Here are some helpful links with great information to help you care for your pets, as well as the answers to the most common questions we get from concerned pet owners like you. If you can’t find what you’re looking for here, don’t hesitate to call or email.

While self-diagnostic tools such as these can be helpful, if you ever feel your dog or cat’s symptoms may be the sign of a serious issue, please bring him in for a checkup right away. It’s always better to be safe than sorry when it comes to the heath of your pets.

What types of pets do you see at your location?

We are happy to offer services for dogs, cats, ferrets, rabbits, guinea pigs, hamsters, gerbils, rats, mice, chinchillas, hedgehogs, and sugar gliders.  We also do wing and nail trims for birds. We refer sick birds to a specialist.

I just started going to Horton Animal Hospitals-does this mean ALL the locations have my information?

No, each of the three Horton Animal Hospitals in Columbia is independently owned and operated, although we can transfer your records if the need arises

I see little black specks on my pet’s skin – what could these be?

Most likely, these poppy seed-sized specks are flea feces, composed of digested blood. If it’s hard to tell whether you’re seeing flea “dirt” or actual dirt, place the specks in a damp paper towel. If they truly are flea feces, a small red spot will show up as the blood re-hydrates and diffuses in the paper towel. If this is the case, it’s time to bring your pet to the vet for flea treatment. Without treatment, the fleas will breed, and your pet may experience fleabite dermitis, a syndrome that causes itching, inflamed skin, and discomfort. 

I have recently found some full-grown fleas on my pet. Have I found them in time, and how do I make sure no one else in the house contracts them?

By the time you see fleas on your pet, they most likely already have a six to 12 week head start on any flea control treatment. On average, a flea’s lifespan is two to three months; however, flea eggs (those not yet living on a pet) can survive undistributed and without a blood meal for about a full year.

We offer several flea treatment options, including both topical and oral tablet medications. Our staff will be glad to help you find the right flea product to protect your pet against these pests.

So you’ve treated your pet for fleas, but what about your house? It needs treatment, too. Treat your yard using sevin dust, which includes flea and tick chemicals (just follow the instructions on the bag). You can also use an insecticidal bomb or premise spray to clean your house. All pets in the family should be treated with flea preventative measures regularly.

Be sure to clean your animal’s bedding, as well as your own, with hot water and detergent at least three times per week. Vacuum at least three times a week, too. Make sure to get the dark areas under your furniture, as this is where fleas thrive. You can also place a flea collar in your vacuum bag if you like – just remove the bag and place it in an outdoor trash can afterward.

What plants are toxic to my pets?

Dogs: Some of the most common plants that are toxic to dogs include carnations, chinaberry tree, baby’s breath, aloe, apples, iris, Jack-in-the-pulpit, avocados, coleus, daisies, foxglove, garlic, leeks, limes, mums, peonies, St. John’s Wort, geraniums, gardenias and tulip plants. For a complete list, including pictures, visit the ASPCA website.

Cats: Some of the most common plants that are toxic to cats include aloe, fig, garlic, apples, gardenias, apricots, avocados, azaleas, baby’s breath, peonies, carnations, periwinkle, daisies, hydrangeas, dahlias, holly, Jack-in-the-pulpit, oranges, onions and mums. For a complete list, including pictures, visit the ASPCA website.

If you suspect your pet is ill or may have ingested a poisonous or harmful substance, contact us right away. If you have a pet emergency after our office is closed, please call the University of Missouri College of Veterinary Medicine at (573) 882-4589. You can also call the ASPCA 24-hour emergency poison hotline directly at (1-888) 426-4435 in the case of an after-hour, poisonous-substance related emergency.

How can I tell if my pet has a dental problem?

It’s easy: just lift the lip and sniff. It’s normal for your pet to have slightly less-than-fresh breath, but a horrible odor is an early indicator that the mouth is harboring bacteria. You can also easily visually identify dental calculus: while normal teeth are white and shiny all the way to the gum line, yellow or brown deposits near the gums indicate a problem. Finally, look at your pet’s gums. They should be pale rose in color and taper down to a knife’s edge where they meet the tooth. If you see a bright red line where the teeth meet the gums, your pet is developing gum disease. 

