Medical Machines: Ultrasound Machines

Medical Machines“Medical Machines” is a new series of blog posts highlighting the equipment AMC veterinarians use to provide state-of-the-art care to thousands of pets annually. These machines save countless lives, but pet families rarely ever have the opportunity to see them up close and personal. This series will give readers a glimpse into the equipment AMC veterinarians rely on every day. The previous blog post in this series highlighted infusion pumps.

The machine for today is an ultrasound machine. I was shocked when I finished counting our ultrasound machines — AMC has ten different ones located on four different floors of the hospital.

An internal view without x-rays

Fifty years ago, if veterinarians wanted to see the inside of the body, we took an x-ray. To take an x-ray, we use a machine that emits radiation, creating an image on film. An x-ray reduces a three-dimensional dog or cat to a two-dimensional image. While x-rays are still used for the heart, lungs and bones, ultrasound is more commonly used to view the inside of the abdomen. The probe of the ultrasound machine bounces sound waves off the internal organs as the probe is moved about. The sound waves then create a gray scale image on the ultrasound screen. The veterinarian performing the ultrasound twists the probe which changes the orientation of the image and allows the various organs to be evaluated from side to side, top to bottom and front to back. By analyzing an organ in multiple directions, a clear picture of any structural abnormalities emerges.

Diagnostic images = radiology

Back when veterinarians only had x-rays, the department in charge of x-rays was called radiology. Now that we have x-rays, CT scans and MRIs, the department has expanded and these imaging modalities reside in AMC’s Diagnostic Imaging Department. Since ultrasound is another method of imaging the body, this group of AMC doctors has two of our best ultrasound machines in the hospital. Our radiologists have special training to perform and interpret ultrasounds. One of their most important skills is using the ultrasound to collect samples for laboratory testing.

Peering into a heart

An x-ray of the chest will identify an enlarged heart or fluid in the lungs as the result of heart failure. To hone in on problems with heart values or a thickened heart muscle, a specialized ultrasound called an echocardiogram is required. AMC’s cardiologists have two such machines: one about the size of a small refrigerator and a portable one for cage side use.

A quick look

The other six ultrasound machines are distributed on four different floors of the hospital, necessitated by AMC’s vertical space. All six of these machines have similar functions. They are quite small, about the size of a toaster and are strapped to a wheeled stand. ICU and ER doctors will wheel their machine to a critical patient to quickly determine if there is internal bleeding or an object stuck in the intestine. Oncology and Interventional Radiology use their mobile ultrasound machines to monitor the effect of treatment, as does Internal Medicine. We all use our ultrasound machines to facilitate collection of urine samples.

With all these essential functions, no wonder AMC needs a denary of ultrasound machines!

Pyometra: A Life-Threatening Infection

Pyometra imageEvery morning at about 5 am, the overnight team of ER doctors at the Animal Medical Center sends an email with the list of the overnight admissions. Last week, two canine patients were listed as being admitted with a diagnosis of pyometra. Both dogs were so sick they underwent emergency surgery in the middle of the night to treat their pyometra.

What is pyometra?

Pyometra is a bacterial infection of the uterus. The most common bacterium identified in pyometra is E. coli, which probably originates in the stool and ascends into the uterus. It often occurs about one month after a dog or cat has been in heat. In both dogs and cats, middle-aged females are at risk. About 25% of unspayed dogs will develop pyometra before age of 10. Oriental purebred cats have a higher risk of pyometra than non-purebred cats. Oriental purebred cats and Sphynx, Siberian, Ocicat, Korat, Ragdoll, Maine Coon and Bengal develop pyometra at a younger age than the general cat population. If your cat is an unsprayed female of a high risk breed, the next paragraph is a must read.

How would I know if my dog or cat has pyometra?

Early in the course of pyometra, there may not be any clinical signs. As the infection worsens, dogs may stop eating, act lethargic, vomit, drink lots of water and urinate excessively.

You might notice a white or bloody vaginal discharge. As the uterus fills with pus, your dog’s tummy might look bloated. If these clinical signs are missed, the infection progresses and can spread throughout the bloodstream. Ultimately, your veterinarian will make the diagnosis based on an abdominal x-ray or ultrasound. An x-ray of a dog with pyometra is shown above.

