Feline Perforating Dermatitis

Summary

In March 2011 we discovered that our Siamese cat had Feline Perforating Dermatitis, which is similar to scurvy! We hope that sharing some information about our case will help anyone else who has similar problems. Our cat already had skin allergy problems, and was creating ever-deepening wounds by constant licking. In previous years the scabs would heal if a 'buster' collar was used, but in 2011 the scabs were large, thick, and not healing. Eventually a biopsy revealed the collagen in the skin had died, and a 3 month course of vitamin C and steroids slowly healed the scabs.

Photo showing strange scabs that would not heal:

History

This poor cat has had allergy problems since it was a kitten. Unable to stop vomiting up normal cat food at the age of 2, he lives off Royal Canin 'Sensitivity Control'. At the age of 5 he began to show signs of a seasonal irritation; he would scratch himself a lot every summer, until areas of his coat were bald. Annual steroid injections solved this for a few years. At the age of 10 it was clear he was still very itchy, and it was not just in the summer. Instead of scratching, the cat would groom (lick) himself constantly, eventually making the skin bald, then bleeding, and finally a vast raw would would develop if unchecked. Some wounds would get infected and seep pus. A 'buster' collar, like a lampshade around the neck, seemed to solve this problem, though being unable to groom caused stress (fighting, urination around the house) and a Feliway plug-in (pheromone spray) helped. Sadly the cat developed every more imaginative ways to escape from the collar. A surgical suit was purchased from VetMedCare and had to be extended by sewing extra fabric around the neck, and then attaching this to the buster collar. The collar itself was not long enough to stop the cat reaching his hind area, so it had to be extended with extra plastic strips. These stopped him being able to get near to his water bowl, so the bowl had to be raised with a special wooden support with a gap underneath. The suit/collar have to be removed for every meal. I've since heard of 'thundershirt' as a better suit for a cat to wear.

Symptoms

The cat did not spend his life in the suit/collar arrangement; once a set of scabs had healed (a month or two), he was allowed to go free again. He would be healthy for a few months, and then begin to lick again, creating new scabs. However, in 2011 we noticed his current set of scabs were not healing, even after a 4 month period where we knew he had not licked/scratched them once. The photo above shows the odd arrangement of the scabs - small thick dots scattered about the larger area of healing. The was no seepage of pus, or visible exudate. Tests ruled out 'pox virus'. Steroid tablets were doing nothing to aid healing.

Biopsy

Eventually, a consultant dermatologist (Dr Ewan Ferguson, London) agreed a biopsy was needed to see what was happening in the skin. A sample of flesh was taken from an area where a new lesion had been noticed; one that was too small to have been created by the tongue. It revealed that the collagen in the skin had died. This condition is know as idiopathic (i.e. no known cause) feline perforating dermatitis. It was described as being similar to scurvy.

Treatment

The animal was put on a 2 month course of vitamin C and steroids. Weighing 4kg, the animal's dose of vitamin C dose was calculated at 200-300mg per day, which was provided by the same tablets sold to humans in Tescos! He did not seem to mind the orange flavour. Prednisolone tablets (5mg per day) were also given by the vet. After 2 months significant progress was seen. Whilst the small scabs had not all disappeared, they had reduced in number, and one of the largest areas of thick scab had healed well. The consultant recommended another month or two on the vitamin C. We eventually found every scab had healed, and our darling cat was free of his coat and collar for the rest of his life. (He later hit age 15 and still no skin problems.)

Other cases

Apparently there are only one or two recorded cases of this disease, and one was a Siamese cat as well. That is not to say the disease is incredibly rare, only that few cases have been documented. That is why we wanted to write this article, in the hope of helping future sufferers.

Contact

Email us at mags@yachtsandyachting.com to find out more.