May 2018 – Pinkeye Season

May 2018 Newsletter PDF

Pinkeye Season

Infectious Bovine Keratoconjunctivitis, commonly known as Pinkeye, is a multifactorial disease caused by a combination of infectious agents and environmental stimulants.


In cattle, the most common primary infectious agent is the bacteria Moraxella bovis, which has over 20 subtypes that all cause Pinkeye, usually in the summer months. In the last few years Moraxella bovoculi and its subtypes have emerged as a slightly less common, but harder to treat primary infectious cause of Pinkeye at any time of year. Most infections involve a combination of both bacteria. In small ruminants, the primary cause of Pinkeye is from Chlamydia psittaci ovis and Mycoplasma conjunctivae. Usually, a healthy animal’s immune system is able to prevent an eye infection. Only when the eye is irritated by something in the environment does the eye become vulnerable to bacterial invasion and infection.

The major source of eye irritation comes from face flies feeding from eye and nasal secretions. Other irritants include tall pasture plants or dust scratching the surface of the eye. A third form of irritation is not commonly thought of:  UV rays from sunlight. Constant sun exposure without shade is very irritating to the eyes, especially in animals with white eyelids such as Herefords.

Face flies are also the main culprit for transmitting the disease within the cattle herd and between herds. Animals that were previously infected can be silent carriers, showing no symptoms of infection but shedding M. bovis or M. boviculi in eye and nasal secretions. The bacteria survive for 3 days on a face fly, so a fly feeding on multiple animals can easily transmit the disease to the entire herd. Carrier animals will shed the bacteria for an extended period, which is the main reason the bacteria survive the winter and cause a new outbreak the following year. Infections are more common in warm months due to the increased presence of eye irritants, but with M. bovoculi infections could happen any time. Bacteria can also be transmitted to an uninfected eye through direct contact with the eye/nasal secretions of an infected animals in both cattle and small ruminants. Infected secretions can also be rubbed onto fencing, gates, feed bunks, etc. and picked up by an uninfected animal.

After transmission and irritation, it takes at least 2-3 days for symptoms to begin. Initially, the infected eye will be excessively watery and squinting. The conjunctiva (inner surface of the eyelid and white part of the eyeball) will become swollen and red while the cornea (transparent part of eyeball over the iris and pupil) remains clear.  Within a few hours the cornea will develop a white haze which slowly intensifies until it’s completely opaque in 48-72 hours. A bluish tinge to the haze (corneal edema) indicates inflammatory cells brought in by blood vessels which very slowly grow into the cornea. The vessels can add a pinkish hue to the eye, hence the name ‘Pinkeye.’ A milky white or yellow cornea indicates a severe infection with pus inside the cornea. Next, an ulcer forms in the center of the opaque cornea which looks like a small divot that will grow wider and deeper and is extremely painful. Left untreated, the ulcer will eventually perforate the cornea, rupturing the eyeball and resulting in permanent loss of vision. Loss of the eyeball is rare since most cases are treated very early when the eyes begin to water. With timely treatment, the eye will fully recover in 3-5 weeks, although a few will retain a small white scar on the cornea.

As with any disease, prevention works better than treatment and for Pinkeye the best method is a combination of vaccination and fly control.

Proper vaccination is critical to prevent infection in cattle herds. Vaccines for M. bovis have been available for years, and for many farms these vaccines provide enough immunity to control infections. However, when a herd outbreaks occurs despite good vaccination, M. bovoculi is likely the major cause and the M. bovis vaccines don’t cover it. Previously, the only way to vaccinate against M. bovoculi was to develop a vaccine specific to the herd, an autogenous vaccine, but it is expensive and takes 4-6 weeks to develop. However, last year a M. bovoculi vaccine was released that is readily available and cost effective. It can be used in combination with the M. bovis vaccines to provide a wide spectrum of coverage and greatly reduce infections for herds that tend to have large outbreaks. Cattle should be vaccinated at 4-6 months of age, with calf-hood vaccinations, and boostered yearly. Check the vaccine labels carefully, some vaccines need a booster 21 days after the very first dose, such as the M. bovoculi vaccine. The yearly boosters can be timed with the season or given at a specific time in each cow’s lactation. Additionally, proper vaccination against IBR, which is included in the cattle respiratory vaccines, reduces the chance of a respiratory infection contributing to a Pinkeye infection. However, during an outbreak of Pinkeye, do not vaccinate infected animals with a modified live vaccine, as it could increase the eye’s sensitivity toward infection. As a general rule, only healthy animals should be vaccinated, and Pinkeye is no exception. Unfortunately, there is no vaccine available for Pinkeye in small ruminants, so prevention efforts involve maintaining a closed herd and isolating new animals for 30 days before introduction to the flock.

