Listeriosis in Goats | Circling Disease in Goats and other Animals
Listeriosis in goats is a sporadic bacterial infection that is found all over the world, but it is more common in temperate and colder climates. Circling disease affects a wide range of animals, including humans(zoonotic) and birds. Listeriosis is more common in ruminants with mark recognition of brain inflammation leading to nervous signs. This article will go over listeriosis in goats and other animals, as well as treatment options. So keep an eye out.
Cause of Listeriosis/Circling disease in Animals:
Circling disease in goats and other animals is caused by Listeria monocytogenes.
Some Characteristics of Listeria monoctyogenes:
- Small, Gram-positive, cocco-bacillary rods, up to 2 μm in length.
- They are catalase-positive, oxidase-negative, motile, facultative anaerobes.
- The organism can grow at 4-45°C and can tolerate pH 5.5-9.6.
Hosts Susceptible to Circling Disease:
A large number of animals are susceptible to listeriosis including birds, humans, pigs, and ruminants. Goats are the most commonly affected species.
Pathogenesis of Listeriosis in Animals:
Listeria monocytogenes is a saprophytic bacteria that normally live in the soil and also in the GIT tract of mammalian animals. Whether it is present in the soil or released in the feces of animals, both are the responsible factors for the contamination of vegetation, and grazing animals during vegetation become exposed to this pathogen. As it is a contagious disease so animal to animal transmission occurs through the oral-fecal route. Humans get infections either from direct contact with bacteria or by eating the contaminated products (milk, meat) of infected animals.
Listeria monocytogenes multiply in intestinal tissues, the medulla oblongata, and the placenta after entering the body.
Listeriosis is primarily a winter-spring disease of ruminants kept in feedlots or in confinement. The less acidic pH of spoiled silage promotes L monocytogenes multiplication. Outbreaks usually occur 10 days after consuming low-quality silage. The removal or substitution of silage in feed rations frequently prevents the spread of listeriosis; however, feeding the same silage months later may result in new cases.
Clinical Signs of Listeriosis in Goats and Other Animals:
Listeriosis manifests itself differently in different animals. Encephalitis is the most well-known form of ruminant disease. Sheep and goats are more severely affected than other ruminants, and death can occur as soon as 1-2 days after clinical signs appear. However, if aggressive treatment is adopted, the recovery rate is close to 30%. In cattle, the cases are not as severe, and the recovery rate is nearly 50%. The clinical signs of listeriosis in goats and other animals are:
- Anorexia, depression
- Animals propel themselves into corners
- Lean against stationary objects
- Facial paralysis with a drooping ear and deviated muzzle
- Profuse Salivation
- Because of masticatory muscle paralysis, food frequently becomes impacted in the cheek.
- Abortion in the last trimester without showing any clinical signs. Stillbirth can occur.
Postmortem Findings in Listeriosis in Animals
- Lesions in brain parts, especially on pons, and medulla oblongata
- Necrosis of the liver and GIT
- Autolysis varies from mild to severe in aborted fetuses, with clear to blood-tinged fluid in serous cavities.
Diagnosis of Circling Disease in Animals:
Forget the treatment, diagnosis is everything
Diagnosis of every disease must revolve around 3 basic steps
2- Clinical examination
3- Necessary lab tests for further confirmation
Sample can be collected from brain tissue and spinal fluid during postmortem examination. In antemortem evaluation, listeria can be detected from milk, urine, and feces.
Samples of lumbosacral CSF can be collected with the patient under local anesthesia. In cases of listeriosis, the CSF has an increased protein concentration (0.6–2 g/L [normal 0.3 g/L]) and a mild pleocytosis composed of large mononuclear cells. (Merck).
Differential Diagnosis of Listeriosis with other Diseases
Listeriosis should be differentiated with other diseases in which such clinical signs persist like rabies, bovine spongiform encephalopathy, lead poisoning, ketosis, and pregnancy toxemia in sheep.
In BSE, difficulty overcoming obstacles, low head carriage aggression and absences of facial paralysis. Furthermore, facial and ear paralysis is absent in pregnancy toxemia or ketosis. Blood tests can help to find the level of lead.
Treatment of Listeriosis in Goats and Other Animals:
The drug of choice for listeriosis in goats and other animals is Oxytetracycline, Procaine Penicillin G, ceftiofor, erythromycin and trimethoprim/sulfonamide.
- Penicillin should be administered at a dosage of 22,000 U/kg wt every 12 hours for 1-2 weeks
- The treatment should be initiated with potassium penicillin IV and followed with procaine penicillin G given IM
- Intravenous Oxytetracycline 16.5 mg/kg per day
Animals who have difficulty eating and drinking require supportive therapy, which includes fluids and electrolytes. Some veterinarians believe that administering high-dose dexamethasone (1 mg/kg, IV) at the initial examination is beneficial; however, it is controversial because it may suppress cell-mediated immunity and cause abortion.
Preventive Protocols in Listeriosis in Animals
- Affected animals should be segregated
- Spoiled silage should be avoided
- Vaccination approach
Listeriosis in goats is a bacterial infection caused by Listeria monocytogenes. Other than goats, ruminants, pigs, birds and even humans are susceptible to circling disease. Transmission is through oral-fecal route. The clinical signs most obvious are encephalitis and facial nerve paralysis. Diagnosis is through clinical signs and bacterial culture. Penicillin and Oxytetracycline are the drugs of choice. Vaccination and feedlot management are the preventive protocols.
1- Quereda, Juan & Morón, Álvaro & Palacios-Gorba, Carla & Dessaux, Charlotte & Portillo, García-Del & Graciela, M & Portillo, Francisco & Pucciarelli, M. (2021). Pathogenicity and virulence of Listeria monocytogenes: A trip from environmental to medical microbiology. Virulence. 12. 2509-2545. 10.1080/21505594.2021.1975526.
2- Merk Manual