Alert

All classes of livestock and poultry are affected by both the seed and the plant. The plant is the most toxic when it is a seedling, but can remain toxic as it grows. Both seeds and young plants contain carboxyactractyloside. Animals can be poisoned by eating less than 0.3% of its body weight of the plant. If not grazed, the plant may be accidentally baled in hay or processed with grain. The seed is covered in many sharp spines that can get stuck in the animals mouth or skin.

Slight to severe hypoglycemia, depression, weight loss, difficult or labored breathing, weakness, convulsions with head and neck spasms, and slow death up to 3 days or sudden death. Clinical signs in goats may mimic polio. Animals who do not die may have liver and gallbladder damage.

Remove animals from problem grazing area. Provide shade, fresh water and quality hay that is free from other weeds or toxins. See veterinarian immediately. Prognosis is bad if poisoning is not caught early or quickly.

Remove the plant by hand (wear gloves) or use approved herbicide for broadleaved
plants.

All classes of livestock, including llamas and alpacas are negatively impacted. Avoid grazing areas during early growth and/or after sudden temperature changes as that is when the plant is the most toxic to livestock. However, toxicity can occur at any time of the plant's growth.

Studies indicate pigweed can cause nitrate and/or oxalate poisoning, and renal failure. Initial symptoms may take days to appear and include labored, shallow and rapid breathing, rapid pulse, body weakness, difficulty walking, and muscle tremors. Pregnant livestock can abort. Studies indicate renal failure is not common unless a large amount of the plant is consumed. Death is likely in extreme cases and may be the only symptom observed.

Diagnosis is done by a veterinarian to determine if the animal is suffering from nitrate positioning, oxalate poisoning or renal failure. Pigweed poisoning is most common in summer and fall. Since testing is different for each concern, all diagnoses need to be done in a veterinary clinic setting.

Remove animals from areas of concern. Provide good quality hay that is weed free and easily digestible. Contact veterinarian immediately. If poisoning is not severe, animals may recover with veterinarian care. Without veterinarian care, death or loss of functional quality of life can occur.

Pigweed is a very competitive annual plant that produces hundred of thousands of seeds per plant. It is also resistant to popular herbicides such as glyphosate. Current guidance states that using multiple applications of herbicide in addition to a pre-emergent will reduce plant numbers. Non-herbicide treatments include hand pulling, removing plants with tools, routine tilling to keep plants from going to seed, and routine mowing to keep plants from seeding. Do not use grazing animals to control pigweed.

All classes of livestock including are negatively impacted. The plant contains toxic saponins which may contribute to animal bloat. The wilted plant is the most toxic. Additionally, the plant can carry fungal toxins which cause photosensitivity skin damage and in the case of sheep, swelling of the head. Lameness and/or infection can also occur in the feet or mouth from seeds that become embedded in the skin of the animal. May cause liver damage in sheep and goats.

Blindness, peeling skin, swelling of the head area (sheep), loss of lips and ears, nitrate poisoning symptoms, mortality of young animals, jaundice, limping, and inability to eat or graze (from seeds lodged in the animals mouth or throat).

Remove animals from problem areas with puncturevine. Provide shade, fresh water and quality hay that is weed free and easily digestible. See veterinarian immediately if poisoning or liver damage is suspected. Anti-inflammatory and anti-histamines may help with photosensitivity burns. Adapt new grazing strategies for more palatable plants. Puncturevine is best controlled by hand removal or hoeing through the taproot. Monitoring the area and removing puncturevine in spring and summer will reduce the impact of the weed the next year. Younger plants are more susceptible to postemergent broadleaf herbicides with the exception of 2,4 -D can control this plant.

Highly Pathogenic Avian Influenza, or avian flu or bird flu, is a disease caused by infection with avian Type A viruses.
This virus spreads naturally among wild aquatic birds via the fecal-oral route, but it can infect other birds, such as poultry and other animals. While HPAI can infect humans via direct contact (e.g., touching eyes, mouth, etc., with contaminated hands) and/or the respiratory route, it is rare. The transmission route is from a wild or domestic bird that may or may not have clinical signs to other birds and dairy cows nearby. Cow-to-cow spread is possible, but the specific transmission methods have not yet been determined. As of April 1, 2024, APHIS confirmed HPAI in dairy herds in Texas, New Mexico, Michigan, Idaho, and New Mexico, and the CDC confirmed HPAI in one dairy farm worker

