Contagious Agalactia: Economic Losses and Good Practice

Special Article – Bacterial Diseases

J Bacteriol Mycol. 2018; 5(5): 1076.

Contagious Agalactia: Economic Losses and Good Practice

Loria GR¹, Puleio R² and Nicholas RAJ³*

1Director of Specialized Diagnostic Area Experimental Zooprophylactic Institute of Sicily via G. Marinuzzi 3, 90129 Palermo, Italy

2Experimental Zooprophylactic Institute of Sicily via G. Marinuzzi 3, 90129 Palermo, Italy

3The Oaks, Nutshell Lane, Farnham, Surrey GU9 0HG, UK

*Corresponding author: Robin A J Nicholas, The Oaks, Nutshell Lane, Farnham, Surrey GU9 0HG, UK

Received: August 08, 2018; Accepted: September 05, 2018; Published: September 12, 2018


Contagious agalactia (CA), a disease of dairy sheep and goats mainly caused by Mycoplasma agalactiae, is known to have been present in Europe for over 200 years (Nicholas et al 1998). While it can present as a mild disease in small ruminants CA has proven difficult to eradicate as it may persist on farms contaminating successive flocks. The disease is first noticed when milk production falls usually a few days after the introduction of healthy carriers or from mixing with affected herds at pasture, markets or water sources. Milk becomes abnormal in appearance, mastitic then production ceases in one or both udders, often permanently. Keratoconjunctivitis and arthritis are chronic sequelae, particularly severe in the young preventing them from keeping up with the rest of the group during transhumance and other animal movements. CA is found wherever sheep and goats are kept but concentrated in countries surrounding the Mediterranean and western Asia, especially in Iran and Mongolia where large numbers of outbreaks are reported [1].

Unusually for a World Association for Animal Health (OIE)- listed disease four agents, all mycoplasmas, are listed as causing a clinically indistinguishable syndrome although M agalactiae accounts for more than 80% of outbreaks; the other three pathogens, M. mycoides subsp. capri, M. capricolum subsp capricolum and M. putrefaciens are more often found in goats. There are indications that the disease is spreading in Europe with increase numbers of cases seen in France and new outbreaks in Corsica [2].

Economic Impact

The economic costs of CA as a result of deaths, treatment, lowered milk production, spoiled products, abortions and animal welfare problems are not widely known. Previously the impact of the disease was thought to be most severely felt by farmers using traditional husbandry for producing milk products on a small scale essentially destroying their livelihoods [2]. However the disease probably also has a major impact on the larger commercial farms [3]. Made the first attempts at estimating the economic losses of acute disease suffered in Greece between 1997-1994 using official data. The losses, made up of milk reduction, abortions, neonatal deaths and dead animals, were estimated at 24.5 million euros per year. However, the author stated that these losses were almost certainly under estimated because the compulsory reporting of the disease in Greece leads to severe restrictions resulting in farmers often not reporting their affected flocks. Furthermore, the impact of the subacute or chronic disease, which causes physical weakness and clinical complications, is very hard to measure. Other figures not taken into account are the significant costs of vaccination and veterinary costs.

More recently, we studied the losses from two different farm types in Sicily: A large commercial farm of mixed small ruminants and smaller family farm. The first farm was located in the Enna district and comprised over 1000 sheep and goats. Milk production suddenly dropped from 650 to only 100litres/day in October 2015. Every day of the outbreak 10-15 animals developed characteristic clinical signs of CA. The course of the infection stopped in January 2016 when all animals entered the dry period following vaccination with an inactivated CA vaccine on two occasions. The disease was found to have arrived on the farm through a group of 120 apparently healthy Etna goats in March 2015. Those goats were newly lactating animals without any unusual signs until the new parturition season the previous July when 18 goats delivered weak kids and an unexpected drop in milk production. As is normal practice, the goats had not been screened for CA before introduction to the farm. After this, clinical signs began to develop in the goats and in September, CA spread eventually to 30% of the 1000 susceptible ewes.

Following notification of the disease, costs incurred included: Slaughtering of 200 sick sheep and all 240 goats; administration of a full course of commercial autogenous vaccine according to manufacturer’s recommendations to all remaining animals; and purchasing of replacement animals and milk from other farmers to maintain the dairy business. Although the disease appears to have been controlled on this farm the cost of the disease was estimated at over 100,000 euros to the farmer (Table 1).

Citation: Loria GR, Puleio R and Nicholas RAJ. Contagious Agalactia: Economic Losses and Good Practice. J Bacteriol Mycol. 2018; 5(5): 1076.