How can I make sure my pet’s teeth stay healthy? What is the best way to manage gum disease?

The key to managing gum disease in your pets is to prevent it in the first place. As long as you clean the surfaces of your pet’s teeth frequently, the gums will stay healthy. We recommend daily brushing and chewing activities to maintain your pet’s oral health. Many pets, especially middle-aged and older cats and dogs, also require periodic professional scaling in addition to on-going plaque control, which we offer at our location.

I have missed two months of heartworm prevention for my dog. What should I do?

You need to consult your veterinarian right away and start your dog back on monthly preventative treatments as soon as possible. If your dog is infected, heartworm disease will progress and damage the heart and lungs, which leads to life-threatening, serious problems. Retest your dog six months after resuming treatment. (Heartworms must be approximately six months old before the infection can be diagnosed.)

I have a cat. Should I still worry about Heartworms?

Yes. Heartworm infection in cats is on the rise, and it is less easy to detect than heartworms in dogs. The preferred method for screening cats includes the use of both an antigen and antibody test. Your vet may also use x-rays or an ultrasound to look for heartworm infection. Since there is no approved treatment for heartworm infection in cats, prevention is absolutely critical.

What if my cat stays indoors? Does she still need a heartworm preventive?

Cats can be exposed to mosquitoes carrying heartworm disease whether they live indoors or outdoors. While the outdoor cat is more likely to be bitten, multiple studies have reported a significant number of heartworm infections in cats living exclusively indoors. If dogs in your area are found to have heartworm disease, your cats are also at risk and should be placed on preventive medication immediately. Even a single heartworm can cause severe consequences and possibly death.

When is a good age to spay or neuter a new puppy or kitten?

We recommend spaying or neutering all dogs and cats by the age of six months. The minimum weight for surgery is 3 pounds and we recommend completing the puppy or kitten vaccine series prior to surgery. Our staff will help you determine the best time to schedule this important procedure for your individual pet.

Why is spaying or neutering my pet recommended?

“The Top Ten Reasons to Spay or Neuter Your Pet” provided by the ASPCA:

Your female will live a longer, healthier life. Spaying helps prevent uterine infections and breast cancer, which is fatal in about 50 percent of dogs and 90 percent of cats.  Spaying your pet before her first heat offers the best protection from these diseases.

Neutering provides major health benefits for your male. Besides preventing unwanted litters, neutering your male companion helps prevent testicular cancer.

Your spayed female won’t go into heat. In an effort to advertise for males, female cats in heat will yowl and urinate more frequently-sometimes all over the house! Female dogs in heat bleed for several days, which can be very messy.

Your male dog won’t want to roam away from home. An intact male will do just about anything to find a mate! That includes digging his way under the fence and making like Houdini to escape from the house.  And once he’s free to roam, he risks injury in traffic and fights with other males.

Your neutered male will be much better behaved. Neutered cats and dogs focus their attention on their human families.  On the other hand, unneutered dogs and cats may mark their territory by spraying strong-smelling urine all over the house.  Many aggression problems can be avoided by neutering by the age of 6 months.

Spaying or neutering will NOT make your pet fat. Don’t use that old excuse! Lack of exercise and overfeeding will cause your pet to pack on the extra pounds-not neutering.  Your pet will remain fit and trim as long as you continue to provide exercise and monitor food intake.

It is highly cost effective. The cost of your pet’s spay/neuter surgery is a lot less than the cost of having and caring for a litter.  It also beats the cost of treatment when your unneutered tom escapes and gets into fights with the neighborhood stray!

Spaying and neutering your pet is good for the community. Stray animals pose a real problem in many parts of the country.  They can prey on wildlife, cause car accidents, damage the local fauna, and frighten children.  Spaying and neutering packs a powerful punch in reducing the number of animals on the street.

