Monday, June 17, 2013

Tick Season is here and it's worse than ever!

Common ticks in Southern California

Bottom of Form
Ticks are little guys with big problems. Many species of ticks reside throughout California however the three most common ticks are distant cousins in the Ixodes family that includes, Ixodes Pacificus (Western Black Legged Tick), Dermacentor variabilis (American Wood Tick) andDermacentor occidentalis (Pacific Coast Tick). These ticks are found in moist coastal regions, the Sierra foothills and central valley.

Ticks scout out their hosts by crawling up vegetation near a trail and wait with arms extended on a well-placed grass stem or leaf. When an unintentional animal or human passes by, they climb onto them. Once onboard, ticks literally dig in to the host’s using their needle like mouthparts to puncture the skin and obtain a blood meal.

Although some ticks can cause an intense inflammatory reaction, the tick itself does not cause the severe illnesses associated with ticks. Bacteria living within the tick’s gut are transmitted to the host when the tick draws blood. These bacteria are responsible for debilitating illnesses such as Lyme disease,Tularemia and Rickettsia.
Ixodes Pacificus commonly known as the Western Black Legged Tick is widely distributed in hardwood forests, woodlands within the leaf litter and open habitats such as grasslands. This tick has a lifecycle and appearance typical of ticks in the Ixodes family. The tick has four life stages, egg, nymph, larvae and adult, of which nymphs and adults are capable of transmitting disease. Nymphs look like a poppy seed with four legs and a translucent belly. Unfed adult females are 0.12 inches long with eight legs and a dark brown plate covering a light reddish back. Feeding ticks can expand up to 150% of their body size. This tick is best known for harboring the corkscrewed bacterium, Borrelia burgorferi responsible for Lyme disease. Colorado tick fever, Q fever and tularemia are also associated but less likely.
Dermacentor occidentalis also known as the Pacific Coast Tick is distributed throughout California. These ticks harbor the bacterium Rickettsia rickets the disease causing agent of Rocky Mountain Spotted Fever. Tularemia, Colorado Tick Fever and the newly discovered 364D Rickettsiosis are equally associated with D.occidentalis.
Dermacentor variabilis, known as the American Wood Tick, is widespread in the US, Canada and Mexico. Notorious hotspots in California are the Coastal areas, Eastern Sierra range and central valley. These ticks carry Anaplasma phagocytophilum and Ehrlichia chaffeensis- causative agents of ehrlichiosis.
Rhipicephalus sanguineus also known as the Brown Dog Tick, is unique in that it can complete its entire lifecycle indoors using dogs as it's preferred host. These ticks are disease vectors forEhrlichia canis and Babesia canis.
If you or your pet is bitten by a tick- remove it immediately. Ixodes Pacificus transmits its bacterial friend, B.burgdorferi after two days of feeding whereas other tick-borne agents can be transmitted within the first day. Ticks are best removed with tweezers or a tick key, but fingers (no squashing!) can also work. Remove the tick by pulling steadily and straight-out, being sure to remove the mouthpiece. Applying alcohol, fingernail polish, petroleum jelly or heat from a lighted match is basically ineffective. However be sure to clean and disinfect the puncture wound. It is also a good idea to contact your physician or veterinarian. Resist the urge to smash the tick so it can be identified and tested for tick borne agents.
If you or your pet begin to display signs of illness such as lethargy, joint pain, rash or enlarged lymph nodes- see your doctor or veterinarian immediately. Untreated tick associated diseases have the potential to damage your heart, vision, respiratory system and mental acuity.

Thursday, June 6, 2013

When it's dogs vs porcupines, the porcupine always wins.......

Vet Talk
Dog vs. Porcupine: Same Winner Every Time
June 3, 2013 (published)
In any dog vs. porcupine encounter, the dog is guaranteed to lose. The dog will never learn to believe this, despite the pain from having quills stuck in his body. Despite the anesthesia typically required while the vet pulls the quills out, by hand, one at a time. Despite any repetitive lessons that should constitute aversive conditioning.

