Pepper, a 3 yo FS DSH, presents on a busy Friday afternoon for a recent history of skin irritation and licking. She is an indoor/outdoor cat and is up-to-date on FVRCP, Rabies, and FeLV vaccines, but not much is known about her medical history.

She was adopted from a shelter just a few months earlier. Pepper’s owner reports that she tries to give Revolution^® monthly, though she has missed a few doses; Pepper’s most recent dose was administered roughly five weeks ago. 

After speaking with Pepper’s owner, you perform a brief triage exam so you can give the veterinarian a heads-up about what’s going on with Pepper. Pepper’s BCS is 5/9, her mucous membranes are pink and moist, her capillary refill time is < 2 seconds, and she is bright, alert, and responsive. As you lift her lips to check her gum color and dental health, you notice a thickened, ulcerated area on Pepper’s upper lip. 

You ask the owner about the lesion, but she hasn’t noticed it at home. She doesn’t know how long it has been there but says that it doesn’t seem to bother Pepper.

Pepper’s temperature, heart rate, and respiratory rate are all within normal limits. You examine her closely for fleas, but you don’t see any live fleas or flea dirt. 

When you roll Pepper on her back to examine her belly, you notice this lesion on the medial aspect of her left hindlimb: 

She also has a similar lesion on the medial aspect of her right hindlimb. 

Based on the appearance of Pepper’s skin, you advise the client that the veterinarian may want to perform some tests on Pepper’s skin to get to the bottom of what’s going on. You reassure the client that you and the veterinarian will discuss Pepper’s treatment plan, including associated costs, thoroughly before proceeding. Then, you go find the veterinarian and present the case to her. 

Diagnostic Testing 

After performing a thorough physical exam, the vet suspects feline eosinophilic granuloma complex (ECG). Both the hindlimb lesion and lip lesion would be consistent with this diagnosis. Other differentials could include bacterial pyoderma, fungal infection, trauma, or neoplasia. 

The veterinarian explains to the owner that histopathology (performed with sedation and a local block) is the best way to diagnose ECG. Once a definitive diagnosis has been obtained, effective treatment can be initiated. 

The client, however, is unwilling to pursue histopath. She has some financial constraints and is also reluctant to have Pepper sedated. Therefore, the vet recommends a CBC (to look for the presence of increased circulating eosinophils) and a fine needle aspirate (FNA) of the lesions. The owner consents to these diagnostics. 

Increased eosinophils are observed on both the CBC and FNA of the hindlimb lesion. The vet advises the owner that these results do not completely rule out other conditions, but they are strongly suggestive of ECG. Based on these findings, the veterinarian and the client decide to move forward with treatment. 

Treatment 

The immediate treatment of ECG typically relies upon steroids, in order to provide the cat with some relief. The veterinarian prescribes oral prednisolone, to be gradually tapered to the lowest effective dose. The client asks for a “steroid shot” instead of oral prednisolone, but the vet advises her that Depo-Medrol^® is associated with the development of diabetes in cats and therefore is best avoided. 

The vet also asks you to talk to the client about parasite prevention. Both flea allergies and mosquito bite sensitivity are thought to play a role in the development of ECG. Cats should remain on flea prevention year-round with consistent dosing; it’s important that the owners not miss or delay doses. Additionally, cats should be kept indoors to limit mosquito exposure if possible. They should at least be kept indoors at dawn and dusk when mosquitoes are most active. 

Recheck 

Pepper returns for a recheck in two weeks and her skin is dramatically improved. While the hair has not yet regrown on her hindlimbs, the inflammation and swelling of the skin has markedly decreased, and her owner is pleased with her progress. The veterinarian instructs Pepper’s owner to continue her gradual steroid taper and focus on parasite prevention, with the goal of preventing a recurrence of this issue.