   Of course, at some point, the urge to do something more meaningful will be upon me, and I will pursue it wherever it leads (although I have a strong hunch that veterinary medicine won’t be involved), but for now, I really want to harken back to the days when I was a kid in Brooklyn and had the summers off.  I spent those summers playing stickball and stoop ball, riding my bike, and hanging out in the neighborhood park with my friends.  Forty-something years later, there won’t be any stickball or stoop ball, but I’m definitely on a mission to check out every little park in Manhattan.

Wednesday, May 10, 2017

Panleukopenia - a very bad viral disease of kitties

            Cats are uniquely susceptible to a variety of viral villains, and one of the most challenging culprits is the virus that causes feline panleukopenia.         

            Panleukopenia (pronounced “pan-luke-oh-pee-nee-a”) is a highly contagious viral disease caused by a parvovirus.  Most people mistakenly consider parvovirus to be a dog disease only, but this not the case.  All felids, as well as raccoons, mink, and foxes are also susceptible.

            The symptoms of panleukopenia are similar to those seen in dogs with parvovirus: fever, vomiting, diarrhea (possibly bloody), and poor appetite.  The symptoms are explained by the propensity of the virus to attack cells in the body that are rapidly dividing, namely cells of the digestive system and the bone marrow.  Virally induced damage to the intestinal tract leads to vomiting, diarrhea, and poor appetite.  Infection of the bone marrow with this virus impairs the ability of the marrow to produce white blood cells, leading to a low white blood cell count.  This explains the name of the disorder: in Latin, “pan” means all; “leuko” means white, and “penia” means “decreased amount”. Cats with panleukopenia have low numbers of all white blood cell types.  Panleukopenia is sometimes referred to as “feline distemper”, however, this is a misnomer.  It probably started because some of the symptoms of panleukopenia are similar to those of dogs with distemper.  Veterinarians don’t like to use that term because the virus that causes canine distemper is a completely different virus that is in no way related to the parvovirus that causes feline panleukopenia.

            The panleukopenia virus is most commonly transmitted when a vulnerable cat comes into contact with the feces, urine, blood, or nasal secretions of an infected cat.  Contaminated objects, such as bedding, cages, shoes, clothing, hands, and food bowls can harbor and transmit the virus.   It can also be transmitted from the mother to the developing kittens in her uterus.

            Although the panleukopenia virus can infect cats at any age, kittens aged three to five months are particularly susceptible.  These poor kittens often experience severe clinical signs, such as profuse diarrhea, frequent vomiting, abdominal pain, high fevers, and marked lethargy.  Owners of affected cats often report finding their cats with their heads hanging over their water dish. With their small body size, kittens may rapidly become dehydrated.  There are no medications that kill the virus itself.  Treatment consists of aggressive supportive care with intravenous fluids, antibiotics, anti-nausea drugs, and nutritional sustenance.  Severely affected kittens or cat may require plasma or blood transfusions. The prognosis for recovery is guarded.  The mortality rates for panleukopenia are high, and most kittens less than eight weeks old succumb to the disease.  Older kittens, if they survive the first 48 hours of hospitalization, may pull through.  Kittens that contract the virus in utero, if they survive, may be born with a brain disorder called cerebellar hypoplasia.   The cerebellum is responsible for balance and coordination.  Because these kittens have an underdeveloped cerebellum, they go through life a little clumsy and ungraceful, but are otherwise fine.  Due to the contagious nature of the disease, hospitalized cats should be strictly isolated from other cats. Cats that recover from panleukopenia are believed to be immune from the disease for the remainder of their lives.
            A presumptive diagnosis is usually made based on the age and vaccination status of the cat and the clinical symptoms.  Because panleukopenia is caused by a parvovirus, the rapid in-house parvovirus tests for dogs will also detect the virus in feline feces.  Although the test has some limitations in cats, it does allow immediate, in-house detection of the virus in just a few minutes, confirming the diagnosis.

            The best way to treat any problem is to prevent it from occurring in the first place, and this certainly holds true for feline viral diseases.  Fortunately, vaccination offers safe and effective protection.  Initially, kittens receive immunity from the antibodies in the mother’s milk.  This immunity is temporary, however, lasting only a few weeks. As the kittens’ antibody level drops, they become very vulnerable to infection. To best protect kittens, they should be vaccinated against the virus.  The initial vaccine is given between six and eight weeks of age, and then every two to four weeks thereafter until about 16 weeks of age.  Panleukopenia can be a major cause of mortality in cats in shelters and rescue homes.  With rare exceptions, all kittens and cats in a cattery or shelter over 6 weeks of age should be vaccinated, regardless of their physical condition and pregnancy status.

