Health Canada issued a temporary stop sale order for all Deccox products in Canada due to a regulatory compliance issue with an ingredient supplier said animal nutrition company Philbro Animal Health Corporation.

Deccox, the trade name for decoquinate products sold by Philbro, is a non-antibiotic medication for preventing coccidiosis in calves. It’s administered through feed, milk or milk replacers, according to Philbro’s site.

There are no safety or efficacy concerns with Deccox, the company said in a fact sheet posted to the Ontario Sheep Farmers website. It said the issues are with the manufacturer of the active pharmaceutical ingredient (API), not Philbro and are procedural in nature. Products are not being recalled.

No other products in the company’s portfolio are affected.

Health Canada hasn’t provided a timeline for the stoppage, Philbro said.

“Philbro is working closely with the API manufacturer to obtain clarification and will communicate updates as soon as additional information becomes available,” it added.

Coccidiosis is a disease affecting calves which is caused by protozoan parasites according to an article from Ohio State University. Infection can cause symptoms ranging from depressed appetite and poor weight gain to bloody diarrhea and death.

Coccidiosis can affect calves as young as three weeks of age but is most frequently diagnosed at stressful times like weaning or entry to a backgrounding operation or feedlot, the Ohio State University article said. Calves usually develop immunity by one year of age.

The post Health Canada stops sales of coccidiosis medication Deccox on procedural issue appeared first on Manitoba Co-operator.

On that day, backbench Conservative MP Arnold Vierson — who represents the Peace River-Westlock riding in Alberta — stood next to members of the Canadian Beekeepers Federation and Alberta Beekeepers Commission to highlight obstacles facing the honey sector.

Those included some now well-known problems that have seriously cut at honeybee stocks and hurt producers’ bottom lines in recent years, as well as a brand new parasite threat looming — tropilaelaps mites, or t-mites.

WHY IT MATTERS: Packaged bee trade, and whether or not the U.S. should be allowed as a source, has been a hot topic among a beekeeping sector where persistent production problems have pushed some farms to the edge of viability. Beekeepers in favour of the idea aren’t backing down.

Parts of Canada, including Manitoba, have suffered a string of hard winters where many colonies failed to survive. The industry is embroiled in an increasingly difficult battle with varroa mites, with products previously used to control the parasites no longer delivering the same results.

Linked to those, the debate over bulk packaged bees from the U.S. has roared to the forefront in recent years. Without replacement stock, beekeepers with poor bee survival often split hives, something that limits their honey harvest that year.

Some beekeepers want the U.S. border thrown back open, after decades of restriction due to pest and disease risk. Earlier this year, the CFIA shut down a list of industry proposals that had been submitted in the hopes of convincing the agency that those pest risks could be mitigated. That, in turn, frustrated beekeepers, who felt the agency had dismissed them out of hand.

That same day, Vierson brought a new motion forward in the House of Commons, the M-22 Honeybee Importation and Regulation motion.

Vierson’s motion would put five recommendations on the table for the CFIA:

• restore free trade of honeybee packages from safe zones in the United States (something that industry had argued for in its rejected list of proposals),
• develop a clear, consistent methodology for assessments,
• work with beekeepers to review and update the national farm-level biosecurity standard,
• partner with Animal Health Canada to create a tropilaelaps mite emergency plan, and
• improve and speed up the approval process of management tools for bee pests, such as varroa mites.

Drama on honeybee trade

The blanket ban on U.S. packaged bees doesn’t make sense, argued Peter Awram, director of the Canadian Beekeeping Federation. Awram said the CFIA has held the line on the packaged bee ban since 1987, despite mounting evidence that there are significant risks from bees brought in from the list countries that the CFIA does allow.

“They want to say the U.S.A. is dangerous, yet they are allowing from places that are easily 10 times, if not 100 times, more dangerous,” he said.

The cross-section of the beekeeping sector that stood with Vierson Nov. 25 suggests that perhaps Canada should halt packaged bee shipments from these designated safe countries. That’s partly from concern over emerging pest threats, and partly to underline what they see as CFIA’s inconsistency.

They note beekeepers are free to import queen bees from approved zones in the U.S., which suggests risk can be appropriately managed.