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Location: Idaho, Kansas, New Mexico, Michigan, Texas

For the most recent updates from USDA:

https://www.aphis.usda.gov/livestock-poultry-disease/avian/avian-influenza/hpai-detections/livestock

https://www.aphis.usda.gov/animal-emergencies/hpai

Name: Highly Pathogenic Avian Influenza (HPAI) 

Type: Virus 

Affected Livestock: Dairy Cattle

Clinical Signs in Dairy Cows: Clinical signs that have been seen include a drop in milk production, thickened or colostrum-like milk, appetite loss, manure inconsistencies, or a low-grade fever. Cows that are infected typically display symptoms for a period ranging from 7 to 10 days before experiencing a recovery. Approximately 10% of afflicted cows do not fully recuperate and fail to return to their previous levels of milk production, particularly those exhibiting the most severe symptoms. Moreover, those with severe symptoms can contract secondary infections like mastitis, pneumonia, or salmonellosis. Most infected have been multiparous, with signs occurring after early lactation.

Diagnosis: Producers working with their herd veterinarian and State Animal Health Officials and/or ALIRT veterinarians will collect a series of samples including nasal swabs and milk samples from all 4 quarters of symptomatic and asymptomatic dairy cows on a premises under investigation. These samples will be analyzed at both the National Animal Health Laboratory Network (NAHLN) lab in-state (Arizona Veterinary Diagnostic Lab) and National Veterinary Services Laboratory for confirmation of a non-negative.

Treatment: Following investigation by State Animal Health Officials, treatment shall be directed by the herd veterinarian and typically consists of supportive care (managing hydration and electrolytes, anti-inflammatory medication for fever, antibiotics if secondary bacterial pneumonia or mastitis are identified etc.) To prevent the virus from spreading and to protect human health, cows showing clinical signs should be isolated, and their milk must be diverted from the supply chain per Pasteurized Milk Ordinance requirements. Precautions for disposal of discarded milk should be taken, such as heat treatment or pasteurization. Cattle movement in and near the affected areas should stop immediately. Prevention is the best strategy and should focus on wild bird control on premises, limiting unnecessary animal or human movement on or off farm and quarantine of replacement animals prior to introduction to the herd. 

Prognosis: Affected cows recover 7-10 days after showing first clinical signs. About 10% of affected cows do not recover fully in response to milk productivity. 

Prevention: Biosecurity measures are the best tools for prevention. Avoid interstate movement of cattle when possible. Quarantine new cattle and avoid interacting with other cows. Sanitation of clothes, footwear and vehicles is recommended for those traveling in between several operations. Practice good hygiene when working with infected or non-infected cows, including frequent washing with virus-killing soaps, sanitizing shoes, and wearing appropriate masks. Controlling or avoiding wild bird populations although extremely difficult should be prioritized on farm. Equipment maintenance and appropriate milk parlor and claw sanitation and udder preparation should be of paramount importance.

Food Safety: *Dairies are required by law to send only milk from healthy cows to the processing plant for human consumption. Furthermore, pasteurization kills the virus, making milk safe to drink. Raw milk, however, carries risk for not only this virus but other pathogens as well so consumers assume their own risk with raw milk products. For more information on milk testing, see https://www.aphis.usda.gov/livestock-poultry-disease/avian/avian-influe….

Cattle, sheep and goats are all impacted.

Listlessness, nasal discharge with crusting, anorexia/weight loss, rough hair coat, diarrhea followed by constipation, blood noticed in urine stream, degeneration and necrosis of the liver, mild jaundice or yellowing of skin and the white of eyes, and kidney failure. Pregnant cows may have edema of uterus and possibly fetal membranes, swelling of the vulva, swelling and earlier-than-normal udder development, and abortion usually with a retained placenta.

Contact veterinarian if any of the above symptoms occur. Test for selenium poisoning.

Remove affected livestock from area and consult with your veterinarian. Provide
supportive care as directed by veterinarian. 

Avoid overgrazing rangelands. Ensure palatable forage and water is available at all times. Snakeweed can be treated with herbicide if applied during early growth stage of the plant.