            The parvovirus that causes panleukopenia in cats is highly resistant to some disinfectants and may survive in the environment for several months.  This has significant implications in shelters and catteries trying to limit the spread of the disease.  Disinfectants containing sodium hypochlorite (bleach) have been shown to be effective in killing the virus in the environment. 

Friday, April 28, 2017

Anemia in Cats

Like every veterinarian, when I’m performing a physical examination, I evaluate the mouth and gums of my patient.  I expect to find nice pink gums, and most of the time, I do.  Occasionally, however, I’ll note with dismay when I lift the cat’s lip, that the gums are pale, or even white.  This finding immediately sets off alarm bells in my head: this cat is anemic. The task of making a diagnosis now begins.

            Anemia is a decreased amount of red blood cells.  It is a laboratory finding, not a diagnosis.  By approaching an anemic cat in a systematic fashion, a definitive diagnosis can be achieved in most cases. 

            Attention should first be paid to the breed and age of the cat. Although cats have fewer breed-related red blood cell disorders compared to dogs, some Abyssinians and Somalis have been reported to have excessively fragile red blood cells, making them prone to anemia.  Young cats, with their small blood volume, are more susceptible to blood-sucking internal parasites like hookworms, or external parasites, like fleas.  Middle aged cats are most likely to develop immune-mediated anemia (see below), while older cats have a higher likelihood of developing kidney disease or cancer, two common causes of anemia (see below).
            Physical examination findings can provide valuable information regarding potential causes for the anemia.  The presence of a fever may indicate an infection or inflammation.  Muffled heart or lung sounds may suggest bleeding into the pericardium (the membranous sac around the heart) or the chest cavity.  An enlarged spleen felt during physical exam might indicate a splenic tumor. One particular splenic tumor – a hemangiosarcoma – frequently bleeds into the abdomen. 

            The most important test to run when assessing an anemic cat is the complete blood count (CBC).  This test measures several important parameters, and provides both diagnostic and prognostic information.  First and foremost, the CBC measures the hematocrit, an assessment of the severity of the anemia.  Other important parameters on the CBC are the MCV (mean cell volume) and MCHC (mean cell hemoglobin concentration).  The MCV is a measure of how large or small the red blood cells are, while the MCHC assesses the amount of hemoglobin in the red cells.  Evaluation of MCV and MCHC can give strong hints as to the possible cause of the anemia.

            The first step in trying to elucidate the cause of a cat’s anemia is to determine whether the anemia is “regenerative” or “non-regenerative”.  A regenerative anemia is one in which the bone marrow responds to the anemia by releasing immature red blood cells, called reticulocytes, into the bloodstream.  These reticulocytes aren’t fully mature, but they can still carry oxygen.  A non-regenerative anemia is an anemia in which the bone marrow is not responding to the blood loss and not releasing reticulocytes in an attempt to replace the missing red blood cells.  Reticulocytes are larger than mature red blood cells, and this is reflected in the MCV; a cat with a high MCV has larger than normal red blood cells.  Reticulocytes also have less hemoglobin in them, which will lower the MCHC.  Thus, a cat with both a high MCV and low MCHC has red blood cells that are larger and have less hemoglobin in them than normal, suggesting the presence of many reticulocytes, i.e., a regenerative anemia.  The true way to determine whether the anemia is regenerative or not is to directly count the number of reticulocytes present. This is something that should be done for all cats with significant anemia. 

            There are basically two main causes for regenerative anemia:  blood loss and hemolysis.  Most causes of blood loss can be identified relatively easily.  Cats with a history of trauma (hit by a car, falling from a height) often suffer blood loss as a result of their injury.  The bleeding may be internal, for example, from a ruptured spleen, or it may be external.  Ultrasound of the abdomen and/or x-rays of the chest may reveal the presence and source of internal bleeding.  External bleeding is usually apparent on physical examination.  If blood loss has been ruled out in cases of regenerative anemia, hemolysis becomes the most likely explanation for the anemia.  Hemolysis is the destruction of red blood cells.  Hemolysis can be either immune-mediated (the cat’s immune system is attacking and destroying the red blood cells) or non-immune mediated.  Immune mediated destruction of red blood cells (a.k.a. immune-mediated hemolytic anemia, or IMHA) is the most common cause of hemolysis in small animals.  In some cases, the immune system is attacking the red blood cells for no obvious cause at all.  This is termed primary hemolytic anemia.  More often, there is a secondary cause for the immune system to attack the red blood cells, such as infection with a virus or a red blood cell parasite, or cancer. Non-immune-mediated hemolytic anemia has a variety of causes, including onion ingestion, snake bite envenomation, severely low blood phosphorus levels, and zinc toxicosis (usually caused by swallowing pennies minted after 1983).