Because cats are not simply little dogs, pyometra looks different in the cat. Female cats are much less likely to act sick when they have pyometra until the infection is advanced and the uterus is very large. Because of the fastidious nature of cats, vaginal discharge is easily missed. Cat or dog, pyometra can be so serious that emergency surgery is required and your pet could end up in ICU.

How is pyometra treated?

The short answer to this question is surgical removal of the uterus. But the severity of illness may require extensive treatment prior to and following surgery. Pets with pyometra are frequently dehydrated, febrile and may have low blood sugar that must be corrected before surgery. In preparation for surgery, intravenous fluids, antibiotics and glucose may be administered. Veterinarians reserve non-surgical treatment of pyometra for valuable breeding animals.

Will my pet recover from pyometra?

Despite the urgency of surgery to remove the infected uterus from a critically ill pet, nearly all will make a full recovery. Fatalities in dogs tend to occur when the uterus is leaking pus into the abdominal cavity.

Since pyometra is a uterine infection caused in part by the normal reproductive cycle of cats and dogs, one of the advantages of spaying your female cat or dog is prevention of pyometra.

Pyometra can be found in many species, including this recent report about a white Bengal tiger who was successfully treated by veterinarians at Oregon State University.

Sudden Acquired Retinal Degeneration Syndrome (SARDS) in Dogs

Amanda SARDS
Photo courtesy of Jonathan Montagu

One of my patient’s winter vacations was cut short last week when her owner noticed she was bumping into the furniture and reluctant to jump on and off the bed. A quick trip to the Animal Medical Center and consultations with internal medicine, neurology and ophthalmology specialists determined this cute pug, named Amanda, was blind and suffering from sudden acquired retinal degeneration syndrome or SARDS.

SARDS not to be confused with SARS

Sudden acquired degeneration syndrome was first described in dogs in the mid 1980’s. The acronym SARDS is very similar to SARS, which was a highly contagious respiratory disease originating in China in 2002 and causing hundreds of deaths worldwide. SARDS is not contagious, is not fatal and does not cause respiratory signs, but dogs with SARDS do have clinical signs beyond the acute blindness.

Hungry, thirsty and then blind

Prior to the loss of her vision, Amanda’s owner noticed she was eating more, drinking more and urinating more. Amanda had gained a pound and a half over 6 months. Since the cause of SARDS remains elusive, the physiology behind the increased thirst and appetite are unknown, but two thirds of dogs diagnosed with SARDS have these clinical signs. A month prior to the vision loss, Amanda had been treated for redness in her eyes, another common finding in SARDS dogs.

A textbook case

Amanda was nearly a textbook case of SARDS. In addition to eating and drinking more, she is a pug. Pugs, dachshunds, miniature schnauzers, cocker spaniels and maltese dogs are at increased risk for developing SARDS. Elevations in liver tests are common in dogs with SARDS and Amanda has not one, but two different liver tests that were above the normal range.

Electrorentinogram

In dogs with SARDS, the retina (or light perceiving lining of the eye) stops working but still appears normal when a veterinarian looks at the back of the eye using an ophthalmoscope. An electroretinogram is the test used to make a diagnosis of SARDS. The electroretinogram flashes bright lights directly at the retina and measures the brain’s electrical activity in response to the flashing lights. Dogs with SARDS show no brain electrical activity in response to the light flashes.

Living with a blind dog

Watching your suddenly blind dog learn to navigate the world without vision can be heartbreaking. In reality, as long as you don’t rearrange the furniture, she will quickly learn to cope and have an excellent quality of life. There are a number of resources to help you provide a safe and stimulating environment for your non-visual dog. Here are links to just a few of them.

Living with Blind Dogs

Blind Devotion: Enhancing the Lives of Blind and Visually Impaired Dogs

My Dog is Blind – but Lives Life to the Full!: A practical guide for owners with a blind or sight-impaired dog

Everyday Medicine: What is a spay?

“Everyday Medicine” is an intermittent series of blog posts highlighting tests, treatments, and procedures common in daily Animal Medical Center practice. Some past examples of this type of blog post include fecal analysis and vomiting or regurgitation.

Since February 26, 2019 is World Spay Day, today’s post focuses on spaying a healthy dog or cat as a method of contraception rather than as a treatment for a disease.

What is a spay?