All classes of livestock are affected. The toxin (Swainsonine) is produced by an endophyte fungus that inhabits the plant. This compound impairs several cellular processes which ultimately disrupts organ systems including the nervous system, digestive system, and reproductive organs. Not all species of Astragalus or Oxytropis are toxic, but it can be difficult to distinguish between species in the field. Unlike most toxic plants, locoweed is relatively palatable to most classes of livestock and animals can become habituated to consuming it. Poisonings typically occur in early spring before other forages are readily available, or late fall when other forages have matured out for the winter. Locoweed seeds can “bank” in the soil for many years and germinate quickly following unusually wet seasons. This leads
to some years seeing especially large numbers of locoweeds and cases of locoweed poisoning. The plant remains toxic
when dried.
 

Symptoms can vary, but poisoning from locoweeds is a chronic process, animals must consume the plant regularly over a period of weeks. Signs of toxicity include odd or erratic behavior, extreme nervousness, a slow, staggering gait, staring, depression, weight loss, and lack of coordination. Horses are especially sensitive, and may develop dangerous behavior patterns that do not resolve, making them permanently unsafe to ride. The toxin is secreted in milk and may affect nursing calves, foals, or lambs.
 

Remove animals from problem grazing area, especially if evidence of locoweed grazing is present. Herbicide
treatment is very effective for controlling locoweed however large-scale application can be difficult or costly, and the
application must be repeated yearly due to the seed banks present in the soil. Some producers in heavily infested areas
have found regular herbicide treatments to be beneficial in preventing economic losses to their operations

 Major Known Incident: National Incident in Elk City, Oklahoma

Name: Ionophore (Brand Names: Monensin, Rumensin, Bovatec, Cattlyst, and others)

Type: Toxic Feed Ingredient for Equids (Horses, Donkeys, Mules)

For more information: https://extension.arizona.edu/pubs/ionophore-toxicity-horses

Affected Livestock: More than 70 horses have died so far at Beutler Ranch in Elk City, Oklahoma. Ionophore toxicity is not a new issue, but it has garnered national attention due to the number and value of the horses affected.

Transmission: Horses and other equids are usually exposed to ionophores by gaining access to medicated feed containing ionophores intended for cattle, goats, or poultry. In this case, monensin was accidentally mixed into feed intended to be fed to horses at the mill due to human error and a possible sensor malfunction.

Signs of Ionophore Toxicity: Sudden death, Exercise intolerance, Feed refusal, Colic, Increased heart/respiratory distress, Hypotensive shock. Often multiple horses eating the same diet will be affected.

Prognosis: Horses are very susceptible to ionophore toxicity; the lethal dose is less than 1/10th of the amount that can be safely fed to cattle. For monensin, 2-3 mg/kg, or about 1 gram, is enough to poison a 1,000 lb. horse. For salinomycin, that amount decreases to 0.6mg/kg.

How do I evaluate my horse’s risk? The first thing to look at is where a feed is produced and what else is produced in that particular feed mill. There are different risk levels ranging from feed production to storage and feeding practices.

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Ionophore Free Mills: This type of mill does not produce any medicated feeds that contain ionophores, and equid feed from here should be 100% safe for your horse.

Feed Stores Selling Both Ionophore-Medicated and Equid Feeds: These stores have a very low contamination risk, however it is fair to ask how they handle, store, and/or prevent potential exposure of equid feeds to feeds containing ionophores.

Ionophore Safe Mills: These mills can vary on how they ensure the safety of equine feed. Some mills have two separate production lines for equid feed and feed containing ionophores, however, some mills use the same production line, but have specific cleaning methods and/or sensors for detecting the presence of ionophores in the system. These facilities have the highest risk for machine or human error, even if that is a very rare occurrence.

Facilities where Cattle/Goats/Poultry and Horses are housed together: This can be a high risk if the facility is using feed with ionophores, because that feed will not necessarily look different than the horse feed. Additionally, if the horses are fed separately, but turned out where cattle have been fed, there is no guarantee that the horse won’t find/eat leftover feed. An additional risk occurs when feed storage containers are not labeled clearly and separated in the feed room, or if a “new” person is feeding and doesn’t know.

• Ionophores are a valuable and safe way to improve cattle/goat/poultry health without the use of excess antibiotics. While ionophore poisonings in equine are not common, they still occur. Human and machine error can happen. It is easy to feel panic or frustration when major incidents occur. On occasion, mistakes in mixing or cleaning protocols at feed mills have happened, resulting in distribution of horse feed tainted with ionophores.

