By Matt Reese
It wasn’t the first time and probably won’t be the last. This summer, Morgan County Extension educator Chris Penrose came to his office to find a jar containing a questionable creature that needed to be identified. In many cases, the contents of the glasses turn out to be inconspicuous. That wasn’t the case with this one.
“When I opened it, I saw a whole bunch of ticks in there and I was like, ‘Oh, oh,'” Penrose said.
After samples from the jar were sent to Columbus for further analysis, Penrose’s suspicions were confirmed: the Asiatic longhorn tick had made its way to Morgan County’s cattle pastures.
The Ohio Department of Agriculture (ODA) announced in the summer of 2020 that the US Department of Agriculture’s National Veterinary Services Laboratory has confirmed the discovery of an Asian longhorn tick in Gallia County. The tick was found on a stray dog. The tick was identified by Ohio State University and sent to the federal laboratory for confirmation.
The Asian longhorn tick is an exotic East Asian tick known to be a serious pest of livestock. The US Department of Agriculture first confirmed the presence of this tick in the US in New Jersey in 2017. Asian longhorn ticks are light brown in color and very small, often smaller than a sesame seed. An adult female is about the size of a pea when covered in blood. Larva, nymph and adult can all be present at the same time.
Asian longhorn ticks are difficult to spot due to their size and rapid movement. They are known to transmit pathogens that can cause disease in humans and livestock, and can also distress the host by feeding them in large numbers, leading in some cases to death. Since it was first discovered in Ohio, the Asian longhorn tick has spread.
“I think last year they were found over in Monroe County and maybe another county in southern Ohio,” Penrose said. “We kept it in mind to keep an eye on it. When the jar came in it piqued my interest and of course our local vet’s interest.”
Along with all the creepy traits ticks share, Asian longhorn ticks can reproduce asexually.
“You don’t need a mate to reproduce,” Penrose said. “Each tick can lay up to 2,000 eggs, so you can see how quickly they can expand and basically overwhelm a cow. I think those numbers can stack up so fast and so much that they can actually suck enough blood out of a cow to kill her.”
This was obviously a concern of the rancher behind the tick-filled jar in the extension’s office.
“Earlier this summer the farmer noticed a few ticks on some baby calves when he went to work with them after they were born. He didn’t think much about it, but later he saw some of his cattle with a whole bunch of ticks on them. Our local vet went out and was able to treat her. The farmer eventually took the cattle to another field. Much discussion has centered around how these ticks reproduce quickly, but they don’t travel very far. More nymphs were found this fall but they got it under control for this season. Farmers next door who had cattle had no problem with it at all,” Penrose said. “And not only are our local vet, OSU Extension and OSU vets committed to this, but also our friends at the Ohio Department of Agriculture and our USDA vets. We have also informed the local health department. It was really reassuring to have a multi-agency team working together to really get a handle on this.”
As tick season draws to a close at the end of the year, it remains important to monitor livestock for Asian longhorn ticks (and the potential for diseases they transmit) while there is time to develop a strategy for 2023. On cattle, look for ticks where the skin is thin on the head, neck, ears, flanks, armpit, groin, udder and under the tail.
“There are some insecticides or some pour-ons that can be used, but there can be some resistance to some specific types. Another issue is that many of the pour-ons we use aren’t labeled for ticks, even though they work on ticks,” Penrose said. “That’s why it’s so important to have a good veterinary patient-patient relationship with a vet if you’re lucky enough to have one in your area so you can find a solution. Some of the Ivomec products will work for a long time, others may not. If it’s really bad, you might want to consider something like a back bungee that contains an insecticide that you can put out next to the mineral bath or water source.”
Ticks move by hitchhiking something else.
“You can move wildlife, people, equipment, anything. That makes it kind of scary. You not only have to check your livestock, but also your goats, your sheep, your dogs and cats. It’s really important to keep pets on one of these good preventative medicines to keep ticks off our animals,” Penrose said. “They’re still trying to learn about it, but it certainly can be a problem. We need to figure out how to stop these ticks from spreading. We really have to be careful because problems are much easier to solve if they are dealt with early than if it is too late for the cattle. This is an evolving situation that hopefully we can learn more from and really not cause any additional problems for livestock.”
