Author Archives: Mark Shackelford

The Importance of Giving Heartworm Prevention All Year in Oklahoma

posted October 15th, 2010 by

BY MARK SHACKELFORD, DVM

Mosquitoes transmit heartworm disease, which affects both dogs and cats. Due to our temperate climate in Oklahoma, mosquitoes can be seen at various times all year long. I have swatted mosquitoes in my home in January and February, which shows how resilient these insects can be. We can have one or two days of above freezing temperatures that will cause otherwise dormant mosquito eggs and pupae to hatch and become active.

When a mosquito bites an animal, the larva, or immature form of the heartworm is deposited on the skin, and from there makes a journey to the bloodstream, which takes 30 days, eventually taking it to the heart, where it will mature to an adult heartworm. This is the reason that heartworm preventatives can be given once per month…they kill the immature heartworm that is migrating through the skin. But, once the larva reaches the bloodstream, the preventative is ineffective. Therefore, it is very important to give the heartworm medication on a strict monthly schedule.

Heartworm disease can be hidden for a long time, sometimes taking years before symptoms appear. One of the first things that dog owners will notice is a decrease in exercise tolerance, which means there is a shorter period before the dog gets tired and stops playing or running. As the disease progresses, a chronic cough may be heard and an even greater exercise intolerance may be noticed. Other symptoms may include weight loss, lethargy due to pneumonia, and signs associated with congestive heart disease. Cats will have episodes of sneezing and coughing, and may eat less and become more isolated from their owners.

Annual heartworm testing for dogs is very important, even if you are giving heartworm preventative every month of the year. Sometimes the preventative will be given late or incorrectly applied to the skin, as in the case of topical products. This is why a heartworm test should be performed yearly in conjunction with a check up and vaccinations.

Treatment for active heartworm infection in dogs consists of a series of injections given in the muscle of the back. This is usually a painful procedure but the pain can be controlled with analgesics and other medications that are given at the time of treatment and at home for several days afterwards. In our hospital, we will pre-treat with an antibiotic for a month and will have the client start pain medication 2-3 days before the injections start. We will give injections on one day, then wait one month and give injections for 2 days in a row. This makes a total treatment time of 2 months, which is uncomfortable for the dog and can be expensive for the owner. Unfortunately, there is no treatment for heartworms for the cat, simply because the drugs are too toxic.

There are many types of heartworm preventatives available for both the dog and the cat. When I first started practicing veterinary medicine, the only available heartworm preventatives were pills that were given on a daily basis. Now we have medications that are given or applied monthly, and even an injection that is administered every six months. We have monthly oral heartworm preventatives in combination with intestinal wormers, and we have oral preventatives in combination with intestinal wormers that also can inhibit the hatching of flea eggs. There are also products available, that, when applied to the skin, will prevent heartworms, intestinal worms, and will kill fleas, their larvae, and their eggs. Your veterinarian will be able to advise you on what is the best product for your pet.

Giving heartworm preventative all year is very important for the health of your pet due to the prevalence of mosquitoes and other parasites in Oklahoma. Yearly testing for dogs is also necessary to ensure that treatment will never have to be a necessity for these important companions and family members.

Mark Shackelford
Mark Shackelford is a co-owner and veterinarian at the 15th Street Vet Group, Tulsa.

Ask the Vet

posted July 15th, 2007 by

This issue’s participating veterinarian:    Mark Shackelford, 15th Street Veterinary  Group, Tulsa

Q: I have a 15 year old lab female who’s in pretty good shape for her age.   Lately, though, she’s developed this “cough.”   She does it mainly in the mornings and recently it’s become more persistent.   Should she be checked for this?

A: Most definitely.  Coughing can be a symptom of several maladies, including heartworm disease, chronic obstructive pulmonary disease, allergic bronchitis, cardiomyopathy, congestive heart disease, lung cancer, and several other pathologies that can affect the upper and lower airways.  You should see your veterinarian for a full examination, which will probably include a chest radiograph and blood tests.

 

Q: My older dog has a nasty habit that could be medical-related.  After she goes out to do her “business,” she comes back in a “scoots” across the rug.   It’s especially embarrassing when guests are here.   Is there anything I can do about this?  

A: Your veterinarian can perform an examination to that area of your dog’s anatomy to rule out several causes of her scooting.  Among other things, anal sacs, which are located on either side of the anus, can become impacted and are usually easily emptied by a qualified professional.  Skin allergies can be another major cause of itching, which will cause the scooting.  You want to be sure that fleas are not a problem by using any one of the recommended topical and oral products that are available. 

Q: My old dog (13) is showing signs of cataracts.   How do I know when it’s time to remove them?

A: Cataracts, or an opacity of the lens of the eye, are fairly common in older animals.  Cataracts should not be confused with a more common condition in the older animal called lenticular sclerosis, which is a thickening of the lens of the eye.  This condition of the lens causes a gray color, but does not usually cause blindness.  Cataracts are a complete opacity of the lens, which means light cannot penetrate to the retina at the back of the eye.  This barrier to the retina results in blindness.  Other causes of cataracts are diabetes and trauma to the eye. Observing symptoms of blindness, such as running into walls or furniture, is the time to consider removing cataracts.  A qualified veterinary ophthalmologist can surgically remove cataracts, which can result in a significantly improved field of vision.

Have a question for October’s Ask the Vet Column?   Email [email protected].