I can also guarantee that the dog will never learn that the porcupine has no need to run away. Why would a porcupine run? He may only have one defense, but it's a heck of a good one. He protects his quill-less belly by rolling into a ball, like a giant hedgehog, and the attacker simply falls onto a few of his 30,000 barbed quills. Who knows, maybe part of his defensive move is to hold his breath while waiting for a dog to start screaming in surprise. But that old saw about porcupines throwing their barbed quills as though they were some kind of rodent mega-warrior? Totally not true.

Granted, the porcupine has a few predators - martens, fishers, wolverines, pythons, eagles, great horned owls, cougars, and bobcats - but for porcupines, a dog will always rank as a predator wanna-be.

Porcupines eat foliage. They live all over; check out the map.

The North American porcupine lives in the western U.S. and throughout Canada. This porcupine climbs trees and noshes on pine trees - that's why they are called porcuPINEs. Kidding! They're called porcupines because the name in Latin means "quill pig" (some sources say it means "pig thorn") even though it is not a pig but a rodent of unusual size weighing 12 to 35 pounds. They mostly eat pine needles (not kidding) and bark, plus some roots, stems, leaves, and so on. Their preference for dining al fresco among the trees is why dogs tend to have up close and personal encounters in wooded areas.

In my 20 years of being a veterinarian, I've never seen a dog who learned to leave porcupines alone. They're all repeat offenders. When I was a kid, one of our dogs had three encounters with them in the forest, after which we finally wised up and leashed him when we were there. That leash is the only thing that kept him away from the porcupines. It's too bad more people don't do the same.

Like vampires, porcupines are creatures of the night. That's why dogs don't get nailed during the business day when it would be less expensive to run the dog into the vet for an emergency appointment. Heck no, they only do it when the emergency hospital is the only place open, or you have to call your vet after hours. I've never had one of these cases where the encounter happened in daylight.

It's so painful for the dog that you don't want to wait to see the vet. Immediately after the encounter, the dog will try to rub the quills out by rubbing his face anywhere he can, including on you (you won't be in pain...the sharp end is in the dog). He won't understand he's just pushing the quills in deeper and breaking the ends off so that they are harder to pull out.

The dog certainly won't understand that part of those quills will start migrating immediately. Quills can migrate to nearly anywhere: his face, lungs, haunches, and so on. A migrated quill came out right in front of one of my patient's eye globe; it had traveled up his sinuses and came out between his lower lid and globe. Quills can pop out weeks after the incident and can protrude from almost anywhere on the dog's body. I've heard of dogs dying from quills in the lungs or heart, and I heard of one that migrated to the brain. Here in Wyoming, pet owners know to bring the dog in immediately after the run-in.

Photo by Teri Ann Oursler, DVM
Dogs need general anesthetic to withstand all the yanking. Nonetheless, I've only had one dog, a lab mix, that could sit there awake while I pulled them out. Normally you'd get bitten trying to do that while they are awake. That dog is an escape artist and has five or six encounters a year.

The top photo was taken by a colleague, Dr. Chiara Switzer. She said that Buddy, the lab/chow mix, went flying to the other dog's rescue when he heard Dexter yelping. Dexter got about two dozen quills; needless to say, Buddy got the worst of the damage. She said Buddy still looked kind of proud of himself, though. There were a few buried in his feet that she couldn't get out.

The dog in the other photo was one of my patients. Looks uncomfortable, doesn't he?

Unlike bees who die after the loss of their only stinger, the porcupine grows new quills to replace the ones embedded in a dog. With over 29,000 quills to spare, he doesn't have to worry about predators while he grows new quills. Dogs are the ones who should worry, but of course they don't, the poor daft babies. They're too busy having fun romping in the forest until they find a porcupine and their brains evaporate.

The only prevention that I know of is to leash the dog when you're in the woods. Dog owners need to understand that the dog will not learn about porcupines, so when you're hanging out together in the forest enjoying the fun part of nature, Your best friend's best friend is the leash.