            Non-regenerative anemia may be due to several causes, the most common being some type of chronic illness.  A multitude of inflammatory, infectious, and cancerous disorders can lead to anemia, most cases being of mild to moderate severity.  Infection with the feline leukemia virus often leads to severe non-regenerative anemia. Chronic kidney disease is a very common cause of non-regenerative anemia in cats.  The kidneys produce a hormone called erythropoietin. This hormone instructs the bone marrow to produce red blood cells.  When the kidneys are failing, they often do not produce enough of this hormone, and the bone marrow therefore doesn’t produce enough red blood cells.  Anemia from chronic kidney disease can sometimes be quite severe.

            Treatment of anemia in cats depends on the cause. Cats with life-threatening anemia may need to be stabilized with a blood transfusion.  Like humans, cats have distinct blood types, and it is imperative that the donor and recipient are compatible.  If blood loss was determined to be the cause of the anemia, the reason for the blood loss must be addressed and remedied for treatment to be successful.  Cats with immune-mediated hemolytic anemia are typically treated with immunosuppressive medications so that the immune system stops attacking the red blood cells.  The most common drug prescribed for this purpose is prednisolone.  In stubborn cases, additional drugs may be needed to get the condition under control.
As mentioned above, a common cause of non-regenerative anemia in cats is reduced production of the hormone erythropoietin in cats with kidney disease.  This type of anemia can be treated by giving injections of the hormone erythropoietin under the skin.  In the past, up to 25% of treated cats eventually developed a life-threatening immune reaction to the injection, but a newer form of the hormone, called darbepoietin, is very effective and rarely causes adverse reactions in cats.

            Anemia is a common finding in cats.  Because there are so many potential causes for anemia, making a definitive diagnosis can be a challenge.  By taking a systematic approach, performing a good physical exam, and properly interpreting the complete blood count and other diagnostic tests, most clinicians can clearly elucidate the cause of the cat’s anemia.  Prognosis depends on the cause, as well as the cat’s individual response to treatment.

Saturday, April 15, 2017

Fleas and Flea Control in Cats

Summer is over, and a lot of cats are rejoicing. It may be a fun season for people, but it can be miserable for cats, because warm and humid weather is paradise for fleas.  Few creatures living on Earth today have had as much impact on world history as the common flea.  From the black plague during the 14th century to the present, fleas have been the cause of much grief. 

            To better understand how fleas torment cats and humans, and how best to combat them, it is important to understand the life cycle of the flea.  Once a flea jumps on a cat, it stays there for its entire life.  Contrary to popular belief, fleas do not jump from one cat to another. Although the flea spends its entire life on the cat, the majority of the flea’s life cycle occurs while off the cat.  When a female flea hops on a cat, it begins feeding on blood within minutes.  Ingestion of blood is required for the flea to be fertile and reproduce.  Approximately 24 hours later, the flea begins to lay eggs, about 40-50 per day.  As the cat moves around the house, it acts like a living salt-shaker, disbursing the flea eggs in the environment, mainly in the areas where the cat sleeps or rests.  Within a week, larvae hatch from flea eggs. The larvae try to avoid light and burrow into carpets, cracks in hardwood floors, and other humid areas such as concrete floors in damp basements.  Five to twelve days after that, larvae spin a cocoon in which they develop into pupae. One to three weeks later, baby fleas emerge from pupae.  These newly hatched fleas wait for the cat to pass by, and then they hop on, and the life cycle starts all over again. The entire flea life cycle takes 3 to 6 weeks.  If you were to assess all of the life stages of the flea as a population, adult fleas comprise only about 5 per cent.  Eggs make up 50% of the population, with larvae at 35% and pupae at 10%.  In other words, if you’re seeing adult fleas on your cat, you can be sure that there is a veritable flea factory looming nearby. Even if a cat spends its entire life indoors, it is not immune from these pesky critters.  Fleas are hitchhikers – they jump onto your clothing, and you bring them back home, where they hop onto your unsuspecting cat.

            At best, fleas can make your cat itchy and uncomfortable.  At worst, they can transmit dangerous diseases.  While dogs usually bite or scratch at fleas, cats use their barbed tongues to remove them, often abrading the skin in the process. The most prevalent skin disorder in small animals is flea allergic dermatitis (FAD). This is more than just a mechanical irritation from the flea.  When fleas bite the cat, they deposit their saliva into the skin before ingesting blood.  Proteins in the flea saliva can induce a hypersensitivity reaction in some cats.  This allergic reaction causes severe itching, and cats often develop small crusty papules and hair loss on their neck and face, and most notably down their back, in the classic “racing stripe” pattern.