• The U.S. Food and Drug Administration introduced specific rules in 2011 to establish CGMP’s (Current Good Manufacturing Practices) and preventative controls for animal feed manufacturers. These animal feed regulations should decrease the potential of feed mill errors. In Arizona, there is a required feed distribution license that requires manufactures and feed distributors doing business in Arizona to be registered and licensed. This list can be found at https://agriculture.az.gov/animals/feed.

• If you are considering removing grain from your horse’s diet over the fear of ionophore toxicity, work with your veterinarian or professional nutritional consultant to ensure the animal's nutritional needs will be met without a grain based feed. If you have any question or concern that your equine(s) may have accessed feed containing ionophores, contact your veterinarian immediately.

• What feed mill is used to produce and package thefeed

• If the feed mill follows good manufacturing practices (Hazard Analysis and Critical Control Point (HACCP)) and other controls

• Is the mill “ionophore free” or “ionophore safe”

• Ranches and other operations that house both horses and cattle (such as feedlots and roping arenas) where there are often many different species on-site including cattle and horses may be the most at risk for feeding mishaps caused by human error.

• Additionally, many of these operations employ temporary seasonal workers to assist operations  during particularly busy times of the year. Management needs to see to it that quality help is being hired and that clear education, training and Standard Operating Procedures (SOPs) are provided and being followed to ensure that feed deliveries, inventory management and feeding of the animals themselves are all according to the established process.

• Always maintain good records of feed provided to your horse, including labels and lot numbers in the case of a recall or suspected poisoning. Tear off the entire label (including the lot number), mark it with the date opened, and place it in your filing cabinet.

• Careful consideration of the source of social media informational posts (knowledge, professional credentials) is necessary if looking at social media for updates on current incidents of interest. Disinformation, bias, and sensationalism are often used to direct web traffic, and outright wrong information are rampant in this arena. Generally speaking, quality information should be sourced from universities and cooperative extension, qualified medical or industry professionals, and other reputable sources that may have a social media presence.

https://extension.arizona.edu/pubs/ionophore-toxicity-horses

https://pubchem.ncbi.nlm.nih.gov/compound/Rumensin

https://utbeef.tennessee.edu/cattle-nutrition-faq-what-is-an-ionophore/

https://agriculture.az.gov/animals/feed

Strangles is a bacteria that impacts equine (horses, donkeys and mules). This ALIRT was initially issued for Maricopa County in January 2022. 

Images below show strangle symptoms including swollen mandibular lymph node (left), open abscesses (middle) and healing absecess (right). Note that flies can transfer bacteria between horses. 

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It is spread both directly (horse to horse, pus or nasal discharge) and indirectly (through contaminated and shared feed/water buckets, grooming tools, fencing, tack, and even people caring for multiple horses). In the case of bastard strangles, which is much more rare, the bacteria can form abscesses internally (on organs). Clinical signs of sickness start after 3 to 14 days from exposure. Recovered horses may shed the bacteria for up to 6 weeks. It is highly contagious and can spread quickly from horse to horse.

These can vary from horse to horse. Early signs include early onset of fever (over 100.5 F in adults, over 101.5 F in foals), mild cough, sluggish, reduced appetite and clear nasal discharge. More advanced signs include wheezing and coughing, thicker nasal discharge that is white or yellow, difficulty swallowing from inflammation of the throat, swelling (externally) from abscesses (internally) forming in the lymph nodes (throatlatch and below the jaw). In rare cases, there may be red spots
on the horse's gums (purpura hemorrhagica) , and swelling of the head, legs, or muscles.

Diagnosis is confirmed through culturing swabs of nasal mucus or abscess pus, or through blood work.

Immediately isolate sick horse(s) from other horses. Monitor the temperature of all horses on property, and isolate horses that develop fevers. Provide supportive care including keeping the horse dry and protected, and provide a soaked and/or easy to swallow feed. Work with your veterinarian for appropriate treatment for your horse.

Full recovery is up to 4 weeks if treated by veterinarian protocols. It is rarely fatal.

Practice good biosecurity techniques such as quarantining sick animals, not sharing feed buckets, stalls and tack with other horses. Feed sick horses last. Clean, remove, and/or sanitize all soiled bedding. Ensure cross contamination is not occurring between horses or handlers. Discuss vaccination options with your veterinarian. 

Note that strangles is a reportable disease because it can not only effect your horse, but the health of the horses around you.