Your pet doesn’t need to have a litter for your children to learn about the miracle of birth. Letting your pet produce offspring you have no intention of keeping is not a good lesson for your children-especially when so many unwanted animals end up in shelters.  There are tons of books and videos available to teach your children about birth in a more responsible way.

Spaying and neutering helps fight pet overpopulation. Every year, millions of cats and dogs of all ages and breeds are euthanized or suffer as strays.  These high numbers are the result of unplanned litters that could have been prevented by spaying or neutering.

 I see “worms” in my pet’s feces. What should I do? Can all worms be seen easily?

We recommend a fecal exam to check for intestinal parasites every 1-2 months for puppies and kittens and twice yearly for adult dogs and cats.  Some parasites are microscopic and cannot be seen with the naked eye.  Parasites are shed intermittently so a negative fecal exam does NOT mean there are no parasites anywhere in your pet’s body.

The most common types of intestinal parasites include:

Roundworms A puppy or kitten infected with roundworms may display the following symptoms: abdominal discomfort, a dull coat and a pot-bellied appearance. Common in puppies and kittens, these long, cylindrical worms are transmitted in a variety of ways. Because larvae can cross the placenta, puppies and kittens can actually be born with a roundworm infection. The larvae can also be ingested in milk while the newborn nurses. Infective eggs can be ingested from the soil contaminated by the feces of an infected dog or cat, or a puppy or kitten can become infected by eating a mouse or bird containing roundworm larvae.

To help prevent roundworm infection of both your pet and your family, be sure to bring your new pet, along with its de-worming history, to us as soon as possible after acquiring your new friend. Keep your yard and kennel area clean. Because it takes two to three weeks for eggs to become infective for both humans and animals, proper disposal of your pet’s feces will greatly reduce the number of larvae in your soil. Make sure that any sandboxes are covered when not in use, and be sure to change the sand if feces are found in the box.

It’s very important that your children wash their hands before eating, especially after playing in the soil. Park soil in particular can be heavily contaminated with roundworms.

Finally, make regular de-worming part of your pet’s health program. Bring in fecal samples and have your pet checked for worms at whatever frequency your vet directs, based on your pet and its history. You should also use a heartworm preventative that helps control roundworms as a precautionary measure.

Hookworms “graze feed” off the intestinal wall of your pet, inducing many punctures in the lining of the small intestine. The resulting loss of blood into the digestive tract may give a blackish appearance to your pet’s feces, which can become foul-smelling and fluid. Puppies especially may develop symptoms of pale mucus membranes, weakness and anemia. Severe hookworm infection in puppies can even result in death.

Should your pet become infected, we can prescribe a variety of effective drugs. In most cases, we de-worm your pet twice within three weeks to ensure that all worms are gone, including those that may have not matured yet at the time of the first de-worming. Make sure to bring in a stool specimen six weeks after the second de-worming to verify the infection has been completely cleared.

Preventative programs for hookworms are similar to those for other worms and parasites and include routine fecal examinations, prompt treatment of infected pets, proper disposal of infected pets’ feces and the use of a heartworm preventative that also helps control hookworms. Ask your veterinarian for brand recommendation for these preventative programs.

Whipworms infection in dogs can only be determined by microscopic examination of a fecal flotation.  Whipworms are spread by the ingestion of eggs from the feces of an infected dog.  These eggs hatch in the small intestine before migrating to the cecum, a pouch located between the large and small intestines, after about a week.  They develop into adults here and begin passing eggs within three months.

We will recommend a treatment for whipworms based on several factors, including the age and condition of your dog.  Whipworms can be very difficult to eliminate due to their location in the cecum, so we may wish to test fecal samples periodically after treatment to determine if further treatment is needed.

A preventative program to control the occurrence of whipworms should include routine fecal examinations and prompt treatment of infected dogs.  Properly dispose of feces from infected dogs and thoroughly clean their housing and run areas.  Trifexis and Advantage Multi, monthly heartworm preventatives, will help to control whipworm infections.