The CFIA, meanwhile, argues that the risk of queen bees is a much different thing than bringing in packages that contain hive material. The industry’s rejected submission, which would have set up trade from select areas of the U.S., also needed zoning approval from U.S. officials, the CFIA said in a summary report earlier this year.

Danger from abroad

The current list of approved countries doesn’t take proper account of t-mite risk, the motion’s advocates say, nor do they seem to acknowledge that countries on the approved list aren’t varroa-free. Australia, one of the last bastions against varroa, had its defences breached in 2022. In 2023, authorities decided that eradication of the mite was no longer achievable.

The current list includes:

• Australia
• New Zealand
• Chile
• Italy, and
• formerly included Ukraine

Australia is only 93 kilometres from tropilaelaps-infected Papua New Guinea at the closest point between the two countries’ nearest borders, those in favour of M-22 worry.

The packages from the approved regions are also simply not very good for Canadian production, Awram said. Mismatched seasons and 16-hour flights take their toll on the bees, killing many of them before reaching Canadian shores.

“The danger from outside of North America is far greater than any benefit we get,” he said.

“We import a very tiny amount of stock from Australia, New Zealand, Chile (and) Italy. The stuff we get from those areas; it’s poor for a number of reasons. Some of it is the genetics. The genetics from those regions just are not well-adapted for what we have.”

Awram has verified at least one example of high varroa mite content in packages from New Zealand.

“The lowest was at four per cent varroa in there, which means four mites per 100 bees in a package — up to 20 per cent. According to the regulations from CFIA, it shouldn’t be more than one per cent, but this is the way it is.

“It’s just a bad idea from a biological point of view to be pulling (packages) out of the southern hemisphere.”

The promise of U.S. bees

The situation would change if beekeepers were allowed to bring their packages north from the U.S., he said. They would arrive much faster, and in trucks, which allow greater control over shipping conditions.

“You can have somebody who actually knows how to take care of them watching the temperature and things like that,” Awram said. “This is what was done for decades and decades before 1987. They were brought up by truck, and we never had (these) sort of transport problems.”

CFIA report creates bad blood

Some beekeepers — Awram included — saw the CFIA’s denial of their proposals earlier this year as the final straw.

Along with set safe zones for trade, industry associations across Canada had pitched measures like transport inspections upon entering Canada, current import conditions of queens being expanded for packaged bees, using of best management practices to limit risk and evaluating the impact on inter-provincial movement.

The CFIA, however, responded that “after careful evaluation of all input received, the CFIA concluded that no feasible, scientifically-supported (sic) mitigation measures are currently available to bring all identified risks within acceptable levels,” an Aug. 6 agency statement read.

“As a result, Canada will maintain its current import restrictions and will not permit the importation of honeybee packages from the United States at this time.”

Awram — who maintains the recommendations were based on sound science — sees the feedback as evidence that the CFIA cannot be engaged on a scientific level.

“We’ve been fighting this non-scientific nonsense forever. They did this new risk assessment and despite the fact that there’s plenty of scientific evidence to the contrary, they still made the same claims.

“We’re not talking about an issue that is going to be solved by showing the scientific data or being logical. There is a block somewhere in the CFIA,” he said.

Industry ban not a done deal yet

Those who appeared in Ottawa in November, however, don’t represent the whole honey sector in Canada.

Ian Steppler of the Manitoba Beekeepers Association, who serves on the Canadian Honey Council’s (CHC) tropilaelaps mite committee, said the CFIA has been actively working to minimize beekeepers’ woes. He has been among those representing beekeeper interests with the CFIA on several fronts.

Manitoba’s official beekeeping organization was among those pushing the CFIA to reassess risks posed by U.S. bee shipments in the face of high winter losses.

Steppler says not every beekeeper will want to cease importing packages under the current protocols.

“There’s also a lot of beekeepers who will say, ‘Well, we utilize these packages from overseas to make up replacement losses, which is important to our industry, and if (the countries are) following all the surveillance protocols and preventative measures to ensure the pest doesn’t get in their country, then that should be enough to mitigate the risk.’”

Although the Canadian Beekeepers Federation and Alberta Beekeepers Commission have made their stance on these packages known, any industry-wide decision to push for reducing or stopping the import of bee packages from CFIA-approved countries will depend on what the various industry organizations say at their annual general meetings, Steppler noted.

“Our (MBA) meeting is in March and we’re going to be presenting that question to our membership to see where they would like to land on that position,” he said.

