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Dr. Little is a professor of parasitology at the Center for Veterinary Health Sciences, Oklahoma State University, where she is active in veterinary parasitology teaching and oversees a research program focusing on zoonotic parasites and tick-borne diseases.
In your opinion, what’s the single greatest tick-borne disease risk facing dogs in your region [South-Central USA]?
Ehrlichiosis is by far the most common infection we see in dogs. In some areas, over half of the dogs have been infected. We also worry about Rocky Mountain spotted fever and hepatozoonosis; both are potentially fatal to dogs. We certainly see anaplasmosis caused by Anaplasma platys as well as babesiosis in dogs. Cats are at risk for Cytauxzoon felis, which causes a severe, rapidly fatal disease in cats throughout the southern US. Ideally cats should be kept inside and away from tick-infested environments but if that just isn’t possible, a tick control product should be used to try to reduce the risk as much as possible.
Are there any specific disease signs or symptoms a pet owner should watch for, and when should you take your dog to the vet?
In additional to routine wellness exams, owners should call their veterinarian at the first sign of lethargy, muscle pain, joint pain, or reluctance to move, particularly when those behaviors are out of character for their pet. When acutely ill, dogs and cats with tick-borne diseases often stop eating. Dogs may have reddened, droopy eyes, fever, and dehydration – you can tell a dog is dehydrated by checking its gums to see if they are warm and moist, which is normal, or hot and sticky or dry, which could mean the dog has a fever. Cats tend to be more stoic and so owners may not realize they are sick until they begin to have trouble breathing and become jaundiced, both signs that can be associated with cytauxzoonosis.
Is there a time of year in the South-Central USA that tick encounter risk for dogs is particularly high?
We literally pull ticks off unprotected dogs 12 months of the year. Tick populations outdoors are definitely higher in the spring and summer months when we see heavy blooms of lone star ticks, American dog ticks, and Gulf Coast ticks. Lone star ticks in particular can be very dense in wooded areas in the spring and even through the summer if it stays humid enough for them. When dogs aren’t kept on tick control and manage to get access to a wooded area frequented by deer they may have hundreds or even thousands of lone star ticks attach. Dogs in a kennel or home infested with brown dog ticks, the only tick species in the US that can thrive indoors, may have near constant exposure every day for months or years until the population is brought under control. We tend to see home infestations with brown dog ticks fairly regularly, probably because of our milder climate and the ability of that species to survive in both humid and arid environs.
What do you look for in selecting effective tick control products for protecting your pet?
Definitely safety – the product has to be safe to apply and I want to be confident that toxicity will not occur. The EPA registered products available through veterinarians such as those that contain permethrin or fipronil, or collars with flumethrin, amitraz or deltamethrin, are safe and effective. I also look for something that kills the ticks fairly quickly. Unfortunately ticks are much more difficult to kill than fleas. We have fewer choices of products that are effective for ticks and they often take a bit longer to work than they do for fleas, but when used consistently they can make a huge difference. I also like repellency for both my pets and myself and family. Preventing attachment of the ticks is important, not just to avoid the discomfort caused by a tick bite, but also to prevent disease transmission. Although there is a delay in transmission for most of the pathogens, some agents like those that cause Rocky Mountain spotted fever and ehrlichiosis are thought to be transmitted on the first day of attachment.
What proportion of dog owners in your region are doing an adequate or better job of keeping their pets tick-safe?
It’s pretty likely that fewer than half of the dogs, and an even smaller proportion of the cats, receive protection from ticks. My sense is that pet owners definitely want to keep their pets free of ticks but feel like they aren’t sure what is the best way to protect their pets. We know from a variety of research projects that routine application of tick control products by the calendar – every month, or even more often at certain times of the year and if the label allows – protects dogs from ticks and from the diseases they transmit. Even in highly endemic areas where tick populations are staggering, keeping dogs on tick control can dramatically reduce their risk of becoming infected with a tick-borne disease agent.
Do you have any tips for helping pet-owners make tick-bite protection a high priority action?
I think when people recognize how dangerous ticks and tick-borne diseases are in the south-central US, they’re usually more willing to try and combat the problem. It’s next to impossible to entirely avoid ticks and tick infested areas when you live in the south-central US, but you can try to minimize the time dogs spend in tick infested habitats and make sure that every dog is treated with an effective and long-lasting tick control product every month. Also, by treating dogs with a product that kills the ticks it encounters can reduce the number of ticks in the environment where the dog spends its time, usually right around the home. Fewer ticks around the home benefits people as well as pets, as infection risk, although not eliminated, is reduced.