She's Crazy!!!

“I think I have a cow with Rabies.” A phone call you DON’T want to get on a beautiful Sunday morning.  This past weekend, I unfortunately did get this call.  Cow #2980 had been found down in the manure alley in the morning. When asked to get up, the owner described how she had no control of her legs, her bladder, was “walking crazy ,” and appeared aggressive.  Her ears were forward and her eyes even “looked crazy”. When the owner tried to get her to the special needs pen, the cow would turn around at her, like cows often do when they are about to charge.

IF YOU READ NOTHING ELSE IN THIS POST, PLEASE READ THIS--- When dealing with a neurologic animal of ANY KIND, DO NOT TOUCH THE ANIMAL, MAKE ANY ATTEMPT AT CATCHING THE ANIMAL OR GO NEAR THE ANIMAL. CALL YOUR VETERINARIAN!!!! Always, always, always remember that a neurologic animal has the possibility of having rabies and it just takes a little saliva or nasal secretion, loaded with the virus, to infect a human. Veterinarians have been vaccinated against rabies and are some of the very few qualified individuals, other than public health individuals to handle an animal with Rabies. If you absolutely MUST touch a neurologic animal that you suspect might be rabid, WEAR GLOVES, and make sure you do not have ANY exposed open wounds or sores. 

Back to #2980. When I arrived on the farm, all the cows were laying down in the pen. Trying to decipher which cow it was, I made a kissing noise to get the cows up. #2980 JUMPED to her feet and took off at a very fast walk around the pen, while the other cows took their time getting to their feet.  #2980 was very dirty, from falling down in the alley and seemed like she was super excitable. 

I’ve talked about cow flight zones in a previous post. Each cow has a different flight zone; meaning you can get variable distances to and from a cow before she will move and try to get away.  Younger heifers usually have a bigger flight zone than older cows. #2980 seemed to have a bigger flight zone than just about any young heifer. It was difficult to get within 15 feet of her before she would take off, unsteadily, away from me.  We managed to get her in a headlock, so that I could examine her.  Keeping safety in mind, with a very neurologic 1500 pound animal, I decided it was best to lock other cows in next to her and keep her somewhat steady while I approached her. 

To restrain her from kicking me as I approached, we carefully raised her tail straight in the air.  This is a common restraint used with cattle which temporarily “paralyzes” their back feet so they are unable to kick.  Normally, this does not hurt a cow, as it lessens the sensation in the back end. Upon raising 2980’s tail, she let out a terrible bellow, like we were severely hurting her.  Her temperature was 103.9F degrees (normal body temperature for a cow is 101-102.5F) and her heart, lungs and stomach all sounded normal. She tested negative for ketosis. As I was standing next to her examining her, her entire body was quivering and when I would touch her, she would excessively twitch at the spot I was touching.

Her head was in the headlock and she seemed interested in food. She was eating normally and not dropping food out of either side of her mouth. When examining her eyes, her third eyelids were both up, which is abnormal and you could see the whites of her eyes otherwise. Notice the eyes of the cow behind #2980 in the picture; her eyes are normal, whereas you can see the 3^rd eyelid of #2980.  I took some videos of her, but unfortunately because she is mostly black; it is hard to see the quivering.  If you watch the posted video, you can see her stagger a little when she is walking and turning around, and she seems to have an exaggerated gait.  Of course when I was videoing her, she was more “normal” than she was when the camera wasn’t rolling…. 

When we see neurologic cases in the Northeast, we ALWAYS keep Rabies on our list of possibilities. Unlike other parts of the country, raccoons, bats, foxes and coyotes will carry rabies.  This particular farm seems to have an excessive amount of raccoons around, having trapped and killed 10, most of which have been found in the milking parlor! Because rabies can be spread via infected saliva, through a bite wound, I was also looking for bite wounds on the cow, and found none.  There are a few other diseases, such as lead poisoning, meningitis, Bovine Spongiform Encephalopathy (BSE) and listeria that can cause similar neurologic signs in a cow.  Lead poisoning was unlikely, based on the environment on the farm, and the lack of an obvious source of lead, and BSE was lower on my list because we don't feed ruminant proteins back to ruminants anymore. 

Listeria was the other most likely possibility in this cow.  This is a soil born bacteria that often gets into the silage fed to cows.  The bacteria make their way to the brainstem of cows and causes severe nerve damage. It is commonly known as “circling disease” as infected cows tend to turn in circles, have a droopy face and can have their tongue sticking out one side. They can have difficulty eating food, swallowing, and depression. Because it affects multiple major nerves, they can walk unsteadily and fall down. Not all Listeria cows act or appear the same. Depending on when in the course of the disease the animal is noted to be abnormal, they may exhibit less severe or various neurologic signs. With very high doses of Penicillin, Listeria cows can recover and go on to be productive animals. #2980 did not seem to show the more typical signs associated with Listeria and the neurologic signs she was displaying were severe enough, that Listeria seemed less likely, but I didn’t want to completely disregard it as a possibility.

After discussion with the owner, we decided that we would treat her for Listeria and give her 24 hours.  After donning 2 pairs of gloves on both my hands, we tied her head and she was given a very large dose of Penicillin, and medicine to help with the fever and the inflammation, that may be associated with nerve damage. 

24 hours later, well more like 30 hours, I went back to the farm and again the cow was lying down in the pen. When I entered the pen, her ears went forward and she looked like she wanted to run away, but she struggled getting to her feet. Once she was up, she stood with all 4 feet stretched out in a "sawhorse" stance. Then she went about her craziness and was rapidly walking around the pen, staying very far away from me. When we were able to get her in the head lock, she started eating and was able to grab the food normally, but seemed to have to stick her neck out straight to swallow. Her fever had responded to the medicine, but everything else on her physical exam was the same as the day before. She even bellowed again when I raised her tail in the air.

Because this is a special cow to the owner, she wanted to give it yet another 24 hours, to see if she improved or declined, with another round of treatment. I agreed, and went back again Tuesday afternoon. Her status had not changed. She still had trouble getting up and when she was up, was very spastic. Based on the lack of change in her status and the continued concern for Rabies, I recommended euthanizing her. I sedated her, euthanized her and then needed to remove her brain to be sent to the state lab to test for Rabies. When I removed the head from the rest of the body, I noticed that there was a bit more spinal fluid that poured out of the spinal column than normal. I then removed a portion of the skull to get to the brain, and noticed that the brain was extremely dry. Normally there is cerebrospinal fluid (CSF) around the brain, that keeps the brain moist, but the brain of #2980 was more dry than normal. Once the brain was removed, I split the cerebral hemispheres and noticed that the ventricles inside the brain seemed more dilated than normal. Rabies was moving lower on my list of possibilities, but I still didn't have a good idea of what this could be.

Just to be sure, the brain was sent to the state lab for Rabies testing and came back negative. The owner declined sending it on for further testing, so I don't have a definitive answer on the cause of the neurologic signs. However, based on her physical exam signs, I feel like whatever the cause, the prognosis was poor and we made the right decision by euthanizing her.

This was a very interesting and challenging case. I am very relieved that she is Rabies negative, but I will always wonder what the true cause of the neurologic signs were.