Awareness efforts pay off

Connie Phillips, Alberta Beekeepers Commission executive director, believes the press conference, in addition to the delegation’s well-attended Honey on the Hill reception, broadened awareness of the plight of beekeepers in Canada.

“In addition to what Arnold put forward, we had brought materials and information to that event that we could hand out or people could take away. That just reiterated what Arnold was presenting in his motion.”

The delegation, which Philips was a part of, also met with the Conservative Party of Canada caucus, officials at the Mexican embassy and representatives of the United States Department of Agriculture . She believes these meetings were fruitful.

Phillips is optimistic about the future of the Canadian beekeeping industry but urges mindfulness when planning the future.

“I think they’re just really on the cusp of a big paradigm shift in the industry and a needed one. So that’s good. But I also think we have to be careful how we go about it so that you have time to grow into that change, rather than just ripping the Band-Aid off all at once.”

The post Canadian beekeepers call for regulatory accountability appeared first on Manitoba Co-operator.

We need to all think more about timing for both lice and internal worms so that control products can do the best job possible.

We can also save money if treatment proves unnecessary.

Easier methods are being developed to determine parasite levels to make the treat-or-not-treat decision easier.

External parasites

With lice, kill rates are better if we wait until well into the winter.

They become active in the winter, so a warmer fall will see them emerge later. This is why we will see lice outbreaks in a very cold winter, especially if treatment was too early.

It’s also why we don’t have lice problems when the winters are milder.

There are only a few good products left for lice control, and they are getting fewer all the time. The products that are left have very specific treatment application methods and times.

In the old days, before good treatments were available, producers would cull animals that carried an obvious lice burden. Over time, producers essentially began selecting for a type of genetic resistance to lice.

Cattle oiler products are good for lice and flies, but while lice are controlled in the winter, flies are managed in the summer when populations become high enough.

Worm problems

The U.S. cattle sector has fewer problems with lice because of the warmer climate, but that means more issues with internal worms, which aren’t as much of a problem in Western Canada.

They are the worst in sheep, but bison are also bad.

With bison, I have seen worms kill some animals if they aren’t dewormed.

We see pockets of high incidence, and to complicate matters, some species of worms are more harmful than others.

Also, some species don’t lay as many eggs, so finding even a few species of certain types is significant.

Work done by Merck Animal Health in North America and Dr. John Gilleard found that an egg count of 10 per gram could have a significant impact on weight gain.

As well, the higher the worm count, the harder the animal’s immune system must work at getting rid of them, making them more susceptible to other infections. We call this co-morbidity, which can increase the incidence of conditions such as pneumonia and coccidiosis.

Fecal counts are a good way to determine worm loads in a herd, which are made easier by pooling samples done at the lab.

If done properly, a few pooled results can provide a good idea of what the worm population is in a herd.

These are best done in the fall when worm results will be highest.

It also gives producers a really good idea of how contaminated or not contaminated their pastures are.

Even if these fecal results are done every few years, it still lets producers know what they’re up against.

Maybe cattle can miss deworming for a year or maybe the count is high.

There are management strategies that can help eliminate worm burdens or keep them low.

Pasturing on higher grass (greater than six inches) ensures that cattle will rarely come in contact with the larval stages of worms.

Our cold Canadian winters kill a high percentage of the overwintering larvae, and desiccation in the summer also kills many.

With bison, increasing the time between rotational grazing is helpful.

Also, producers could take a crop of hay and leave a year in between grazing, which is even more beneficial for removing worms.

Besides the pour-on products, there are others that can be put in the drinking water, fed or put in the minerals in the summer.

There is also a product that has a double release. The only problem here is that the first release may be wasted if cattle were treated the previous winter.

Managing resistance pressure

Spending some money doing fecal counts and parasite checks may allow producers to skip deworming. This then lessens the likelihood of resistance.

Remember the 80-20 rule: 80 per cent of the parasites are in 20 per cent of the animals, increasing the importance of determining the right 20 per cent to treat.

Also if checking for parasites, it’s best to check older calves in the fall or yearlings. Cows will likely almost always have much lower counts than the older calves or yearlings.

Some clinics will do parasite checks in-house.

It’s best to avoid unnecessary deworming and lice.

We need to use the products we have properly because I don’t see any new ones coming down the line.