Spaying is a surgical procedure that makes pregnancy impossible in a female dog or cat. Traditionally, both the ovaries and uterus are removed during a spay, but recent advances in veterinary surgery make removal of the ovaries without removal of the uterus a more common procedure.

What are the benefits of spaying my female dog or cat?

Most female pet dogs and cats are spayed to prevent unwanted litters of puppies and kittens. Removal of the ovaries also halts a female dog or cat’s reproductive cycle and prevents them from going into heat. When dogs are “in heat,” their vaginal discharge can be messy around the house. A female cat “in heat” yowls, cries, and is generally very disruptive to the humans in the household, especially those trying to sleep. “In heat” female dogs and cats attract undesirable male suitors. Spaying prevents all of these issues.

Additionally, dogs (and less commonly cats) can develop a life-threatening uterine infection called pyometra. Because spaying removes the ovaries, it removes the ovarian hormones and prevents pyometra from occurring. Finally, spaying your dog before the first heat cycle decreases their risk of breast cancer.

How is a spay performed?

There are two primary methods for performing a spay. The traditional one is through an incision in the middle of the abdomen; although spays can also be performed through an incision in the flank. However, minimally invasive methods of spaying, via laparoscopic surgery, have recently become more popular and more widely available. Laparoscopic surgery employs a tiny, high-resolution camera inserted through a small incision in the abdomen to perform surgery. The main difference between an abdominal surgery and laparoscopic surgery is the former removes both ovaries and uterus while the latter only the ovaries.

Finally, contraception is not just for girls and the surgical birth control procedure in males is often referred to as neutering.

Dog shows are more than just pretty dogs

2019 Annual Westminster Kennel Club Best in ShowCongratulations to last night’s best in show winner, GCHB CH Kingarthur Van Foliny Home at the Annual Westminster Kennel Club show at Madison Square Garden. Best in Show completes a week of canine events with a sprinkling of cats thrown in for variety.

In addition to the Westminster Kennel Club show, Westminster week features both Masters Agility and Obedience competitions. Meet the Breeds hosts both dogs and cats from the Afghan hound to the Turkish van and every breed in between. To get the inside scoop on the dog show, last week’s guest on “Ask the Vet” (SiriusXM Stars 109) was AMC’s own Anne Marie Kubacz, LVT. In addition to being AMC’s longest serving nurse, Anne Marie has shown dogs at the Westminster Kennel Club show, worked as an expert during the broadcast and been involved in veterinary care for dogs from the show treated at AMC. Here are some of her insights on the second longest running sporting event in America.

Dog shows are for families

Anne Marie got her start in dog shows when someone noticed her beautiful Irish setter in Prospect Park and suggested she show her dog. She met her husband showing dogs and her son is now a professional dog handler. This family trio of dog show specialists spends nearly every weekend at dog shows, but Anne Marie said devoting every weekend to dog shows is not necessary to have a great family experience.

Dog shows have something for everyone

Anne Marie’s family specializes in showing purebred dogs, but dog shows provide opportunities for every type of dog. Dogs in five height divisions competed in the Masters Agility event at the WKC show. These energetic dogs raced over and under obstacles, through tunnels and zipped back and forth competing for the best time. There were even cameras inside the tunnels and the view from inside made it look like the dogs were running inside a set of lungs! To see for yourself, watch the highlight video.

The Masters Obedience competition is a more creative event where the dog and his partner perform a routine of obedience moves. This year’s winner is the Tiger Woods of the dog world and became a four time Masters Champion in Obedience. This year’s performance will bring a smile to your face.

Dog shows have cats too

If you’re not interested in participating with your dog, Anne Marie suggested attending the event just to meet some dogs and cats. Meet the Breeds gives dog lovers the unique opportunity to meet and play with more than 100 different dog breeds in booths cleverly decorated to depict each breed’s country of origin, historical purpose/function and attributes as a family pet, all while learning about responsible dog ownership and which breeds may be right for them. This year, cats made their triumphant return to the AKC Meet the Breeds® event with The International Cat Association® giving animal lovers the unique opportunity to meet and play with 35-40 different cat breeds.

The dog show and AMC

When I asked Anne Marie what her best back story about the WKC show was, she recounted the story of a Doberman pinscher, Indy. He flew to New York City for the WKC and when he got off the plane, everyone knew he was not right. Indy came straight from the airport to AMC where a case of bloat was diagnosed and treated. Indy went on to win Best in Show that year to the cheering of many delighted AMC veterinarians.