Tapeworms are different than other worms in that they require an intermediate host to be transmitted from pet to pet. The most common intermediate hosts include fleas and small rodents. Your pet must actually ingest the intermediate host in order to become infested with tapeworms. This is fortunate if you have more than one pet, because it means you only need to treat the animal that is infected; the parasite cannot be transmitted through contact with stool alone.

Unlike other types of worms, tapeworms cannot often be diagnosed by checking a stool sample. Instead, you may find segments of these flat, parasitic worms in your pet’s bedding or in the fur around the rectum and tail. These segments are yellowish to white in appearance, and approximately one-fourth inch long, and may expand and contract. When dry, they resemble grains of rice.

To treat a tapeworm infection, we put your pet through two stages of treatment. First, we destroy any tapeworms currently infecting your pet. Next, we control reinfection by eliminating contact with the intermediate host. All the medicines we prescribe are extremely effective, but they will not prevent reinfection if your pet continues to have contact with the intermediate host. For this reason, it’s of utmost importance to limit your pet’s contact with possible hosts, such as fleas and small rodents.

Other Helpful links

The following links are external sources for help on everything from local dog parks and shelters to some important steps to follow if you have lost or found a pet in Columbia.

Veterinary Partner

Pet Product Recalls

American Kennel Club

Links to Pet Stores and Dog Parks

Columbia Pet Center

Award Pet Supply

PetCo, Columbia

Dog Parks in Columbia, Missouri


What to do if your pet has been lost

This page from No Kill Columbia gives eight important steps to follow if you believe you have lost your pet.

No Kill Columbia Lost a Pet?

This page offers 6 important steps to follow if you believe you have found someone’s pet, again from No Kill Columbia

No Kill Columbia Found a Pet?


Local Shelters

Columbia Second Chance

CMHS (Central Missouri Humane Society)

Dogs Deserve Better

Callaway Hills Animal Shelter

Happy Tails Articles

articles from the Columbia Tribune authored by Dr. Marshall 

By the Grace of a Dog
October 28, 2012 – I was told she had already had three litters of pups. Grace was only 3 years old herself. Neighbors witnessed what they felt was their “last straw” and reached out for help. By their accounts, evidently the family that owned Grace, and several other dogs, did not believe in sterilization. Their form of animal population control was shooting them.

Through the efforts of many, Grace was saved, along with several other animals. We took in those that were most damaged — Grace, one of her pups and Boomerang. Her pup had been shot in both front legs. Veterinarian Michelle Marshall miraculously saved one of her legs so she could at least walk. Boomerang also had been shot in the leg. Surgery took care of his leg, and months later, healed and ready, he went to his new home. Little Lizzie, the pup, is living a wonderful life with her new person. Gracie remained. Now I know why.

Happy Tails to you
July 22, 2012 – The Happy Tails Tips column is undergoing some changes. Jim Johnson will now continue as the sole author. Susan Hatfield and I have decided to pursue other interests.

Loud noises can set off severe anxieties in pets
June 24, 2012 – The Fourth of July is approaching soon. Those of us with pets who suffer from noise-associated anxiety do not look forward to this holiday. Our dog, Harry, hates loud noises. He paces around the house, pants, salivates excessively, can’t settle down and looks for a place to hide.

Tainted pet food can make pet, owner sick
May 27, 2012 – In April, Diamond Pet Foods announced a voluntary recall on three brands of pet food because of concerns the food was contaminated with salmonella. In May, two more recalls involving several brands of dry dog and cat foods were issued. The latest recall includes foods that were distributed in Missouri. Some of the recalled foods include Diamond Naturals Small Breed Lamb and Rice Formula, Chicken Soup for the Pet Lover’s Soul, Canidae, Taste of the Wild and Kirkland. For a complete list of involved foods, production dates and areas of distribution, go to

Story gets to bottom of being a mom
May 13, 2012 – Happy Mother’s Day! Officially made a national United States holiday in 1914, Mother’s Day is a day to honor one’s mother and celebrate the maternal bond.

