Is my pet getting old?

A common question that I get when seeing patients is how old would my pet be if it were a human.  There are a lot of formulas out there that claim to change your pets age into human years.  Many of these do work fairly well, but as far as figuring out an exact human age I wouldn't put huge faith in them.  What I can tell you is that I see many older dogs and cats and have a general rule of thumb when seeing them:

1. For smaller breed dogs (less than 10-15 lbs) I can routinely see 14-15 year old dogs.  I usually start to classify them as senior around 8-9 years of age.

2. Larger breed dogs (>60-70 lbs) tend not to have as long of a life span and I typically start to call them senior around 6-7 years of age

3. Cats can differ, especially between indoor or outdoor cats.  Indoor cat can live a very long time and I see many 16+ year old cats.  I usually classify them as middle age around 7 years and senior after 10 years.  Outdoor cats tend not to live as long, but I usually classify them the same way.

So, why does it matter when your pet gets older?  Well, just like with people, pets tend to develop medical problems as they age.  They might not show outward signs of problems, but bloodwork can sometimes pick up early signs of problems.  This is why we recommend a senior screening examination for pets determined to be elderly.

What does a seniors screening exam involve?

1.  With dogs, after the exam we run bloodwork that includes a complete blood count, a six panel chemistry (looking at liver, kidney, blood sugar, and protein values), urinalysis, heartworm test, fecal floatation test, and eye pressures.

2. Cats are slightly different and along with an exam we perform a complete blood count, six panel chemistry panel, urinalysis, thryoid values, and fecal floatation test

The reason that we run these tests are to screen for medical problems where we might be able to intervene and prevent further damage or manage the diseases successfully.  For dogs, we worry about liver disease, Cushing's disease, kidney disease and these tests help determine whether a problem is present.  With cats, we are looking for signs of kidney disease, hyperthryoidism, diabetes, or liver disease.

If changes are seen on bloodwork, then your veterinarian can recommend further diagnostic tests that should be pursued to better evaluate for what may be going on.  They can then recommend treatment options to help manage problems that are found.

Make sure to ask your veterinarian about your pet's senior health at your next visit.

Trouble Breathing

With selective and successful (or unsuccessful depending on how you view it) breeding in dogs, veterinarians see a lot of congenital problems in pets.  One of the more common problems we see is in short nosed breed dogs (Boston Terriers, Bulldogs, etc) called brachycephalic airway syndrome.  This isn't just one problem, but a combination of problems that can lead to difficulty breathing.

If you talk to the owner of one of these dogs, you likely will hear them describe noisy breathing, snoring, and sometimes gagging; but problems can also become more serious with faining episodes, turning blue, or even death in severe cases.  So what causes these problems?  It all stems from the selective breeding of the shorter or no-nose at all trait.  This has lead to collateral problems; in particular an elongated soft palate, stenotic nares (narrow nasal passage), and hypoplastic trachea (narrow windpipe).  Over time this can lead to negative pressure in the back of the throat, which can cause further damage including everted laryngeal saccules (these interfere with the opening of the airway) and in worst case scenarios laryngeal collapse (complete blockage of the airway).

 

So why is it such a big deal to have these traits?  If the traits are mild, then it may not be a huge deal; however, with extreme cases the traits can interfere with breathing.  As you can see from the above image, the larynx is the area in the back of the throat where two functions connect (breathing and eating).  There is a small structure called the epiglottis that covers the opening of the airway (windpipe) when a pet is eating and drinking to prevent food or water from entering the windpipe.  This should only cover the windpipe during swallowing and otherwise the larynx and windpipe should be open and free to allow air to pass into the lungs.  Dogs with long soft palates have problems because the back of the soft palpate can interfere with the windpipe opening and prevent air from passing into the windpipe and lungs.  The noisy breathing or snoring is from the air being blocked by the soft palate.  The narrow nasal passages also interfere with the movement of air.  Like I said before, in mild cases this is not terrible, but as dogs age or in extreme cases the soft palate can get worse (swollen) and completely obstruct the airway.  This can become life threatening if the pet cannot get this unblocked as they essential suffocate from lack of oxygen.

If the soft palate dose not completely block the airway, over time the back of the throat (larynx) can get worse as the negative pressure placed on the larynx from the narrowed passageway can cause it to weaken and essentially collapse leading to blockage of the airway as well.  In these cases, the only real way we can help is to perform a permanent tracheostomy (make a hole in the neck of the dog that connects to the windpipe) for them to breath through.

Obviously, making a hole in the neck of a pet is not the most ideal.  Fortunately, there are some things we can do prior to this point to help out dogs with serious breathing problems.  We essentially correct the problems surgically.  This typically involves widening the openings of the nostrils to allow more air to move through the nasal passage along with shortening the soft palate to a more normal length.  These procedures are most effective when performed on younger dogs as it prevents pressures from working on the larynx and weakening it.  Many times these can be performed during a spay or neuter procedure, so a second anesthetic event is not needed.

