Mountain Vets Season 4 is yet to be announced by BBC Two

Vet Jennie must save a litter of puppies, Nuala carries out an important job on her family farm, and an emergency case leaves Darren delivering two sets of twins.

Vet Jennie saves the life of a show chicken, Darren helps a pregnant cow avoid a caesarean section, and Maurice comes face to face with an exotic visitor.

Newly qualified vet Patrick is called out to help a farmer whose cow has been struggling all night with a difficult labour. Patrick discovers her calf is breached, and has to reposition it. However, once it's in the correct position, a shock discovery makes his job twice as precarious. Back in Castlewellan, a farmer arrives with a two-week-old lamb that's developed a limp. Some antibiotics and a dose of anti-inflammatories will help the lamb back on its feet. However, vet Maeve notices its eyes are milky white and she has to use all her expertise and knowledge to save the lamb's sight.

As winter morphs into spring, lambing and calving keeps the team busy out on the farms. However, their small animal clinic is also packed with pets and Martin Fitzpatrick - the man who founded the practice 35 years ago - faces a difficult case concerning a Highland terrier. Young vet Darren is called out on an emergency to a farm where a prize cow is struggling to deliver a calf. An examination reveals it's simply too big to come out naturally. Darren decides the safest option, for both the cow and the calf, is to perform an emergency Caesarean section. It's a risky operation, but without it, the cow will die.

Maurice delivers a valuable litter of 11 sniffer-dogs, Rachel operates on a therapy dog with possibly cancerous skin growths, and a woman with a particular affinity with animals adopts a wild bird.

Vet Cahir is surprised by an unexpected turn of events while helping a pregnant ewe, Nuala amputates a calf's toe to save its life, and Daisy treats a dog that may have swallowed rat poison.

Vet Rachael Frew heads out to a pre-booked appointment with a farmer she knows well. Damien produces meat from a large herd of Dexter cattle and his prize possession is bull Charlie, who has won several awards. Damian has had his eye on a young bull to follow in Charlie's footsteps, but it is not working out. Elsewhere, tests are carried out on a Yorkshire terrier that has stopped eating, stable-hand Caroline prepares cow Daisy for her first competition at the Balmoral Show and Inge D'Haese uses all of her skills to perform a tricky procedure to correct a horse's stance.

The vets care for animals with all kinds of value - from high worth racehorses to pedigree bulls and irreplaceable family pets.

Maurice delivers a valuable litter of 11 sniffer dogs, Rachel operates on a therapy dog with possible cancerous skin growths, and a woman with Asperger's adopts a wild bird.

Rachael attends to a cow with a potentially fatal displaced stomach, and vet Martin operates on a valuable sheepdog to try to save its injured leg.

A pregnant sheep must undergo an emergency caesarean, while Flame the dachshund and Monty the fell pony present worrying symptoms that put the vets' knowledge to the test.

Vet Maurice is called to an extraordinarily rare birth, equine vet Inge tries to help a dangerous donkey, and Rachel helps a hedgehog who's woken early from hibernation.