Q. My dog has lost all interest in his toys, ones he has had all his life, and instead just explores the room and goes upstairs, (something he has never done) and has started soiling the house.

He isn’t old (only eight) and he is not in pain as we had him checked by the vet. He has always been a top dog and I am finding his erratic behaviour very upsetting. He asks for food even when I have just put out fresh.

Might he be going blind?

P WALTERS, Radley

A. It is possible your dog is showing early signs of dementia (canine cognitive dysfunction).

You may also notice other changes in his behaviour like unusual aggression to people he knows or other dogs, disorientation and changes in his sleeping habits.

You should discuss your concerns with your vet sooner rather than later; there are medicines which can help and new products appear from time to time to help manage this distressing disease.

Q. I have an 18-month-old weimaraner that has had an accidental mating. I have made an appointment for her to have the injections to stop the pregnancy but I’m not sure if this will cause problems in her health or later matings. Could you please advise me as to what would be the best for her?

SALLY MAYERS, Bicester

A. Termination in the early stages of pregnancy carries little risk but later in pregnancy there is a possibility of a partial termination and this could result in damage which may affect her future ability to have puppies.

The most common side effect is an unpredictability about the timing of a return to her normal breeding cycle; her next season could be late or early. The drugs used have an oily base and can produce an inflammatory reaction with pain and swelling at the injection site.

It is possible a bitch can have a much more serious allergic, life-threatening reaction but thankfully this is extremely rare.

The best way is for her to have her puppies but then you have the problem of an unwanted litter.

Q. I give each of my cats a small bowl of cheese twice a week as a treat.

One of them recently had a check-up and I was shocked to hear that he had high cholesterol. I lied when the vet asked what he ate, but would it kill him, like a heart attack?

AUDREY ROBERTS, Oxford

A. Cholesterol is a fatty substance which is mainly produced in the liver of the cat and a high blood cholesterol reading may indicate a problem with organs like the liver, kidneys, thyroid, adrenal glands or pancreas.

In the cat it does not cause clogging of blood vessels like it does in humans (a major cause of heart attacks).

Cats do not have heart attacks. A single high cholesterol reading is not necessarily significant as this can happen after a meal. A repeat blood sample should be analysed after 12 hours without food. If this sample is fine, then I would suggest a little bit of cheese is fine every now and then and worry more about their weight than heart attacks!

Lying to your vet is totally pointless...