There are sporadic reports of liver flukes and lungworms, and if they are diagnosed in your area, it would be a good idea to talk to a veterinarian about how and when to treat.

Changes in how parasites are managed may see less product used overall.

As well, ensuring products are used at the right times and when needed should lead to better control.

The post Shifting standards on cattle parasite control appeared first on Manitoba Co-operator.

This is why researchers at the University of Manitoba and Agriculture and Agri-Food Canada are examining the role arthropods play in anaplasmosis, as well as designing better tests.

“There’s a potential that it exists in cattle herds in certain parts of the country. So we want to get an idea of that, because until we have an understanding of some of those baseline risks, we don’t know maybe where to go, or if it’s really important to spend much time looking at this disease,” says Shaun Dergousoff, a research scientist with Agriculture and Agri-Food Canada.

WHY IT MATTERS: The scope of treatment tools available for farmers to manage parasites, including ticks, and biting insects in their herds has changed compared to decades past.

Anaplasmosis is caused by a bacterial parasite called Anaplasma marginale, which attacks the red blood cells. It affects cattle, sheep, goats and deer, but in Canada, it is more commonly seen in cattle.

Clinical signs of anaplasmosis include fever, anemia, weakness, weight loss and issues with breathing. It is rare for it to affect calves under six months of age and symptoms will be mild in calves younger than a year. It is rarely fatal for animals under two years old. In animals older than two years that have shown signs of illness, mortalities can range from 29 to 49 per cent.

Anaplasmosis is usually treated with an antibiotic, which helps with the symptoms but won’t get rid of the disease.

“Once an animal’s infected, it pretty much always stays infected, even if they’re not sick. But then the problem is they could become a source now of transmitting and moving that bacteria to other animals,” Dergousoff says.

Anaplasmosis is transmitted by anything that can spread infected blood, such as needles, dehorning tools, castration tools, etc. Biting pests also spread anaplasmosis. Arthropods well known for spreading anaplasmosis include the Rocky Mountain wood tick and the American dog tick.

Ticks and flies

Kateryn Rochon is an entomologist at the University of Manitoba and is working alongside Dergousoff on this project. She is focused on the insect side of the research, looking specifically at ticks and flies.

When it comes to ticks and flies spreading anaplasmosis, it is not really known how often it is transmitted from those sources, and how often from livestock management practices. That is part of Rochon’s work.

While ticks are known biological vectors, biting flies are not. However, they could still transmit the disease as a mechanical vector, which means the bacteria does not multiply inside them, but might be passed on from the blood around the fly’s mouth parts after feeding on an animal.

The question is whether they are transmitting the disease this way.

“We might not be able to find it in the ticks or the flies, but we’re looking because we’re trying to determine what role they play,” Rochon says. “For me, as an entomologist, there’s the interest of just what’s going on out there.”

To conduct this research, Rochon would collect ticks and flies in producers’ pastures. She’d collect ticks by dragging a white piece of flannel through the grass. This attracts the ticks because of something they do called questing, which is when they climb to the top of the grass and wave their claws in the air to latch on more easily. The light colour of the flannel attracts them.

Fly traps

They used two different types of fly traps for biting flies: horse fly traps and a Manitoba trap.

The Manitoba trap is an inverted canopy trap with a black yoga ball dangling below the canopy, and a container of some sort at the top. The ball attracts the flies into the trap because the colour and the gleam trick them into thinking it’s an animal. They then fly up, are caught within the canopy, crawl into the container and are trapped.

Rochon says this trap has been very successful, but sometimes, not even necessary.

“There’s some places where we go, there’s so many horseflies, we can just catch them with a net.”

During the summer of 2024, they caught over 1,300 flies at two different locations in Manitoba. After the insects were collected, they were taken back to the lab to be frozen and identified.

Then, after identification, each fly was dissected so their gut could be tested for the bacteria that causes bovine anaplasmosis. Since only females bite, they examine the flies’ ovaries to find out how many batches of eggs each female fly has laid. This is because each batch of eggs requires a blood meal. So, the researchers can see which species bite more, are more likely to spread diseases among cattle and at what point in the season.

This study will end in 2027.

A new anaplasmosis test

Alongside this research, another project is underway to create a reliable anaplasmosis test.