Fight deadly parvovirus with full vaccine series
March 18, 2012 – Canine parvovirus, an extremely contagious viral disease of dogs, continues to be a problem in our area. Puppies and older dogs with incomplete vaccinations are at increased risk of becoming ill. The good news is that vaccination, when performed as recommended, is extremely successful in preventing this deadly disease.

Laws keep pets on short leash
February 5, 2012 – Responsible pet owners like to keep up with the legal requirements for owning a pet.

Tabbies never change their stripes
December 25, 2012 – I hope that during this holiday season, everyone finds some time to slow down, relax and enjoy the company of family and friends. When life is hectic and I feel stressed, it often helps to emulate my cat, Woodrow. Cats are masters of relaxation. There is nothing better than a purring feline thermal unit to help you relax and keep you warm on a cold winter night. Woodrow is a handsome domestic cat with a classic tabby pattern. All breeds of domestic cats originated from the African wild cat and carry the tabby gene. Although many people believe tabby is a type of cat, it actually describes a color pattern.

Pet ownership has healthy benefits
November 13, 2011 – When counting your blessings this November, don’t forget to count your pets. Pet owners have many reasons to appreciate their furry companions. Who else can you always rely on to greet you at the door at the end of a long day, with a happy face and wagging tail? Pets give complete loyalty and are the most tolerant and forgiving of friends.

Pets’ arthritis can be managed
October 2, 2011 – The cooler temperatures of fall and winter are often a challenge for pets suffering from arthritis. Also called osteoarthritis, or OA, arthritis refers to a breakdown of the cartilage in a joint, which allows the bones to rub against each other. This leads to inflammation and pain, often so severe that animals are unable to walk or move comfortably.

Protect your pet from heat injury
August 21, 2011 – Although the excessively high heat index seems to have taken a break for the moment, heat stroke is still a concern for a while. Often, pet owners keep this risk in the forefront of their minds when the temperature is extreme, but forget that heat stroke can occur even when the temperature is not out of the ordinary.

Six things your vet wants you to know
July 10, 2011 – A physical exam at least once a year is vital to your pet’s health and well-being. Pets age much more quickly than humans, so skipping an annual exam is like skipping eight-12 years for people.

Many factors lead to litter box trouble
May 24, 2011 – Cats that have been using the litter box and suddenly begin to eliminate elsewhere present a complex and frustrating problem. Before becoming upset with the cat, it is important to determine if there is an underlying medical problem responsible for the change.

Litter-train your kitten early
April 17, 2011 – A cat that does not use the litter box appropriately is the most common behavioral complaint of cat owners. It is, unfortunately, also a leading reason for euthanasia.

Early treatment helps thyroid cure in felines
March 6, 2011 – Max is a 13-year-old domestic cat who has been feeling poorly lately. He eats well but is losing weight, his coat is unkempt, and he vomits occasionally. Max’s owners also have noticed that his water bowl needs to be filled more often and the litter box is wetter than usual.

Keep your pet’s teeth clean
January 24, 2011 – February, National Pet Dental Health Month, is upon us again. Time to take a look in your pet’s mouth. Dental disease remains the most commonly diagnosed health problem in dogs and cats. Signs of dental disease include bad breath, tooth loss, painful or bleeding gums, drooling, and the presence of tartar — a yellow-brown crust on the teeth.

Antifreeze a danger for pets
December 12, 2010 – Winter has arrived. As you are preparing for the cold weather, I would like to remind you of the dangers of antifreeze.

Holiday can be scary for pets
October 31, 2010 – As you are enjoying the holiday today, remember that costumes and trick-or-treaters are great fun but can also be frightening for pets. Strangers in scary outfits ringing your doorbell and shouting “trick-or-treat” might not be your pet’s idea of a good time.

Xylitol products pose a real danger to dogs
September 19, 2010 – Do you think sugar-free gum in your purse is harmless? If it contains xylitol and your dog eats it, think again. New research has shown that ingesting xylitol can cause life-threatening liver failure and coagulopathy, or failure of the blood to clot, in dogs.