In Kentucky, the bite of the Asian longhorn tick has been blamed on cattle with a microscopic unicellular parasite (Theileria orientalis) which infects the red blood cells of cattle and causes anemia. The problem can also be transmitted through blood transfusions from contaminated needles and devices.
“The tick can feed on many animal species including humans, but the blood parasite only affects cattle. Once a cow is infected, it can take 1 to 8 weeks to show symptoms of the disease,” said Michelle Arnold of the University of Kentucky Veterinary Diagnostics Laboratory. “There is a spring peak in disease incidence in March-April and an autumn peak in September-October. There is no effective treatment for sick livestock or a vaccine to prevent infection. However, once infected cattle become vectors and are protected from new infections. There are no recognized long-term health or production effects from persistent infection. Theileria is not a public health concern and contact with affected cattle poses no risk to human health or food safety.”
Regarding TheileriaArnold suggests ranchers look out for the following:
• The majority of infected cattle have limited or mild clinical signs. Symptoms are very similar to anaplasmosis, another tick-borne cattle disease that causes anemia.
• Affected cattle show signs of anemia, including lethargy, pale or jaundiced (yellow) mucous membranes, and increased respiratory and heart rates. Shortness of breath can be mistaken for pneumonia, especially in young animals.
• Affected cattle may be stress intolerant and lag behind the rest of the herd or go away on their own.
• Affected cows may be starved, have a fever and suddenly lose weight.
• Can cause sudden death, particularly in late-pregnant and early-lactating cows.
• Late miscarriages can occur due to lack of oxygen in the fetus with subsequent death of the calf. Metritis in the cow may follow. Breeding bulls can have a decreased libido for 1 to 1.5 months.
• Calves, especially those aged 6 to 8 weeks but up to 6 months, may show symptoms.
For cattle showing signs of anemia, Arnold recommends:
• Contact a veterinarian. Theileriosis and anaplasmosis look almost identical, so treatment with an approved antibiotic (LA-300 or Baytril 100-CA1) is recommended to treat anaplasmosis. however, if Theileria The cause is that antibiotic therapy does not respond. A blood test is available to check for this disease.
• Stress and exercise in affected animals should be minimized as their reduced red blood cell count reduces their ability to carry oxygen throughout the body. This can lead to collapse and death. Affected animals should be rested, given high-quality food and water, and treated only as needed.
• There is no treatment for Theileria other infection as supportive care. Blood transfusions can be used for valuable animals. Recovery can take 1 to 2 months depending on the severity of the anemia.
• Relieve underlying illness or stress. Cows in late pregnancy, early lactation and young calves (2 to 3 months old) are more susceptible to serious diseases. Pay close attention to cows during calving, avoid trace element deficiencies, and vaccinate cattle against the immunosuppressive BVD virus.
On controlling Asian longhorn ticks, Arnold said:
• Ticks spend most of their time, almost 90%, in the environment. Although only a small portion of the tick population is livestock at the same time, treating cattle with a tick repellent will reduce the number of animals that feed and progress to the next phase of the tick life cycle. This affects the number of eggs that are eventually laid on the pasture and helps control the spread of the disease. There are currently no acaricides labeled for use against Asiatic goat ticks. Using pesticide-impregnated ear tags, pour-ons, sprays, and back rubs that control the American dog tick and the Lonestar tick should provide beneficial tick control. There are testimonials of success with macrocyclic lactone dewormers such as Cydectin Pour-on and Dectomax Injectable products.
• Environmental controls to reduce exposure to ticks include mowing pastures, particularly in shady areas, and fencing cattle away from wooded areas. Fencing at least 20 feet of wooded areas will reduce the number of ticks in grazing land. All stages of the tick such as warm, humid conditions and long grass. Avoiding long rank pastures that have not been grazed, e.g. B. at the edges of crops and bush areas, reduces the likelihood that animals pick up ticks. Keep in mind that wild animals serve as tick hosts and can introduce ticks to new areas.
• Treat new cattle for ticks when they arrive at the farm and before moving cattle from one property to another to avoid spreading infected ticks.
• Calves should also be checked closely for ticks and signs of anemia.
The Ohio State University Extension has a fact sheet on Asian longhorn ticks at: https://ohioline.osu.edu/factsheet/vme-1035.