Currently, the diagnostic tests used for anaplasmosis are Giemsa-stained blood smears and serologic tests, according to Merck Animal Health. The bovine blood smear tests blood samples from the animal for the bacterial parasite that causes anaplasmosis.

Serologic tests are used to identify antibodies against Anaplasma marginale in cattle, which suggests past or present infection. These tests can help diagnose carrier animals who may be spreading the disease and not showing clinical symptoms, but it is not very accurate. The tests often misdiagnose anaplasmosis because the bacteria are similar to those from other diseases. This is why Dergousoff wants to make a more reliable, accurate test.

“A rapid test would be very beneficial, but also because some tests have had the problem where they’ve said that animals are infected with Anaplasma marginale, but it really was something else or not at all,” he says. “So they’re not perfect, and no test is, but we’re looking for an improvement.”

Dergousoff is working with beef producers and their veterinarians to take blood samples from their herd and test them for the presence of Anaplasma marginale. This will determine which animals are infected, even if they are not showing clinical signs of infection.

To create the new test, Dergousoff says they have to look closely at the molecules present and at the Anaplasma marginale bacteria.

Then, they will develop a method for testing and preparing the blood and start making a prototype for a device for blood testing. The goal is to create a device that can be used by producers so they can determine the health of their animals while doing other things, such as branding or vaccinating.

“It could potentially be simple enough for anybody to use and quick enough so that it can just be that chute-side rapid test,” he says.

They are working in areas of the country with the highest risk: Manitoba and south-central B.C. Manitoba was picked because of the historical context of the disease in the province. Southern B.C. was selected because they have seen misdiagnosed cases there.

“We don’t necessarily suspect that there will be Anaplasma marginale there,” Dergousoff says. “You can always be surprised, but they may be very useful samples to use in the development of our test if there’s a bacteria present there that’s very similar that we want to exclude from the test.”

The timeline for this project is less concrete — there are many things to accomplish before it can become commercially available. Dergousoff says he hopes to have a prototype in the next few years.

Anaplasmosis impact

Though anaplasmosis is a disease not many think about and was removed in 2014 from the Canadian Food Inspection Agency’s list of federally reportable diseases, it should still be on people’s radar.

“Sometimes the risk might be low, but also those things change over time. We’re seeing changes in the distribution of the ticks that can transmit this,” Dergousoff says.

Factors such as the number of ticks and flies are subject to change, which is why research like this is important.

Knowing about this issue is also important because that knowledge can help with prevention.

“Awareness is a big issue, because then we could take measures to maybe prevent these things before they become a big issue,” Dergousoff says. “So if we understand these things ahead of time, especially if we have a good, even better test … those kinds of things will help things from becoming a much larger issue over time.”

Rochon says while anaplasmosis isn’t currently an issue, that doesn’t mean producers shouldn’t be aware of what it is and what the effect might be.

“These little things can have an impact. And the little decisions sometimes can lead to problems that you don’t necessarily notice right away. And so I think being aware that this is something that is in Canada and might be becoming more prevalent, we don’t know.”

Dergousoff says they are currently looking for more producers in Manitoba and in southern B.C. to get involved in their research, to look at the risk and potential presence of anaplasmosis in the area. Data from B.C., specifically, would help them determine what other bacteria are confusing current diagnostic tests and eliminate them from their tests. There is financial compensation for involvement in the study.

If there is a positive test on an operation, researchers will notify the local vet and chief veterinary officer for the province. After a case of anaplasmosis is reported, the chief veterinary officer usually doesn’t require disease control measures. However, they may provide information and diagnostic support to help herd owners manage the infection and reduce the risk of spreading to other herds.

“It’s important to recognize these cases so we know what’s going on. But it’s also important to support the producers,” Dergousoff says.

The post Manitoba tick study focuses on testing, other carriers for anaplasmosis appeared first on Manitoba Co-operator.

That was the message at a fecal egg count workshop hosted in Ontario by that province’s sheep association in June.

WHY IT MATTERS: Worm drug resistance remains a concern in Canada for both sheep and cattle, especially with no new treatments on the horizon.

Dr. Brad DeWolf, a veterinarian, and Victoria Allcock, a master’s student at the University of Guelph, are researching parasite control in small ruminants. They led 12 sheep and goat producers through the hands-on workshop, covering Modified McMaster fecal egg count (FEC) training, parasite identification and tools essential for reducing parasite loads.

