Why Does my vet...
Ask for annual heart worm and fecal testing?

When you bring your dog or cat in for their annual wellness exam, your vet (or their assisting staff) may recommend that you complete a heart worm test and fecal examination. If your pet is on a routine prevention product, or if your pet rarely (or in the case of many cats, never) ventures outside, this may seem unnecessary... but your vet has sound reasons behind the recommendation!  

100% Compliance with prevention products is uncommon! Most people miss a dose. 

Many pets on prevention products do not get them as routine as we would hope, and having the prevention product late, or missing a month, can allow for an infection with heart worms or intestinal parasites to take hold. One study found that on average, only about 7 months of prevention product are purchased per dog per 12 months, among dogs for which at least one prevention purchase was documented. This means that somewhere along the way, the average pet on prevention is missing almost half the months in the year.

While many prevention products are sufficient for preventing an infection from developing, they cannot always treat one once it is present, meaning that getting back on the wagon alone may not be enough. 

Even with 100% compliance, product failure can occur

Unfortunately, prevention products can also experience failure in the form of resistance . This is something that is currently being investigated in heart worm products and observed in some intestinal parasite products. The only way to identify that resistance is occurring is to routinely assess the effectiveness of products through screening, such as annual testing. 

There is also the possibility of product failure even when you are administering the product. For example, your dog may later vomit the product outside unnoticed, or in rare instances, have impaired absorption of the product. In these instances, even though the product was provided diligently, it may not be able to do what it is intended to. 

Many of these products come with guarantees, where the manufacturer will reimburse the costs of treatments if the product fails. A stipulation of the guarantee is typically routine proof of negative status. 

Primarily indoor pets can still be at risk.  

Even when pets are primarily, or even exclusively indoors, they can still be at risk of exposure. Mosquitos, the organism that transmits heart worms, can come indoors, and often do at least one or two times per season in high burden areas in the summer. Intestinal parasites and their eggs, which live in the soil, can be inadvertently brought in on our shoes, or our pet's paws after only a short walk outside. Fleas, which spread tapeworms when eaten, can also hitch a brief ride inside on our pant legs or when our pet goes outside for a short period. 

In cats affected by heart worm disease, one study found that as many as 1 in 4 were reportedly kept exclusively indoors. 

Annual testing is less expensive and less invasive than treating complications from severe infections left undiagnosed for a prolonged period of time.  

Heart worm disease can cost thousands of dollars to treat, especially when advanced. The longer a pet is infected, the worse the damage to the heart and lungs, and it can be a long time for an infection to progress from asymptomatic (no signs at home)) to non-specific signs like coughing and exercise intolerance. Testing annually ensures that any infections will be caught promptly to be treated appropriately, hopefully without the need for more invasive treatments like surgical removal of a high worm burden. 

Intestinal parasites can also wreak havoc on your pet's digestive system, leading to malnutrition and blood loss if a worm burden gets severe enough. Additionally, many intestinal parasites, including hook worms and round worms, are contagious to people and can rarely cause serious life-threatening conditions when worms migrate through our tissues. 

Following your vet's recommendation for annual testing is for the safety of your pet and yourself. If these tests come back negative, it's a positive sign that the prevention products being used are effective and your dog (or cat) is safe from the parasites in question. If the tests are positive, it allows for early intervention and treatment, keeping your pet healthier for longer. 

Do you have a question about veterinary care you'd like to have answered?

Submit requests for this series to info@AllTradesDVM.com -- and ask your vet at your next visit, if time allows!