The Growing Need for Parasite Control

Parasites – including fleas, ticks, mites and lice – can cause more than just discomfort for pets. In fact, bites from parasites can transmit a number of serious diseases, some of which can be fatal. Because parasites can spread from pets to their families, they are a concern not just for pet health, but human health as well.

Most importantly, it has recently been observed that many parasites are growing in number, expanding to new areas, and remaining active for longer periods of time throughout the year. In the U.S., for example, efforts to restore forested areas have led to a surge in deer populations, which has in turn led to increasing numbers of ticks, since deer are a primary host for this parasite. Fluctuating weather trends have also resulted in both fleas and certain tick species thriving in areas where they previously did not cause significant problems. For example, tick-borne diseases have now been reported in most states in the U.S. Similarly, while flea infestations tend to peak in summer and fall, studies show that they now occur throughout the year1.

In tandem with the increasing sighting of parasites, many areas have seen an increase in the diseases they transmit. In Asia, officials have recently identified a new tick-borne virus – the Severe Fever with Thrombocytopenia Syndrome (SFTS) virus. First seen in China in 2011, the SFTS virus has now also been identified in Japan and Korea. With 21 human deaths attributed to the disease2, the Japan Health Ministry issued a health warning in 2014 about the ticks that transmit the deadly virus. In the U.S., ticks that transmit Lyme disease have also gained considerable attention because of the increasing incidence and geographic range of the disease. 

Because of the risk parasites pose to pets and people, effective parasite control is increasingly important. Year round parasite control is now often recommended. Improvements in parasite control have been significant in recent years, with new treatments introduced that last long and are more convenient, making it easier for pet owners to administer regularly and eliminate gaps in protection. Products such as these that are fast acting and long lasting can help reduce the potential for pets to bring parasites into the home, or to become infected with a disease as a result of infestation.

As more people around the world keep pets, MSD Animal Health is committed to providing solutions to help them look after their pets’ health and wellbeing, including by protecting them from parasites.


  1. Companion Animal Parasite Council. Current Advice on Parasite Control. Companion Animal Parasite Council website. Accessed July 21, 2015.
  2. Hofilena, John. “‘Killer ticks’ leave 21 dead in Japan, spreads deadly virus.” Japan Daily Press. February 26, 2014. Accessed July 16, 2015 via