Soft palate after resection. Courtesy of Vet Specialists of South Florida

Although the procedures may not completely rid a pet of noisy breathing, in most cases dogs show considerable improvement in breathing, as well as exercise tolerance.  For more information on this condition, you can visit this link.

Feeding Your Cat

Giving advice on feeding your pet can be quite difficult with so many options available in pet foods these days.  For the most part, many of the diets out there are well balanced and your cat will likely receive the proper nutrition with a majority of the diets that they eat.  I would like to give a few suggestions though when choosing a diet for your cat.

First, a little background on cat's nutritional needs.  Unlike dogs that are omnivores, cats are strict carnivores.  In the wild, they would typically eat small mammals like rabbits and mice, so their protein and fat requirements are high while their need for carbohydrates is low.  When you break down a typical mouse they are around 55% protein, 38% fat, 2% carbohydrates, and the remainder a mixture of minerals and vitamins (with a moisture level of around 65%).  Looking at many commercial diets you may see that they can have carbohydrate loads upwards of 20-30% (which is typically very high for cats) and the dry diets have moisture levels of around 10% (which is very low for cats).

So then, what do I suggest that a cat eat.  First, feeding an all wet food diet or mostly wet food diet is helpful.  This helps a lot with hydration, which is important (especially in male cats).  Many cats can get urinary issues when they are chronically dehydrated and keeping them on a wet diet helps prevent this.  Also, a diet low in carbohydrates (hopefully less than 15%) with a protein level higher than 30% would be ideal.  You can check out this table to see where your pet food stands.  Making sure that the protein sources are from a meat source and not plant source is important as well.  

The other issue is feeding the correct amount of food for your cat.  Most cats only need between 150-250 calories per day of food, which typically comes to around one 6 oz can of food or 1/3-1/2 cup dry food per day.  More active cats will need more food while less active ones need less.  A typical cat is ideally around 12 pounds.

Another good resource for feeding your cat can be found here.

Tapeworms

Although there are a lot more intestinal parasites out there, I am going to finish the discussion of parasites with the last of the most common parasites we see: Tapeworms.

There are numerous species of tapeworms in the environment, but the two most common that we see in pets are Dipylidium and Taenia species. These two species have a slightly different life cycle. Both live in the small intestine and anchor to the wall with mouth pieces in the head of their body. They are composed of multiple, small segments that mature and eventually detach and are shed in the environment in the feces. These segments are around 6 mm in length and look similar to a rice segment. These segments are packed full of eggs, which then go on to complete their life cycle.

Dipylidium eggs are then ingested by the larval stage of a flea. Once the flea matures into an adult, it finds a dog or cat to feed on. When fleas bite a pet, it typically causes an itch response which leads them to lick and scratch. During this licking, pets can often ingest the flea (with the eggs of the tapeworm inside) and then complete the life cycle in the small intestine.

Taenia tapeworms are different in that they don't use fleas to transfer to another pet. After the eggs are shed in the feces, they are ingested by a intermediate hosts (mouse, deer, cow) and then hatch in the intestines. From here, they spread to other parts of the body and encyst in a small sac. The dog or cat then eats the intermediate host, thereby eating the tapeworm stage and completes the life cycle.

Many times you won't see any clinical signs when your pet has tapeworms. With heavy infections, you may see weight loss (even with a good appetite), diarrhea, or rectal itching. Without clinical signs, you may just see the tapeworms segments in the feces and that is all.

Because tapeworms are in a different family of intestinal parasites, they do require a different dewormer than hookworms, roundworms, and whipworms. The typical treatment is with a medication called pranziquantal. Typically only one injection or pill is needed; however, it may be suggested to repeat the treatment in a few weeks, especially in households where fleas are a problem and reinfection is possible.

I hope that these discussions on intestinal parasites were helpful. Please let me know if you have any questions about any of the common parasites that we see. With the warmer weather our next topic will be heartworm disease. Stay tuned.

Whipworms

Another of the common intestinal parasites are whipworms. These are slightly different from hookworms and roundworms in that they live in the large intestines (particularly the cecum) versus the small intestine. Like the other worms, pets pick up eggs in the environment which travel to the stomach, through the small intestine, and into the large intestine. It can take a long time from ingestion of the egg to maturation of the adult worm (75 days) when it can lay eggs of its own. After eggs are passed into the environment in the feces it takes 2-4 weeks for them to become infective, so early pick up of the feces can help prevent reinfection in affected animals.