AMC congratulates all winners from Westminster week, but the biggest winners of all were the humans who had a wonderful time with their dogs.

Dental Don’ts in Celebration of National Pet Dental Month

Pet Dental Health Month: Slab FractureDuring a routine examination of your pet, your veterinarian will look in the mouth to assess his pearly whites. During National Pet Dental Month (every February), veterinarians and pet owners alike should remember to focus just a little bit more on healthy teeth. This concern for animal dental health is nothing new. In a recent article from the Proceedings of the National Academy of Sciences, archeologists from the Max Planck Institute have found evidence of equine dentistry in Mongolia as early as 1150 BCE.

To help you celebrate National Pet Dental Month using the most up to date veterinary oral hygiene recommendations, this blog post points out some common pet dental mistakes to avoid.

Don’t use human toothpaste

Fluoride-containing toothpaste has helped to revolutionize dental care in humans. But there is something drastically different about pets when it comes to toothbrushing: spitting. Dogs and cats don’t spit. This means toothpaste gets swallowed when you brush your pet’s teeth. Chronic ingestion of toothpaste can result in fluoride accumulating in your pet’s body, which can be toxic. Some toothpastes contain xylitol, an artificial sweeter. Dogs are exquisitely sensitive to xylitol and just a little bit can cause dangerously low blood sugar and liver damage. Way better to use the meat flavored toothpaste from your veterinarian’s office or get some nice dental wipes at your local pet emporium. Not sure how to brush your pet’s teeth? Watch our video featuring AMC board certified dentists.

Don’t chose anesthesia-free dental cleaning

The Animal Medical Center board certified dentists administer general anesthesia to all pets undergoing a dental cleaning. During this procedure they can clean both the cheek side and the tongue side of the teeth as well as beneath the gumline to prevent periodontal disease.

Anesthesia-free cleaning is currently in vogue in pet dental care. However, even the most well-trained pet will not tolerate dental instruments in their mouth and under the gums. Anesthesia-free dental cleanings just can’t provide the level of care your dog or cat deserves.

The American Veterinary Dental College has a policy statement on anesthesia-free dentistry in companion animals.

Avoid a nasty slab fracture of your dog’s tooth

The photo above shows a slab fracture (circled in red) of a canine premolar. This type of tooth injury is common and completely preventable. Dog’s given the opportunity to chew on bones, hooves, antlers, nylon dog chews and similar objects tend to crunch down on these hard, inflexible objects, cracking off half of their premolar. If the central pulp of the tooth is exposed, an infection can easily develop. AMC’s dentists either must repair or extract these fractured teeth.

By avoiding these dental don’ts, you will accomplish a major dental do – better oral health for your favorite fur person.

10 ways your family can enjoy animals without owning a pet

pet ownershipIn every family without a pet, there’s at least one child begging for one. But for health reasons, finances, travel or time in the daily schedule, a pet may not fit into your family’s lifestyle. But there are other ways, that you can bring animals into your family’s life without owning a pet of your own. Here are my top ten tips to add the fun and rewards of animals in your life without actually owning a pet:

  1. Attend a local animal show. The owners of dogs, cats, birds and reptiles love to show off their pets and talk to children about responsible pet ownership. In New York City we have the annual Westminster Kennel Club Show and Meet the Breeds. Local, smaller shows are great fun as well.
  2. Volunteer to walk dogs at your local shelter or to help socialize the cats residing there. Our friends at Animal Haven Shelter have a great webpage on how kids can help shelter animals.
  3. Be a foster pet family. My local rescue group is always looking for host families for cats in need. I wrote about my experiences with my foster cat family several years ago and since that time we’ve hosted more than 60 kittens or cats in our home.
  4. While it sounds a bit low tech, there are plenty of books on being a veterinarian for children of all ages. Here’s a really nice list of some of them.
  5. If your child loves dogs, but doesn’t love reading, sign up for one of the therapy dog programs where children read to dogs. This might be in a library, school or animal shelter. Participate in your library’s reading program featuring certified therapy dogs to promote reading skills in children. Reading Education Assistance Dogs (R.E.A.D.) has local programs nationwide. Therapy Dogs International sponsors “Tail Wagging Tutors.” A program like this might transform your child’s reading skills.
  6. Volunteer to pet sit for a neighbor while they are on vacation. This could be a really fun family project.
  7. Become a member of your local zoo. Many zoos have an area where children can pet the animals. In the New York metropolitan area, the Wildlife Conservation Society — which includes the Bronx Zoo, the Queens Zoo, the Central Park Zoo, Prospect Park Zoo and the New York Aquarium — has hands-on programs for various age groups, as well as educational exhibits and free demonstrations daily. Some zoos even have sleepovers and summer camp!
  8. Volunteer at a pet outreach program at your local hospital, Ronald McDonald House or senior citizens home. Ask the program coordinator if they know of a pet volunteer who you can “borrow” for the visits.
  9. Check out veterinary camp. Besides camps at zoos, many camps like the ones on this list are run by colleges of veterinary medicine. Most are for high school age students, but some accept students as young as 10 years of age.
  10. If your child dreams of being a veterinarian, it is never too soon to start planning. For tweens, Vet Set Go provides age appropriate resources and fun games. The American Association of Veterinary Medical Colleges has information online for prospective students in high school and college.