Condition tricky to diagnose, easy to treat
August 8, 2010  – Hypothyroidism is the most common hormone imbalance of dogs. This inability to produce an adequate amount of active thyroid hormone leads to a decrease in the metabolic rate, causing a variety of symptoms in multiple body systems.

Smoking takes toll on pets, too
June 27, 2010 – The effects of secondhand smoke on humans are well known. Studies have shown that up to 20 different carcinogens found in tobacco smoke may be inhaled by nonsmoking bystanders. The deaths of 53,000 people in the United States are attributed to secondhand smoke each year. 300,000 cases of bronchitis or pneumonia in children under 18 months of age are associated with second hand smoke annually. Several studies done in recent years have shown the serious side effects that secondhand smoke also has on pets who live in smoking households.

Your pet’s mouth needs proper care
January 10, 2010 – This past summer, our family adopted a puppy from Happy Tails. His name is Axel, and he is a rat terrier-Chihuahua mix. He is a sweet, happy puppy and fits in nicely with our other dog, Harry. The cats don’t care for him much. Axel is around 6 months old and now teething. The halitosis is enough to knock your socks off, but soon those sharp puppy teeth will be gone, and he will have a nice, white set of adult teeth. Now is the time to start a dental care routine — getting him used to having his teeth checked and brushed two or three times a week. Dental disease is the most commonly diagnosed health problem of dogs and cats, so regular attention to a pet’s teeth and mouth is a vital part of home health care.

Pets also vulnerable to flu
November 29, 2009 – Flu season has arrived, and humans are not the only species that can be affected by these nasty viruses. It was previously considered unlikely that pets would be affected by the 2009 H1N1 influenza virus because it is uncommon for flu viruses to jump between species quickly, but recent events are challenging that assumption.

Unwelcome habit can have simple fix
October 18, 2009 – Inappropriate urination is the most common behavioral problem of cats. Unfortunately, it also is a frequent cause of euthanasia.

Bacterial disease turning up locally
September 6, 2009 – Leptospirosis is a bacterial disease that affects many different species of animals. More severe symptoms are usually seen in humans, dogs and livestock. Cases in cats are rare. The spiral-shaped bacteria are called leptospires, and more than 200 strains, or serovars, have been identified.

Moving is stressful for pets, too
July 26, 2009 – Moving is a big job, and when you have pets it becomes even more complicated.

Hairballs natural but controllable
July 5, 2009 – If you are a cat owner, you have most likely experienced the fun of finding a hairball around the house now and then.

Prevention important with heartworm disease
June 14, 2009 – Heartworm disease in cats is caused by the same mosquito-borne parasite as heartworms in dogs, Dirofilaria immitis.

Heartworms in dogs easily preventable
May 24, 2009 – Canine heartworm disease continues to be a major, life-threatening issue for dogs all over the world. It has been found in all 50 of the United States, and the American Heartworm Society recently released a new study showing an increase in the incidence of heartworm disease throughout the country.

Keep pet kit handy for medical emergencies
May 3, 2009 – You probably have a first-aid kit for the human members of your family, but what about your pets? Accidents can happen anywhere, so keeping a pet emergency kit is a great idea.

Your pet’s itches are treatable
April 12, 2009 – The March 15 Happy Tails article discussed allergies in pets and the causes. This week we will focus on treatment. If your pet is scratching excessively, a trip to your veterinarian will be needed to rule out other potential causes of itching.

Spring allergens can also affect your pet’s health
March 22, 2009 – The number of people living in my house who are sneezing, coughing and have red eyes tells me that allergy season is well under way. Pets are also affected by allergies but usually exhibit different symptoms than people.

Aging cats require special attention
March 1, 2009 – Cats are living longer lives now than ever before. More cat owners keep their pets indoors, the health care available for cats has improved, and it is not unusual for cats to live 15 to 20 years.

Dealing with the death of pet is difficult
February 8, 2009 – My previous column dealt with the practical considerations regarding the decision to euthanize a pet. Dealing with the loss of a pet, whether by euthanasia, accident or natural causes, can be difficult. If someone you know has lost a pet and you are not sure how to offer support, these suggestions might help.