“There’s not going to be a magic bullet,” said DeWolf, adding long-term sustainable parasite management requires a combination of strategies, including FECs to maximize dewormer benefit and slow resistance.

The workshop focused on identifying two major parasite types in sheep and goats:

Gastrointestinal nematodes (often called GINs), such as Haemonchus (barber pole worm),Trichostrongylus — which live in the digestive system and cause disease — and Coccidia, typically affecting lambs, which leads to diarrhea and impaired growth performance.

“It’s no surprise parasites are costing every sheep producer money to some degree,” DeWolf said, whether that’s due to drug costs for deworming or animal deaths.

Canada hasn’t reached the dewormer resistance levels encountered in New Zealand, but DeWolf noted some resistance is already present, making selective and targeted treatment critical.

Timing is crucial, as worm development and shedding fluctuate with lambing, pasture conditions, farm practices and seasonal reductions in egg production, which can affect FEC accuracy.

Worms have a chance to build resistance with every dewormer application and under dosing increases that opportunity, DeWolf explained.

“We would much rather err on the side of overdosing slightly than under dosing,” he said. “People tend to under dose slightly, and that’s a way to promote resistance. Making sure you have an accurate idea of what animals are weighing is absolutely essential.”

He emphasized that many farms already face low-level resistance, and monitoring FEC of individual animals showing parasite stress, rather than pool testing, helps identify high-burden animals, leading to more effective treatment decisions.

Treat your dogs

Anita O’Brien, on-farm program lead with the Ontario Sheep Farmers, explained that Taenia ovis, a tapeworm found in farm dogs, guardian dogs or visiting dogs is not detectable through small ruminant FEC tests. The parasite causes “sheep measles,” which is on the rise and can lead to carcass condemnation.

Dogs contract the parasite by eating raw meat infected with “sheep measles” cysts. They then shed tapeworm eggs onto grass, which sheep ingest while grazing. The parasite moves into the muscle, forming cysts that result in meat being condemned.

“We recommend getting a dog worming program that targets tapeworms,” said O’Brien. “And any dogs that are coming to the farm, we need to be confident that they are not carrying this tapeworm and leaving it behind.”

The OSF emphasized that deadstock must be dealt with promptly to prevent scavenging by dogs or wildlife, which can spread or restart infection cycles.

The post Smart deworming for sheep starts with individual fecal egg counts appeared first on Manitoba Co-operator.

The good news is we can test for these parasites, and if thresholds are passed, then those herds or pens are treated.

Work done a few years ago by a pharmaceutical company with which I was involved found that we could put most beef herds into low, medium and high categories for internal worms, and only the medium and high herds would need to be dewormed.

The best time to check is after cattle have been on grassy pasture later in the summer when burdens increase.

Testing your cattle for parasite load

Cattle are generally pretty low shedders of eggs because of low infestation, but later summer is the best time to check.

Yearlings generally have higher counts, followed by calves. The cows are most resistant.

Fresh manure is needed when doing a manure test.

The modified Wisconsin test is the most accurate test for cattle.

It’s possible to pool samples instead of doing a group of 10. This should save time and money and be just as accurate if done properly.

This should save the clinic time.

We all need to test more before treating the entire herd.

It has been found that ivermectin resistance is increasing, which reduces effectiveness.

Resistance varies greatly from herd to herd.

Check to see if your herd veterinarian does parasite testing at their clinic or sends them out.

The problem here is the number of tests that are needed as well as the cost and time.

Some producers complain about spending money on tests, only to have the deworm the herd anyway. Their response is that they might as well have just dewormed them in the first place.

This response is understandable, and quicker chute side tests need to be developed to reduce this problem.

I am sure some researcher will develop a quick, lower-cost method.

Another class of parasite treatment is the benzimidazoles, including products such as Safeguard and Valbazen.

The problem is that only internal worms are treated, and the products don’t include treatment for lice.

Until the last decade or so, ivermectin products accomplished both parasite and lice control.

Ivermectin products came on the market when my generation of veterinarians (baby boomers) were practising, and everything was treated.

Lice were most visible, which internal worms rarely got bad enough in Canada to cause outward clinical disease.

However, this is changing.

Now, veterinarians must help producers fine-tune their entire parasite treatment program as well as the fly control treatment program.