            Fleas are responsible for transmitting tapeworms to cats. Heavily parasitized cats, especially kittens, can develop anemia due to blood loss from flea bites.  Fleas also transmit Bartonella, the organism responsible for cat-scratch disease in humans.  Most cases of cat-scratch disease are self-limiting, however, Bartonella infections can cause very serious illnesses in people with immune deficiency disorders. Fleas can also pass Bartonella from one cat to another.  Most cats infected with Bartonella are clinically normal, however, infection in cats can sometimes lead to fever, lethargy, lymph node enlargement, eye inflammation, and other disorders in cats.                
            Because some of the infectious agents transmitted by fleas may affect humans, the American Association of Feline Practitioners recommends year-round flea control.  Historically, the most effective approach was the three-step method:  treatment of the yard, home, and cat.  The newer flea and tick control products, however, are so effective that treatment of the premises is rarely necessary, especially if the cat resides totally indoors.

            Fleas sprays, flea dips, and flea shampoos have become obsolete.  Flea control is now achieved through the use of products that are either given orally or topically once a month.  Some of these products are effective not only against fleas, but other parasites as well, including ticks, heartworms, ear mites, hookworms, and roundworms. 

            A variety of flea control products are available to cat owners. Common products include those that contain either imidacloprid (Advantage), fipronil (Frontline), dinotefuran (Vectra), spinetoram (Cheristin) or selamectin (Revolution).  These products are applied to the skin on the back of the neck.  They  sink into, and then spread through, the layer of fat beneath the skin, killing any adult fleas that are present on the cat.  The advantage of these products is their residual activity; they continue to kill fleas for at least thirty days.  After 30 days, a new dose is applied.  These products are very safe, and very effective.   Oral flea control products are also available. Nitenpyram (Capstar) is an oral medication that is good for heavy flea infestation.  A single oral dose of nitenpyram will kill all of the adult fleas on a cat. It starts to work within 30 minutes of administration.  Nitempyram has no residual effect, so if the cat gets re-infested with fleas, an additional dose may be required.  It can be given safely as often as every day.  Nitenpyram can be used together with other flea products.  Spinosad (Comfortis) is an oral formulation that kills 100% of adult fleas on a cat by 24 hours after administration.  Spinosad has residual effect; it continues to kill adult fleas for 30 days before the next oral dose is required. Lufenuron (Program) is an insect growth regulator – a product that works by interfering with the growth and development of fleas, but has no effect on adult fleas.  It is given orally once a month, however, an injectable form is available that is effective for six months.  When a female flea ingests blood from a cat treated with lufenuron, the eggs she produces will be infertile.  Because lufenuron does not kill adult fleas, it is better suited to prevent a continual flea problem.  It does not stop a flea from biting, so it is not ideal for cats with flea allergic dermatitis.  If quicker results are needed, a product that kills adult fleas should be used.

            For cat owners who prefer to use flea collars, there is a collar (Seresto) that contains a sustained release formulation of the flea-killing compound imidacloprid, in combination with flumethrin, which kills ticks.  The collar kills fleas and ticks for 8 months, reducing the need for monthly application of topical products. The collar also has a “break-away” mechanism, so if it gets caught on something, it will release, rather than cause injury to the cat. 

            Cat owners should be aware that in an effort to tap into the lucrative flea-control market, some manufacturers have produced flea control products with packaging similar to the veterinary products, i.e. in small, single dose tubes for topical application.  These products contain permethrin, an insecticide commonly found in low concentrations in a variety of canine and feline flea sprays and shampoos.  In low concentrations, cats tolerate these products with minimal adverse effects.  These small single-dose tubes, however, contain concentrated permethrin (45% to 65%) as the active ingredient.  Concentrated permethrin spot-on products are labeled for use in dogs only, and may cause severe and often fatal toxicosis if applied to cats. 

            Fleas have been a source of much misery for pet cats and dogs. They can transmit diseases to cats, as well as to humans.  Fortunately, modern flea control products can provide an amazing level of efficacy. Understanding the flea life cycle is critical in formulating a comprehensive flea-and-tick control strategy.  Talk to your veterinarian about which products are right for you, as different products offer different benefits.  Be aware, however, that improper use of these products can result in treatment failure, and use of unsuitable or mislabeled products can have dire health consequences.

Related Posts Plugin for WordPress, Blogger...