I hope these suggestion will help fill the gap in your pet loving child’s life until the time is right for your family to love a pet of its very own.

How to feed your cat

Last fall, the American Association of Feline Practitioners released documents Tips and tricks to feed your cat for optimal healthfrom an expert panel of feline specialists including a client brochure entitled “How to feed a cat.”

Since one contributing factor to feline longevity is an ideal body condition, I thought summarizing the panel’s recommendations would be helpful to feline families.

Nota bene, this the point of these recommendations is not to help you choose between canned versus dry food, or premium versus grocery store brands, but how to take normal cat behavior into consideration when choosing feeding methodology.  Feeding strategies that capitalize on your cat’s normal predatory drive will enhance your cat’s health and well-being.

Feed frequently

In the wild, cats hunt multiple times per day to meet their daily calorie requirement.  Most housecats are fed one or two large meals per day.  This meal feeding method leaves your cat unsated and with time on her paws to pester you for snacks, irritating you and packing the pounds on her.  An automatic feeder will help in this regard, since it can dispense multiple small meals per day, but it will not be as mentally challenging as puzzle feeding or forage feeding.

Use puzzle feeders

Hunting for small rodents is a mentally challenging activity for cats.  Eating tasty, soft food from a conveniently placed bowl offers no mental challenge.  Puzzle feeders, also known as food puzzles, are objects that hold and release food when your cat manipulates the feeder.  No matter how smart your cat is, expect a learning curve while she solves the puzzle feeder.  Monitor your cat’s weight as she learns to use the feeding puzzles to sure she’s getting enough calories.

Try forage feeding

And no, I don’t mean feed your cat a bale of hale.  Cats are obligate carnivores, meaning they must eat meat as their main protein source.  Here I use the word forage as verb meaning “to hunt.”  Since cats are programmed to hunt for their food, instead of putting the food in a bowl, make your home a cat buffet by putting bowls in various locations. Better yet, put puzzle feeders throughout your home and let your cat forage to find out where lunch is being served today!

Optimal feeding locations

Avoid putting food too close to the location of your cat’s litter box as cats do not like to eat near the box.  Be sure the food location works for all cats.  Cats don’t necessarily understand sharing and if there are not enough opportunities to forage, some cats may go hungry.  Some cats fare better if they are fed individually.  Don’t forget to use your cat’s elevated space (window sill perch or cat tree) as one of the feeding locations.

Ready to get started using puzzle feeders?  Try your hand at making some before you shop.

Everyday medicine: fecal analysis

Visual fecal analysis exam“Everyday Medicine” is an intermittent series of blog posts highlighting tests, treatments, and procedures common in daily Animal Medical Center practice. Some past examples of this type of blog post include hospital wards and vomiting or regurgitation.

Today’s post focuses on fecal analysis.

The 2011 American Veterinary Medical Association and American Animal Hospital Association Canine Preventive Healthcare Guidelines recommend a minimum of an annual fecal examination to diagnose intestinal parasites.  This recommendation explains why your veterinarian gives you a little cup or tube in advance of your dog’s annual exam and asks you to collect a fecal sample.  Fecal analysis is frequently part of the testing performed when your dog has a bout of diarrhea.

