An Agricultural High School on the Central Coast called the Cumberland Livestock Health and Pest Authority in Maitland as their seven piglets that were five weeks of age had very thickened skin, alopecia, severe rubbing and shaking ears. The piglets had multiple scabs mostly over head and forequarters. The sow had had the same clinical signs around farrowing time but had been given only one dose of Ivermectin as treatment which appeared to clear the clinical signs up.
The piglets presented with hyperkeratosis (Figure 1), large amount of scale in the external ear canals (Figure 2), alopecia and severe pruritus.
Several deep skin scrapings were taken from the edge of lesions on the skin and thick swaps were taken from the external ear canal (note: a teaspoon is ideal for taking a scaping from external ear canal, spread material on black paper and wait 10 minutes to see if you can see mange mites. The mange mites are rounded and 0.5mm just visible to the naked eye). I was unable to see any mites under the schools microscope but was pretty convinced that Sarcoptes was what we had so I recommended treatment with Ivermectin injection (two injections 10 days apart) while we waited for the lab results to come back.
Differential diagnoses include the following. Hyperkeratinisation (Figure 5) is normal dead flaky skin that can be rubbed off leaving normal skin underneath. Greasy Pig Disease (Figure 6) is caused by a bacterium Staphylococcus hyicus. Swine Pox (Figure 7) is a viral disease that is characterized by the acute appearance of round to oval cutaneous lesions that heal in three to four weeks. Sun Burn (Figure 8), caused by exposure to ultraviolet light, is not possible in this case as the piglets were housed in an indoor pen.
Insect / Mite Specialist ID (Figure 9):
Common name sarcoptic mange mite
Sarcoptic mange in pigs
All the piglets had been weaned from the sow one week before visiting the High School; they were given Ivermectin injections (300ug/kg s/c) 14 days apart. The sow was also treated even though she appeared to have recovered; she was only given one dose of Ivermectin at the time she showed clinical signs of Sarcoptic Mange so this ensured that she was free from infection.
This parasite like many others will lead to a decrease in weight gain in weaner piglets and if the sows are affected it will lead to her being more restless and hence more piglet mortalities.
'Prevention is better than cure', as all treatments add up to take out a good chunk of the producer's profit, especially in this case when multiple treatments are required. Ways to maintain a Mange free herd include