Dear PDSA Vet, my two-year-old dog, Charlie, always barks aggressively at children when we take him on walks. How can I prevent this? Octavia

Charlie may be barking because he’s not used to the sight of children and is trying to tell you that he feels worried by them. To change his behaviour, you can try introducing reward-based training. Do this by maintain a good distance between Charlie and any children, and when he is calm and doesn’t react reward him with a treat. Once he’s calm with them at a distance, close that gap slowly, rewarding each time and only when he’s not reactive. If this doesn’t seem to work, it’s best to speak to your vet for advice or see an animal behaviourist for professional help – look for one registered with the Animal Behaviour & Training Council (ABTC). For more advice on dealing with aggression in dogs, visit www.pdsa.org.uk/dogbehaviour.

Dear PDSA Vet, my goldfish looks really lethargic when he swims around the tank and he’s hardly touching his food. What could be wrong? Rishi

It sounds like your goldfish may be feeling under the weather - it’s time to speak to your vet for advice. The tank environment is important to maintain, so ensure you’re properly cleaning your finned-friend’s home. Waste products can soon build up, which may be what’s making your fish poorly. Any uneaten food should be removed daily with a net and you should also follow a weekly cleaning regime, removing 20 per cent of water from the tank and cleaning away any green algae. Make sure you treat the replacement water with de-chlorination drops and let it sit for 15 minutes so it reaches the same temperature as the tank before carefully adding it into the tank.

Dear PDSA Vet, my cat, Trixie, is starting to look very thin, but she’s been eating the same as usual. What could be causing the weight loss? Iona

Rapid or unexpected weight loss can be a symptom of several health conditions, so you need to take Trixie to a vet as soon as possible to find out what could be the problem. Certain conditions such as diabetes, kidney disease and hyperthyroidism can all cause weight loss, along with other symptoms. Your vet will appreciate any information that you can provide, so do watch and let your vet know if Trixie is drinking more, if there are any changes in her urination, appetite or behaviour or any other changes in her behaviour that you may notice. The earlier your vet gets to check Trixie over the better; as they’ll be able to carry out tests and get her the treatment that she needs.

Dear PDSA Vet: Every time I try to pick up my new ferret he seems uncomfortable, even nipping my hand sometimes. How can I make him more relaxed? Stephen

Make sure you and your ferret get to know each other properly first. Encourage him to play around you as you sit on the floor, rewarding him when he gets close. Once he becomes confident being near to you and voluntarily sits on you then you can attempt to lift him – it’s important to do this properly so he feels safe and secure. Place one hand under or around his chest, then lift and support the hind legs with your other hand, holding him close to your body for security. If you’re nervous or worried about handling your ferret always handle them while sitting down or over a surface so if you do let go, they won’t fall and hurt themselves.

PDSA is the UK’s largest vet charity. We’re on a mission to improve pet wellbeing through prevention, education and treatment. Support from players of People’s Postcode Lottery helps us reach even more pet owners with vital advice and information. This winter, your support is vital for poorly pets – find out how you can help us give pets a fighting chance at www.pdsa.org.uk/pdsa-chance