You are probably familiar with the rigid paralysis that comes with tetanus (commonly called lockjaw). Today, we’ll discuss tetanus’ sister illness, botulism, which causes flaccid paralysis. I always think of the two together because – like most sisters – they are similar, yet very different.
Like tetanus, botulism is caused by a bacterium in the Clostridium family called Clostridium botulinum. This bacterium also produces a neurotoxin, but it acts in a much different way than the neurotoxin produced by Clostridium tetani.
Our feline friends get a pass when it comes to botulism; they are resistant to this particular disease. However, dogs are exposed to the botulinum toxin when they eat dead animals or other raw meat. After it is ingested, the toxin survives the acidic environment of the stomach and finds its way into the small intestine, where it is absorbed into the lymphatic system and then into the blood stream. Eventually, the botulinum toxin binds to neurons, causing dysfunction in the nerves that allow muscles to contract. This leads to flaccid paralysis through weakened muscles.
Clinical signs can occur within a few hours of ingestion up to a few days after ingestion of the neurotoxin. The earlier the signs appear, the more severe the disease course will be. In general, the severity of the disease depends on the amount of toxin ingested.
Clinical signs typically involve ascending weakness that starts in the hind limbs and progresses up to the front limbs. Other signs that can occur are excessive drooling (because affected animals cannot swallow), a slack jaw, and dilated pupils. Constipation, urinary retention, and eye ulcers can also accompany these signs. In severe cases, death can occur due to respiratory paralysis, so seeing the vet at the first sign of a veterinary emergency is crucial.
Treatment for botulism is similar to the treatment for tetanus. There is an antitoxin specific for botulinum toxin which can be given if there is still toxin circulating in the intestines. Otherwise, supportive therapy is needed until the patient can recover. IV fluids to maintain hydration are important, as is proper bladder care and enemas if needed. Patients often have slow blink reflexes, so maintaining eye health will be addressed during the hospital stay as well. Antibiotics are not typically given unless there are secondary infections.
Recovery can be a slow process and may take up to three weeks or more. During this time, the degree of supportive care needed will be assessed daily.
Botulism can be avoided by never allowing your dog to eat raw meat or dead animals. The organism that causes botulism can be killed by heating food at 80oC for thirty minutes or 100oC for ten minutes.