Internal parasites such as liver flukes and external ones such as ticks may also be showing up in slightly increasing frequency.

These parasite problems are in more specific geographic regions, and they can have complicated life cycles so may even show up in specific years under specific conditions.

Again, your herd veterinarian can help with specific treatments and monitoring if either liver flukes or ticks become prevalent in your area.

For fly control, especially, there are fewer and fewer products to use, and they are all similar chemically with no new ones on the horizon. Many have actually been taken away from us.

Treatments must be used only when fly numbers get high enough. If oilers are used, they can only be charged with product when necessary. This saves product and cost and slows down the development of resistance.

Preventing parasite problems

Canadian winter slows down the transmission of internal parasites, killing the eggs and reducing the survivability of larvae.

Rotational grazing with a long time between regarding allows more larvae to desiccate and die.

Producers should be able to keep parasites in check with selective and timely use of products, specific management changes and checking for eggs in the manure.

It might also be a good idea to cull cows that are determined to be lice carriers.

Parasites evolve and have been survivors, so constant research going is needed in this field so that we are aware of new developments and products.

Most research is species specific, but transmission can occur between similar species such as bison and cattle, horses and donkeys.

Ticks, on the other hand, can involve several different species in their life cycle, as do liver flukes.

It’s a complicated world when it comes to parasite management, and herd management needs to be reviewed from time to time.

The post The end of a parasite control era in livestock appeared first on Manitoba Co-operator.

During a BCRC-hosted webinar on March 19, John Gilleard, a professor of parasitology and associate dean of research at the University of Calgary’s Faculty of Veterinary Medicine, pointed to growing dewormer resistance in gastrointestinal roundworms and lice.

The industry has become very dependent on macrocyclic lactones such as ivermectin, he said.

“When we apply these products, by killing the susceptible parasites and allowing the few resistant ones to survive, (this) gradually gives selective advantage to the resistant ones, which gradually increase in frequency in the population until we get to a point where the majority of the population is consistent, and then the product no longer works,” he said.

WHY IT MATTERS: Once chemical parasite control drops, research suggests that resistance can last for years, even if the producer stops using the product.

Gilleard stressed a targeted, risk-based approach to parasite control. Applying treatments as a preventative measure is the old way of doing things, he said, and not necessarily the best practice. Instead, producers should assess their herds using fecal egg counts and grazing management strategies.

He envisions a switch from “this treat-first approach of, ‘We’ll just treat anyway, because they may well need it,’ to more of an assess-first approach.”

Grazing management is parasite management

Good grazing management plays a pivotal role in controlling parasite burdens, Gilleard said. Overgrazed pastures can increase parasite transmission. There are more larvae lower down in the forage, and cows taking those lower levels are feeding in the risk zone.

Dewormers also carry environmental risk, Gilleard added. Residues from these products can accumulate in soil and water, affecting invertebrate populations and raising public perception challenges around sustainability.

’Silent profit thieves’

External parasites, especially lice, have been a growing issue for cattle producers in recent years.

Dr. Carling Matejka, a veterinarian with Alberta-based Veterinary Agri-Health Services, described parasites as “silent profit thieves” due to their ability to impair immune function, lower reproductive rates and reduce feed efficiency.

Matejka agreed that producers should monitor their cattle and use strategic deworming rather than routine treatments.

“There’s lots of different treatments out there…and depending on your production and management practices, your veterinarian will be able to align a treatment program that works great for you,” she said.

The veterinarian further advised producers to categorize their pastures into high-risk and low-risk groups and to tailor their management approach accordingly.

“High-risk pastures are going to be wetter pastures, cooler spring and summer weather conditions, overgrazed or overstocked pastures, fall grazed pastures used in the spring and pastures grazed by young stock,” she said.

Matejka advocates for the 80-20 rule: about 80 per cent of the parasites tend to be carried by 20 per cent of the animals.

“Based on that 80-20 rule, you’re going to treat 80 per cent of the population. So, you’re going to treat your thin cows, you’re going to treat your moderate cows and you’re going to leave your obese cows untreated,” she said.

Proper application techniques play a critical role in external parasite treatments.

“Please do not just open the jug and pour it on the back of the animal. Weigh a couple cows running through the chute and adjust your dosing gun for the appropriate weight of that animal,” Matejka advised.

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