Clinical Manifestations of Anthrax in Animals

Clinical signs vary from animal to animal and the severity of infection. Infections can be categorized into three classes:

  1. 1. Peracute

It is common in cattle and sheep and is characterized by fever, congestion of mucosa, dyspnea, muscle tremor, and convulsions followed by the death of the animal. The course of the disease is the shortest of other categories i.e., only 2 hours.  Death is usually accompanied by bloody discharges from the animal’s natural openings like nostrils, mouth, anus, and vulva.

  1. 2. Acute

The disease course for the acute form of anthrax is about 2 days. The common symptoms in the case of cattle and sheep are fever, an interval of excitement, followed by depression, troubled breathing, cardiac distress, seizures, and at last death. ruminal stasis, reduced milk production, yellow milk or blood stains in milk, abortion in pregnant cows, diarrhea, and edema in ventral areas of the neck, shoulder, and thorax have also been observed.

  1. 3. Chronic

The chronic form of anthrax is common in swine though it can also occur in cattle, horses, cats, and dogs. Usual manifestations include extensive subcutaneous, localized, edematous swelling in anterior areas of the neck, shoulder, and thorax.

Causes of Anthrax Spread

As anthrax spores are highly resistant, it is quite difficult to clear the area after exposure to anthrax. Moreover, anthrax spores are microscopic and might not be detected by smell or sight. Following are some sources of transmission of anthrax in animals:

  • – Grazing in fields which has previously been exposed to anthrax
  • – Consumption of contaminated fodder, water, and hay
  • – Utilization of contaminated equipment at the farm
  • – Ingestion of bone meal and blood meal from infected animals
  • – Moving or post-mortem inspection of infected animal’s carcass
  • – Shoes, vehicles, clothing, machinery, etc. from the contaminated area
  • – Flies and some insects can also transmit anthrax

There is a greater risk of humans getting anthrax if they are:

  • – Working in an anthrax research lab
  • – Farm workers
  • – Tanneries workers
  • – Slaughterhouse workers
  • – Veterinarians
  • – Game animals handlers
  • – Soldiers on duty in contaminated areas

Reference;

Galante, D. (2022). Anthrax in Animals. Retrieved from MSD mannual: https://www.msdvetmanual.com/generalized-conditions/anthrax/anthrax-in-animals