Your sad boy can get relief! As veterinarians we see a lot of similar cases each week in practice and it is likely allergies. The coughing comment is quite worrisome, though. Coughing is usually not related. Please see your veterinarian again and have him or her listen closely to his chest and take chest xrays. I hope a problem is not found, but respiratory problems are not something to wait around on. If not already done within the last 4 months, it would also be beneficial to test him for heartworms to ensure that's not the culprit of the cough.
Back to allergies.... (I hope I can keep this complex topic short and understandable. Also I am not a veterinary dermatologist, so hopefully one will chime in as well.)
Allergies in pets don't cause the sneezing and other signs that people get, but instead pets lick and lick - especially at their paws. They can cause skin infections from licking excessively, but the infections can be many mini coalescing infections on the skin. Basically the body over reacts to normal bacteria on the skin and sets up tiny skin infections. These "zits pop," form a circular crust. Often times antibiotics are needed to clear up the skin infection. To keep the allergies controlled for a bit, steroids are needed. I usually recommend Temaril P - as one can use 1/10 of the amount of steroid and get a similar effect due to the synergistic action of the two meds in the product (and have less to no side effects of: increased drinking, increased urination, increased appetite, and some times increased panting.) Benadryl alone often only works in 30% of the cases. I'm glad it's helping your boy though. Allergies work on thresholds. To try to increase the threshold or decrease the amount of things he may be sensitive to, you can: treat the symptoms (infection), treat the underlying cause (allergies) with steroids (in low safe doses) or atopica, increase the fatty acid BALANCE within the diet, provide novel protein food and no treats, and use frontline or comfortis each month always. Baths can soothe the skin, but they aren't fixing the problem. Please see your veterinarian for some other therapies to help your boy - so he's not so sad! :)
I agree with Dr. Mathis, your dog may indeed have allergies and a secondary skin infection, but chest xrays are certainly indicated to evaluate the cough. Additionally, older dogs can develop hormonal problems such as hypothyroidism, which can cause recurrent skin infections and subsequent itching, so I recommend having his bloodwork and thyroid level checked if it has not already been done.
Itchy skin and sores in pets with normal bloodwork are indeed all often allergy related. The scabby skin indicates secondary infection, usually bacteria and less commonly skin mites or fungus. Your veterinarian can take samples of the scabby areas to look for infection and parasites and if only bacteria are found then I would recommend a 3 week course of oral antibiotics. The three types of underlying allergies are parasite (fleas, mites), food allergy, and pollen/dust allergies. If your dog is already on a good flea control such as Advantage or Revolution, then parasites are less likely. Options to treat allergies are to continue to treat symptoms with medications such as antihistamines, fatty acids, bathing, antibiotics, occasional steroids, etc, or to identify and treat the underlying cause. There is no accurate skin or blood test for food allergy in pets, the test and treatment are the hypoallergenic diet trial with a single protein and carbohydrate source that he has never been exposed to before (Royal Canin rabbit/potato is my favorite) and nothing else for 8 weeks. If the symptoms go away and stay away, then its food allergy and the hypoallergenic diet is continued lifelong. If the itch comes back despite the hypoallergenic diet, then the reason/diagnosis would be pollen/dust allergies (Atopy) and referral to a veterinary dermatologist for allergy skin testing and desensitization injections (just like allergy shots in kids) would be warranted.
Kimberly Coyner DVM
Diplomate American College of Veterinary Dermatology
Thanks for your prompt responses. I have a quick update on Jake and one more question. Chest xrays were done last week and thankfully were normal. Extensive blood work indicates that Jake does have hypothyroid. Vet has explained that the thyroid problem is more than likely causing alot of his skin, ear, dry eye and weight issues. He will begin meds for the treatment of this disorder next week. However, he is still coughing and the vet has not been able to give me a good explanation for his persistent cough. She has stated that it "could be related to his thyroid". She suggested that I give him Tussin as needed. I am giving him a dose approximately every 4 hours and haven't noticed much mprovement. Meanwhile, a friend has been researching canine coughs on the web and thinks that Jake could be affected by second hand smoke. Is this a possibility? If so, how can it be confirmed? His lungs were clear in the xray. Could he have bronchitus or emphysema and still have a normal xray? Thanks again for your time and invaluable information.
Dogs indeed can be affected by second hand smoke, but typically changes would be found on the chest xrays. If the cough persists, then further diagnostic options that your veterinarian may wish to pursue include having the xrays reviewed by a radiologist, or to discuss referral to an internal medicine specialist for more in depth work up such as bronchoscopy (using a flexible tube with a camera to examine the trachea, bronchi and lungs and obtain samples to look for inflammation or infection).
Kimberly Coyner, DVM DACVD