Sows and Reproduction

Whilst pregnancy and birth is as individual as the guinea pigs themselves here are a few facts about sows and reproduction:
Sows can become fertile from 4 – 6 weeks of age, separate from boars from 3 weeks if healthy and by 4 weeks to avoid early unwanted pregnancy.
Sows become fertile every 15-17 days for approximately 12 hours at a time.
Sows are fertile immediately after littering for 2-15 hours, if mating is allowed to happen it is referred to as ‘back to back breeding’ or a ‘back to back’ pregnancy.
Sows are fertile throughout their life. It is not recommended to breed from older sows as Dystocia is more likely.
• The Pubic Symphysis ( cartilaginous joint that is movable to allow the birth) does not fuse, it becomes less flexible with age, which sometimes makes birthing difficult for first time Mums that are over a year old. Many sows litter successfully though the risk of Dystocia increases with age. Similarly breeding with sows that are too immature is undesirable.
Sows have 2 nipples and feed on supply and demand, because the pups eat from an early age they (the sows) cope well with large litters.
Sows come into milk up to 12 hours after the birth.
Pregnancy lasts for approximately 10 weeks, during which the sow will change shape and increase in weight. She may increase fluid intake, her need for Vitamin C could be as high as 30mg per day towards the end of pregnancy. Care should be taken not to give this by overfeeding dry food that will, in turn, make her obese and put her at risk from Toxemia.
• Opinion is divided as to whether pregnant sows should be separated and not allowed give birth together. Points of view are that one sow will help the other with birthing and provides company, whilst there are reports of one birth inducing another prematurely which causes litters to be stillborn.
• Pregnant sows may develop a Calcium deficiency from the demands of birthing and lactation. This can occur 1 or 2 weeks before the birth or soon after giving birth. It is seen more often in obese or stressed sows. Affected sows may die suddenly or show signs such as dehydration, depression, anorexia, muscle spasms and/or convulsions. Prevention lies with feeding a high quality diet and ensuring sows are fit as opposed to fat. Treatment is with Calcium Gluconate from the vet, and should be prompt.
Toxemia (Ketosis) can happen where there is a large litter or obesity leading to a decrease in the blood supply to the uterus, environmental stress or lack of exercise. There is an unmistakeable smell on her breath too. Death is either sudden or can be progressive with the sow exhibiting signs of lethargy (such as sitting hunched up), anorexia, convulsions or muscle spasms. Prognosis is not usually good for the sow but veterinary treatment should be sought. Preventative measures are not overfeeding but feeding quality foods, breeding from fit not fat sows, avoiding exposure to stress during late pregnancy.
Breech births will, for the most part, need immediate assistance, although a vet visit is advisable after the birth, time is of the essence when a pup presents itself in a breech position. If the sow has been straining for 15 minutes with no ‘resulting pup’ it is time to be concerned. Wash your hands. Put the sow in a vertical/diagonal position (resting on your arm is useful), that is comfortable for sow and Human, this allows gravity to play a part too. Do NOT pull the pup straight down. A gentle twisting action is needing, firm but not forcing anything. Above all don’t panic.It may be necessary to insert a finger into the birth canal to help the birth, avoid this if possible but if necessary inform your vet as antibiotics will be needed, by entering the birth canal it introduces the risk of infection. Fluids given by a subcutaneous injection are very advisable for any sow that has visited the vet with birthing problems. Oxytocin may be given to pass any matter that may be left in the uterus, including Placentas. Placentas may be passed up to an hour or so after the birth sometimes. There is no fixed pattern/rule when they are passed.
• Some sows get Maternal hairloss, this can be because of the stress of the birth or because of mites ‘kicking in’ after the birth. Contact for information on the correct product to use on pregnant/lactating sows. Regrowth of hair often happens within a couple of weeks and some relief may be all that is needed.
Mastitis is where the mammary glands become inflamed during lactation. The cause is infection which may due to husbandry practices such as the use of abrasive beddings that cause scratches which in turn get infected…Affected mammary glands are warm and firm. The sow may become anorexic, depressed, and dehydrated. The milk may be thick or/and bloody, treatment with antibiotics is needed. Prevention is good husbandry practises and removal of abrasive beddings.
Sore Nipples are common where the litters are large. The nipples should be washed and dried, contact for an appropriate product to use. Do not use anything that will harm the pups if ingested.

Pups/Mini Pigs