Since a vaccine won’t stop flies from carrying the bacteria fly control is also essential for cattle and small ruminants, whether it’s in the form of fly tags, insecticidal pour-ons, back rubbers, dust bags, knock-down sprays or fly traps, ideally a few of them combined. Cattle manure management is important since flies need manure to reproduce. Regularly removing manure from pens and spreading it to dry quickly will drastically reduce the flies’ ability to reproduce. There are feed-through products available which are fed to cattle, pass through the animal unchanged and then either inhibit or delay fly reproduction in the manure. However, these products only help if they’re fed starting a month before fly season begins (start now!) and the animal must consume the correct dose. If flies are already out, it’s too late for these products. Also, they can’t be confused with treatment for the animals, they have no effect on the animal.

Use multiple methods for the best control, but make sure to switch any pesticide drug classes regularly to avoid encouraging resistance amongst the flies. Use appropriate rotational grazing practices or clip pastures to reduce the potential for eye irritation from long plants. Lower overhead feeders and roll out round bales so that cattle can eat without sticking their entire head in and risk scratching their eyes. Proper bunk space reduces direct contact between infected and uninfected animals. Ideally, separate cattle with active infections until lesions resolve. And since we can’t give all the cows, sheep and goats sunglasses, ample shade and breeding animals for pigmented eyelids will help reduce irritation from UV light.

If an infection happens despite multiple methods of prevention, early treatment (when the only symptoms are a watery eye and squinting) not only stops the active infection quickly but prevents bacterial shedding that would infect other animals in the herd. The vast majority of initial infections in cattle and even those with small ulcers respond well to long-acting tetracyclines like 300 Pro LA or LA200. Non-steroidal anti-inflammatories (NSAID’s) like meloxicam or Banamine will help control the pain (it’s incredibly painful) and encourage feed intake during recovery. Treatment options for small ruminants are extra-label, so consult a veterinarian prior to treatment. Advanced stages of infection with large ulcers may require an eye-patch or antibiotics injected directly into part of the eye and is best done by a veterinarian. There are antibiotic sprays and ointments, but they only work if applied 3-4 times daily until the cornea heals, which is usually not feasible. Additionally, keep in mind that most commercial ointments are either illegal to use in cattle or have extremely long withdrawal times. Currently, there is no labeled/legal feed-additive treatment for pinkeye in any species.

Hopefully summer is finally on its way, so start making plans now to booster Pinkeye vaccines and control flies before they appear!

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April 2018 – Preventing Antibiotic Residues

April 2018 Newsletter PDF

Preventing Antibiotic Residues

One of every producer’s biggest fears is having a drug residue found in the milk or meat from their farm. Before the planting seasons begins, take the time to review the systems you use to prevent drug residues and make sure everyone on the farm understands as well. The risk of a residue can be very low if everyone understands and systematically follows the process.

Once a cow has been treated with a drug, no matter where it was given, it is distributed throughout the body. The body will begin to break down the drug, sometimes fast, sometimes slowly. The pieces then exit the body through different means, like the milk or urine. The withdrawal time that is established for each drug is how long after the final treatment that it takes for the cow’s body to break down and eliminate the drug so that what is left is below the maximum established threshold allowed. Withdrawal times depend on the kind of drug used, the dose, how it was given, how often and for how long, as well as the age of the cow and her health. Healthier cows clear drugs from their bodies faster than sick or thin cows. Milk withdrawal times are often shorter than meat withdrawal times because it takes longer for the drug to leave muscle tissue than mammary tissue; the drug exits the body every time a cow is milked.

Use the following practices laid out by the National Dairy FARM Program and the New York State Cattle Health Assurance Program (NYSCHAP) to prevent drug residues.

Establish a Valid VCPR. In a valid Veterinary-Client-Patient Relationship (VCPR) a veterinarian (RVVC, we hope!) is regularly visiting the herd and discussing animal management and health issues. The veterinarian assumes the responsibility for making medical judgments and is readily available for follow-up care in case treatment fails or there is an adverse reaction. The vet also establishes antibiotic use protocols and an approved drug list and reviews them with the client. The client in turn agrees to use the protocols and follow the vet’s instructions.

Proper Drug Use on Farm. Use only prescription (Rx) drugs or FDA-approved Over-the-Counter (OTC) drugs, with a vet’s guidance. All drugs should have their product labels and the drug inserts available. Drugs with labels for use in specific groups (lactating, non-lactating, <20mo of age) are used only in their approved groups.