The adult worms imbed deep into the intestine wall, so with heavy infestations you can see some major problems including chronic diarrhea, blood in the stool, weight loss, and on occasion a syndrome that mimics Addison's disease. That is why annual stool checks for parasites are important.

If whipworms are found, then your pet should be dewormed. Not all dewormers treat whipworms, so it is important to treat with the right kind of dewormer (typically Panacur). Because the whipworm take so long to mature and the dewormers typically only kill the adult worm and not larval stages, deworming multiple times at 3 weeks and 3 months is recommended. It is also recommended to continue on a heartworm prevention that also prevents whipworms (Interceptor) as the eggs persist in the environement for years and reinfection is always possible.

The one good point about whipworms is that they are not readily transmitted to humans, so you do not have to worry about picking up these parasites yourself. Coming up next are tapeworms.

Hookworms

Hookworms are another of the common intestinal parasites that we see in small animals. The life cycle of hookworms is similar to that of roundworms with a few differences. Like the roundworm, hookworms live in the small intestine. They have sharp teeth that attach to and penetrate the intestinal wall where they are able to live off of the blood of their host. While in the intestine the adult worm lays eggs which are then passed out into the environment in the feces. Once in the outside environment, the eggs hatch and larva emerge. It is the larva that is infective to the dog or cat. The larva can enter the host in a couple of different ways: 1.) by being ingested while the pet is sniffing around outside 2.) penetrating the paw pads or skin of the host.

Once inside the the intestines, the larva can grow into an adult worm and complete the life cycle. Other larva may take an additional step of migrating out of the intestines and making their way to the lungs. They are then coughed up and swallowed to complete the life cycle in the intestines.

Just like roundworms, hookworms can also be passed on to unborn puppies and kittens in the placenta. During stressful events like pregnancy, larva that are dormant in the body can awaken and then spread to the puppies in the placenta. They are also passed in the mother's milk, so if puppies are not infected in the placenta they can be infected soon thereafter while nursing.

If left untreated (especially in the young animals) and the infection is heavy enough, infections can lead to malnutrition, anemia, and possibly death. The good news is that the parasite is readily treatable with common anti-parasite medications like Strongid (pyrantel) or fenbendazole. We recommend that all puppies be dewormed at least 3 times spread out every 2 weeks starting around the time they are 4 weeks old.

Similar to roundworms, hookworms can also be transferred to humans (either through ingestion of contaminated soil or penetration of the feet by larva). This can lead to a condition called cutaneous larva migrans where the larva migrate under the skin in infected people. This is why it is important to not only deworm puppies, but to also check an annual poop sample of your pet to make sure they are clear of parasites.

The next parasite up is whipworms. Stay tuned for more information.

Roundworms

Roundworms are one of the most common parasites that we see in dogs and cats. As their name implies, the adult worms are long and round. They live in the intestines (and occasionally) the stomach of pets. It is not uncommon to see worms in the feces of puppies and, if the infection is large enough you, can see animals vomit up the worms.

Roundworms can be transmitted in a number of different ways. In adults, the worms can actually encyst in a few areas of the body and during stressful events (such as pregnancy) can be shed and spread. The worms can be passed to puppies in the uterus as well as in the mother's milk. In addition, animals can pick up eggs outside by coming in contact with infected soil or poop or by eating animals that are carrying a life cycle stage (like a mouse or other rodent).

After being ingested the eggs hatch in the stomach and then larvae migrate to the lungs. The larvae are then coughed up and swallowed where they make it back to the intestines. Here they grow into adult worms. The adults then lay eggs which are passed out in the feces. These eggs can stay viable in the environment for months to years, so infections can be more common than you think. In puppies we typically see some vomiting or diarrhea when they are infected with roundworms. Adults, however, are usually symptom free, which is why we ask that you bring a stool sample in yearly to evaluate for any parasite infections.

The good news is that the parasites are typically very easily treatable. A medication called Strongid (pyrantel) is the most common dewormer that is used to treat roundworm infections. Since puppies have a very high likelihood of exposure through their mother, we do recommend that all puppies be dewormed with Strongid. The first deworming is done around 2 weeks of age and then repeated every 2 weeks for 3-4 treatments. A poop sample is then checked to make sure that the puppy is parasite free.

Although as a veterinarian I am concerned about your pet, another part of my job is to make sure owners are aware of dangers posed to humans. It is uncommon, but roundworms can be transferred to people (typically through inadvertent ingestion of dirt or with curious toddlers eating dirt). Since the human is not the typical host for the worm, these worms tend to migrate throughout the body of a person and can end up in weird places like the eye and the brain. When here they can obviously cause some unwanted problems. Because of this we like to know your pet's parasite status and if positive treat them for the disease to not only keep them healthy, but also keep you at a lower risk of exposure.

In the next few days I will discuss another of the common parasites, Hookworms. Stay tuned.