Q. I get confusing advice about how to feed my guinea pigs. What would you recommend?

A Bampton, Wallingford.

A. The main ingredient of the guinea pig diet should be quality hay; this contains the essential fibre for proper gut function and tooth wear.

Offer high-fibre nuggets e.g. Burgess Excel guinea pig, about a teacup of fresh vegetables/fruit daily and fresh water.

Suitable vegetables are: broccoli, Brussels sprouts, cabbage, carrots-plus-tops, celery, parsley, cucumber, watercress, Romaine lettuce, green pepper, spinach, baby corn.

Fruits: melon, apple, orange, kiwi, grapefruit. Limit fruit to one-inch chunks, two to three times weekly.

Q. I have two geckos and a bearded dragon. If I put them together will the bearded dragon attack or fight with my geckos?

D Stirling, Cowley.

A. I would not recommend you try putting them together or housing them in the same space.

There is likely to be a size difference and territorial behaviour which is likely to result in one or the other being bullied/attacked.

Altogether far too stressful for all.

It is also possible that internal parasites (like coccidia) which can be carried by dragons without showing symptoms may be transferred to the geckos, with potentially fatal results.

Q. I have a 10-month-old boxer puppy. One of his testicles never dropped. A vet told me that if I do not get him neutered he would acquire cancer. Is that correct?

B Watling, Oxfordshire.

A. In a developing puppy the testicles drop from inside the body through a hole in the body wall in the groin (the inguinal ring) to lie in the scrotum.

Normally both testicles are in the right place by two to three months of age. However, occasionally one or both do not drop properly and may remain in the tummy or lie under the skin in front of the scrotum.

A dog with this condition is called cryptorchid and the testicle which does not drop is usually non-functional. It is true that testicles which do not drop are more likely to develop cancer than normal testicles and it is for this reason that castration is recommended.

The surgery is more complicated than a standard castration and will often involve making an opening into the tummy to remove the retained testicle and as a result it is likely to be more expensive.

Q. One of my parrot’s feet has began to turn a purple colour. It seems to be getting darker and he is able to support himself with it less and less. What could this be?

L Wright, Banbury.

A. This purple discolouration does not sound good at all and is usually associated with reduced blood flow and tissue death.

The fact he is not using the foot properly suggests pain or a loss of sensation or both.

Damage to the blood flow may be caused by an injury or it may be as a result of a more generalised disease. This I consider is an emergency and he needs to be seen by your vet very soon.