*314Opinion by
Mr. Chief Justice McBride.1. This appeal presents two questions: (1) Whether the court erred in refusing plaintiff’s motion to direct a verdict.in his favor; and (2) whether the court erred in refusing to give certain instructions requested by plaintiff, and hereinafter to be considered. Before discussing the first proposition, it will be necessary to analyze the pleadings to ascertain exactly the issue therein presented. As will be seen, the complaint presented a plain charge of deceit, consisting of alleged affirmative false representations that the horse was sound and did not have the heaves. There is no allegation of fraudulent concealment of a latent defect, so that the whole issue turns upon whether the defendant made the affirmative representations charged in the complaint and whether those representations were false. The plaintiff testifies that he asked defendant whether the horse had the heaves, and was answered that he had not. The defendant and his wife testify, in substance, that when the question was asked defendant replied, “I don’t know; I don’t think so.” Both these witnesses testify positively that they did not know that the animal had the heaves, and . several neighbors familiar with the horse,- including the blacksmith, who habitually shod him, testify that they never detected any symptom of such disorder. The evidence of veterinary surgeons and others indicates strongly that the animal had the disease, and to such an extent that one familiar with horses would probably have detected it; but this was a matter exclusively for the jury, and they had a right to accept and act upon defendant’s statement that he did not detect it, if it existed, and did not believe that the animal was so affected, but supposed that such infirmity or unsound*315ness as it might have existed was the result of an attack of distemper.
2. It is undoubted law, as shown by the decisions collated in appellant’s brief, that if an animal has any latent defect or unsoundness affecting his usefulness or salability, it is the duty of the seller to make known such defect, and that for his failure to do so he will be liable in damages for such fraudulent concealment: 35 Cyc. 69, 70; Walters v. Morgan, 3 De Gex, F. & J. 713. But a mere honest expression of opinion, although the seller may be mistaken, is not such a constructive fraud as will avoid a sale: 35 Cyc., supra; Coddington v. Goddard, 16 Gray (Mass.), 436. Whatever opinion the members of this body might have as to the good faith of defendant’s reply to plaintiff’s question as to whether the animal had the heaves, it was the privilege of the jury to assume that it was an honest expression of his opinion. Following that often quoted provision of the Constitution which prohibits us from interfering with the verdict of a jury where there is any evidence to support it, we are not at liberty to substitute our own judgment for theirs, upon a question of fact.
3. Counsel for plaintiff asked for the following instruction, which was refused:
“It is not necessary to show that Mr. Forrest at the time intended to cheat or deceive Mr. Clearwater in the sale, nor is Mr. Clearwater required to show that Mr. Forrest at the time knew the representation to be false; but he has a right to rely upon the representations or affirmations so made.”
This request was faulty, in that it assumes that representations were made, and does not distinguish between a mere expression of opinion and a false representation, and for that reason might tend to mislead a *316jury. It also leaves out the important factor in every action for deceit, namely, that the plaintiff must have believed the representation and acted upon that belief.
4. Another instruction requested and refused reads as follows:
“You are instructed that if you find from the evidence that the horse sold to Mr. Clearwater was diseased, that is to say, if he was wind-broken, or had .what is commonly called the ‘heaves’ or ‘thumps,’ at the time Mr. Clearwater purchased him, and that Mr. Forrest stated to Mr. Clearwater that the horse was sound, or that the'horse was all right, you will find for the plaintiff.”
This instruction is subject to the same criticism as that above mentioned. It entirely ignores the principle that in actions for deceit the buyer must have relied and acted upon the alleged false representation.
5. A further instruction is to the effect that if the animal had any latent disease or defect unknown to the plaintiff, but known to the defendant, it was the duty of defendant to have disclosed the existence of such disease or defect to plaintiff. As before observed, this construction presents a case entirely outside the pleadings, and was properly refused for that reason. “Where plaintiff alleges that false representations were made in respect to the existence of material facts, he cannot recover upon proof of fraudulent concealment of other facts which ought to have been disclosed”: 20 Cyc. 106.
Finding no substantial error, the judgment is affirmed.
Affirmed.
Mr. Justice Eakin, Mr. Justice Bean and Mr. Justice McNary concur.