On the lookout for rabies | TSLN.com

On the lookout for rabies

Dave Barz, DVM

The summer continues to heat up, but we need some BTU’s to help the corn left after the hail storms to mature. It seems this time of year we see more small mammals on the highway. Most are spring born, but others are mature adults enlarging territories. These sightings at abnormal times of the day stimulate a lot of questions about rabies.

Rabies is a viral disease of warm blooded animals. It requires direct spread from contact with an animal shedding virus. This means there must be a reservoir host or a group of animals which harbor the virus over periods of time. In some areas this is the bat, the fox, the raccoon, but in our area it appears to be the skunk. In my practice area we sometimes see rabid cattle, but it is very rare (10-12 in 35 years). Last year I euthanized a cow with rabies on the same section of pasture I euthanized a bull 15 years earlier. We must assume there is a wild animal vector serving as a reservoir host in that area and it remained over the years.

Horses and cattle as well as pets and wild mammals are susceptible to the virus. Many ranchers are exposed when one of their horses becomes sick and won’t eat. The disease travels up the nerves from the point of exposure, (tail, nose etc.). Therefore an exposure to the face and head is more severe than one to the tail in that it takes more time for the virus to reach the brain. There is not treatment once clinical signs begin so prevention is very important.

Most of us remember ‘Old Yeller’ and the aggressive behavior he displayed at the conclusion of the movie. Many animals don’t develop the aggressiveness, at least not until late stages of the disease. After the virus reaches the brain it tends to centralize in the nerves responsible for swallowing. With the animal unable to swallow we try to place feed and water in the animals’ mouth thereby exposing ourselves to the virus.

Early signs of rabies may be merely a change in attitude. The horse or cow may be depressed, and reluctant to eat. I have seen a dairy cow which was milked until she finally became unable to walk and was euthanized. She went off feed, appeared to be in heat and then terminally bellowed like she was calling her calf. She never became aggressive.

The virus is also shed in milk and that is a good reason all milk should be pasteurized. There are some records of humans contracting rabies from drinking unpasteurized milk from a cow shedding virus. If there is no treatment once signs begin, you must begin preventive treatment as soon as possible after exposure enabling the body to form immunity to the disease.

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All domestic can be vaccinated for rabies, but most are not. The vaccine is relatively expensive and requires a yearly booster. Some horse owners vaccinate their using horses on a yearly basis and we recommend pets be vaccinated yearly. If a vaccinated animal is exposed, you should booster the vaccine immediately to protect the animal. You need to keep records of when your animals were vaccinated and the products used in case they are exposed.

The only assured diagnosis involves the examination of the brain tissue at a diagnostic lab. This makes it important to try to capture the shedding animal without exposing yourself. When handling these animals and your own animals which may be exposed it is important to wear rubber gloves to minimize exposure.

Rabies is an old disease which invokes fear in the populace because there is no practical treatment. If you or your animals contact wild animals which may be shedding, you should contact your veterinarian. They will help you understand quarantine, testing, isolation and revaccination procedures. Hopefully you or your family will never encounter this disease.

The summer continues to heat up, but we need some BTU’s to help the corn left after the hail storms to mature. It seems this time of year we see more small mammals on the highway. Most are spring born, but others are mature adults enlarging territories. These sightings at abnormal times of the day stimulate a lot of questions about rabies.

Rabies is a viral disease of warm blooded animals. It requires direct spread from contact with an animal shedding virus. This means there must be a reservoir host or a group of animals which harbor the virus over periods of time. In some areas this is the bat, the fox, the raccoon, but in our area it appears to be the skunk. In my practice area we sometimes see rabid cattle, but it is very rare (10-12 in 35 years). Last year I euthanized a cow with rabies on the same section of pasture I euthanized a bull 15 years earlier. We must assume there is a wild animal vector serving as a reservoir host in that area and it remained over the years.

Horses and cattle as well as pets and wild mammals are susceptible to the virus. Many ranchers are exposed when one of their horses becomes sick and won’t eat. The disease travels up the nerves from the point of exposure, (tail, nose etc.). Therefore an exposure to the face and head is more severe than one to the tail in that it takes more time for the virus to reach the brain. There is not treatment once clinical signs begin so prevention is very important.

Most of us remember ‘Old Yeller’ and the aggressive behavior he displayed at the conclusion of the movie. Many animals don’t develop the aggressiveness, at least not until late stages of the disease. After the virus reaches the brain it tends to centralize in the nerves responsible for swallowing. With the animal unable to swallow we try to place feed and water in the animals’ mouth thereby exposing ourselves to the virus.

Early signs of rabies may be merely a change in attitude. The horse or cow may be depressed, and reluctant to eat. I have seen a dairy cow which was milked until she finally became unable to walk and was euthanized. She went off feed, appeared to be in heat and then terminally bellowed like she was calling her calf. She never became aggressive.

The virus is also shed in milk and that is a good reason all milk should be pasteurized. There are some records of humans contracting rabies from drinking unpasteurized milk from a cow shedding virus. If there is no treatment once signs begin, you must begin preventive treatment as soon as possible after exposure enabling the body to form immunity to the disease.

All domestic can be vaccinated for rabies, but most are not. The vaccine is relatively expensive and requires a yearly booster. Some horse owners vaccinate their using horses on a yearly basis and we recommend pets be vaccinated yearly. If a vaccinated animal is exposed, you should booster the vaccine immediately to protect the animal. You need to keep records of when your animals were vaccinated and the products used in case they are exposed.

The only assured diagnosis involves the examination of the brain tissue at a diagnostic lab. This makes it important to try to capture the shedding animal without exposing yourself. When handling these animals and your own animals which may be exposed it is important to wear rubber gloves to minimize exposure.

Rabies is an old disease which invokes fear in the populace because there is no practical treatment. If you or your animals contact wild animals which may be shedding, you should contact your veterinarian. They will help you understand quarantine, testing, isolation and revaccination procedures. Hopefully you or your family will never encounter this disease.