Question

Permethrin - how safe is it?
Dear FAB
I read your information on flea products and permethrin with interest. I have noticed that a mattress protector I have has pemethrin in it - will it harm my cat?

Answer
We contacted Alex Campbell of the Veterinary Poisons Information Service for his help with your query. many products contain permethrin as it works well against insects. However there are problems using it with cats - when we should worry?

Alex explains that you can look at concentration as w/v (weight for volume), or w/w (weight for weight).
Permethrin ant powders for example usually contain about 0.5% w/w (ie, 500 mg/100g of bait, so equivalent to 5mg/g of the powder) and this rarely causes more than a bit of salivation in dogs or cats.

Insecticidal shampoos are about 1% w/v usually and dusting powders about the same (1% w/w), and these also rarely cause more than signs of local irratation.

However, compare this to flea treatments for dogs, applied using the spot-on method, aprting the hair at the back of the neck and putting the liquid on the skin. These products are more concentrated - often concentrations greater than 60% w/v (ie, 60g per 100ml, so equivalent to 600mg per ml). Accidentially used on cats, they can be lethal.

Permethrin-based ant killer products, household sprays, dusting powders and insecticidal shampoos usually contain permethrin at concentrations lower than 1.5% and are therefore unlikely to cause signs other than salivation, and perhaps vomiting and diarrhoea if ingested.

Where cats have been exposed to products with concentrations higher than 2% then it is advisable to contat your veterinarian for further advice.

For information on flea control products please visit www. fabcats.org/owners/fleas
Information for vets who diagnose permethrin poisoning in a cat can be found on FAB's veterinary site at www.fabvets.org

Question

Lead poisoning?

My cat drinks out of puddles which collect on part of our roof which is lined with lead – is there any danger of lead posioning?

Answer

The answer is courtesy of Alexander Campbell of the Veterinary Poisons Information Service (VPIS). The VPIS is not contactable by the general public.

My view on this would be that although the hazard is there, the risk of significant lead exposure by this route would be extremely small. Metallic lead as used in roof linings in the past does not leach the lead ion very readily and I think the likelihood of significant concentration being achieved to cause poisoning is unlikely from pooling rainwater. I do not think our acid rain problem is yet this severe!

Lead poisoning in cats is characterised by severe colic and vomiting and also a generalised 'depression'. Neurological signs such as pica (eating unusual things) are extremely rare. Lead can be measured in blood and urine so a poisoning diagnosis is relatively easy to confirm.

Question

Is ant poison dangerous to cats?

Answer

The answer is courtesy of Alexander Campbell of the Veterinary Poisons Information Service (VPIS). The VPIS is not contactable by the general public.

The answer is 'it depends'... Although many different active constituents may be used, three seem to be encountered by the Poisons Information Service on a regular basis.

There are the gel/liquid types (of which Nippon would seem to be the brand leader) which tend to contain borax/boric acid. These are apparently very sweet to taste (I have not tried it personally I hasten to add) and therefore presumably palatable. Borax is readily absorbed and could cause gastrointestinal irritation and salivation. Severe cases (extremely rare as the concentrations in these products are very low and therefore monster amounts would need to be ingested) would cause shaking, shivering, tremors, drowsiness, excessive thirst and in theory coma, renal impairment and convulsions. In practice these are not really a problem.

Powder versions can potentially be more toxic. We have many enquiries about pyrethroid-containing ones (which are obviously known to cause problems to cats). They cause excessive salivation, tremors, hyperaesthesia and fitting which can, in some susceptible animals, be prolonged and sometimes difficult to control.

Some contain carbamates such as bendiocarb which can cause salivation, hypersecretions, constricted pupils, shaking, incontinence, restlessness, bradycardia, respiratory depression, etc. However, in most bendiocarb ant powders the bendiocarb is present at a concentration of 0.5 per cent and so in practice the risk is pretty low.

My advice would be stick to gels and bendiocarb ones with suitable precautions about isolating animals from laid bait as far as possible.

Question

Poisonous yew?

Can you please help? I have sold my property and the one I would like to move to has a 300 year old yew tree in the garden. Now while this would be a fantastic climbing frame for my seven rescued cats, I know it is poisonous, and wonder if it would indeed do any harm to the cats. There is no way I could stop them from climbing it, its right outside the front door!! I understand that it is poisonous only if the fruit/seeds are eaten, and the leaves of some varieties. Can you advise please? I do not with to harm my 'friends' (two of them are sitting on my lap as I type - not easy!) but I have to find somewhere soon. Thank you.

Answer

The answer is courtesy of Alexander Campbell of the Veterinary Poisons Information Service (VPIS). The VPIS is not contactable by the general public.

We have only had five enquiries about yew in cats since the VPIS started in 1992, and one of these was a prospective enquiry about what might happen rather than a case where it, in theory, had!

Of the remainder only one case involved a cat with clinical signs - dyspnoea, pale mucous membranes, vomiting, panting and collapse. The query for this case was `Was yew a possible cause?'. The outcome of the case was unknown, but the general consensus was that although a causal relationship was possible it was unlikely (given the circumstances!).

Of course, all parts of the yew are potentially poisonous - with the exception of the reddish (sometimes yellowish) aril. Indeed you can make jam from this part!

We would certainly not advocate removal of any yew tree from a garden, as serious poisonings in animals, particularly domestic pets, are extremely rare. Where horses and livestock are concerned one would be careful to limit access, but with cats and dogs risk of intoxication appears to be very low.