Only vets can prescribe drugs in an “extra-label” manner. Extra-label use is where a drug is administered in a use that deviates from what is specified on the printed label. This could be a difference in the disease being treated, the dose, the duration or how its given. Some extra-label drug use is allowable under certain circumstances and some is illegal in food animals.  Your vet knows which is what. Extra-label use often involves a prolonged withdrawal time.

Records. Maintain a record-keeping system for all treated cows, and make sure all treatments are recorded immediately after they are given. Treated animals should be identified with a leg band or marked in some other way to indicate a treatment was given. Regularly review the records with a veterinarian and use them to identify potential issues and reduce the risk to milk quality.

Every treatment record should contain the following:

  • Identity of the animal being treated
  • Drug given
  • Reason it was given
  • Route of drug administration
  • Dose given
  • Who gave it
  • Meat and milk withdrawal times and dates when the meat and milk can be used for milk again
  • If treatment was prescribed/recommended by a vet

Drug Storage. All drugs for lactating and non-lactating cows are stored separately and well labeled, with nothing being stored in the milk house. All prescription drugs should have a label with information about the prescribing veterinarian. Throw out expired drugs.

Testing. Make sure to test every cow before her milk goes back in the tank, especially any cow that was treated in an extra-label manner. Dry cows that freshened early should be tested as well as any new cows entering the herd before adding their milk to the tank. Never decrease the meat or milk withdrawal time from what is on the label. While the meat can’t be tested on farm for residues, follow a premarket/slaughter checklist to review treatments and withdrawal times to be sure the cow is free of drugs. If two antibiotics were used in combination, their individual withdrawal times should be combined and that number used as the withdrawal time.

Training. Discuss all protocols and recommendations from the vet with employees and family and have regular training sessions for everyone on preventing milk and meat residues.

For the full materials on drug residue avoidance, go to the National Dairy FARM Program website (www.nationaldairyfarm.com) or the NYSCHAP website (https://ahdc.vet.cornell.edu/programs/NYSCHAP/). Below is a chart of common drugs and their risk factors for residues. Your vet is also an excellent resource on proper drug use; its part of our training. Plus, with your VCPR, we should be helping you with protocols and correct drug use practices anyway!


Common Drugs and their Residue Risk Factors

Drug Name Trade Name Risk for Residues
Ceftiofur Ceftiflex, Excede, Excenel, Naxcel, Spectramast -Using a withdrawal time from one product when using another.
-All have different withdrawal times!
-Keep accurate records of the exact product used
-All have different approved routes of administration and can’t be used otherwise
Enrofloxacin Baytril -NO Extra-Label use!
-Only use to treat dairy animals <20mo of age or beef animals for pneumonia. Nothing else.
Norfenicol Nuflor -Only for dairy cattle <20mo or beef
-Single dose treatment has a longer meat withdrawal than the 2-day treatment
-No amount is tolerated in dairy cattle
Flunixin meglumine Banamine -IV only! Cannot be given IM or SQ
Penicillin Penicillin -Increased dose, frequency or duration of treatment requires increased withdrawal time
-Giving more than 10mL per injection site requires increased withdrawal time
Tetracyclines OT100, LA200, PRO 300LA -Large-volume injection in one site
-Extra-label use such as giving as an infusion for an infected uterus
-Long meat withdrawal time

SubZero Calf Care – Jan ’18

January 2018 Newsletter PDF

Checklist for Subzero Calf Care

Since temperatures will be below zero, single digits at best, for the foreseeable future, here’s a checklist to help you make sure your calves will make it through.

  • Extra Calories: In this weather calves are using all available energy to just stay alive and warm. Whether its extra quarts of milk, extra feedings or a scoop of fat additive, it’ll keep them from losing weight.
  • Calf Jackets: All calves on milk should have a jacket on at these temperatures – just like you!
  • Deep, Dry Bedding: 12 inches of dry bedding is essential for staying warm.
  • Windbreaks: Temporary windbreaks to the windward side of a block of calf hutches or along calf pens will reduce windchill.
  • Staying Dry: All newborn calves should be completely dry before being put in a barn or hutch. Nothing initiates hypothermia or frostbite faster than being wet.

Other Considerations:

  • Buddy System: Two calves in a hutch together will be warmer than one!
  • Ear Muffs: frostbite is a real threat, calf-specific ear muffs can protect those delicate ears.

Newborn of the Month!

It is our pleasure to announce the arrival of the newest member of the RVVC family!! Monty Gene Stika was born December 18th, weighing 7lbs 11oz. Dr. Stika and family are doing very well!! If you’re lucky, you might catch a glimpse of him visiting the Reedsburg Clinic!

Monty Gene Stika