Visual examination

Most intestinal parasites are not visible to the naked eye.  The exception is tapeworms.  Tapeworms are a segmented worm and the little segments pass out of the intestine with the stool.  Above, you can see the tapeworm segments the owners found when cleaning up after her dog.

Microscopic examination

In cases of acute diarrhea, a bit of stool and some saline mixed on a microscope slide can result in a quick diagnosis of Giardia when your veterinarian sees the little parasites swimming around when the slide is examined using a microscope.  Occasionally, if I am are lucky, I might identify a coccidian organism or a worm egg.

Fecal floatation

The fecal floatation technique requires the stool sample to be mixed with a special solution and sometimes the protocol requires centrifugation of the sample.  The process causes worm eggs to float up and stick to a coverslip which is then placed on a microscope slide and evaluated.  This is thought to be one of the most reliable tests for intestinal parasite like roundworms, hookworms, whipworms, tapeworms and stomach worms.

Baerman technique

While the fecal floatation technique identifies eggs in the stool sample, the Baerman test looks for larva or immature worms.  Baerman technique requires special equipment and is not typically done in a private practice but in the commercial veterinary laboratory.  This is the test veterinarians use to diagnose lungworms which can cause a chronic cough in dogs.

New generation of fecal analysis

The newest type of fecal analysis uses a technology called enzyme linked immunosorbent assay (ELISA) that recognizes a protein on the parasite.  The advantage of this type of test is that the parasite does not have to be shedding eggs for the test to detect an infection like for a fecal floatation.  This allows earlier diagnosis and prompt treatment.  The most commonly used ELISA detects Giardia infection.

The importance of a fecal analysis in keeping your dog healthy is undeniable, so be sure to bring that sample to your dog’s next examination.

Making your cat live to be 100!

This photo is my patient, Jake, celebrating his 18th birthday which is approximately 86 in cat years.  But Jake is not my longest-lived patient, Sparky, an orange gentleman at 18 and a half takes that prize.  Weezer, a stripey spring chicken is the runner up at nearly 16 years.  What do these three elderly cats tell us about aging in our feline companions?

Many diseases, one cat

Research stemming from a Swedish pet insurance database indicates that cats like Jake represent the typical older feline patient.  In the Scandinavian cohort of cats, cancer, kidney disease and intestinal disease increase in frequency as cats age. Medically speaking, Jake has intestinal lymphoma, recurrent kidney infections, heart disease, pancreatitis and an occasional flare up of diabetes, all of which are currently under control.  Older cats, with a myriad of medical conditions, need a plethora of carefully titrated drugs to keep their problems well controlled.   From my veterinary viewpoint, these cases are incredibly challenging because one disease may need a medication like steroids while another disease like diabetes can flare up with steroid therapy.

Intestinal lymphoma

One diagnosis common to all three of these cats is cancer.  Jake, Sparky and Weezer all have lymphoma and for that matter, the same form of lymphoma, gastrointestinal small cell lymphoma.  This little fact should give you hope since all three cats have exceeded the reported average lifespan of cats which is 14 years, despite a diagnosis which is expected to send their owners into a blue funk.  Gastrointestinal small cell lymphoma has become the most common form of lymphoma diagnosed in cats and carries a good prognosis when treated early.  The take home message here is if your cat has a cancer diagnosis, despair should not be your first emotion.

Good news, cats are living longer

Sparky, Weezer and Jake reflect a new trend in cat lifespans.  Information from the Swedish pet insurance database I mentioned above suggests that cats are living longer.  For example, between 1998 and 2002, 58% of Birman cats lived on average 12.5 years and between 2003 and 2006 68% of Birman cats lived 12.5 years.  An increase in longevity was seen across the spectrum of cats including other purebreds and domestic cats.  The reason for this increase is currently a mystery.

How can you get your cat to live like Weezer, Sparky and Jake?

To have a geriatric cat, you first need your young cat to be healthy. Some very simple lifestyle modifications will help that happen.  Neutering has been shown to be associated with an increased lifespan.  Since trauma is a big killer of young cats, make your cats indoor ones.

Another killer of young cats is infectious disease.   Keeping your cat indoors will help protect your favorite fur person against contracting an infectious disease like FeLV and FIV, but vaccinations are another important component of protection against infectious disease.

Finally, feeding the right food will also help your cat grow old, but not too much, since overweight cats have a truncated lifespan.